THORATEC LABORATORIES CORP
S-3, 2000-03-17
ELECTROMEDICAL & ELECTROTHERAPEUTIC APPARATUS
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<PAGE>   1

     AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON MARCH 17, 2000

                                                     REGISTRATION NO. 333-
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                            ------------------------

                                    FORM S-3
                             REGISTRATION STATEMENT
                                     UNDER
                           THE SECURITIES ACT OF 1933

                       THORATEC LABORATORIES CORPORATION
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)

<TABLE>
<S>                                              <C>
                   CALIFORNIA                                       94-2340464
        (STATE OR OTHER JURISDICTION OF                          (I.R.S. EMPLOYER
         INCORPORATION OR ORGANIZATION)                        IDENTIFICATION NO.)
</TABLE>

       6035 STONERIDGE DRIVE, PLEASANTON, CALIFORNIA 94588 (925) 847-8600
    (ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER, INCLUDING AREA CODE,
      OF THORATEC LABORATORIES CORPORATION'S PRINCIPAL EXECUTIVE OFFICES)

                               D. KEITH GROSSMAN
       6035 STONERIDGE DRIVE, PLEASANTON, CALIFORNIA 94588 (925) 847-8600
 (NAME, ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER, INCLUDING AREA CODE,
                             OF AGENT FOR SERVICE)
                            ------------------------

                                   COPIES TO:

<TABLE>
<S>                                              <C>
               AUGUST J. MORETTI                               ALEJANDRO E. CAMACHO
                   KYLE GUSE                            CLIFFORD CHANCE ROGERS & WELLS LLP
      HELLER EHRMAN WHITE & MCAULIFFE LLP                        200 PARK AVENUE
         2500 SAND HILL ROAD, SUITE 100                      NEW YORK, NEW YORK 10166
       MENLO PARK, CALIFORNIA 94025-7063                    TELEPHONE: (212) 878-8000
           TELEPHONE: (650) 234-4200                        FACSIMILE: (212) 878-8375
           FACSIMILE: (650) 234-4299
</TABLE>

        APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE TO THE PUBLIC:
    As soon as practicable following the effectiveness of this Registration
                                   Statement.

     If the only securities being registered on this Form are being offered
pursuant to dividend or interest reinvestment plans, please check the following
box.  [ ]

     If any of the Securities being registered on this form are to be offered on
a delayed or continuous basis pursuant to Rule 415 under the Securities Act of
1933, check the following box.  [ ]

     If this Form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act of 1933, please check the
following box and list the Securities Act registration number of the earlier
effective registration statement for the same offering:  [ ]  ______________

     If this Form is a post-effective amendment filed pursuant to Rule 462(c)
under the Securities Act of 1933, check the following box and list the
Securities Act registration statement number of the earlier effective
registration statement for the same offering:  [ ]  ______________

     If delivery of the prospectus is expected to be made pursuant to Rule 434,
please check the following box:  [ ]

                        CALCULATION OF REGISTRATION FEE

<TABLE>
<S>                             <C>                   <C>                   <C>                   <C>
- ----------------------------------------------------------------------------------------------------------------------
- ----------------------------------------------------------------------------------------------------------------------
                                                        PROPOSED MAXIMUM      PROPOSED MAXIMUM
     TITLE OF SECURITIES            AMOUNT TO BE         OFFERING PRICE      AGGREGATE OFFERING        AMOUNT OF
       TO BE REGISTERED            REGISTERED(1)           PER SHARE              PRICE(2)          REGISTRATION FEE
- ----------------------------------------------------------------------------------------------------------------------
Common Stock, no par value....       5,175,000               $15.75             $81,506,250             $21,518
- ----------------------------------------------------------------------------------------------------------------------
- ----------------------------------------------------------------------------------------------------------------------
</TABLE>

(1) Includes up to 675,000 shares of common stock which the underwriters have
    the option to purchase solely to cover over-allotments, if any. See
    "Underwriting."

(2) Estimated solely for the purpose of computing the amount of the registration
    fee pursuant to Rule 457(c) under the Securities Act of 1933, as amended,
    based on the average of the high and low prices of the common stock on the
    Nasdaq National Market on March 13, 2000, as reported on the Nasdaq National
    Market.
                            -----------------------------

     WE HEREBY AMEND THIS REGISTRATION STATEMENT ON SUCH DATE OR DATES AS MAY BE
NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL WE SHALL FILE A FURTHER AMENDMENT
WHICH SPECIFICALLY STATES THAT THIS REGISTRATION STATEMENT SHALL THEREAFTER
BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(a) OF THE SECURITIES ACT OF 1933
OR UNTIL THE REGISTRATION STATEMENT SHALL BECOME EFFECTIVE ON SUCH DATE AS THE
COMMISSION, ACTING PURSUANT TO SAID SECTION 8(a), MAY DETERMINE.
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<PAGE>   2

     THE INFORMATION IN THIS PRELIMINARY PROSPECTUS IS NOT COMPLETE AND MAY BE
     CHANGED. WE MAY NOT SELL THESE SECURITIES UNTIL THE REGISTRATION STATEMENT
     FILED WITH THE SECURITIES AND EXCHANGE COMMISSION IS
     EFFECTIVE. THIS PRELIMINARY PROSPECTUS IS NOT AN OFFER TO SELL THESE
     SECURITIES, AND WE ARE NOT SOLICITING OFFERS TO BUY THESE SECURITIES, IN
     ANY STATE WHERE THE OFFER OR SALE IS NOT PERMITTED.

                  SUBJECT TO COMPLETION, DATED MARCH 17, 2000

PROSPECTUS

                                4,500,000 Shares

                                      LOGO

                                  Common Stock

- --------------------------------------------------------------------------------

We are offering 3,000,000 shares of our common stock, and the selling
shareholder is offering 1,500,000 shares. We will not receive any of the
proceeds from the sale of shares being sold by the selling shareholder.

Our common stock is listed on the Nasdaq National Market under the symbol
"THOR." On March 16, 2000, the last reported sale price of the common stock on
the Nasdaq National Market was $15.50 per share.

    INVESTING IN THE SHARES INVOLVES RISKS. "RISK FACTORS" BEGIN ON PAGE 4.

<TABLE>
<CAPTION>
                                                               PER
                                                              SHARE        TOTAL
                                                              ------    -----------
<S>                                                           <C>       <C>
Public Offering Price.......................................  $         $
Underwriting Discount.......................................  $         $
Proceeds to Thoratec........................................  $         $
Proceeds to Selling Shareholder.............................  $         $
</TABLE>

The selling shareholder has granted the underwriters a 30-day option to purchase
up to 675,000 additional shares of common stock to cover over-allotments, if
any.

NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY OTHER STATE SECURITIES
COMMISSION HAS APPROVED OR DISAPPROVED OF THESE SECURITIES OR DETERMINED IF THIS
PROSPECTUS IS ACCURATE OR COMPLETE. ANY REPRESENTATION TO THE CONTRARY IS A
CRIMINAL OFFENSE.

Lehman Brothers expects to deliver the shares on or about              , 2000.

- --------------------------------------------------------------------------------
LEHMAN BROTHERS

                BEAR, STEARNS & CO. INC.
                                 ADAMS, HARKNESS & HILL, INC.
                                              FIDELITY CAPITAL MARKETS
                                               a division of National Financial
                                                     Services Corporation
            , 2000
<PAGE>   3


The TLC-II Portable VAD Driver allows patients to more easily ambulate and
rehabilitate, and to ultimately go home, improving the quality of life for our
patients.

         [Photograph of VAD System patient using dual drive console and
                          TLC-II Portable VAD Driver]

The Thoratec ventricular assist device blood pump is the only U.S. approved
device that provides total mechanical circulatory support, i.e., left, right or
biventricular.

                 [Photograph of Thoratec VAD System blood pump]


The Thoratec implantable ventricular assist device, or IVAD, which weighs less
than one pound.


            [Photograph of prototype of the Thoratec Implantable VAD]



                            [Photograph of patient]


Kim Farias and daughter Karley. After Karley's birth, Kim was supported for 23
days by our Thoratec VAD System. Today, both are world travelers.

<PAGE>   4

                               TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                       PAGE
                                       ----
<S>                                    <C>
Prospectus Summary...................    1
Risk Factors.........................    4
Use of Proceeds......................   12
Dividend Policy......................   12
Price Range of Common Stock..........   13
Capitalization.......................   14
Dilution.............................   15
Selected Consolidated Financial
  Data...............................   16
Management's Discussion and Analysis
  of Financial Condition and Results
  of Operations......................   17
</TABLE>

<TABLE>
<CAPTION>
                                       PAGE
                                       ----
<S>                                    <C>
Business.............................   21
Management...........................   41
Principal Shareholders and Selling
  Shareholder........................   43
Description of Capital Stock.........   45
Underwriting.........................   47
Legal Matters........................   49
Experts..............................   49
Where You Can Find More
  Information........................   49
Index to Consolidated Financial
  Statements.........................  F-1
</TABLE>

                           FORWARD LOOKING STATEMENTS

     This prospectus, including the documents incorporated by reference in this
prospectus, includes forward-looking statements. We have based these
forward-looking statements on our current expectations and projections about
future events. Our actual results could differ materially from those discussed
in, or implied by, these forward-looking statements. Forward-looking statements
are identified by words such as "believe," "anticipate," "expect," "intend,"
"plan," "will," "may" and other similar expressions. In addition, any statements
that refer to expectations, projections or other characterizations of future
events or circumstances are forward-looking statements. Forward-looking
statements include, but are not necessarily limited to, those relating to:

     - our ability to obtain and maintain regulatory approval of our products in
       the United States and internationally;

     - the other competing therapies that may in the future be available to
       heart failure patients;

     - our plans to develop and market new products; and

     - our ability to improve our financial performance.

     Factors that could cause actual results or conditions to differ from those
anticipated by these and other forward-looking statements include those more
fully described in the "Risk Factors" section and elsewhere in this prospectus.
We are not obligated to update or revise these forward-looking statements to
reflect new events or circumstances.

     You should rely only on the information contained in this prospectus. We
have not authorized anyone to provide you with different information. We are not
making an offer to sell these securities in any jurisdiction where the offer or
sale is not permitted. You should assume that the information appearing in this
prospectus is accurate as of the date on the front cover of this prospectus
only. Our business, financial condition, results of operations and prospects may
have changed since that date.

     Thoratec, the Thoratec logo and Thoralon are registered trademarks, and
TLC-II, Vectra and Aria are trademarks of Thoratec Laboratories Corporation.

                                        i
<PAGE>   5

                               PROSPECTUS SUMMARY

     This summary highlights information contained elsewhere in this prospectus.
You should read the entire prospectus carefully, including the "Risk Factors"
section and our financial statements and the related notes contained herein.
Unless otherwise indicated, the information in this prospectus assumes that the
underwriters do not exercise their over-allotment option.

                                  OUR COMPANY

OUR PRODUCTS

     We develop, manufacture and market proprietary medical devices used for
circulatory support and for vascular graft applications. We currently market the
Thoratec Ventricular Assist Device System (the VAD System) in the United States
and internationally for use as a bridge to heart transplant and for use in the
recovery of the heart after open-heart surgery. Our VAD System is currently the
only device approved by the FDA that can provide left, right or biventricular
support for both of these indications. At March 14, 2000, the VAD System had
been used in more than 1,200 patients worldwide ranging in age from seven to 77
years and in weight from 38 to 316 pounds (17 to 144 kg). We are also pursuing
additional indications for the VAD System and developing other circulatory
support products for patients suffering from heart failure.

     We have also developed small diameter vascular grafts for use in
hemodialysis access and coronary artery bypass surgery. Our hemodialysis access
graft, which we call the Vectra, is undergoing clinical trials in the United
States and is currently marketed in Europe. Unlike current grafts, which require
up to several weeks of patient recovery prior to use, the Vectra's self-sealing
design allows patient use as soon as 24 hours after surgical implantation.

     We are applying the same technological expertise used in the Vectra for use
in coronary artery bypass surgery through development of our Aria graft. This
small diameter graft is designed for use by patients who have too few suitable
blood vessels of their own. We believe that in as many as 20% of the 900,000
bypass surgeries performed worldwide, the unavailability of any or sufficient
suitable vessels creates a treatment problem. We expect to commence clinical
trials in the United States of our Aria coronary graft in the first half of
2000.

     All of our products that come into contact with human tissue or blood
incorporate Thoralon, our proprietary biomaterial. Thoralon is a unique
biomaterial that provides strength and flexibility to our products with surface
properties designed to minimize patient blood clotting and inflammatory
response.

OUR STRATEGY

     Our goal is to be a leading developer and manufacturer of medical devices
for the congestive heart failure, cardiac surgery and vascular graft markets.
Our key strategies to achieve this goal are:

     - increase the market penetration for our VAD System;

     - obtain U.S. approval and support for the market launch of our Vectra
       product;

     - attain global approval to commercialize our Aria product for use in
       coronary artery bypass surgery;

     - explore the use of Thoralon for additional medical products; and
                                        1
<PAGE>   6

     - explore the acquisition of, or partnership with, companies that possess
       complementary products or technologies.

     We are a California corporation. Our principal offices are located at 6035
Stoneridge Drive, Pleasanton, California 94588. Our telephone number is (925)
847-8600, and our fax number is (925) 847-8625.

                                  THE OFFERING

Common stock offered by our
company.............................     3,000,000 shares

Common stock offered by the selling
  shareholder.......................     1,500,000 shares

Common stock outstanding after the
offering............................     23,466,326 shares

Use of proceeds.....................     We intend to use the proceeds from this
                                         offering for:

                                         - clinical trials of products under
                                           development;

                                         - expansion of our sales and marketing
                                           capabilities;

                                         - research, development and potential
                                           acquisitions of complementary
                                           technology; and

                                         - working capital and other general
                                           corporate purposes.

Nasdaq National Market symbol.......     "THOR"

                           -------------------------

     The common stock outstanding after this offering is based on the number of
shares outstanding at January 1, 2000, which was the end of our 1999 fiscal
year, and excludes:

     - 3,139,824 shares of common stock reserved for issuance upon the exercise
       of outstanding stock options at a weighted average exercise price of
       $6.78 per share; and

     - 164,400 shares of common stock issuable upon exercise of warrants
       outstanding at an exercise price of $14.40 per share.

See "Capitalization" and Note 7 to our financial statements.
                                        2
<PAGE>   7

                      SUMMARY CONSOLIDATED FINANCIAL DATA

     The following summary of consolidated financial data is derived from and
qualified by reference to our financial statements and accompanying notes
included elsewhere in this prospectus. You should read the following summary
consolidated financial data in conjunction with our financial statements and
accompanying notes and with "Management's Discussion and Analysis of Financial
Condition and Results of Operations" included elsewhere in this prospectus.

<TABLE>
<CAPTION>
                                                                FISCAL YEAR
                                       (OUR FISCAL YEAR ENDS ON THE SATURDAY CLOSEST TO DECEMBER 31)
                                       -------------------------------------------------------------
                                         1995         1996         1997         1998         1999
                                       ---------    ---------    ---------    ---------    ---------
                                                   (IN THOUSANDS, EXCEPT PER SHARE DATA)
<S>                                    <C>          <C>          <C>          <C>          <C>
STATEMENT OF OPERATIONS DATA:
Product sales........................   $ 3,489      $ 7,503      $ 9,441      $16,320      $22,508
Gross profit.........................     1,517        4,249        5,436        9,816       12,769
Loss from operations.................    (1,768)      (3,423)      (5,156)      (2,981)      (2,196)
Net loss.............................    (1,894)      (3,263)      (4,402)      (2,321)      (1,789)
Basic and diluted loss per share.....   $ (0.13)     $ (0.20)     $ (0.24)     $ (0.11)     $ (0.09)
Shares used to compute basic and
  diluted loss per share.............    14,429       16,694       18,360       20,340       20,446
</TABLE>

<TABLE>
<CAPTION>
                                                                    JANUARY 1, 2000
                                                                (FISCAL YEAR-END 1999)
                                                                -----------------------
                                                                 ACTUAL     AS ADJUSTED
                                                                --------    -----------
                                                                    (IN THOUSANDS)
<S>                                                             <C>         <C>
BALANCE SHEET DATA:
Cash, cash equivalents and marketable securities............    $  1,697     $ 44,830
Working capital.............................................      10,533       53,666
Total assets................................................      25,060       68,193
Total liabilities...........................................       4,784        4,784
Accumulated deficit.........................................     (55,191)     (55,191)
Shareholders' equity........................................      20,276       63,409
</TABLE>

     The as adjusted column of the balance sheet data at fiscal year end 1999
reflects our sale of 3,000,000 shares of common stock under this prospectus at
an assumed public offering price of $15.50 per share and the application of the
net proceeds, after deducting the estimated fees of the underwriters and our
estimated offering expenses. See "Use of Proceeds" and "Capitalization."
                                        3
<PAGE>   8

                                  RISK FACTORS

     This offering and an investment in our common stock involve a high degree
of risk. You should consider each of the risks and uncertainties described in
this section and all of the other information in this prospectus before deciding
to invest in our common stock. Our business, financial condition and results of
operations could be severely harmed by any of the following risks. The trading
price of our common stock could decline if any of these risks and uncertainties
develop into actual events. You may lose all or part of the money you paid to
buy our common stock.

WE HAVE A HISTORY OF NET LOSSES, AND WE MAY NOT ACHIEVE OR MAINTAIN
PROFITABILITY.

     We were founded in 1976 and have incurred a loss from operations in all but
one of the years of our existence. At the end of fiscal year 1999, our
accumulated deficit was approximately $55.2 million. We expect to continue to
incur additional losses until we achieve substantial product revenues. Even if
we do achieve profitability, we may not be able to sustain or increase
profitability on a quarterly or annual basis. In addition, we anticipate that
our expenses will increase as a result of increased preclinical and clinical
testing, research and development and selling, general and administrative
expenses. We have commenced sales in the United States of our ventricular assist
device, which we call the Thoratec VAD System, for use as a bridge to heart
transplant and for recovery after open-heart surgery. Sales of our other
products in the United States, however, cannot begin until the products have
received FDA approval. We may not receive FDA approval for several years, if at
all.

WE ARE SUBSTANTIALLY DEPENDENT ON A LIMITED PRODUCT LINE, AND WE MAY NEED TO
DEVELOP AND INTRODUCE NEW PRODUCTS TO ACHIEVE PROFITABILITY.

     To date, substantially all of our revenue has resulted from sales of the
Thoratec VAD System. We expect worldwide sales from the Thoratec VAD System and
limited sales of our Vectra vascular access graft products in markets outside of
the United States to account for a significant portion of our near-term revenue.
As a result, factors adversely affecting the pricing of or demand for such
products could have a material adverse effect on our financial condition and
results of operations. These factors include market acceptance, competition and
technological change.

     Our future financial performance will depend, in significant part, on our
successful development, introduction and customer acceptance of products under
development. We have very little preclinical and clinical data relating to our
products under development. Prior to any commercial use, our products currently
under development will require significant additional research and development
efforts, extensive preclinical and clinical testing and regulatory approval. New
product development is highly uncertain. The factors that could slow or prevent
the successful completion of our product and technology development efforts
include clinical and regulatory delays, adverse or unexpected side effects and
inadequate therapeutic efficacy.

PHYSICIANS MAY NOT ACCEPT OR CONTINUE TO ACCEPT OUR PRODUCTS AND PRODUCTS UNDER
DEVELOPMENT.

     The success of our current and future products will require acceptance or
continued acceptance by cardiovascular and vascular surgeons and interventional
cardiologists. Such acceptance will depend on clinical results and the
conclusion by these physicians that our products are safe, cost-effective and
acceptable alternative methods of treatment. Our products may not provide
benefits considered adequate by providers of cardiovascular and vascular
treatments or a sufficient number of such providers may not use our products. In
addition, because our products are based on innovative technologies and, in some
cases, represent new methods of treatment, there may be greater reluctance

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<PAGE>   9

to accept these products than would occur with products utilizing established
technologies or methods of treatment. Even if the safety and efficacy of our
products are established, physicians may elect not to use them for a number of
reasons. These reasons could include the high cost of equipment and training
associated with the use of our Thoratec VAD System or unfavorable reimbursement
from health care payors. If our products do not achieve significant market
acceptance, we will not achieve profitability.

     A limited number of cardiovascular and vascular surgeons and interventional
cardiologists influence medical device selection and purchase decisions for a
large portion of the target cardiac patient population. We have developed
working relationships with cardiac surgeons and cardiologists at a number of
leading medical centers in connection with developing our Thoratec VAD System.
In addition, surgical teams at these medical institutions have performed
clinical trials to support our applications to be filed with the FDA. A
continuing working relationship with these and other physicians and medical
centers will be important to the commercial acceptance of the Thoratec VAD
System and future circulatory support and graft products. We may fail to
maintain existing relationships and arrangements and we may fail to establish
new relationships in support of our circulatory support and graft technology.
Furthermore, economic, psychological, ethical and other concerns may limit
general acceptance of ventricular assist and graft devices.

WE RELY ON SINGLE SOURCE SUPPLIERS. OUR BUSINESS WILL BE HARMED IF OUR SUPPLIERS
INTERRUPT THE SALE OF MATERIALS TO US.

     We depend on single source suppliers for most of the critical components
and materials used in the manufacture of our products. If we need alternative
sources for key raw materials or component parts for any reason, such materials
or component parts may not be available. For example, Arrow International, Inc.
is currently the single source of supply for valves used in our VAD System.
Sales of the VAD System accounted for substantially all of our revenue in 1998
and 1999, and we expect those sales to account for substantially all of our
revenue for at least the next year. Cessation or interruption of VAD System
sales would have a material adverse effect on our business, financial condition
and results of operations.

     Alternative suppliers may not agree to supply us. In addition, new
suppliers must be approved by the FDA. If alternative suppliers are not
available, we may not have the expertise or resources necessary to produce such
materials or component parts internally. For example, in 1999 we decided to
change manufacturers for a valve in our portable drives, which we call our
TLC-II. We experienced delays in shipping the TLC-II while we qualified a new
component manufacturer for these valves. As a result of this delay, we put a
voluntary hold on further enrollment in U.S. clinical trials for the TLC-II
portable driver and on shipments of this device to new centers in Europe. Any
interruption in supply of raw materials or component parts could have a material
adverse effect on our ability to manufacture products until a new source of
supply is located.

WE MAY ENCOUNTER PROBLEMS MANUFACTURING OUR PRODUCTS.

     In 1999, we moved our manufacturing headquarters to a 62,000 square foot
leased facility in Pleasanton, California. We believe that we currently have the
ability to produce sufficient quantities of the Thoratec VAD System and the
Vectra to support our current needs, and our needs for early-stage clinical
trials of the TLC-II portable driver. We may, however, encounter difficulties
manufacturing our products for the following reasons:

     - we do not have experience in manufacturing our products in the commercial
       quantities that might be required if we receive FDA approval of several
       or all of the products currently under development;

                                        5
<PAGE>   10

     - the manufacture of our products is complex and costly, involving a number
       of separate processes and components; and

     - certain manufacturing processes for our products are labor intensive, and
       achieving significant cost reductions will depend in part upon reducing
       the time required to complete these processes.

     In addition, manufacturers often encounter difficulties in scaling up
manufacturing of new products. These difficulties include, for example:

     - problems involving product yields, quality control and assurance;

     - component and service availability;

     - adequacy of control policies and procedures; and

     - lack of qualified personnel.

     We will continue to consider whether we should internally manufacture
components that are currently provided by third parties. We will also continue
to consider the implementation of new production processes, some of which may
require prior FDA approval. We may not be able to obtain or manufacture such
products in a timely fashion at acceptable quality and prices. In addition, we
may not be able to comply with the FDA's current good manufacturing practices,
also called cGMP. We and our suppliers may not be able to manufacture an
adequate supply of products.

INTENSE COMPETITION COULD HARM OUR FINANCIAL PERFORMANCE.

     Competition from medical device companies and medical device subsidiaries
of health care and pharmaceutical companies is intense and expected to increase.
Many of our competitors have substantially greater financial, technical,
distribution and marketing resources than we do. In addition, many of these
competitors have significantly greater experience than we do in obtaining
regulatory approvals for medical devices. Accordingly, our competitors may
succeed in obtaining regulatory approval for products more rapidly than we.
Furthermore, many of these competitors have superior manufacturing capabilities,
and such competitors may be able to manufacture products more efficiently and at
a lower cost than we can. Our competitors may therefore offer competitive
products at a lower cost than our products. Any product we develop that gains
regulatory approval will have to compete for market acceptance and market share.
An important factor in such competition may be the timing of market introduction
of competitive products. Accordingly, we expect that competitive factors will
include the relative speeds with which we can:

     - develop products;

     - complete clinical testing;

     - receive regulatory approval; and

     - manufacture and sell commercial quantities of products.

OUR COMPETITORS MAY DEVELOP MORE EFFECTIVE PRODUCTS AND RENDER OUR PRODUCTS
OBSOLETE.

     Our competitors may succeed in developing and marketing technologies and
products that are more effective than ours. Any such products may render our
technology and products obsolete or noncompetitive. Additionally, new surgical
procedures and medications could be developed that replace or reduce the
importance of current procedures that use our products. Accordingly, our

                                        6
<PAGE>   11

success will depend in part on our ability to respond quickly to medical and
technological changes by developing and introducing new products, or modifying
existing products.

IF WE FAIL TO OBTAIN APPROVAL FROM THE FDA AND FROM FOREIGN REGULATORY
AUTHORITIES, WE CANNOT MARKET AND SELL OUR PRODUCTS UNDER DEVELOPMENT IN THE
UNITED STATES AND IN OTHER COUNTRIES.

     Before we can market new products in the United States we must obtain
clearance from the FDA. This process is lengthy and uncertain. In the United
States, one must obtain clearance from the FDA of a 510(k) premarket
notification or approval of a more extensive submission known as a premarket
approval (PMA) application. If the FDA concludes that any of our products do not
meet the requirements to obtain clearance under Section 510(k) of the Federal
Food, Drug and Cosmetic Act, then we would be required to file a PMA
application. The process for a PMA application is lengthy, expensive and
typically requires extensive preclinical and clinical trial data.

     We may not obtain clearance of a 510(k) notification or approval of a PMA
application with respect to any of our products on a timely basis, if at all. If
we fail to obtain timely clearance or approval for our products, we will not be
able to market and sell our products, which will limit our ability to generate
revenue. We may also be required to obtain clearance of a 510(k) notification or
PMA application from the FDA before we can market certain previously marketed
products which we modify after they have been cleared.

     The FDA also requires us to adhere to cGMP regulations, which include
production design controls, testing, quality control, storage and documentation
procedures. The FDA may at any time inspect our facilities to determine whether
we have adequately complied. Compliance with cGMP regulations for medical
devices is difficult and costly. In addition, we may not be found to be
compliant as a result of future changes in, or interpretations of, regulations
by the FDA or other regulatory agencies. If we do not achieve compliance, the
FDA may withdraw marketing clearance, require product recall or take other
enforcement action. Any change or modification in a device is required to be
made in compliance with cGMP regulations, which may cause interruptions or
delays in the marketing and sale of our products.

     Sales of our products outside the United States are subject to foreign
regulatory requirements that vary from country to country. The time required to
obtain approvals from foreign countries may be longer or shorter than that
required for FDA approval, and requirements for foreign licensing may differ
from FDA requirements.

     The Federal, state and foreign laws and regulations regarding the
manufacture and sale of our products are subject to future changes, as are
administrative interpretations and policies of regulatory agencies. If we fail
to comply with applicable federal, state or foreign laws or regulations, we
could be subject to enforcement actions. Enforcement actions could include
product seizures, recalls, withdrawal of clearances or approvals, and civil and
criminal penalties.

OUR INABILITY TO PROTECT OUR PROPRIETARY TECHNOLOGIES COULD HARM OUR COMPETITIVE
POSITION.

     Our success will depend, in part, on our ability to maintain the
proprietary nature of our technology, products and manufacturing processes. We
rely on trade secrets, know-how and patents to maintain our competitive
position. We have been issued or have licensed a number of U.S. and foreign
patents covering our core biomaterials technology and our graft technologies. In
addition, we have filed many other U.S. and non-U.S. patent applications. Aside
from the biomaterials patents mentioned above, which are utilized in our VAD
System blood pump and cannulae, and one TLC-II patent, our VAD System is not
protected by any patents. We do not believe that this lack of patent protection
will have a material adverse effect on our ability to sell our VAD System
because of the

                                        7
<PAGE>   12

lengthy regulatory period required to obtain approval of a ventricular assist
device. We are not aware of any ventricular assist devices that are based on our
product design currently approved by the FDA or undergoing clinical trials.

     Any existing or future patent applications may not result in issued
patents. In addition, current or future trade secrets, know-how or issued or
licensed patents may not sufficiently protect us from competitors with similar
technologies or processes. Others may independently develop proprietary
technologies and processes which are the same as or substantially equivalent to
ours. Any patents issued may be infringed upon or designed around by others.

     Our products may be found to infringe prior or future patents owned by
others. We may need to acquire licenses under patents belonging to others for
technology potentially useful or necessary, and such licenses may not be
available to us. We could incur substantial costs in defending suits brought
against us on such patents or in bringing suits to protect our patents or
patents licensed by us against infringement.

     We also protect our proprietary technology and processes in part by
confidentiality agreements with our licensees, employees and consultants. These
measures may not provide adequate protection for our trade secrets or other
proprietary information. Employees and consultants may still disclose our
proprietary information, and we may not be able to meaningfully protect our
trade secrets.

WE HAVE LIMITED SALES AND MARKETING CAPABILITY, AND WE MAY NOT BE ABLE TO
SUCCESSFULLY MARKET OUR PRODUCTS.

     We have limited sales and marketing capabilities. Although we expect to
increase our sales and marketing forces, we may not be able to recruit and train
adequate sales and marketing personnel. We compete with other companies that
have extensive and well-funded sales and marketing organizations. Our sales and
marketing staff may not compete successfully against such other companies.

SINCE WE DEPEND UPON DISTRIBUTORS, IF WE LOSE A DISTRIBUTOR OR A DISTRIBUTOR
FAILS TO PERFORM, OUR OPERATION WOULD BE HARMED.

     With the exception of Canada and Europe, we sell our VAD System in foreign
markets through distributors. In addition, we sell our vascular access graft
products through Goodman Co. Ltd., our distributor in Japan, and through Guidant
Corporation in the rest of the world. We will rely on Guidant for sales of the
Vectra in the United States, if we receive regulatory approval. To the extent we
rely on distributors, our success will depend upon the efforts of others, over
which we may have little control. If we lose a distributor or a distributor
fails to perform, our revenues will be adversely affected.

SINCE WE DEPEND ON THIRD PARTY REIMBURSEMENT TO OUR CUSTOMERS, IF THIRD PARTY
PAYORS FAIL TO PROVIDE APPROPRIATE LEVELS OF REIMBURSEMENT FOR OUR PRODUCTS, OUR
OPERATION WOULD BE HARMED.

     Significant uncertainty exists as to the reimbursement status of
newly-approved health care products such as our VAD System and our vascular
grafts. Government and other third party payors are increasingly attempting to
contain health care costs. Payors are attempting to contain costs by, for
example, limiting coverage and the level of reimbursement of new therapeutic
products. Payors are also attempting to contain costs by refusing in some cases
to provide any coverage of uses of approved products for disease indications
other than those for which the FDA has granted marketing approval.

                                        8
<PAGE>   13

     To date, some private insurers, Medicare and Medicaid have determined to
reimburse the costs of our VAD System. Our VAD System may not continue to be
approved for reimbursement. In addition, changes in the health care system may
affect the reimbursability of future products. If we fail to obtain such
reimbursement or if the reimbursement levels are reduced, our revenues would be
reduced.

PRODUCT LIABILITY CLAIMS COULD DAMAGE OUR REPUTATION AND HURT OUR FINANCIAL
RESULTS.

     Our business exposes us to an inherent risk of potential product liability
claims related to the manufacturing, marketing and sale of human medical
devices. We maintain only a limited amount of product liability insurance. We
also maintain general commercial and property insurance. Our insurance policies
generally must be renewed on an annual basis. We may not be able to maintain or
increase such insurance on acceptable terms or at reasonable costs, and such
insurance may not provide us with adequate coverage against potential
liabilities. A successful claim brought against us in excess of, or outside of,
our insurance coverage could have a material adverse effect on our financial
condition and results of operations. Claims against us, regardless of their
merit or potential outcome, may also reduce our ability to obtain physician
endorsement of our products or expand our business.

ANY CLAIMS RELATING TO IMPROPER HANDLING, STORAGE OR DISPOSAL OF HAZARDOUS
CHEMICALS AND BIOMATERIALS COULD BE TIME CONSUMING AND COSTLY.

     Producing our proprietary biomaterial, Thoralon, requires the use of
hazardous materials, including chemicals and biomaterials. We cannot eliminate
the risk of accidental contamination or discharge and any resultant injury from
these materials. Federal, state and local laws and regulations govern the use,
manufacture, storage, handling and disposal of these materials.

     We could be subject to civil damages in the event of an improper or
unauthorized release of, or exposure of individuals to, hazardous materials. In
addition, claimants may sue us for injury or contamination that results from our
use or the use by third parties of these materials, and our liability may exceed
our total assets. Compliance with environmental laws and regulations may be
expensive, and current or future environmental regulations may impair our
research, development or production efforts.

IF WE MAKE ACQUISITIONS, WE COULD ENCOUNTER DIFFICULTIES THAT HARM OUR BUSINESS.

     We may acquire companies, products or technologies that we believe to be
complementary to our business. If we do so, we may have difficulty integrating
the acquired personnel, operations, products or technologies. Acquisitions may
dilute our earnings per share, disrupt our ongoing business, distract our
management and employees and increase our expenses, which could hurt our
business.

OUR STOCK PRICE HAS BEEN VOLATILE, AND YOU MAY NOT BE ABLE TO RESELL YOUR SHARES
AT OR ABOVE THE OFFERING PRICE.

     The price of our common stock has been, and is likely to continue to be,
highly volatile. The price of our common stock could fluctuate significantly for
the following reasons:

     - future announcements concerning us or our competitors;

     - quarterly variations in operating results;

     - introduction of new products or changes in product pricing policies by us
       or our competitors;

                                        9
<PAGE>   14

     - acquisition or loss of significant customers, distributors and suppliers;

     - changes in earnings estimates by analysts;

     - changes in third party reimbursement practices;

     - regulatory developments; or

     - fluctuations in the economy or general market conditions.

     In addition, stock markets in general, and the market for shares of health
care stocks in particular, have experienced extreme price and volume
fluctuations in recent years which have frequently been unrelated to the
operating performance of the affected companies. These broad market fluctuations
may adversely affect the market price of our common stock. The market price of
our common stock could decline below its current price and the market price of
our stock may fluctuate significantly in the future. These fluctuations may be
unrelated to our performance.

     In the past, shareholders have often instituted securities class action
litigation after periods of volatility in the market price of a company's
securities. If a shareholder files a securities class action suit against us, we
would incur substantial legal fees and our management's attention and resources
would be diverted from operating our business in order to respond to the
litigation.

FUTURE SALES OF OUR COMMON STOCK COULD ADVERSELY AFFECT OUR STOCK PRICE.

     Future sales of substantial amounts of our common stock in the public
market, including the shares covered by this prospectus, or the perception that
these sales could occur, could adversely affect the market price of our common
stock. After giving effect to the offering, we will have 23,466,326 shares of
common stock outstanding, plus 3,139,824 shares of common stock reserved for
issuance upon exercise of outstanding options and 164,400 shares issuable upon
exercise of warrants. Holders of 7,030,502 shares of common stock and options to
purchase 1,795,025 shares of common stock have agreed not to sell, transfer or
otherwise dispose of their shares of common stock for a period of 90 days from
completion of this offering. All other outstanding shares of our common stock
are freely saleable except shares held by our affiliates, which are subject to
limitations on sales imposed by Rule 144 under the Securities Act.

MANAGEMENT MAY INVEST OR SPEND THE PROCEEDS OF THE OFFERING IN WAYS YOU MAY NOT
AGREE WITH AND IN WAYS THAT MAY NOT YIELD A RETURN.

     Our management will have broad discretion as to how the net proceeds of
this offering will be used. Investors will be relying on the judgment of
management regarding the application of the proceeds of this offering. The
results and effectiveness of the application of the proceeds are uncertain.

THE OCCURRENCE OF A CATASTROPHIC DISASTER COULD CAUSE DAMAGE TO OUR FACILITIES
AND EQUIPMENT, WHICH WOULD REQUIRE US TO CEASE OR CURTAIL OPERATIONS.

     We have only one facility in the United States, which is located in
Pleasanton, California. We are vulnerable to damage from various types of
disasters, including earthquake, fire, flood, power loss, communications
failures and similar events. For example, in October 1989 a major earthquake
that caused significant property damage and a number of fatalities struck near
the area in which we are located. If any disaster were to occur, we may not be
able to operate our business at our facilities. The insurance we maintain may
not be adequate to cover our losses resulting from disasters or other business
interruptions.

                                       10
<PAGE>   15

WE DO NOT ANTICIPATE PAYING DIVIDENDS.

     We intend to retain all of our earnings for the future operation and
expansion of our business. We do not anticipate paying cash dividends on our
common stock at any time in the foreseeable future.

AS A NEW INVESTOR, YOU WILL EXPERIENCE IMMEDIATE AND SUBSTANTIAL DILUTION.

     If you purchase shares of our common stock in this offering, you will incur
immediate and substantial dilution of $12.80 per share in pro forma net tangible
book value based on an assumed price to the public of $15.50 per share. If the
holders of outstanding options or warrants exercise those options or warrants,
you will incur further dilution. See "Dilution."

                                       11
<PAGE>   16

                                USE OF PROCEEDS

     We estimate net proceeds to our company from the sale of the 3,000,000
shares of common stock of approximately $43.1 million, assuming a public
offering price of $15.50 per share and after deducting the estimated
underwriting discounts and offering expenses. See "Underwriting." We will not
receive any proceeds from the sale of 1,500,000 shares by the selling
shareholder.

     We intend to use the net proceeds for:

     - clinical trials of products under development;

     - expansion of our sales and marketing capabilities;

     - research, development and potential acquisitions of complementary
       technology; and

     - working capital and other general corporate purposes.

     Although we may also use a portion of the net proceeds to acquire or invest
in businesses, products and technology that are complementary to our own, no
acquisitions are planned or being negotiated as of the date of this prospectus,
and no portion of the net proceeds has been allocated for any specific
acquisition. Pending these uses, the net proceeds will be invested in
investment-grade interest-bearing securities.

     The principal purposes of the offering are to increase our capitalization,
financial flexibility and the liquidity for our common stock. As of the date of
this prospectus, we cannot specify with certainty all of the particular uses for
the net proceeds we will have upon completion of the offering. Accordingly, our
management will have broad discretion in the application of net proceeds.

                                DIVIDEND POLICY

     We have never declared or paid cash dividends on our capital stock and do
not plan to pay any cash dividends in the foreseeable future. Our current policy
is to retain all of our earnings to finance future growth.

                                       12
<PAGE>   17

                          PRICE RANGE OF COMMON STOCK

     Our common stock is traded on the Nasdaq National Market under the symbol
"THOR." The following table sets forth, for the periods indicated, the high and
low closing sales prices per share of our common stock, as reported by the
Nasdaq National Market.

<TABLE>
<CAPTION>
                                                               HIGH      LOW
                                                              ------    ------
<S>                                                           <C>       <C>
Fiscal Year 1998
  First Quarter.............................................  $ 7.50    $ 5.56
  Second Quarter............................................    9.63      7.38
  Third Quarter.............................................    9.06      6.13
  Fourth Quarter............................................    7.50      4.00
Fiscal Year 1999
  First Quarter.............................................  $ 8.63    $ 6.25
  Second Quarter............................................   11.00      6.50
  Third Quarter.............................................   11.63      6.38
  Fourth Quarter............................................    9.75      5.50
Fiscal Year 2000
  First Quarter (through March 16, 2000)....................  $19.88    $ 8.50
</TABLE>

     The last reported sale price of our common stock on the Nasdaq National
Market on March 16, 2000 was $15.50 per share. At March 16, 2000, there were
approximately 700 holders of record of our common stock, including multiple
beneficial holders at depositories, banks and brokers listed as a single holder
in the "street" name of each respective depository, bank or broker.

                                       13
<PAGE>   18

                                 CAPITALIZATION

     The following table sets forth our capitalization at January 1, 2000 on an
actual basis, and on an as adjusted basis to reflect our receipt of the
estimated net proceeds of $43.1 million from the sale of common stock in this
offering, after deducting estimated fees of the underwriters and estimated
offering expenses. This table should be read in conjunction with our financial
statements and accompanying notes included elsewhere in this prospectus.

<TABLE>
<CAPTION>
                                                                  JANUARY 1, 2000
                                                              (FISCAL YEAR-END 1999)
                                                              -----------------------
                                                               ACTUAL     AS ADJUSTED
                                                              --------    -----------
                                                                  (IN THOUSANDS)
<S>                                                           <C>         <C>
Shareholders' equity:
  Preferred stock, 2,500,000 shares authorized; no shares
     issued and outstanding.................................        --           --
  Common stock, 100,000,000 shares authorized; 20,466,326
     shares issued and outstanding; and 23,466,326 shares
     issued and outstanding as adjusted.....................  $ 72,911     $116,044
  Additional capital........................................     2,541        2,541
  Accumulated deficit.......................................   (55,191)     (55,191)
  Accumulated translation adjustment........................        15           15
                                                              --------     --------
     Total shareholders' equity.............................  $ 20,276     $ 63,409
                                                              ========     ========
     Total capitalization...................................  $ 20,276     $ 63,409
                                                              ========     ========
</TABLE>

     The number of shares of our issued and outstanding common stock shown in
the table above excludes:

     - 3,139,824 shares of common stock reserved for issuance upon the exercise
       of stock options outstanding at a weighted average exercise price of
       $6.78 per share; and

     - 164,400 shares issuable upon exercise of warrants outstanding at an
       exercise price of $14.40 per share.

See "Selected Consolidated Financial Data," "Management's Discussion and
Analysis of Financial Condition and Results of Operations" and our financial
statements and notes thereto included in this prospectus.

                                       14
<PAGE>   19

                                    DILUTION

     If you invest in our common stock, your interest will be diluted to the
extent of the difference between the public offering price per share of our
common stock and the as adjusted net tangible book value per share of our common
stock after this offering.

     Our net tangible book value at January 1, 2000 was $20.3 million, or $0.99
per share of common stock. Net tangible book value per share represents total
tangible assets less total liabilities divided by the number of outstanding
shares of common stock on January 1, 2000. Our net tangible book value at
January 1, 2000, after giving effect to the sale of the 3,000,000 shares of
common stock at an assumed public offering price of $15.50 per share, and after
deducting estimated underwriting discounts and offering expenses would be $63.4
million or $2.70 per share. This represents an immediate increase in tangible
book value of $1.71 per share to existing shareholders and an immediate dilution
of $12.80 per share to new investors, or approximately 83% of the assumed
offering price of $15.50 per share. The following table illustrates this per
share dilution:

<TABLE>
<S>                                                             <C>       <C>
Assumed public offering price per share.....................              $15.50
  Net tangible book value per share at January 1, 2000......    $ 0.99
  Increase in net tangible book per share attributable to
     this offering..........................................      1.71
                                                                ------
Net tangible book value per share after this offering.......                2.70
                                                                          ------
Dilution in net tangible book per share to new investors....              $12.80
                                                                          ======
</TABLE>

     The following table shows at January 1, 2000, the number of shares of
common stock purchased from us, the total consideration paid to us and the
average price paid per share by existing shareholders and by new investors
purchasing common stock in this offering at an assumed public offering price of
$15.50 per share, before deducting estimated underwriting discounts and
estimated offering expenses.

<TABLE>
<CAPTION>
                             SHARES PURCHASED           TOTAL CONSIDERATION
                         ------------------------    --------------------------    AVERAGE PRICE
                           NUMBER      PERCENTAGE       AMOUNT       PERCENTAGE      PER SHARE
                         ----------    ----------    ------------    ----------    -------------
<S>                      <C>           <C>           <C>             <C>           <C>
Existing
  shareholders.........  20,466,326        87%       $ 75,453,000        62%          $ 3.69
New investors..........   3,000,000        13          46,500,000        38            15.50
                         ----------
  Total................  23,466,326       100%       $121,953,000       100%            5.20
                         ==========       ===        ============       ===
</TABLE>

                           -------------------------

     The computations in the table above assume no exercise of any outstanding
stock options or warrants outstanding after January 1, 2000. At January 1, 2000
there were:

     - options outstanding to purchase a total of 3,139,824 shares of common
       stock at a weighted average exercise price of $6.78 per share and, if any
       of these options or warrants are exercised, there will be further
       dilution to new public investors; and

     - 164,400 shares issuable upon exercise of warrants outstanding at an
       exercise price of $14.40 per share.

                                       15
<PAGE>   20

                      SELECTED CONSOLIDATED FINANCIAL DATA

     The selected consolidated financial data presented below for the five
fiscal years ended January 1, 2000 is derived from our audited financial
statements. We have a 52 or 53 week fiscal year that ends on the Saturday
closest to December 31. Our consolidated financial statements at the fiscal
years ended January 1, 2000 and January 2, 1999 and for each of the years in the
three-year period ended January 1, 2000, and the independent auditors' report
thereon, are included elsewhere in this prospectus. Our selected consolidated
financial data for fiscal 1997, 1996 and 1995 are derived from audited
consolidated financial statements not included in this prospectus. You should
read the data set forth below in conjunction with "Management's Discussion and
Analysis of Financial Condition and Results of Operations" and our financial
statements and related notes thereto appearing elsewhere in this prospectus. The
selected data in this section is not intended to replace our financial
statements.

<TABLE>
<CAPTION>
                                                              FISCAL YEAR
                                          ----------------------------------------------------
                                            1995       1996       1997       1998       1999
                                          --------   --------   --------   --------   --------
                                                 (IN THOUSANDS, EXCEPT PER SHARE DATA)
<S>                                       <C>        <C>        <C>        <C>        <C>
INCOME STATEMENT DATA:
Product sales...........................  $  3,489   $  7,503   $  9,441   $ 16,320   $ 22,508
Cost of product sales...................     1,972      3,254      4,005      6,504      9,739
Research and development................     1,984      3,724      4,583      5,096      5,793
Selling, general and administrative.....     1,301      3,948      6,009      7,701      9,457
Other operating income..................        --         --         --         --        285
                                          --------   --------   --------   --------   --------
Loss from operations....................    (1,768)    (3,423)    (5,156)    (2,981)    (2,196)
Interest and other income (expense),
  net...................................      (126)       160        754        660        407
                                          --------   --------   --------   --------   --------
Net loss................................  $ (1,894)  $ (3,263)  $ (4,402)  $ (2,321)  $ (1,789)
                                          ========   ========   ========   ========   ========

Basic and diluted loss per share........  $  (0.13)  $  (0.20)  $  (0.24)  $  (0.11)  $  (0.09)
                                          ========   ========   ========   ========   ========
Weighted average shares used in
  computing basic and diluted loss per
  share.................................    14,429     16,694     18,360     20,340     20,446
                                          ========   ========   ========   ========   ========

BALANCE SHEET DATA:
Cash, cash equivalents and marketable
  securities............................  $  1,646   $  5,348   $  9,469   $  2,713   $  1,697
Working capital.........................     2,808     17,266     15,885     11,251     10,533
Total assets............................     4,380     21,847     28,477     25,208     25,060
Long-term obligations and deferred
  revenue...............................     1,675         --         --         --        854
Accumulated deficit.....................   (43,416)   (46,679)   (51,082)   (53,402)   (55,191)
Total shareholders' equity..............     1,663     19,330     24,027     21,877     20,276
</TABLE>

                                       16
<PAGE>   21

                    MANAGEMENT'S DISCUSSION AND ANALYSIS OF
                 FINANCIAL CONDITION AND RESULTS OF OPERATIONS

     The statements in "Management's Discussion and Analysis of Financial
Condition and Results of Operations" that relate to future plans, events or
performance are forward-looking statements which involve risks and
uncertainties. Actual results, events or performance may differ materially from
those anticipated in these forward-looking statements as a result of a variety
of factors, including those set forth under "Risk Factors" and elsewhere in this
prospectus. Readers are cautioned not to place undue reliance on these
forward-looking statements, which speak only as of the date hereof. We undertake
no obligation to publicly release the result of any revisions to these
forward-looking statements that may be needed to reflect events or circumstances
after the date hereof or to reflect the occurrence of unanticipated events.

OVERVIEW

     We develop, manufacture and market medical devices for circulatory support
and vascular applications. We market our first product, the Thoratec VAD System,
in the United States and internationally for use as a bridge to heart transplant
and for recovery of the heart after heart surgery. We are pursuing additional
indications for the VAD System and developing other circulatory support products
for patients suffering from heart disease. We are also developing vascular
grafts for hemodialysis and coronary artery bypass surgery. All of our products
utilize our proprietary biomaterial, Thoralon, with surface properties designed
to minimize patient blood clotting and inflammatory response.

     We have experienced operating losses in all but one year since inception in
1976. We incurred net losses of $1.8 million in 1999, $2.3 million in 1998 and
$4.4 million in 1997. At January 1, 2000, we had an accumulated deficit of $55.2
million. We operate in a single business segment with different products in
circulatory support and vascular grafts. We expect to continue to incur
substantial additional losses until we can achieve substantial product revenues.
We conduct business both domestically and internationally. Our domestic business
comprises the United States, and our international operations comprise Europe
and the rest of the world.

RESULTS OF OPERATIONS

     PRODUCT SALES

     Product sales in 1999 were $22.5 million compared to $16.3 million in 1998,
an increase of approximately $6.2 million, or 38%. This increase is attributable
to sales of the VAD System disposable blood pump which increased to
approximately $16.2 million in 1999 from $11.0 million in 1998, an increase of
approximately $5.2 million, or 47%. The growth of sales in VAD pumps was
primarily attributable to an increase of approximately 33% in the quantity of
VAD pumps sold, which resulted from the growth in the number of new centers
using our VAD System. An increase in the average selling price of the VAD pumps
also contributed to the increase in revenue.

     Product sales in 1998 were $16.3 million compared to $9.4 million in 1997,
an increase of approximately $6.9 million, or 73%. Product sales from the sales
of VAD pumps increased to approximately $11.0 million in 1998 from $6.6 million
in 1997, an increase of approximately $4.4 million, or 67%. The growth of sales
in VAD pumps was primarily attributable to an increase of approximately 54% in
the quantity of VAD pumps sold, which resulted from the growth in the number of
centers using our VAD System. An increase in the average selling price of the
VAD pumps also contributed to the increase in revenue.

                                       17
<PAGE>   22

     GROSS PROFIT

     Gross profit was $12.8 million, representing approximately 57% of product
sales in 1999 compared to a gross profit of $9.8 million, representing
approximately 60% of product sales in 1998. The decrease in the gross profit
percentage in 1999 as compared to 1998 was due to approximately $400,000 of
higher inventory scrap and rework costs associated with a component part used in
the TLC-II portable driver, approximately $400,000 associated with higher
overall manufacturing and service overhead costs associated with the new
Pleasanton facility, and approximately $200,000 of costs associated with the
move to the Pleasanton facility. We expect gross profit to increase as a
percentage of product sales as we increase the number of devices manufactured
and improve the efficiency with which we manufacture.

     Gross profit was $9.8 million, representing approximately 60% of product
sales in 1998 compared to a gross profit of $5.4 million, representing
approximately 58% of product sales in 1997. The increase in the gross profit
percentage in 1998 as compared to 1997 was primarily due to our ability to raise
selling prices in the VAD blood pumps and cannulae faster than our costs have
increased.

     RESEARCH AND DEVELOPMENT

     Research and development expenses increased to $5.8 million in 1999,
representing 26% of sales, from $5.1 million in 1998, representing 31% of sales,
an increase of $697,000, or approximately 14%. Of the total increase in research
and development expenses, $372,000 was associated with the implantable VAD,
which we call IVAD, $251,000 was associated with graft products, and $210,000
was associated with the TLC-II. Partially offsetting the above increases was a
decrease of approximately $216,000 in manufacturing support overhead applied to
research and development activities. Expenses for the graft products increased
primarily from the clinical trials for the Vectra. Expenses for the TLC-II
included costs to upgrade a component part. Expenses for the IVAD included
product prototype and testing costs. We expect research and development expenses
to increase in 2000 principally as a result of clinical trial costs for our
graft products and our TLC-II portable driver. We expect research and
development expenses to decrease in 2000 as a percentage of product sales.

     Research and development expenses increased to $5.1 million in 1998,
representing 31% of sales, from $4.6 million in 1997, representing 49% of sales,
an increase of $513,000, or approximately 11%. Of the total increase in research
and development expenses, $152,000 was associated with graft products, $133,000
was associated with the VAD blood pump, and $145,000 was associated with the
IVAD.

     SELLING, GENERAL AND ADMINISTRATIVE

     Selling, general and administrative expenses increased to $9.5 million in
1999, representing 42% of sales, from $7.7 million in 1998, representing 47% of
sales, an increase of $1.8 million, or approximately 23%. Of the total increase
in selling, general and administrative expenses, $1.3 million is associated with
higher payroll and related costs associated with the continued development and
expansion of our domestic sales and marketing organization. We expect selling,
general and administrative expenses to increase in 2000 as we continue to build
our sales and marketing organization and as salaries for all personnel increase.
We expect selling, general and administrative expenses to decrease in 2000 as a
percentage of product sales.

     Selling, general and administrative expenses increased to $7.7 million in
1998, representing 47% of sales, from $6.0 million in 1997, representing 64% of
sales, an increase of $1.7 million, or approximately 28%. Of the total increase
in selling, general and administrative expenses, $726,000 was

                                       18
<PAGE>   23

associated with the continued development and expansion of our domestic sales
and marketing organization, $420,000 was associated with higher costs of the
Pleasanton facility, $163,000 was associated with the development and expansion
of our European sales organization, and $141,000 was associated with advertising
costs associated with new product introductions.

     OTHER OPERATING INCOME

     Other operating income includes amortization of deferred revenue from the
1999 Guidant agreement and was approximately $285,000. We expect other operating
income to remain the same or increase if the Vectra receives FDA clearance and
Guidant pays us $2.0 million under to our distribution agreement with them.

     INTEREST AND OTHER INCOME

     Interest and other income includes interest earned on cash income and
marketable securities and income from government research grants. Interest and
other income decreased to $407,000 in 1999 representing 2% of sales, from
$661,000 in 1998 representing 4% of sales, a decrease of $254,000, or
approximately 38%. The decrease in interest and other income was primarily
attributable to lower interest income earned on lower cash balances.

     Interest and other income decreased to $661,000 in 1998 representing 4% of
sales, from $753,000 in 1997 representing 8% of sales, a decrease of $92,000, or
approximately 12%. The decrease in interest and other income was primarily
attributable to lower interest income earned on lower cash balances partially
offset by higher income from government research grants.

     NET LOSS

     Our net loss decreased $531,000 to approximately $1.8 million in 1999 from
$2.3 million in 1998, a decrease of approximately 23%, as a result of the
factors discussed above.

     Our net loss decreased $2.1 million to approximately $2.3 million in 1998
from $4.4 million in 1997, a decrease of approximately 47%, as a result of the
factors discussed above.

LIQUIDITY AND CAPITAL RESOURCES

     We had cash, cash equivalents and short term investments at the end of 1999
of $2.0 million compared with $4.7 million at the end of 1998. The decrease in
cash was due principally to the loss from continuing operations and capital
expenditures associated with our new manufacturing facility. Accounts receivable
increased $1.3 million in 1999 principally due to increased sales in the fourth
quarter. Inventory increased $1.3 million in 1999 in preparation for planned
increases in sales activity and the introduction of a new product. Accounts
payable and accrued liabilities increased principally due to higher inventory
balances in anticipation of increased production to meet higher planned sales,
overall higher operating costs and the short-term portion of deferred
distributor revenue associated with the Guidant agreement discussed below.

     In 1999, we entered into a distribution agreement with Guidant Corporation.
Under the terms of the agreement, Guidant receives exclusive worldwide marketing
and distribution rights to the Vectra product line, except in Japan. In exchange
for these rights, Guidant has paid us $1.5 million, and will pay up to an
additional $2.0 million when the Vectra product line receives FDA approval for
use in the United States. Guidant also issued a four-year, unsecured line of
credit in the amount of $10.0 million to us, which may be used, if needed, for a
variety of business purposes. We have not utilized this line of credit to date.
We will recognize the $1.5 million ($1.4 million net of expenses)

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<PAGE>   24

contract payment received in the first quarter of 1999 as revenue ratably over
the five year life of the contract.

     In 1996, we entered into a lease agreement on a new manufacturing facility
in Pleasanton, California which accommodates all of our manufacturing,
engineering and administrative activities. The administrative and engineering
portion of the building was completed and occupied in late 1997. The
manufacturing portion was completed in 1998 and occupied in April 1999. We
invested approximately $9.0 million in equipment and leasehold improvements to
the building. Annual payments under the lease are approximately $751,000 for a
lease term of 15 years beginning August 1997. The lease includes provisions,
among others, for annual cost of living adjustments to the lease payments, two
five-year renewal options, a purchase option, a security deposit of $885,600,
which we paid in 1996, and an additional $500,000, which we paid in 1997. The
1997 payment was returned to us in 1998. We can reduce or eliminate a
significant portion ($750,000) of the remaining security deposit before the end
of the initial lease term if we meet the criteria specified in the lease.

     We believe that current cash and short term investments together with
expected cash flow from operations and the net proceeds of this offering, will
be sufficient to fund our operation for at least the next two years.

     YEAR 2000 COMPLIANCE

     We have completed our goal of an uninterrupted transition to the Year 2000.
We assessed all of our affected systems, our products and the readiness of our
third parties. We have not experienced significant Year 2000 issues subsequent
to 1999's fiscal year end. Although we believe we have taken the appropriate
steps to address our Year 2000 readiness, there is no guarantee that our efforts
will prevent a material adverse impact on the results of operations and
financial condition.

     Through fiscal year end 1999, we have incurred less than $35,000 of Year
2000 costs. All costs associated with Year 2000 compliance were funded with cash
flow generated from operations and existing cash balances and were expensed as
incurred.

     DISCLOSURE ABOUT MARKET RISK

     We do not use derivative financial instruments in our operations or
investment portfolio. We do not have material exposure to market risk associated
with changes in interest rates, as we have no long-term debt obligations or
long-term investments outstanding. Our investment portfolio consists of
short-term corporate debt instruments and Federal government agency debt
instruments that are classified as available-for-sale. The weighted average
maturity of our investment portfolio was less than 90 days in both 1998 and
1999. Accordingly, we do not expect to be subject to material interest rate risk
with respect to our short-term investments. We do not believe we have any other
material exposure to market risk associated with interest rates.

     Although we conduct business in foreign countries, our international
operations consist primarily of sales and service personnel for our VAD System.
These employees report into our U.S. sales and marketing group and are
internally reported as part of that group. Additionally, foreign currency
transaction gains and losses were not material to our results of operations for
1999. Accordingly, we do not expect to be subject to material foreign currency
risk with respect to future costs or cash flows from our foreign operations. To
date, we have not entered into any significant foreign currency forward exchange
contracts or other derivative financial instruments to hedge the effects of
adverse fluctuations in foreign currency exchange.

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<PAGE>   25

                                    BUSINESS

GENERAL

     We began our business in March 1976 and are incorporated in the State of
California. Our initial public offering of common stock occurred in 1981.

     We develop, manufacture and market proprietary medical devices used for
circulatory support and for vascular graft applications. We currently market the
Thoratec Ventricular Assist Device System (which we call the Thoratec VAD System
or the VAD System) in the United States and internationally for use as a bridge
to heart transplant and for use in the recovery of the heart after open-heart
surgery. We have also developed small diameter vascular grafts for use in
hemodialysis access and coronary artery bypass surgery. All of our products that
come into contact with human tissue or blood incorporate Thoralon, our
proprietary biomaterial. Thoralon is a unique biomaterial that provides strength
and flexibility to our products with surface properties designed to minimize
patient blood clotting and inflammatory response.

     Our VAD System is currently the only device approved by the FDA that can
provide left, right or biventricular support for both bridge to heart transplant
and for recovery of the heart after open-heart surgery. We are also pursuing
additional indications for the VAD System and developing other circulatory
support products for patients suffering from heart failure. At March 14, 2000,
our VAD System had been used in more than 1,200 patients worldwide ranging in
age from seven to 77 years and in weight from 38 to 316 pounds (17 to 144 kg).

     Our hemodialysis access graft product, which we call the Vectra, is
undergoing clinical trials in the United States and is currently marketed in
Europe through Guidant Corporation and in Japan through Goodman Co., Ltd. We
believe this graft offers significant advantages over currently available
prosthetic grafts used in hemodialysis. Unlike current grafts, which require up
to several weeks of patient recovery prior to use, the Vectra's self-sealing
design allows patient use as soon as 24 hours after surgical implantation. We
are applying the same technological expertise used in the Vectra for use in
coronary artery bypass surgery through our development of our Aria CABG
(coronary artery bypass graft) product. This small diameter graft is designed
for use by patients who have no or too few suitable blood vessels of their own.
We expect to commence clinical trials in the United States of our Aria coronary
graft in the first half of 2000.

OUR STRATEGY

     Our goal is to be a leading developer and manufacturer of medical devices
to the congestive heart failure, cardiac surgery and vascular graft markets. Our
key strategies to achieve this goal are:

     Increase VAD System Market Penetration. The Thoratec VAD System is the only
ventricular assist device with approvals for both bridge-to-transplant and
recovery after open-heart surgery indications. Our VAD System can be used to
treat both ventricles for patients of all sizes, and in a less invasive manner.
We intend to utilize our existing sales channels throughout the world to
continue to gain acceptance and adoption by both transplant and non-transplant
open heart centers, and to treat a greater number and variety of patients within
our current customer base. In addition, in order to further expand the clinical
utility of the VAD System, we intend to pursue:

     - the U.S. launch of the TLC-II Portable VAD Driver, which weighs
       approximately 20 pounds and operates interchangeably with current
       products. The TLC-II improves patient mobility, and is designed to allow
       patients to be discharged from the hospital while still using the VAD
       System;

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<PAGE>   26

     - the development of our implantable ventricular assist device, which we
       call the IVAD, for use in longer term bridge-to-transplant patients as
       well as some alternative-to-transplant patients;

     - the education of cardiac surgeons and heart failure cardiologists as to
       the benefits of the Thoratec VAD System; and

     - the regulatory approval of a therapeutic recovery indication.

     The therapeutic use of the Thoratec VAD System in treating specific types
of end-stage heart failure patients could represent a significant market
expansion opportunity for us. We estimate there are as many as 160,000 late
stage CHF patients in the United States whose cardiac recovery may potentially
be facilitated by the use of our VAD System.

     Obtain U.S. Approval and Support European and the U.S. Market Launch of
Vectra. We believe the clinical use of synthetic grafts for dialysis access is
an established clinical practice. However, existing commercial graft
technologies have significant shortcomings that are widely recognized. We
believe the Vectra device will address some of the most significant of those
shortcomings. We have completed patient enrollment in our U.S. clinical trial
and intend to submit a 510(k) to the FDA this year for U.S. approval to market
the Vectra. We have established distribution partnerships for the Vectra product
line, the most significant of which is Guidant. We will continue to identify and
pursue opportunities for product line extensions that enhance the Vectra product
offering.

     Attain Global Approval to Commercialize the Aria Coronary Artery Bypass
Graft. We intend to initiate and complete Aria coronary artery bypass clinical
trials and seek approvals in all major medical device markets. Through clinical
trials, we expect to demonstrate the efficacy of the Aria as an option for
completing the revascularization of coronary artery bypass patients. These
patients' only other option may be very poor quality veins, or even no available
veins at all. Therefore, our objective in these clinical trials is to show that
the Aria has similar or superior patency rates as compared to poor quality
veins. We believe that in as many as 20% of the 900,000 bypass surgeries
performed worldwide, the unavailability of any or enough suitable vessels
creates a treatment problem.

     Explore the Use of Thoralon for Additional Medical Products. Thoralon was
developed for safe and effective use in long-term cardiovascular implants, with
properties designed to provide:

     - excellent blood and tissue compatibility;

     - thromboresistance, which means resistance to blood clotting;

     - durability; and

     - stability.

     These properties allow Thoralon biomaterials to be configured and applied
in a variety of ways and may allow its use for other medical device applications
as a coating or stand-alone material. We intend to apply our biomaterials
technologies to those applications where our high-value, critical care
implantable medical devices are desired.

     Explore the Acquisition of, or Partnership with, Companies that Possess
Complementary Products or Technologies. We expect to leverage our expertise and
technologies with other products and technologies being developed by other firms
or research centers. We have established a strong direct sales presence with
some of the world's largest heart centers. We believe other companies, product
lines or technologies may benefit from this sales and distribution capability.
We intend to pursue opportunities to acquire products or technologies that
complement our products and allow us to leverage our competencies in selling and
marketing, regulatory affairs and manufacturing.

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<PAGE>   27

CIRCULATORY SUPPORT MARKET

     Cardiac failure is the leading cause of death in the United States,
accounting for more deaths than all forms of cancer combined. Deaths associated
with cardiac failure fall into two broad categories:

     - congestive heart failure, which is a chronic disorder that occurs when a
       weakening of the heart muscle reduces the pumping power of the heart; and

     - acute cardiac failure resulting from heart attacks and various infections
       of the heart muscle.

     CONGESTIVE HEART FAILURE

     CHF is a slow, degenerative process leading to cardiac insufficiency
resulting in a decreased supply of oxygen and nutrient rich blood to various
vital organs such as the lungs, brain and kidneys. CHF tends to be progressive
and is associated with profound symptoms that limit daily activities. Long-term
survival rates are low. We estimate that more than 85% of patients die within
eight to twelve years of diagnosis. CHF is the most common cause of
hospitalization in patients over 65 years of age. According to the American
Heart Association, there are currently four million to five million CHF patients
in the United States, and approximately 550,000 newly diagnosed patients each
year. While most patients suffering from CHF are initially treated with
medication, which may delay the progression of CHF, conventional drug therapy
cannot cure the disease. The only available method of treating end-stage CHF is
a heart transplant.

     Although heart transplants have been very successful, there are too few
donor hearts available to adequately address the problem of cardiac failure. The
United Network for Organ Sharing reported that there were only approximately
2,400 hearts available for transplant in the United States in 1998, a level that
has remained relatively unchanged for the last several years. However, published
government sources estimate that the number of patients suffering from CHF who
could benefit from some form of permanent cardiac assist is 30,000 to 50,000 per
year. The median wait for a donor heart by patients on a heart transplant
waiting list is approximately seven months, and many patients have to wait as
long as one to two years before receiving one of the few donor hearts available
each year. In 1998, approximately 19% of such patients died while waiting for a
donor heart.

     When other therapies are unsuccessful, ventricular assist devices can be
used to support one or both sides of the patient's heart until a donor heart can
be found. Ventricular assist devices are mechanical systems used to assist the
heart's function. In patients awaiting heart transplants, physicians decide to
use a ventricular assist device when the death of the patient appears imminent.

     ACUTE CARDIAC FAILURE

     In addition to providing a bridge to heart transplant, ventricular assist
devices have other potential applications. It is estimated that out of
approximately 800,000 open-heart surgeries performed annually in the United
States, some 15,000 to 20,000 patients die following such procedures, resulting
in a total market potential of over $300 million. We believe that only
approximately ten percent of the potential market is currently being treated
with VAD devices. Many of these deaths are caused by heart failure when the
heart, weakened by disease and the additional trauma of surgery, fails to
maintain adequate blood circulation. The use of a ventricular assist device
after surgery can provide support to the heart until it can recover. In
addition, ventricular assist devices may also be useful in assisting the
recovery of the heart in a small portion of patients suffering from acute
cardiac failure that may result from heart attack and various infections of the
heart muscle.

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<PAGE>   28

     There is significant demand for effective ventricular assist devices.
However, most systems available today or under development have limitations.
Certain systems cannot be used in smaller patients because the blood pump must
be implanted in the abdomen and is too large to fit in such patients. Other
systems require large incisions at the apex of the heart muscle, making recovery
of the heart more difficult if too large an incision is made. Some systems
cannot be used for more than a few days because their blood contacting parts can
cause an adverse reaction in the body. This adverse reaction results in blood
clotting which clogs the system or can cause a stroke in the patient.

THORATEC CIRCULATORY SUPPORT PRODUCTS

     We received FDA approval in December 1995 to market the Thoratec VAD System
as a bridge to heart transplant in patients suffering from heart failure, and
began marketing the VAD System in the United States in January 1996. The VAD
System has also received regulatory clearance and is currently being marketed in
major European countries, Canada and certain other major international markets.
At March 14, 2000, our VAD System had been used in more than 1,200 patients
worldwide ranging in age from 7 to 77 years and in weight from 38 to 316 pounds
(17 to 144 kg). Building on the proprietary technologies contained in the VAD
System, we are attempting to develop a broad line of circulatory support
products to meet the wide range of needs of patients suffering from heart
failure.

     OVERVIEW OF THE THORATEC VAD SYSTEM

     The VAD System consists of three major components:

     - the single-use blood pump, a type of artificial ventricle;

     - the single-use cannulae, which connect the blood pump to the heart and
       vessels; and

     - the Thoratec Dual Drive Console, a multi-use device which pneumatically
       activates the blood pump.

     Also available in international markets is the TLC-II Portable VAD Driver,
a small lightweight unit which can be used interchangeably with the Dual Drive
Console and is designed to allow the patient to move around the hospital or
return home. The VAD System provides partial or total circulatory assistance
when the natural heart is unable to maintain adequate circulation to perfuse
vital organs and permits left, right, or biventricular support.

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<PAGE>   29

                       [Illustration showing placement of
                   left and right ventricular assist devices]

     ADVANTAGES OF THE THORATEC VAD SYSTEM

     Compared to other ventricular assist devices, we believe that the VAD
System has the following principal advantages:

     - Biventricular Support. Most longer-term systems available today provide
       only left ventricular support. While many patients do well with only a
       left ventricular assist device ("LVAD"), we estimate that at least 20-30%
       of these patients also have or can develop right ventricular failure and
       require a right ventricular assist device ("RVAD"). Death and morbidity
       rates are extremely high for this patient group if not adequately
       supported. Since there are no risk factors that allow a surgeon to
       predict reliably which patients will require biventricular support, the
       decision for univentricular or biventricular support is simplified with
       the Thoratec VAD System, as RVAD support may be employed at the time of
       LVAD placement, thus eliminating the need for reoperation to insert an
       RVAD. Isolated RVAD support may also be suitable for patients with right
       heart failure only.

     - Paracorporeal Attachment. With the Thoratec VAD System, the blood pump is
       worn outside the body. This placement facilitates patient movement and
       allows patients to walk, exercise and move around the hospital. This
       paracorporeal placement allows the system to support patients of varying
       sizes, including very small patients such as small women, adolescents and
       children. To date, our VAD System has been used in patients as small as
       38 pounds and as young as seven years old. In contrast, other
       commercially available ventricular assist devices

                                       25
<PAGE>   30

       for bridge to heart transplant must be implanted and can only be used in
       patients large enough to accommodate the device within their abdomen. In
       addition, unlike implantable VAD's, paracorporeal attachment does not
       require two invasive abdominal surgeries. This makes the VAD System more
       suitable for critically ill patients who may potentially recover normal
       function of the heart without this additional surgical trauma.

     - Multiple Indications. Our VAD System is the only device approved in the
       United States to provide circulatory support for both post open heart
       surgery recovery and bridge to transplant indications. To date, the VAD
       System has been used to support patients for periods ranging from a few
       hours to well over one year. This unique flexibility to treat multiple
       patient groups allows hospitals to invest in a single product line and,
       therefore, make a smaller investment in inventory as one product line can
       be used with two patient groups. In addition, the surgical training
       required for our device can apply to a broader patient population. Also,
       for those post open heart surgery patients who become transplant
       candidates, use of our VAD System can eliminate the need for a second
       surgery to remove a device designed or approved for recovery only.

     - Thoratec Biomaterials. Our proprietary biomaterials are used in most
       surfaces of the VAD System that contact blood or are implanted in the
       body, providing biocompatibility, resistance to blood clotting, flex life
       and strength. These materials have been used in cardiovascular products
       for over 14 years. We have also licensed these biomaterials to health
       care manufacturers Gambro, Inc. and Cobe Cardiovascular for use in
       non-competing applications.

     - Multiple Cannulation Options. Cannulae for the VAD System come in a
       number of shapes and sizes, allowing the surgeon to fit the size of the
       cannulae to the size of the patient and to place the cannulae in
       different parts of the heart. Other commercially available systems have
       only limited cannula shape and size. The small size of our cannulae,
       compared to other systems, could make it easier for the heart to recover
       when the cannulae are removed. Variations of our cannulae also allow the
       surgeon to place the cannulae in places other than the apex of the heart
       (the only place used by the currently available left ventricular-only
       systems).

     CURRENT AND POTENTIAL INDICATIONS

     We have identified the following three basic clinical needs for our
circulatory support products:

     - Bridge to Heart Transplant. We commenced marketing the Thoratec VAD
       System in the United States in January 1996 for use as a bridge to heart
       transplant in patients suffering from heart failure following receipt of
       pre-market approval from the FDA in December 1995. In 1999, we sold 534
       VAD pumps to heart centers worldwide. We maintain a record of all
       patients reported treated with the VAD System, which we call the
       Voluntary Registry. Since FDA approval, this registry has relied upon
       strictly voluntary input from our customers. As of March 14, 2000, our
       Voluntary Registry included 912 patients treated with the VAD System for
       bridge to transplant. At any given time, there are approximately 4,000 to
       5,000 patients on the waiting list for a heart transplant in the United
       States, and we believe a comparable number are waiting in Europe. We
       believe that the percentage of these patients bridged to transplant will
       continue to increase, as surgeons' level of comfort with the technology
       increases, particularly for longer-term support cases.

     - Recovery of the Natural Heart. Approximately 2% of patients who undergo
       open heart surgery have difficulty recovering normal cardiac function,
       which makes it difficult to wean the patient from the heart/lung machine.
       Patients can only stay on the heart/lung machine after

                                       26
<PAGE>   31

       surgery for a limited period of time (generally less than six hours), and
       if they are unable to regain normal heart function, they will not survive
       without ventricular support. The use of a ventricular assist device after
       surgery can provide support to the heart until the heart can recover. We
       received FDA approval for this indication in May 1998.

      As of March 14, 2000, our voluntary registry reported that the VAD System
      had been used in 215 patients who were unable to regain normal heart
      function following surgery requiring cardiopulmonary bypass and were,
      therefore, unable to be removed from the heart/lung machine following
      surgery. Normally, patients who cannot be weaned from the heart/lung
      machine die. Of the 215 patients who have been placed on the VAD System,
      35% (75 patients) survived following removal from the heart/lung machine.
      Of those patients, 61% were discharged from the hospital. Duration of
      patient cardiac support ranged from one to 118 days. Although most
      patients were supported less than ten days, several required support for
      between one and three months before they successfully recovered cardiac
      function.

     - Therapeutic Recovery as an Alternative to Heart Transplant. We believe
       that for most patients recovery of their own heart is a better
       alternative than either heart transplantation or permanent implantation
       of a blood pumping device. Based on recently reported cases of recovery
       in heart failure patients, we believe that the VAD System is a potential
       therapy to reverse the complications of late-stage heart failure in
       certain patients.

      While this therapeutic recovery indication is not yet approved for our
      device, we are actively investigating the worldwide experience with the
      Thoratec VAD System and the requirements for pursuing regulatory approval
      for this indication. We estimate that there are as many as five million
      Americans with congestive heart failure each year, and we believe the use
      of the VAD System for therapeutic recovery could represent a therapeutic
      opportunity for many of these patients. We are working with physicians at
      some of the leading cardiovascular centers to track the experience of all
      patients who recover while being treated with the VAD System and are
      formulating a regulatory and clinical strategy both in the United States
      and abroad.

     CIRCULATORY SUPPORT PRODUCTS UNDER DEVELOPMENT

     In addition to our commercially available VAD System, we currently have
under development or in the final stages of U.S. regulatory approval the
circulatory support products described below. We may be unable to successfully
develop any of these products, or if successfully developed, these products may
not obtain regulatory approval or market acceptance or be manufactured and sold
on commercially acceptable terms.

     - TLC-II Portable VAD Driver. Although patients supported with the Dual
       Drive Console can walk throughout the hospital and transfer from critical
       care units to general wards, they usually cannot leave the hospital
       because of the size of the console. We have developed the TLC-II, a
       compact and lightweight (approximately 20 pounds), battery or
       line-operated biventricular pneumatic drive unit designed to promote
       greater mobility and self-care. It is designed to allow the patient to
       exercise more easily and move freely around the hospital grounds and
       eventually leave the medical facility. This device provides several
       portability options, either by hand-carrying the driver or by using a
       shoulder strap or mobility cart. This

                                       27
<PAGE>   32

       portable device connects with a docking station, which houses a battery
       charger and the external monitoring computer.

                        [Picture of patient walking with
                     Thoratec's TLC-II on a mobility cart]

      We received authority to CE Mark (an international symbol of quality
      required for products to be distributed in the European Community) this
      product in March 1998 and introduced the TLC-II in Europe in the middle of
      that year. We received approval for an IDE from the FDA in November 1998
      to begin a clinical trial of this device in the United States for use in
      conjunction with the approved VAD System. We believe that the regulatory
      path to approval for this device will be facilitated by the fact that it
      activates the same VAD System blood pumps that have received FDA approval.

      In 1999, we notified the FDA that we were putting a voluntary hold on
      further enrollment in U.S. clinical trials for the TLC-II and on shipments
      of the device to new centers in Europe, pending completion of a certain
      component upgrade. We expect to complete the testing of that component and
      apply to resume patient enrollment in our U.S. clinical trial and
      shipments of this device to Europe in the first half of 2000.

     - Implantable VAD ("IVAD"). While the placement of the current VAD System
       outside the body of the patient has the advantages described above, we
       are developing an implantable version of our existing VAD blood pump and
       cannulae to provide additional options for surgeons. The Thoratec IVAD is
       designed for patients who require long-term VAD support. It is also
       significantly smaller than the other commercially available implantable
       LVAD devices. Our IVAD weighs less than a pound, which is 50% lighter
       than these competing devices. Because of its small size, the IVAD can be
       used in not only smaller patients, but also, through the use of two
       IVADs, in some biventricular patients, a capability unique to any
       commercially available implanted VAD device. Prototypes have been
       developed, and a pre-IDE filing was made in 1999. We successfully
       completed the first animal implant in January 2000. We believe that the
       regulatory process for the IVAD may be facilitated, in part, by the fact
       that the VAD System has already undergone preclinical testing in the
       implantable configuration prior to being introduced for clinical use in
       the paracorporeal configuration.

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<PAGE>   33

VASCULAR GRAFT MARKET

     VASCULAR ACCESS FOR HEMODIALYSIS

     The principal use of vascular access grafts is for hemodialysis for
patients with end stage renal disease ("ESRD"), a debilitating disorder
characterized by gradual erosion of kidney function. ESRD is irreversible, and
the majority of all patients suffering from this disease worldwide are
maintained by hemodialysis. According to the U.S. Renal Data System's 1999
Annual Data Report, hemodialysis is the primary treatment for approximately 87%
of all end stage renal disease patients in the United States, an estimated
195,000 patients at the end of 1997. Market estimates suggest that approximately
200,000 prosthetic vascular access grafts used for hemodialysis were implanted
worldwide in 1999, representing an annual market approaching $120 million. We
estimate that the United States represents less than one-half of the worldwide
hemodialysis patient population.

     Hemodialysis removes toxins and excess fluid from a patient's blood by
circulating the blood through a dialyzer, or so-called "artificial kidney." This
procedure is generally performed three times per week and lasts three to four
hours. Patients undergoing hemodialysis require easy, routine access to the
blood stream at a high flow rate. This access to the patient's blood stream is
achieved using one of three methods: creation of an arterio-venous ("A/V") shunt
from the patient's blood vessels, inserting a central venous catheter, or
implanting an artificial vascular access graft (VAG). The majority of
hemodialysis patients in the United States depends on the use of a VAG that is
surgically connected between the patient's artery and vein. The vast majority of
available VAG's are made from expanded polytetrafluorethylene (ePTFE). The graft
is accessed using needles connected to tubing that carries the patient's blood
to the dialyzer and returns it back cleansed to the patient.

     Vascular access methods currently available for hemodialysis applications
have certain limitations. Both A/V shunts and ePTFE grafts must mature for two
to six weeks before use and therefore require the use of a temporary central
venous catheter until the graft is ready for use. Such catheters entail
additional cost, including those associated with catheter insertion, maintenance
and treatment for complications, and risk to the patient such as infection,
thrombosis and venous stenosis. Additionally, ePTFE VAGs are usually accompanied
by profuse and prolonged bleeding, often up to 20 minutes, when the needles used
for hemodialysis are removed, increasing patient treatment time at the dialysis
center.

     CORONARY ARTERY BYPASS SURGERY

     Currently, obstructed coronary arteries are either partially cleared
through the use of angioplasty or related procedures or treated surgically
through coronary artery bypass surgery. Coronary artery bypass surgery involves
connecting one or more new vessels from the aorta to the heart to re-route blood
around blockages in the coronary arteries. Grafts using saphenous veins (from
the leg) or the internal mammary artery of the patient have been successfully
used in bypass procedures for a number of years and have shown a relatively high
patency with no risk of tissue rejection. We estimate that in 1997 there were
approximately 600,000 coronary artery bypass surgery procedures performed in the
United States and approximately 300,000 performed outside the United States. We
estimate that on average three bypasses are performed in each surgical
procedure.

     While the use of natural vessels is the standard of care in coronary artery
bypass surgery, the harvesting of vessels from the patient for grafts involves
significant trauma and expense. Use of these vessels requires additional time in
surgery and results in patient morbidity associated with removal of the blood
vessel. In addition, a significant number of patients requiring coronary artery
bypass surgery have insufficient vessels as a result of previous bypass
surgeries, or their vessels are of inferior quality due to trauma or disease. We
estimate that these patients may represent as much as 20% of the total patients
undergoing bypass surgery. No artificial graft currently has full market
approval or is being
                                       29
<PAGE>   34

marketed in the United States for coronary artery bypass surgery, but we believe
a significant market opportunity for such grafts exists. The major reason for
the unavailability of a synthetic graft for this indication has been that
synthetic grafts configured in small diameters (less than five millimeters)
necessary for this indication generally do not remain patent.

THORATEC VASCULAR GRAFT PRODUCTS

     We are developing small diameter vascular graft products intended initially
to address the vascular access and coronary artery bypass surgery markets. Both
products utilize our proprietary Thoralon biomaterial, and are protected by
several patents covering Thoralon as well as the graft design and manufacturing
processes. We believe that our vascular grafts are highly compliant, have
excellent handling and suturing properties and have the "feel" of a natural
blood vessel. Our manufacturing process creates a structure in which the three
different layers in the graft wall have different properties which make the
graft closely resemble natural blood vessels. The inner textured layer is
designed for contact with blood and provides improved resistance to blood clots.
The solid middle layer gives the graft its strength and self-sealing properties.
The outer textured layer is designed to promote tissue ingrowth to promote graft
stability.

     VECTRA VASCULAR ACCESS GRAFT

     Currently available vascular access grafts are commonly made out of ePTFE,
which can lose integrity after repeated punctures and render the patient
susceptible to bleeding and infection. The Vectra is designed for use as a shunt
between an artery and a vein, primarily to provide access to the bloodstream for
renal hemodialysis patients requiring frequent needle punctures during
treatment. We believe that the Vectra may provide significant advantages over
existing synthetic vascular access grafts that may encourage its use by surgeons
who are currently using natural vessels for vascular access. The Vectra received
marketing approval from the Canadian Ministry of Health in March 1996, from the
Japanese Ministry of Health in May 1997, and authority to CE Mark the product in
January 1998. We received approval for an IDE from the FDA in mid-1998 to
commence clinical trials in the United States. Enrollment in that study was
completed in 1999 and patients are now in the six-month to one year follow-up
period. We believe that these clinical trials will be necessary to support the
submission of a 510(k) premarket notification to the FDA.

     Based upon published data obtained in clinical trials outside the United
States and the early results of a prospective, randomized U.S. trial, we believe
that the Vectra offers the following advantages:

     - reduced inflammatory response after implantation;

     - the ability to begin hemodialysis as soon as 24 hours after implantation,
       as opposed to several weeks for ePTFE grafts;

     - reduced bleeding complications during routine use because of the Vectra's
       self-sealing properties; and

     - improved handling and suturability.

     In one retrospective study of the Vectra in Australia, 134 patients who
were implanted by 30 different surgeons were evaluated. In nearly one-third of
the patients, initial use of the Vectra for hemodialysis was performed within
one day of implantation. The median time for initial access was three days after
implantation. Early results of the U.S. clinical trial have also been presented
with the data supporting allowance for early access, as soon as 24 hours after
implantation, without the need for temporary central venous catheters and
similar patency rates to the ePTFE control. Lastly, the

                                       30
<PAGE>   35

preliminary results illustrated a statistically significant improvement in the
time required to seal the graft, with bleeding cessation following needle
removal averaging only three minutes with the Vectra.

     In January 1999, we entered into a distribution agreement with Guidant
Corporation. Under the terms of this agreement, Guidant receives exclusive
worldwide marketing and distribution rights to the Thoratec Vectra product line,
except in Japan. In exchange for these rights, Guidant has paid us $1.5 million,
and will pay us up to an additional $2.0 million when the Vectra product line
receives FDA approval for use in the United States.

     ARIA CORONARY ARTERY BYPASS GRAFT

     We have developed from our proprietary Thoralon biomaterials a small
diameter graft for use in coronary artery bypass surgery patients who have no
suitable vessels of their own. A total of 27 patients in Canada and Germany
received our Aria coronary artery bypass grafts, ranging in internal size from
2.0 to 3.5 millimeters. All patients were extremely ill at the time of surgery,
and the grafts were implanted on a compassionate use basis (i.e., the patients
were found to have no other viable therapeutic options). All 22 surviving
patients were asymptomatic at follow-up points ranging from 2.5 to 5 years after
surgery. Of the five patients who did not survive, none is known to have died
from causes related to the graft. We need long-term test results from a
controlled clinical trial on a much larger patient population before we can
demonstrate the capabilities of this graft.

     The potential for improved long-term patency in small diameter grafts is
the most unique aspect of the Aria. We believe that to date no other suitable
small diameter graft has been developed which will remain patent over long
periods of time when used in this critical application. In January 1999, we
submitted data to the Canadian Health authorities supporting the request to
begin a 330 patient study of the Aria graft. In January 2000, we announced that
four patients had been implanted in our AlternativE Graft Investigational Study
(AEGIS/Canada trial) at a hospital in British Columbia. The first perfusion scan
on the first patient was done and the results were normal. These scans are
designed to be done at one month and six months following implant, although that
timing is at the discretion of the surgeon. We now have permission from two
additional hospitals in British Columbia to enroll patients in this study.

     We submitted an IDE for the Aria to the FDA in December 1999. Our plan is
to conduct the AEGIS/U.S. trial at up to 15 centers and with fewer patients than
the AEGIS Canada trial. Given the similarity to its Canadian effort, we are
hopeful that we can combine data from the two trials, potentially reducing the
number of patients and time required to complete both of them. We believe this
product will require submission of a PMA application to the FDA. We received
questions from the FDA on this IDE submission and intend to respond as quickly
as possible. If the FDA approves the amended IDE, the AEGIS/U.S. trial could
begin enrolling patients in the first half of 2000.

     Peripheral Graft Applications. In addition to the Vectra and Aria, our
graft products and biomaterial technologies may potentially be used in other
applications such as peripheral vascular grafts for patients who require
restoration of circulation to their arms or legs due to blockages caused by
certain disease processes, or for use as a patch material in cardiovascular or
peripheral vascular repair procedures. While we are not currently pursuing
development of these applications, we have completed sufficient early stage
preclinical work in the graft area to believe our graft products could be
developed for these applications. Guidant has a right to negotiate for these
applications for a short period if we decide to develop them during the term of
the Vectra distribution agreement.

                                       31
<PAGE>   36

THORATEC BIOMATERIALS -- THORALON

     We have developed a proprietary biomaterials technology that is used in all
of our products and licensed to other health care manufacturers.

     Our Thoralon biomaterials technology is critical to the successful
performance of all of its products that come into contact with human blood or
tissue. All of our current products and those under development incorporate
these proprietary biomaterials, which are designed to minimize blood clotting
and inflammatory response. In addition, these products must maintain their
strength and flexibility. A VAD System blood pump, for instance, must contract
and expand approximately 40 million times per year without a decrease in
performance or failure. The two major components of Thoralon are surface
modifying additives ("SMAs") and BPS-215 polyurethaneurea ("BPS-215"), a high
flex-life elastomer.

     SMAs are proprietary multipolymers designed to enhance the biocompatibility
of the surface of a device that comes into contact with blood or other tissues.
SMAs are added to the base polymer component of the biomaterial in the bulk
fabrication stage. A unique property of SMAs is their ability to concentrate at
the surface of any finished part, thus determining its surface properties
independent of the base polymer. This SMA-based surface layer is not a coating
but a fully integrated part of the polymer which is not soluble in water or
blood. The result is a biocompatible, thromboresistant surface. BPS-215 is the
base component that provides the bulk properties of strength and flexibility to
Thoralon. The combination of bulk and surface properties provided by SMAs and
BPS-215 provides Thoralon with the critical properties necessary for implantable
cardiovascular and other medical devices.

     In 1992, we granted COBE a royalty-bearing license and sublicense to use
Thoratec's SMAs in certain COBE medical devices. In 1999, this license was
divided into two separate licenses. One is retained by COBE Laboratories, now
called Gambro, Inc., one of our major shareholders, and the other was granted to
Sorin COBE Cardiovascular when that division of Gambro was sold to Sorin.

                                       32
<PAGE>   37

SUMMARY OF EXISTING PRODUCTS AND PRODUCTS UNDER DEVELOPMENT

     The table below summarizes our existing products and products under
development.

<TABLE>
  <S>                           <C>                           <C>                        <C>
  ------------------------------------------------------------------------------------------
  CIRCULATORY SUPPORT           INDICATIONS                   MARKETING STATUS
  PRODUCTS
  ------------------------------------------------------------------------------------------
    Thoratec VAD System,        - Bridge to transplant        - Currently marketed in
    which consists of a                                       the United States and
    single-use blood pump       - Recovery after heart          internationally for
    and cannulae, and a         surgery                         bridge to transplant and
    multi-use drive console                                     recovery of the heart
    which pneumatically         - Therapeutic recovery as       after heart surgery
    activates the blood pump    an alternative to heart
                                  transplantation             - We intend to submit in
                                                              2000 a PMA Supplement to
                                                                seek FDA approval for
                                                                therapeutic recovery
  ------------------------------------------------------------------------------------------
    TLC-II Portable VAD         - Designed to improve         - Currently marketed
    Driver, which is a          patient mobility and            internationally; U.S.
    battery or line operated      facilitate hospital           clinical trial initiated
    pneumatic mobile drive        discharge for the first
    unit weighing                 two indications listed
    approximately 20 pounds       above
  ------------------------------------------------------------------------------------------
    IVAD, implantable VAD       - Designed to support         - Pre-IDE filing complete,
    weighing less than one      longer term bridge to         with successful completion
    pound                         transplant and                of first animal implant
                                  alternative to                in January 2000
                                  transplant patients
  ------------------------------------------------------------------------------------------
    VASCULAR ACCESS PRODUCTS    INDICATIONS                   MARKETING STATUS
  ------------------------------------------------------------------------------------------
    Vectra, small diameter      - ESRD patients needing       - Currently marketed
    graft for patients            hemodialysis                  internationally;
    needing hemodialysis                                        enrollment in U.S.
                                                                clinical trial completed
                                                                and 510(k) to be
                                                                submitted in 2000
  ------------------------------------------------------------------------------------------
    Aria, small diameter        - CABG patients needing       - Canadian clinical trial
    graft for patients with     vessels for                     underway; IDE submitted
    blocked arteries and          revascularization             to the FDA to initiate
    inadequate vessels of                                       trial in United States
    their own
  ------------------------------------------------------------------------------------------
</TABLE>

SALES AND MARKETING

     We operate in a single business segment with different products in
circulatory support and vascular grafts. We present our business geographically
as our domestic operation, which comprises our business in the United States,
and our international operation, which comprises our business in Europe and the
rest of the world. For further enterprise and related geographic information,
see Note 11 to our financial statements.

     CIRCULATORY SUPPORT PRODUCTS

     The potential customers for our circulatory support products are hospitals
that perform open-heart surgery procedures and heart transplants. Based upon
published sources, we estimate that 140 of

                                       33
<PAGE>   38

the approximately 900 hospitals in the United States that perform open-heart
surgery also perform heart transplants. We are initially targeting these 140
heart transplant hospitals and the largest of the remaining 900 hospitals plus
an additional 110 heart transplant hospitals in Europe.

     We have recruited and trained a direct sales force that, as of February 26,
2000, is comprised of 12 experienced cardiovascular sales specialists to sell
the VAD System in the United States, Canada, France, Germany, Spain, United
Kingdom, Austria, Switzerland, Netherlands, Portugal and South Africa.

     The sales effort is complemented by six direct clinical specialists that
conduct clinical educational seminars, assist with a new open heart center's
first VAD implant and resolve clinical questions or issues. We also partner with
universities, experienced clinicians and opinion leaders to assist with
expanding clinical educational needs. The sales team focuses on cardiac surgeons
that perform heart transplantation and transplant cardiologists, perfusionists
and the transplant nursing staff. In addition to our direct selling effort, we
have established a network of international distributors that cover those
markets that represent the majority of ventricular assist device potential. We
employ sales and marketing tactics commonly found within the cardiovascular
capital equipment device market such as direct mail, clinical education
seminars, symposia, equipment purchase and lease programs, and journal
advertisement. We have also assembled a Medical Advisory Board consisting of
opinion leaders who provide clinical input and direction on product development,
marketing and market issues.

     Hospitals or other medical institutions that acquire the VAD System
generally purchase two Dual Drive Consoles (to ensure that a back-up console is
available), VADs, related disposables and training. The time from the initial
contact with the cardiac surgeon until purchase is generally between nine and
eighteen months, due to the expense of the product and common hospital capital
equipment acquisition procedures. Upon receipt of a purchase order, we will
usually ship the products within thirty days.

     The introduction of a new system requires training of the appropriate
personnel. We provide initial training for the surgical and clinical support
teams when a center purchases and takes delivery of the VAD System. As a
follow-up to the initial training, we provide clinical support at the first
implant whenever possible. We also provide 24-hour access to clinically trained
personnel. Our sales force also assists customers with obtaining reimbursement
from third-party payors.

     VASCULAR GRAFT PRODUCTS

     We intend to market the Vectra through our distributor in Japan and through
Guidant in the rest of the world, and to market the Aria CABG device through a
direct sales force in the United States and Europe and potentially through
distributors in other international markets.

     We envision the market positioning of the Vectra as one that replaces an
existing product used in an accepted procedure, and at a comparable or premium
price. We plan to commission additional studies comparing our products to ePTFE
grafts. We believe the Vectra will have significant advantages over these
existing products and will therefore offer significant benefits to users and
patients, without the need for additional clinical training. We also believe the
demand for prosthetic VAGs will continue to grow. The worldwide hemodialysis
patient population continues to grow and is older and living longer, increasing
the requirement for multiple access procedures over many years. Additionally,
this population is increasingly made up of sicker patients, such as diabetics,
who have exhausted the number of sites available for A/V fistula creation,
thereby necessitating the need for a prosthetic VAG.

                                       34
<PAGE>   39

     We intend to initially position the Aria CABG device as a preferable
clinical option for patients who lack suitable native vessels. We believe that
more clinician education will be required for the Aria CABG device in terms of
patient indications, product use, and product capabilities. We may accomplish
this education by sponsoring educational programs, video educational tools, and
scientific lecture programs. We also anticipate that we will need a larger
domestic sales force structure to effectively market the Aria CABG device.

MANUFACTURING

     We manufacture all of our products at our 62,000 square foot leased
facility in Pleasanton, California. This facility was inspected by the FDA under
cGMP regulation prior to entering into production and has received the
International Standards Organization ("ISO") 9001 certification.

     Our manufacturing processes for the VAD System consist of the assembly of
standard and custom component parts, including blood-contacting components
fabricated from our proprietary biomaterials, and the testing of completed
products. We rely on single sources of supply for several components of the VAD
System. We are aware of alternative suppliers for all single-sourced items other
than the mechanical valves. In October 1997, we executed a four-year supply
agreement with Arrow International Inc. for the mechanical valves for the VAD
System.

PATENTS AND PROPRIETARY RIGHTS

     We seek to patent certain aspects of our technology. We hold, or have
exclusive rights to, 20 U.S. patents and have one U.S. patent application
currently in prosecution. Except for the biomaterials patents mentioned below,
which are utilized in the VAD blood pump and cannulae, the VAD System is not
protected by any patents other than one patent pertaining to the TLC-II. We do
not believe that this lack of patent protection will have a material adverse
effect on our ability to sell the VAD System because of the lengthy regulatory
period required to obtain approval of a ventricular assist device. We are not
aware of any ventricular assist devices that are based on our product design
currently approved by the FDA or undergoing clinical trials. Our proprietary
biomaterials technology are covered by eight patents. Three of these were sold
to Th. Goldschmidt AG ("Goldschmidt"), a German chemical manufacturer, in 1989,
but we have retained worldwide, royalty-free, exclusive rights to these patents
for most medical applications. Our vascular graft products are covered by three
manufacturing process patents. Four of our 20 patents are for products which are
not commercially pertinent to us today.

     We hold, or have exclusive rights to, 38 international patents, with 18
applications currently in prosecution. All 38 international patents apply to
products for which patents have been applied for or issued under U.S. patent
law. We license 12 biomaterial patents, valid in 8 countries, from Goldschmidt.
Our three graft patents are valid in Canada, France and the U.K., and one of
these patents is valid in Japan. Of the 18 currently pending patent
applications, all are related to biomaterials.

     The validity of any of our patents may be challenged by others, and we
could encounter legal and financial difficulties in enforcing our patent rights
against alleged infringers. In addition, others could develop technologies or
obtain patents which would render our patents obsolete. Although we do not
believe patents are the sole determinant in the commercial success of our
products, the loss of a significant percentage of our patents or the patents
relating to our graft products could have a material adverse effect on our
business.

     We have developed technical knowledge which, although nonpatentable, we
consider to be significant in enabling us to compete. However, the proprietary
nature of such knowledge may be

                                       35
<PAGE>   40

difficult to protect. We have entered into an agreement with each key employee
prohibiting such employee from disclosing any confidential information or trade
secrets. In addition, these agreements provide that any inventions or
discoveries relating to our business by these individuals will be assigned to us
and become our sole property.

     Claims by competitors and other third parties that our products allegedly
infringe the patent rights of others could have a material adverse effect on our
business. The medical device industry is characterized by frequent and
substantial intellectual property litigation. The cardiovascular device market
is characterized by extensive patent and other intellectual property claims.
Intellectual property litigation is complex and expensive and the outcome of
this litigation is difficult to predict. Any future litigation, regardless of
outcome, could result in substantial expense and significant diversion of the
efforts of our technical and management personnel. An adverse determination in
any such proceeding could subject us to significant liabilities or require us to
seek licenses from third parties or pay royalties that may be substantial.
Furthermore, we cannot assure you that necessary licenses would be available on
satisfactory terms, or at all. Accordingly, an adverse determination in a
judicial or administrative proceeding or failure to obtain necessary licenses
could prevent us from manufacturing or selling certain of our products, any of
which could have a material adverse effect on our business.

COMPETITION

     Principal competitors of the VAD System include:

     - Thermo Cardiosystems Inc., and Novacor, a division of Baxter
       International Inc., which manufacture and market an implantable left
       ventricular assist device approved only for bridge to heart transplant in
       the United States; and

     - ABIOMED, Inc., which manufactures and markets an FDA-cleared
       biventricular assist device for temporary circulatory support of patients
       in post heart surgery shock and other recovery indications.

     We believe that the principal competitive factors in the ventricular assist
device market are patient outcomes, product performance, size and portability,
quality, cost-effectiveness and customer service. We believe that our principal
competitive advantages are:

     - the VAD System can provide left, right or biventricular support;

     - the smaller size and placement of the system outside the body, which
       allows its use with a greater range of patients than competitive devices;

     - the greater range of cannulation options available; and

     - the quality of our biomaterials.

     Although we believe that these attributes of the VAD System offer certain
advantages over existing ventricular assist devices, we expect our current
competitors to defend their market positions vigorously.

     Our principal competitors in the vascular access graft market are W.R.
Gore, Inc., C.R. Bard, Boston Scientific/Vascular, and Baxter Corporation, who
manufacture and market ePTFE grafts worldwide. Smaller competitors include
CardioTech International, Inc., which manufactures and markets a polyurethane
graft that is available for sale outside of the United States. Finally, Possis
Medical, Inc. manufactures a self-sealing silicone rubber graft marketed with
limited indications in the U.S. through Horizon Medical Products, Inc.

                                       36
<PAGE>   41

     There are many companies focusing on the development of circulatory support
devices or vascular grafts that have substantially greater financial resources,
have substantially larger and more experienced sales and marketing organizations
and engage in substantially greater research and development efforts than we do.
One or more of these or other companies could design and develop products that
compete directly with our products, in which case we would face intense
competition. Moreover, certain academic institutions, government agencies and
other research organizations are conducting research in areas in which we are
working. These institutions are becoming increasingly aware of the commercial
value of their findings and are becoming more active in seeking patent
protection and licensing arrangements to collect royalties for use of technology
that they have developed. These institutions may also market competitive
commercial products on their own or through joint ventures and will compete with
us in recruiting highly qualified scientific personnel.

GOVERNMENT REGULATION

     Regulation by governmental authorities in the United States and foreign
countries is a significant factor in the manufacture and marketing of our
current and future products and in our ongoing product research and development
activities. All of our proposed products will require regulatory approval prior
to commercialization. In particular, medical devices are subject to rigorous
preclinical testing as a condition of approval by the FDA and by similar
authorities in foreign countries.

     U.S. REGULATIONS

     In the United States, the FDA regulates the manufacture, distribution and
promotion of medical devices pursuant to the Federal Food, Drug, and Cosmetic
Act and the regulations promulgated thereunder (the "FDC Act and Regulations").
The VAD System, TLC-II, IVAD and Vectra and Aria graft products are, or will be
regulated as medical devices. To obtain FDA approval to market medical devices
similar to those under development, the FDA requires proof of safety and
efficacy in human clinical trials performed under an IDE. An IDE application
must contain preclinical test data demonstrating the safety of the product for
human investigational use, information on manufacturing processes and
procedures, and proposed clinical protocols. If the IDE application is accepted,
human clinical trials may begin. The trials must be conducted in compliance with
FDA regulations. The results obtained from these trials, if satisfactory, are
accumulated and submitted to the FDA in support of either a PMA application or a
510(k) premarket notification. Premarket approval from the FDA is required
before commercial distribution of devices similar to those under development by
the Company is permitted in the United States.

     The PMA application must be supported by extensive data, including
preclinical and human clinical data, to prove the safety and efficacy of the
device. By regulation, the FDA has 180 days to review a PMA application and
during that time an advisory committee may evaluate the application and provide
recommendations to the FDA. While the FDA has approved PMA applications within
the allotted time period, reviews more often occur over a significantly
protracted period, usually 18 to 36 months, and a number of devices have never
been cleared for marketing. This is a lengthy and expensive process and there
can be no assurance that such FDA approval will be obtained.

     Under the FDA's requirements, if a manufacturer can establish that a newly
developed device is "substantially equivalent" to a legally marketed predicate
device, the manufacturer may seek marketing clearance from the FDA to market the
device by filing a 510(k) premarket notification with the FDA. The 510(k)
premarket notification must be supported by data establishing the claim of
substantial equivalence to the satisfaction of the FDA. The process of obtaining
a 510(k) clearance typically can take several months to a year or longer. If
substantial equivalence cannot be established, or if the FDA determines that the
device requires a more rigorous review, the FDA will

                                       37
<PAGE>   42

require that the manufacturer submit a PMA application that must be approved by
the FDA prior to marketing the device in the United States.

     Both a 510(k) and a PMA, if approved, may include significant limitations
on the indicated uses for which a product may be marketed. FDA enforcement
policy prohibits the promotion of approved medical devices for unapproved uses.
In addition, product approvals can be withdrawn for failure to comply with
regulatory requirements or the occurrence of unforeseen problems following
initial marketing.

     In December 1995, we received FDA approval of our PMA for the bridge to
heart transplant indication for the VAD System and in May 1998 received FDA
approval to use the VAD system in the post-heart surgery recovery indication. In
1999 we notified the FDA that we put a voluntary hold on further enrollment in
U.S. clinical trials for the TLC-II and on shipments of the device to new
centers in Europe, pending completion of a component upgrade. We expect to
complete the testing of that component in the first half of 2000. After
completion of testing and following approval of an IDE amendment, we intend to
resume patient enrollment in its U.S. clinical trial and recommence shipment of
this device to Europe.

     We submitted an IDE for the Aria to the FDA in December 1999 and received
questions from the FDA on this IDE in late January 2000. We intend to respond in
the second quarter of 2000 to these questions. We must answer these questions
before the FDA will approve the IDE.

     We expect that our graft products will be classified as either Class II or
Class III medical devices. We received approval for an IDE for our Vectra in
mid-1998 and believe that we will be able to file a 510(k) after the clinical
data is gathered in 2000. We have begun clinical trials with our Aria graft
outside the United States and have begun the IDE process required to begin
clinical trials in the United States.

     The approval process for each of our products is expensive and time
consuming and we cannot assure you that any regulatory agency will grant its
approval. Our inability to obtain, or delays in obtaining, such approval would
adversely affect our ability to commence marketing therapeutic applications of
our products. We cannot assure you that we will have sufficient resources to
complete the required testing and regulatory review processes. Furthermore, we
are unable to predict the extent of adverse governmental regulation which might
arise from future U.S. or foreign legislative or administrative action.

     In addition, any products distributed pursuant to the above authorizations
are subject to pervasive and continuing regulation by the FDA. Products must be
manufactured in registered establishments and must be manufactured in accordance
with cGMP and good laboratory practice regulations and adverse events must be
reported to the FDA. Labeling and promotional activities are subject to scrutiny
by the FDA and, in certain instances, by the Federal Trade Commission. The
failure to comply with the FDA's regulations can result in enforcement action,
including seizure, injunction, prosecution, civil penalties, recall and
suspension of FDA approval. The export of devices also is subject to regulation
in certain instances.

     On March 13, we received a warning letter from the FDA stating that our
manufacturing facility did not comply with cGMPs in several respects. We believe
that we will be able to respond to the FDA satisfactorily without a material
adverse affect on our business.

     INTERNATIONAL REGULATIONS

     We are also subject to regulation in each of the foreign countries in which
we sell products with regard to product standards, packaging requirements,
labeling requirements, import restrictions, tariff

                                       38
<PAGE>   43

regulations, duties and tax requirements. Many of the regulations applicable to
our products in such countries are similar to those of the FDA. The national
health or social security organizations of certain countries require our
products to be qualified before they can be marketed in those countries.

     In order to be positioned for access to European and other international
markets, we sought and obtained certification under the ISO 9000 Series of
Standards. ISO 9000 is a set of integrated requirements, which when implemented,
form the foundation and framework for an effective quality management system.
These standards were developed and published by the ISO, a worldwide federation
of national bodies, founded in Geneva, Switzerland in 1946. ISO has over 92
member countries. ISO certification is widely regarded as essential to enter
Western European markets. We obtained certification and were registered as an
ISO 9002 compliant company in January 1995. Commencing in mid-1998, all
companies are required to obtain CE Marks for medical devices sold or
distributed in the European Community. The CE Mark is an international symbol of
quality. With it, medical devices can be distributed within the European
Community, which is comprised of fifteen European countries representing a
population of over 360 million people. A prerequisite for obtaining authority to
CE Mark products is to achieve full quality system certification in accordance
with ISO 9001 and EN 46001. These are quality standards that cover design,
production, installation and servicing of medical devices. The Company has its
ISO 9001 and EN 46001 certification and has authority to CE Mark the VAD System,
the TLC-II and the Vectra. We are also certified to be in compliance with the
requirements of the European Medical Device Directive, another prerequisite for
applying the CE Mark.

     OTHER REGULATIONS

     We are also subject to various federal, state and local laws and
regulations relating to such matters as safe working conditions, laboratory and
manufacturing practices and the use, handling and disposal of hazardous or
potentially hazardous substances used in connection with our research and
development work. Specifically, the manufacture of our biomaterials is subject
to compliance with federal environmental regulations and by various state and
local agencies. Although we believe we are in compliance with these laws and
regulations in all material respects, we cannot assure you that we will not be
required to incur significant costs to comply with environmental laws or
regulations in the future.

THIRD PARTY REIMBURSEMENT AND COST CONTAINMENT

     Our products are purchased primarily by hospitals and other users, which
then bill various third party payors for the services provided to the patients.
These payors, which include Medicare, Medicaid, private health insurance
companies and managed care organizations, reimburse part or all of the costs and
fees associated with the procedures performed with these devices.

     Third party payors are increasingly challenging the prices charged for
medical products and services and may deny reimbursement if they determine that
a device was not used in accordance with cost-effective treatment methods as
determined by the payor, was experimental or was used for an unapproved
application. To date, some private insurers and Medicare and Medicaid have
determined to reimburse the costs of the VAD System. Changes in reimbursement
policies and practices of third party payors could have a material adverse
impact on sales of our products.

EMPLOYEES

     As of February 26, 2000, we had 166 full-time employees, 65 of whom worked
in manufacturing, 26 in engineering, 21 in quality control and regulatory
affairs, 29 in marketing and sales support, 10 in administration and finance and
15 in other support functions (including personnel, management information,
purchasing and facility). None of our employees is covered by a collective
bargaining agreement. We consider relations with our employees to be good.

                                       39
<PAGE>   44

RESEARCH AND DEVELOPMENT

     Our research and development expenses in 1997, 1998 and 1999 were $4.6
million, $5.1 million and $5.8 million.

FACILITIES

     We occupy leased facilities in Pleasanton, California totaling
approximately 62,000 square feet. The manufacturing areas have been inspected,
approved, and licensed by the FDA and the State of California Department of
Health Services, Food and Drug Section for the manufacture of medical devices.
We also have small leased facilities in the United Kingdom. We believe our
facilities will be sufficient to meet our needs for the next two years and that
additional space will be available at a reasonable price to satisfy space needs
thereafter.

LITIGATION

     The Company is not party to any material legal proceedings.

                                       40
<PAGE>   45

                                   MANAGEMENT

EXECUTIVE OFFICERS AND DIRECTORS

     Our executive officers and directors at March 10, 2000 are as follows:

<TABLE>
<CAPTION>
                NAME                  AGE                        POSITION
                ----                  ---                        --------
<S>                                   <C>    <C>
D. Keith Grossman...................  39     President, Chief Executive Officer and Director
Thomas E. Burnett, Jr. .............  36     Senior Vice President and Chief Operating Officer
Cheryl D. Hess......................  52     Vice President -- Finance, Chief Financial
                                             Officer
                                             and Secretary
David J. Farrar, Ph.D. .............  52     Vice President -- Research and Development
Donald A. Middlebrook...............  48     Vice President -- Regulatory Affairs/Quality
                                             Assurance
Joseph G. Sharpe....................  40     Vice President -- Operations
Howard E. Chase.....................  63     Director
J. Daniel Cole......................  53     Director
J. Donald Hill, M.D. ...............  63     Director and Chairman of the Board
William M. Hitchcock................  60     Director
George W. Holbrook, Jr. ............  68     Director
Daniel M. Mulvena...................  51     Director
</TABLE>

     D. KEITH GROSSMAN, PRESIDENT, CHIEF EXECUTIVE OFFICER AND DIRECTOR, joined
our company as President and Chief Executive Officer in January 1996. He was
elected to the Board of Directors in February 1996. Prior to joining us, Mr.
Grossman was a Division President of Major Pharmaceuticals, Inc., from June 1992
to September 1995, at which time it was sold. From July 1988 to June 1992, Mr.
Grossman served as the Vice President of Sales and Marketing for Calcitek, Inc.,
a manufacturer of implantable medical devices, and division of Sulzermedica
(formerly Intermedics, Inc.). Prior to 1988, Mr. Grossman held various other
sales and marketing management positions within the McGaw Laboratories Division
of American Hospital Supply Corporation.

     THOMAS E. BURNETT, JR., SENIOR VICE PRESIDENT, CHIEF OPERATING OFFICER,
joined our company as Vice President -- Sales and Marketing in August 1996 and
was promoted to his current position in December 1999. Prior to joining us, Mr.
Burnett was Vice President of Sales and Marketing at Calcitek, Inc. from June
1992 to August 1996, where he was responsible for global sales and marketing
which included a direct domestic sales force and an international network
encompassing 30 countries as well as new business development, strategic and
operational planning.

     CHERYL D. HESS, VICE PRESIDENT -- FINANCE, CHIEF FINANCIAL OFFICER AND
SECRETARY, joined our company as Vice President -- Finance and Chief Financial
Officer in December 1983 and became Secretary in 1994. Prior to joining us, Ms.
Hess was a manager with the public accounting firm of Deloitte & Touche LLP,
where she specialized in audit and financial advisory services for
entrepreneurial, rapidly-growing, high technology companies. Ms. Hess is
responsible for the direction of all financial management, control and reporting
activities and a portion of administrative and operational activities. Ms. Hess
is a Certified Public Accountant.

     DAVID J. FARRAR, PH.D., VICE PRESIDENT -- RESEARCH AND DEVELOPMENT, joined
our company as Program Manager of the VAD System in January 1980 and became Vice
President -- Circulatory Support Products in 1988, and Vice
President -- Research & Development in 1996. In addition, Dr. Farrar has a
research appointment in the Department of Cardiac Surgery at the California
Pacific Medical Center of San Francisco. Dr. Farrar has over 20 years of
research experience in the cardiovascular and medical device industry.

     DONALD A. MIDDLEBROOK, VICE PRESIDENT -- REGULATORY AFFAIRS/QUALITY
ASSURANCE, joined our company as Vice President -- Regulatory Affairs/Quality
Assurance in September 1996. Before

                                       41
<PAGE>   46

joining our company, he held the position of Senior Director, Global Regulatory
Affairs and Assurance for Chiron Vision Corporation, a manufacturer of
implantable ophthalmic devices and surgical equipment. Prior to that, Mr.
Middlebrook spent fifteen years with Baxter International in a number of
positions, including Vice President of Regulatory Affairs and Quality Assurance
for the CardioVascular Group, a producer of a wide range of cardiopulmonary,
critical care, vascular and cardiovascular products.

     JOSEPH G. SHARPE, VICE PRESIDENT -- OPERATIONS, joined our company as Vice
President -- Operations in September 1997. Prior to joining us, Mr. Sharpe was
Director of Operations for the IV Systems Division of Baxter International, Inc.
from 1992 to September 1997. Prior thereto, Mr. Sharpe held a number of other
positions at Baxter International, Inc. including Director of Engineering of the
Pharmaseal Division, and Honeywell Information Systems.

     HOWARD E. CHASE became a director of our company in November 1986. Mr.
Chase is President and CEO of Carret Holdings, Inc. (formerly Matrix Global
Investments, Inc.) since April 1999. Mr. Chase served as President and CEO of
Trident Rowan Group, Inc. ("TRGI") from September 1995 to March 1996 and
Chairman of the Board of TRGI from March 1998 to December 1999. From 1984 to
August 1995, Mr. Chase was a partner in the law firm of Morrison Cohen Singer &
Weinstein, LLP in New York City. He acted as an advisor and as a special counsel
to our company from 1979 to 1995. Mr. Chase also serves as a member of the board
of directors of Trident Rowan Group, Inc. and Moto Guzzi Corporation.

     J. DANIEL COLE became a director of our company in July 1997. Mr. Cole is a
general partner of the Spray Venture Fund of Boston. Mr. Cole was President and
Chief Operating Officer of SciMed Life Systems Corporation from April 1993 to
March 1995, and Senior Vice President and Group President of Boston Scientific
Corporation's vascular business from March 1995 to March 1997. He has also held
a number of senior executive positions at Baxter Healthcare Corporation,
including President of its Edwards Less Invasive Surgery Division and its
Critical Care Division. Mr. Cole also serves as a member of the Board of
Directors of Cambridge Heart, Inc. and SurVivaLink.

     J. DONALD HILL, M.D. has been a director of our company since its inception
and is one of our significant shareholders. In January 1995, Dr. Hill became
Chairman of the Board of Directors. Dr. Hill is Chairman of the Department of
Cardiac Surgery at California Pacific Medical Center in San Francisco where he
has been a practicing cardiovascular surgeon since 1966.

     WILLIAM M. HITCHCOCK became a director of our company in September 1996. In
December 1994, Mr. Hitchcock became President and director of Avalon Financial,
Inc. From May 1992 to December 1995, Mr. Hitchcock was President of Plains
Resources International Inc., a wholly owned subsidiary of Plains Resources Inc.
Mr. Hitchcock also serves as a member of the Board of Directors of Plains
Resources Inc. and Oshman's Sporting Goods, Inc.

     GEORGE W. HOLBROOK, JR. became a director of our company in July 1995.
Since 1984 Mr. Holbrook has been the Managing Partner of Bradley Resources
Company, a private investment partnership. Mr. Holbrook is also a director of
Merrill Lynch Institutional Fund and several associated funds.

     DANIEL M. MULVENA became a director of our company in May 1997. Mr. Mulvena
is the founder and owner of Commodore Associates, a consulting company. Mr.
Mulvena was Group Vice President of the Cardiac/Cardiology Division and a member
of the operating committee for Boston Scientific Corporation from February 1992
to May 1995. Prior to that, he was the President and Chief Executive Officer and
Chairman of Lithox Systems, Inc. Prior to that, Mr. Mulvena held a number of
executive positions, including President of the Implants Division and President
of the Cardiosurgery Division, at C.R. Bard, Inc. Mr. Mulvena also serves as a
member of the Board of Directors of EchoCath, Inc., Magna-Lab Inc., Zoll Medical
Corporation and Cambridge Heart, Inc.

                                       42
<PAGE>   47

                 PRINCIPAL SHAREHOLDERS AND SELLING SHAREHOLDER

     The following table sets forth certain information regarding the beneficial
ownership of our common stock as of March 10, 2000:

     - by each of our directors;

     - by each named executive officer;

     - by all directors and executive officers as a group;

     - by each person who is known by us to own beneficially more than 5% of our
       common stock; and

     - by the selling shareholder.

<TABLE>
<CAPTION>
                                            OWNERSHIP BEFORE                                OWNERSHIP AFTER
                                               OFFERING(2)                                    OFFERING(2)
                                      -----------------------------                 -------------------------------
                                       NUMBER OF       PERCENT OF                     NUMBER OF        PERCENT OF
                                         SHARES          SHARES        NUMBER OF        SHARES           SHARES
                                      BENEFICIALLY    BENEFICIALLY      SHARES       BENEFICIALLY     BENEFICIALLY
        NAME AND ADDRESS(1)              OWNED           OWNED          OFFERED         OWNED            OWNED
        -------------------           ------------   --------------   -----------   --------------   --------------
<S>                                   <C>            <C>              <C>           <C>              <C>
Gambro, Inc. (formerly COBE
  Laboratories, Inc.)...............   3,708,077          18.0%         1,500,000     2,208,077            9.3%
Peter R. Kellogg....................   2,328,450          11.3                        2,328,450            9.9
State of Wisconsin Investment
  Board.............................   1,549,800           7.5                        1,549,800            6.6
J. Donald Hill(3)...................   1,421,953           6.9                        1,421,953            6.0
Sulzer Medica USA Inc...............   1,074,074           5.2                        1,074,074            4.5
George W. Holbrook, Jr.(4)..........     461,392           2.2                          461,392            2.0
Bradley Resources Company(4)........     433,059           2.1                          433,059            1.8
James McGoogan(4)...................     433,059           2.1                          433,059            1.8
William M. Hitchcock(5).............     382,073           1.9                          382,073            1.6
D. Keith Grossman(6)................     254,833           1.2                          254,833            1.1
Howard E. Chase(7)..................     110,555             *                          110,555              *
David J. Farrar(8)..................     103,314             *                          103,314              *
Donald A. Middlebrook(9)............      89,125             *                           89,125              *
Cheryl D. Hess(10)..................      74,506             *                           74,506              *
Thomas E. Burnett, Jr.(11)..........      73,125             *                           73,125              *
J. Daniel Cole(12)..................      70,000             *                           70,000              *
Daniel M. Mulvena(13)...............      30,000             *                           30,000              *
Directors and Executive Officers as
  a Group (12 persons)(14)..........   3,139,001          14.6%                       3,139,001           12.8%
</TABLE>

- -------------------------
  *  Less than one percent

 (1) The address of the persons set forth above is our address appearing in
     "Prospectus Summary."

 (2) Applicable percentage ownership for each shareholder is based on 20,623,052
     shares of common stock outstanding at March 10, 2000, together with
     applicable options for such shareholder. Beneficial ownership is determined
     in accordance with the rules of the Securities and Exchange Commission, and
     includes voting and investment power with respect to the shares. Beneficial
     ownership also includes shares of stock subject to options and warrants
     exercisable or convertible within 60 days of March 10, 2000. Shares of
     common stock subject to outstanding options are deemed outstanding for
     computing the percentage of ownership of the person holding such options,
     but are not deemed outstanding for computing the percentage ownership of
     any other person. Except pursuant to applicable community property laws or
     as indicated in the footnotes to this table, to our

                                       43
<PAGE>   48

     knowledge, each shareholder identified in the table possesses sole voting
     and investment power with respect to all shares of common stock shown as
     beneficially owned by such shareholder.

 (3) Includes 110,555 shares issuable upon exercise of options exercisable
     within 60 days of March 10, 2000.

 (4) Bradley Resources Company is an investment partnership which owns 433,059
     shares. George W. Holbrook, Jr., a director of our company, is a general
     partner of Bradley Resources Company and is deemed to share beneficial
     ownership of such shares with Mr. James McGoogan, a general partner of
     Bradley Resources Company. Includes, in Mr. Holbrook's number only, 28,333
     shares issuable upon exercise of options within 60 days of March 10, 2000.

 (5) Includes 28,333 shares issuable upon exercise of options exercisable within
     60 days of March 10, 2000.

 (6) Includes 245,833 shares issuable upon exercise of options exercisable
     within 60 days of March 10, 2000.

 (7) Includes 110,555 shares issuable upon exercise of options exercisable
     within 60 days of March 10, 2000.

 (8) Includes 78,958 shares issuable upon exercise of options exercisable within
     60 days of March 10, 2000.

 (9) Includes 88,125 shares issuable upon exercise of options exercisable within
     60 days of March 10, 2000.

(10) Includes 17,708 shares issuable upon exercise of options exercisable within
     60 days of March 10, 2000.

(11) Includes 69,125 shares issuable upon exercise of options exercisable within
     60 days of March 10, 2000.

(12) Includes 30,000 shares issuable upon exercise of options exercisable within
     60 days of March 10, 2000.

(13) Includes 30,000 shares issuable upon exercise of options exercisable within
     60 days of March 10, 2000.

(14) Includes 890,650 shares issuable upon exercise of options exercisable
     within 60 days of March 10, 2000.

                                       44
<PAGE>   49

                          DESCRIPTION OF CAPITAL STOCK

     Our authorized capital stock consists of 100,000,000 shares of common
stock, no par value, and 2,500,000 shares of preferred stock, no par value.

COMMON STOCK

     Holders of common stock are entitled to one vote per share on all matters
to be voted upon by our shareholders. Subject to the preferences that may be
applicable to any outstanding shares of preferred stock, the holders of common
stock are entitled to receive ratably such dividends, if any, as may be declared
by the Board of Directors out of funds legally available therefor. In the event
of our liquidation, dissolution or winding up, the holders of common stock are
entitled to share ratably in all assets remaining after payment of liabilities,
subject to the prior liquidation rights of any outstanding shares of preferred
stock. The holders of common stock are, and the shares offered by us in this
offering will be, when issued and paid for, fully paid and nonassessable. The
rights, preferences and privileges of holders of common stock are subject to,
and may be adversely affected by, the rights of the holders of shares of any
series of preferred stock which we may designated and issue in the future.

PREFERRED STOCK

     The Board of Directors is authorized, without shareholder approval, to
issue up to 2,500,000 shares of preferred stock in one or more series, to fix
the rights, preferences, privileges and restrictions granted to, or imposed
upon, any unissued shares of preferred stock and to fix the number of shares
constituting any series and the designations of such series. The issuance of
preferred stock could decrease the amount of earnings and assets available for
distribution to the holders of common stock or could adversely affect the rights
and powers, including voting rights, of the holders of the common stock. In
certain circumstances, such issuance could have the effect of decreasing the
market price of the common stock. At the closing of the offering, no shares of
preferred stock will be outstanding and we currently have no plans to issue any
shares of preferred stock.

WARRANTS

     In July 1996, we sold, through an underwritten public offering, 1,644,000
shares of common stock at $12.00 per share. In connection with that offering, we
issued to Vector Securities International, Inc. and Cruttenden Roth Incorporated
five-year warrants to purchase 164,400 shares of common stock at $14.40 per
share. The warrants are currently exercisable and include a net exercise
provision. The holders of the warrants have no voting, dividend or other
shareholder rights until the warrants are exercised.

PROVISIONS OF ARTICLES OF INCORPORATION AFFECTING SHAREHOLDERS

     The existence of the authorized but unissued preferred stock could have the
effect of making it more difficult for a third party to effect a change in the
control of the Board of Directors. This may discourage another person or entity
from making a tender offer for the common stock, including offers at a premium
over the market price of the common stock, and might result in a delay in
changes in control of management. In addition, these provisions could have the
effect of making it more difficult for proposals favored by the shareholders to
be presented for shareholder consideration.

     We have also included in our Articles of Incorporation provisions to
eliminate the personal liability of our directors for monetary damages resulting
from breaches of their fiduciary duty to the

                                       45
<PAGE>   50

extent permitted by the California Corporations Code and to indemnify our
directors and officers to the fullest extent permitted by Section 317 of the
California Corporations Code.

TRANSFER AGENT AND REGISTRAR

     The transfer agent and registrar for our common stock is American
Securities Transfer and Trust, Inc.

                                       46
<PAGE>   51

                                  UNDERWRITING

     Under the underwriting agreement, which is filed as an exhibit to the
registration statement relating to this prospectus, each of the underwriters
named below, for whom Lehman Brothers Inc., Bear, Stearns & Co. Inc., Adams,
Harkness & Hill, Inc. and Fidelity Capital Markets, a division of National
Financial Services Corporation, are acting as representatives, has agreed to
purchase from us and the selling shareholder the respective number of shares of
common stock shown opposite its name below:

<TABLE>
<CAPTION>
                                                              NUMBER OF
                                                               SHARES
                                                              ---------
<S>                                                           <C>
Lehman Brothers Inc.........................................
Bear, Stearns & Co. Inc.....................................
Adams, Harkness & Hill, Inc.................................
Fidelity Capital Markets, a division of
  National Financial Services Corporation...................

                                                              --------
          Total.............................................  4,500,000
                                                              ========
</TABLE>

     The underwriting agreement provides that the underwriters' obligations to
purchase shares of the common stock depend on the satisfaction of the conditions
contained in the underwriting agreement. It also provides that, if any of the
shares of common stock are purchased by the underwriters under the underwriting
agreement, then all of the shares of common stock that the underwriters have
agreed to purchase under the underwriting agreement must be purchased. The
conditions contained in the underwriting agreement include the requirements
that: the representations and warranties made by us and the selling shareholder
to the underwriters are true; there is no material adverse change in our
condition or in the financial markets; and we and the selling shareholder
deliver to the underwriters customary closing documents.

     The following table shows the underwriting fees to be paid to the
underwriters by us and the selling shareholder in connection with this offering.
These amounts are shown assuming both no exercise and full exercise of the
underwriters' option to purchase additional shares of common stock. This
underwriting fee is the difference between the public offering price and the
amount the underwriters pay to purchase the shares.

<TABLE>
<CAPTION>
                                                         NO EXERCISE    FULL EXERCISE
                                                         -----------    -------------
<S>                                                      <C>            <C>
Fee Per Share..........................................    $               $
Total..................................................    $               $
</TABLE>

     We and the selling shareholder have been advised by the representatives
that the underwriters propose to offer the common stock directly to the public
at the public offering price set forth on the cover page of this prospectus and
to dealers (who may include the underwriters) at this public offering price less
a selling concession not in excess of $     per share. The underwriters may
allow, and the dealer may reallow, a concession not in excess of $     per share
to brokers and dealers. After the offering, the representatives may change the
offering price and other selling terms.

     We and the selling shareholder have agreed to indemnify the underwriters
against certain liabilities, including liabilities under the Securities Act, or
to contribute to payments that may be required to be made in respect thereof.

                                       47
<PAGE>   52

     The selling shareholder has granted the underwriters an option to purchase
up to an aggregate of 675,000 additional shares of common stock at the public
offering price less the underwriting discounts and commissions set forth on the
cover page of this prospectus exercisable to cover over-allotments. Such option
may be exercised at any time until 30 days after the date of the underwriting
agreement. If this option is exercised, each underwriter will be committed,
subject to satisfaction of the conditions specified in the underwriting
agreement, to purchase a number of additional shares of common stock
proportionate to such underwriter's initial commitment as indicated in the
preceding table, and the selling shareholder will be obligated, pursuant to such
option, to sell such shares to the underwriters.

     Our company, our directors, our named executive officers, the selling
shareholder and two of our other major shareholders have agreed, for a period of
90 days from completion of this offering, not to directly or indirectly, offer,
sell or otherwise dispose of any shares of common stock or any securities
convertible into or exchangeable or exercisable for any such shares of common
stock or enter into any derivative transaction with similar effect as a sale of
common stock, without the prior written consent of Lehman Brothers Inc. The
restrictions described in this paragraph do not apply to the sale of common
stock to the underwriters.

     Fidelity Capital Markets, a division of National Financial Services
Corporation, is acting as an underwriter in this offering, and will be
facilitating electronic distribution of information through the Internet,
intranet and other proprietary electronic technology.

     Our common stock is quoted on the Nasdaq National market under the symbol
"THOR."

     Until the distribution of the common stock is completed, rules of the
Securities and Exchange Commission may limit the ability of the underwriters to
bid for and purchase shares of common stock. As an exception to these rules, the
representatives are permitted to engage in transactions that stabilize the price
of common stock. These transactions may consist of bids or purchases for the
purpose of pegging, fixing or maintaining the price of the common stock.

     The underwriters may create a short position in the common stock in
connection with the offering. This means that they may sell more shares than are
set forth on the cover page of this prospectus. If the underwriters create a
short position, then the representatives may reduce that short position by
purchasing common stock in the open market. The representative also may elect to
reduce any short position by exercising all or part of the over-allotment
option.

     The representative also may impose a penalty bid on underwriters. This
means that, if a representative purchases shares of common stock in the open
market to reduce the underwriters' short position or to stabilize the price of
the common stock, it may reclaim the amount of the selling concession from the
underwriters that sold those shares as part of the offering.

     In general, purchases of a security for the purpose of stabilization or to
reduce a syndicate short position could cause the price of the security to be
higher than it might otherwise be in the absence of these purchases. The
imposition of a penalty bid might have an effect on the price of a security to
the extent that it were to discourage resales of the security by purchasers in
an offering.

     Neither we, any of the underwriters or the selling shareholder make any
representation or prediction as to the direction or magnitude of any effect that
the transactions described may have on the price of the common stock. In
addition, neither we, any of the underwriters or the selling shareholder makes
any representation that the representatives will engage in these transactions or
that these transactions, once commenced, will not be discontinued without
notice.

     Any offers in Canada will be made only under an exemption from the
requirements to file a prospectus in the relevant province of Canada in which
the sale is made.

                                       48
<PAGE>   53

     Purchasers of the shares of common stock offered in this prospectus may be
required to pay stamp taxes and other charges under the laws and practices of
the country of purchase, in addition to the public offering price shown on the
cover page of this prospectus.

     As permitted by Rule 103 of Regulation M promulgated by the Securities and
Exchange Commission under the Securities Exchange Act of 1934, the underwriters,
if any, that are market makers, referred to as passive market makers, in the
common stock, may make bids for or purchases of the common stock on the Nasdaq
National Market System until such time, if any, when a stabilizing bid for such
securities has been made. Rule 103 generally provides that:

     - a passive market maker's net daily purchases of the common stock may not
       exceed 30% of its average daily trading volume in such securities for the
       two full consecutive calendar months (or any 60 consecutive days ending
       within 10 days) immediately preceding the filing date of the registration
       statement of which this prospectus forms a part;

     - a passive market marker may not effect transactions or display bids for
       the common stock at a price that exceeds the highest independent bid for
       the common stock by persons who are passive market makers; and

     - bids made by passive market makers must be identified as such.

                                 LEGAL MATTERS

     Heller Ehrman White & McAuliffe LLP, Menlo Park, California will pass on
the validity of the common stock offered by this prospectus for us. Clifford
Chance Rogers & Wells LLP, New York, New York, will pass upon certain legal
matters in connection with this offering for the underwriters.

                                    EXPERTS

     The financial statements included in this prospectus and elsewhere in the
registration statement have been audited by Deloitte & Touche LLP, independent
auditors, as stated in their reports appearing herein, and are included in
reliance upon the reports of such firm given upon their authority as experts in
accounting and auditing.

     The statements in this prospectus under the captions "Risk Factors -- Our
inability to protect our proprietary technologies could harm our competitive
position," "Business -- Thoratec Vascular Graft Products," "Business -- Thoratec
Biomaterials -- Thoralon," "Business -- Patents and Proprietary Rights" and
"Business -- Competition" have been reviewed by Fish & Richardson P.C., our
outside intellectual property counsel, as experts on such matters, and are
included herein in reliance upon that review and approval.

                      WHERE YOU CAN FIND MORE INFORMATION

     We file annual, quarterly and current reports, proxy statements and other
information with the SEC. You may read and copy any document we file at the
SEC's public reference room at 450 Fifth Street, NW, Washington, D.C., 20549,
and at the SEC's public reference rooms in Chicago, Illinois and New York, New
York. Please call the SEC at 1-800-SEC-0330 for further information concerning
the public reference rooms. Our SEC filings are also available to the public on
the SEC's Website at HTTP://WWW.SEC.GOV.

                                       49
<PAGE>   54

     We have filed with the SEC a registration statement on Form S-3 under the
Securities Act of 1933 with respect to the common stock offered in connection
with this prospectus. This prospectus does not contain all of the information
set forth in the registration statement. We have omitted certain parts of the
registration statement in accordance with the rules and regulations of the SEC.
For further information with respect to us and the common stock, you should
refer to the registration statement. Statements contained in this prospectus as
to the contents of any contract or other document are not necessarily complete
and, in each instance, you should refer to the copy of such contract or document
filed as an exhibit to or incorporated by reference in the registration
statement. Each statement as to the contents of such contract or document is
qualified in all respects by such reference. You may obtain copies of the
registration statement from the SEC's principal office in Washington, D.C. upon
payment of the fees prescribed by the SEC, or you may examine the registration
statement without charge at the offices of the SEC described above.

     The SEC allows us to "incorporate by reference" the information we file
with them, which means that we can disclose important information to you by
referring you to those documents. The information incorporated by reference is
considered to be part of this prospectus, and information that we file later
with the SEC will automatically update and supersede this information. We
incorporate by reference the documents listed below and any future filings we
will make with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the
Securities Exchange Act of 1934.

          (1) Annual Report on Form 10-K for the fiscal year ended January 2,
              1999;

          (2) Quarterly Report on Form 10-Q for the fiscal quarter ended April
     3, 1999;

          (3) Quarterly Report on Form 10-Q for the fiscal quarter ended July 3,
     1999;

          (4) Quarterly Report on Form 10-Q for the fiscal quarter ended October
     2, 1999;

          (5) Proxy Statement used for our annual meeting of stockholders held
     on May 14, 1999; and

          (6) the description of our common stock contained in our registration
     statement on Form 8-A declared effective by the SEC on March 27, 1988.

     You may request a copy of these filings at no cost, by writing or
telephoning at the following address:

                       Thoratec Laboratories Corporation
                               Investor Relations
                             6035 Stoneridge Drive
                          Pleasanton, California 94588
                                 (925) 847-8600

                                       50
<PAGE>   55

                   INDEX TO CONSOLIDATED FINANCIAL STATEMENTS

<TABLE>
<S>                                                           <C>
Independent Auditor's Report................................  F-2
Consolidated Balance Sheets.................................  F-3
Consolidated Statements of Operations.......................  F-4
Consolidated Statements of Comprehensive Loss...............  F-5
Consolidated Statements of Shareholders' Equity.............  F-6
Consolidated Statements of Cash Flows.......................  F-7
Notes to Consolidated Financial Statements..................  F-8
</TABLE>

                                       F-1
<PAGE>   56

                          INDEPENDENT AUDITORS' REPORT

To the Shareholders and Board of Directors of
Thoratec Laboratories Corporation:

We have audited the accompanying consolidated balance sheets of Thoratec
Laboratories Corporation and Subsidiary (the "Company") as of January 1, 2000
and January 2, 1999, and the related consolidated statements of operations,
comprehensive loss, shareholders' equity and cash flows for the fiscal years
ended January 1, 2000, January 2, 1999, and January 3, 1998. These financial
statements are the responsibility of the Company's management. Our
responsibility is to express an opinion on these financial statements based on
our audits.

We conducted our audits in accordance with generally accepted auditing
standards. Those standards require that we plan and perform the audit to obtain
reasonable assurance about whether the financial statements are free of material
misstatement. An audit includes examining, on a test basis, evidence supporting
the amounts and disclosures in the financial statements. An audit also includes
assessing the accounting principles used and significant estimates made by
management, as well as evaluating the overall financial statement presentation.
We believe that our audits provide a reasonable basis for our opinion.

In our opinion, such consolidated financial statements present fairly, in all
material respects, the financial position of Thoratec Laboratories Corporation
and Subsidiary as of January 1, 2000 and January 2, 1999 and the results of
their operations and their cash flows for the fiscal years ended January 1,
2000, January 2, 1999 and January 3, 1998 in conformity with generally accepted
accounting principles.

/s/ Deloitte & Touche LLP

San Francisco, California
February 18, 2000

                                       F-2
<PAGE>   57

                THORATEC LABORATORIES CORPORATION AND SUBSIDIARY

                          CONSOLIDATED BALANCE SHEETS

<TABLE>
<CAPTION>
                                                                   FISCAL YEAR END
                                                             ----------------------------
                                                                 1998            1999
                                                             ------------    ------------
<S>                                                          <C>             <C>
ASSETS
Current Assets:
  Cash and cash equivalents................................  $  2,712,686    $  1,696,522
  Short-term investments available-for-sale (Note 3).......     2,032,107         276,464
  Receivables, net of allowance for doubtful accounts of
     $32,795 in 1999 and $47,591 in 1998 (Note 9)..........     4,141,854       5,453,187
  Inventories (Note 4).....................................     5,290,745       6,611,487
  Prepaid expenses and other...............................       404,737         425,317
                                                             ------------    ------------
       Total current assets................................    14,582,129      14,462,977
Equipment and Improvements -- Net (Notes 5 and 6)..........     9,625,390       9,560,814
Other Assets (Note 6)......................................     1,000,898       1,036,647
                                                             ------------    ------------
       Total Assets........................................  $ 25,208,417    $ 25,060,438
                                                             ============    ============
LIABILITIES AND SHAREHOLDERS' EQUITY
Liabilities:
  Accounts payable.........................................  $  1,307,768    $  1,703,089
  Accrued compensation.....................................     1,613,334       1,466,147
  Deferred distributor revenue (Note 2)....................            --         284,765
  Other....................................................       409,958         475,870
                                                             ------------    ------------
  Total current liabilities................................     3,331,060       3,929,871
  Long-term deferred distributor revenue (Note 2)..........            --         854,294
                                                             ------------    ------------
       Total liabilities...................................     3,331,060       4,784,165
                                                             ------------    ------------
Commitments (Notes 6, 9 and 12)
Shareholders' Equity: (Notes 7, 8, and 9)
  Preferred shares -- none issued and outstanding..........            --              --
  Common shares, 100,000,000 authorized; issued and
     outstanding: 20,466,326 in 1999; and 20,422,952 in
     1998..................................................    72,810,450      72,911,638
  Additional capital.......................................     2,482,229       2,541,223
  Accumulated deficit......................................   (53,402,106)    (55,191,216)
  Accumulated other comprehensive income (loss):
     Unrealized gain on investments -- net.................             8              --
     Cumulative translation adjustment.....................       (13,224)         14,628
                                                             ------------    ------------
  Total accumulated other comprehensive income (loss)......       (13,216)         14,628
                                                             ------------    ------------
       Total shareholders' equity..........................    21,877,357      20,276,273
                                                             ------------    ------------
       Total Liabilities and Shareholders' Equity..........  $ 25,208,417    $ 25,060,438
                                                             ============    ============
</TABLE>

See notes to consolidated financial statements.

                                       F-3
<PAGE>   58

                THORATEC LABORATORIES CORPORATION AND SUBSIDIARY

                     CONSOLIDATED STATEMENTS OF OPERATIONS

<TABLE>
<CAPTION>
                                                        FOR THE FISCAL YEARS ENDED
                                                 -----------------------------------------
                                                    1997           1998           1999
                                                 -----------    -----------    -----------
<S>                                              <C>            <C>            <C>
Product sales (Notes 9 and 11).................  $ 9,441,302    $16,319,531    $22,507,884
Cost of product sales..........................    4,005,242      6,503,986      9,738,946
                                                 -----------    -----------    -----------
Gross profit...................................    5,436,060      9,815,545     12,768,938
                                                 -----------    -----------    -----------
Operating Expenses:
  Research and development.....................    4,582,745      5,096,110      5,792,635
  Selling, general and administrative..........    6,009,043      7,701,372      9,457,308
                                                 -----------    -----------    -----------
     Total operating expenses..................   10,591,788     12,797,482     15,249,943
                                                 -----------    -----------    -----------
Other operating income (Notes 1 and 2).........           --             --        284,764
                                                 -----------    -----------    -----------
Loss from operations...........................   (5,155,728)    (2,981,937)    (2,196,241)
Interest and other income, net.................      753,369        661,385        407,131
                                                 -----------    -----------    -----------
Net loss.......................................  $(4,402,359)   $(2,320,552)   $(1,789,110)
                                                 ===========    ===========    ===========
Basic and diluted loss per share (Note 1)......  $     (0.24)   $     (0.11)   $     (0.09)
                                                 ===========    ===========    ===========
Shares used to compute basic and diluted loss
  per share....................................   18,360,336     20,339,816     20,445,837
                                                 ===========    ===========    ===========
</TABLE>

See notes to consolidated financial statements.

                                       F-4
<PAGE>   59

                THORATEC LABORATORIES CORPORATION AND SUBSIDIARY

                 CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS

<TABLE>
<CAPTION>
                                                           FOR THE FISCAL YEARS ENDED
                                                     ---------------------------------------
                                                        1997          1998          1999
                                                     -----------   -----------   -----------
<S>                                                  <C>           <C>           <C>
Net Loss...........................................  $(4,402,359)  $(2,320,552)  $(1,789,110)
Other comprehensive income (loss):
  Unrealized gain (loss) on investments............      (13,190)        7,547            (8)
  Foreign currency translation adjustments.........      (42,384)       16,742        27,852
                                                     -----------   -----------   -----------
Comprehensive Loss.................................  $(4,457,933)  $(2,296,263)  $(1,761,266)
                                                     ===========   ===========   ===========
</TABLE>

See notes to consolidated financial statements.

                                       F-5
<PAGE>   60

                THORATEC LABORATORIES CORPORATION AND SUBSIDIARY

                CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY

<TABLE>
<CAPTION>
                                                                              ACCUMULATED OTHER       TOTAL
                                      COMMON      ADDITIONAL   ACCUMULATED      COMPREHENSIVE     SHAREHOLDERS'
                                       STOCK       CAPITAL       DEFICIT        INCOME (LOSS)        EQUITY
                                    -----------   ----------   ------------   -----------------   -------------
<S>                                 <C>           <C>          <C>            <C>                 <C>
BALANCE, FISCAL YEAR ENDED 1996...  $63,519,139   $2,471,877   $(46,679,195)     $    18,069       $19,329,890
Exercise of 241,937 common stock
  options for cash and exchange
  for 11,609 shares of common
  stock which were canceled.......      335,681                                                        335,681
Issuance of 2,000,000 shares of
  common stock for cash...........    8,809,287                                                      8,809,287
Issuance of common stock options
  for nonemployee services........                    10,352                                            10,352
Other comprehensive loss:
  Unrealized loss on
    investments...................                                                   (13,190)          (13,190)
  Foreign currency translation
    adjustments...................                                                   (42,384)          (42,384)
Net Loss..........................                               (4,402,359)                        (4,402,359)
                                    -----------   ----------   ------------      -----------       -----------
BALANCE, FISCAL YEAR ENDED 1997...   72,664,107    2,482,229    (51,081,554)         (37,505)       24,027,277
Exercise of 292,535 common stock
  options for cash and exchange
  for 42,028 shares of common
  stock which were canceled.......      146,343                                                        146,343
Other comprehensive income:
  Unrealized gain on
    investments...................                                                     7,547             7,547
  Foreign currency translation
    adjustments...................                                                    16,742            16,742
Net Loss..........................                               (2,320,552)                        (2,320,552)
                                    -----------   ----------   ------------      -----------       -----------
BALANCE, FISCAL YEAR ENDED 1998...   72,810,450    2,482,229    (53,402,106)         (13,216)       21,877,357
Exercise of 49,116 common stock
  options for cash and exchange
  for 5,742 shares of common stock
  which were canceled.............      101,188                                                        101,188
Issuance of common stock options
  for nonemployee services........                    58,994                                            58,994
Other comprehensive income:
  Unrealized loss on
    investments...................                                                        (8)               (8)
  Foreign currency translation
    adjustments...................                                                    27,852            27,852
Net Loss..........................                               (1,789,110)                        (1,789,110)
                                    -----------   ----------   ------------      -----------       -----------
BALANCE, FISCAL YEAR ENDED 1999...  $72,911,638   $2,541,223   $(55,191,216)     $    14,628       $20,276,273
                                    ===========   ==========   ============      ===========       ===========
</TABLE>

See notes to consolidated financial statements

                                       F-6
<PAGE>   61

                THORATEC LABORATORIES CORPORATION AND SUBSIDIARY

                     CONSOLIDATED STATEMENTS OF CASH FLOWS

<TABLE>
<CAPTION>
                                                        FOR THE FISCAL YEARS ENDED
                                                 -----------------------------------------
                                                     1997           1998          1999
                                                 ------------   ------------   -----------
<S>                                              <C>            <C>            <C>
CASH FLOWS FROM OPERATING ACTIVITIES:
  Net loss.....................................  $ (4,402,359)  $ (2,320,552)  $(1,789,110)
  Adjustments to reconcile net loss to net cash
     used in operating activities:
     Amortization of deferred distributor
       revenue.................................            --             --      (284,764)
     Common stock options granted for services
       (Note 8)................................        10,352             --        58,994
     Depreciation and amortization.............       262,540        679,669     1,020,634
     Changes in assets and liabilities:
       Receivables.............................      (448,924)    (2,827,077)   (1,344,479)
       Prepaid expenses and other..............        (4,613)      (133,525)      (21,904)
       Inventories.............................    (1,185,453)    (1,380,538)   (1,349,296)
       Other assets............................      (553,068)       472,389       (35,898)
       Accounts payable and other
          liabilities..........................       898,215         36,469       462,939
       Deferred distributor revenue............            --             --     1,423,823
                                                 ------------   ------------   -----------
          Net cash used in operating
             activities........................    (5,423,310)    (5,473,165)   (1,859,061)
                                                 ------------   ------------   -----------
CASH FLOWS FROM INVESTING ACTIVITIES:
  Purchases of short-term investments
     available-for-sale........................   (85,482,972)   (16,176,045)   (7,829,477)
  Maturities of short-term investments
     available-for-sale........................    83,400,000     18,620,000     6,354,000
  Sales of short-term investments
     available-for-sale........................     7,311,109        922,148     3,231,112
  Capital expenditures.........................    (4,823,549)    (4,800,285)     (988,860)
                                                 ------------   ------------   -----------
          Net cash provided by (used in)
             investing activities..............       404,588     (1,434,182)      766,775
                                                 ------------   ------------   -----------
CASH FLOWS FROM FINANCING ACTIVITIES:
  Common stock issued in public
     placement -- net..........................     8,809,288             --            --
  Common stock issued upon exercise of
     options...................................       335,681        146,343       101,188
                                                 ------------   ------------   -----------
          Net cash provided by financing
             activities........................     9,144,969        146,343       101,188
                                                 ------------   ------------   -----------
Effect of exchange rate changes on cash........        (4,936)         4,379       (25,066)
                                                 ------------   ------------   -----------
Net increase (decrease) in cash and cash
  equivalents..................................     4,121,311     (6,756,625)   (1,016,164)
Cash and cash equivalents at beginning of
  year.........................................     5,348,000      9,469,311     2,712,686
                                                 ------------   ------------   -----------
Cash and cash equivalents at end of year.......  $  9,469,311   $  2,712,686   $ 1,696,522
                                                 ============   ============   ===========
NONCASH INVESTING TRANSACTIONS:
  Construction costs and capital assets in
     accounts payable..........................  $  1,402,045   $     71,828   $    54,386
                                                 ============   ============   ===========
</TABLE>

See notes to consolidated financial statements.

                                       F-7
<PAGE>   62

                THORATEC LABORATORIES CORPORATION AND SUBSIDIARY

                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

 1. OPERATIONS AND SIGNIFICANT ACCOUNTING POLICIES

     Operations -- Thoratec Laboratories Corporation and its subsidiary (the
"Company") manufactures and markets medical devices utilizing specialty polymers
and is engaged in ongoing research and development. Thoratec's products are
marketed worldwide.

     The Company reports on a 52 - 53 week fiscal year, which ends on the
Saturday closest to December 31. The fiscal year ended January 3, 1998, (fiscal
1997) includes 53 weeks. The fiscal years ended January 2, 1999, (fiscal 1998)
and January 1, 2000, (fiscal 1999) include 52 weeks.

     Principles of Consolidation -- The consolidated financial statements
include Thoratec Laboratories Corporation (a California corporation) and its
subsidiary company, Thoratec Europe Limited (a corporation organized under the
laws of the United Kingdom). All significant intercompany balances and
transactions are eliminated in consolidation.

     Use of Estimates -- The preparation of the Company's consolidated financial
statements in conformity with generally accepted accounting principles
necessarily requires management to make estimates and assumptions that affect
the reported amounts of assets and liabilities and disclosure of contingent
assets and liabilities at the consolidated balance sheet dates and the reported
amounts of revenues and expenses for the periods presented. Actual results could
differ from these estimates.

     Cash and Cash Equivalents -- Cash and cash equivalents include money market
securities stated at cost, which approximates market value.

     Investments -- The Company's short-term investments are classified as
available-for-sale and reported at fair value. Net unrealized gains and losses
are excluded from earnings and reported as a separate component of shareholders'
equity. As of the end of 1999, short-term investments were comprised primarily
of corporate notes with maturity dates within 12 months of the date of
investment.

     Inventories -- Inventories are stated at the lower of first-in, first-out
cost or market. The Company rents certain medical devices to customers on a
month-to-month basis and includes them in inventories, net of amortization, when
the devices are expected to be sold to customers within one year.

     Equipment and Improvements -- Equipment and improvements are stated at
cost. Equipment is depreciated over estimated useful lives which range from two
to eight years. Leasehold improvements are amortized over the term of the lease
or over the estimated useful life of the improvements, whichever is shorter.
Equipment and improvements includes certain medical devices rented to customers
on a long-term basis. Amortization expense of all rental equipment included in
the Company's rental program is recognized ratably over no longer than 36
months. The straight-line method is used for depreciation and amortization.

     The Company reviews for the impairment of long-lived assets whenever events
or changes in circumstances indicate that the carrying amount of that asset may
not be recoverable. An impairment loss would be recognized when the sum of the
undiscounted future net cash flows expected to result from the use of the asset
and its eventual disposal is less than carrying amount.

     Income Taxes -- The Company follows an asset and liability approach for
financial accounting and reporting of income taxes. Under this approach, the
Company computes its tax liability at each

                                       F-8
<PAGE>   63
                THORATEC LABORATORIES CORPORATION AND SUBSIDIARY

             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)

consolidated financial statement date by applying provisions of current tax laws
to temporary differences between consolidated financial statement and income tax
bases. Changes in tax law may result in an adjustment to deferred tax assets.

     Fair Value of Financial Instruments -- The Company's financial instruments
include cash and cash equivalents, customer receivables, accounts payable, and
certain other accrued liabilities. The carrying amounts of these items are a
reasonable estimate of their fair values.

     Foreign Currency Translation -- All assets and liabilities of the Company's
non-United States operations are translated into United States dollars at fiscal
period-end exchange rates, and, except as follows, the resulting translation
adjustments are included in comprehensive income. Income items are translated at
actual or average monthly rates of exchange. Exchange rate fluctuations
resulting from the period-end translation of the current portion of the
intercompany obligation of the Company's wholly-owned subsidiary into United
States dollars are recorded in the income statement as foreign currency
translation gains or losses and are included in selling, general and
administrative expenses.

     Revenue Recognition and Product Warranty -- The Company recognizes product
sales upon shipment of the related product. A provision for estimated future
costs relating to warranty expense is recorded when products are shipped. The
Company rents certain medical devices to customers on a month-to-month basis.
Rentals are based on utilization and included in income as earned. Included in
product sales for 1997, 1998 and 1999 are approximately $461,000, $1,064,000 and
$1,082,000, respectively, or income earned from the rental of these certain
medical devices. Sales related to training provided to customers are recognized
as services are provided.

     The Company recognizes distributor revenue ratably over the life of the
related distributor agreement. Other operating income of approximately $285,000
represents the amortized distribution revenue recognized in 1999 (see Note 2).

     Accounting for Stock-Based Compensation -- The Company accounts for
stock-based awards to employees using the intrinsic value method in accordance
with Accounting Principals Board Opinion No. 25, "Accounting for Stock Issued to
Employees." Proforma disclosures of net earnings and earnings per share
consistent with the method of Statement of Financial Accounting Standards No.
123, "Accounting for Stock-Based Compensation" are included in Note 7.

     Loss Per Share -- Basic earnings per share are computed by dividing net
income (loss) by the weighted average number of common shares outstanding during
the period. Diluted earnings per share reflect the potential dilution that could
occur if securities or other contracts to issue common stock were exercised or
converted into common stock. Diluted earnings per share for 1997, 1998 and 1999
exclude any effect from such securities as their inclusion would be
antidilutive, therefore, diluted earnings per share is the same as basic
earnings per share for all periods presented.

     Comprehensive Loss -- Comprehensive loss, as recorded in the financial
statements, includes net loss, unrealized gains and losses on investments and
foreign currency translation adjustments.

     Operating Segments -- The Company is organized as a single operating
segment, whereby the chief operating decision maker assesses the performance of
and allocates resources to the business as a whole. See Note 11.

                                       F-9
<PAGE>   64
                THORATEC LABORATORIES CORPORATION AND SUBSIDIARY

             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)

     Recently Issued Accounting Standard -- During June 1998, the Financial
Accounting Standards Board (FASB) issued Statement of Financial Accounting
Standards No. 133, "Accounting for Derivative Instruments and Hedging
Activities", which defines derivatives, requires that all derivatives be carried
at fair value, and provides for hedging accounting when certain conditions are
met. Such Statement is effective for all fiscal quarters of fiscal years
beginning after June 15, 2000. The Company has not yet evaluated the impact of
the new standard.

 2. FINANCIAL POSITION AND LIQUIDITY

     During the first quarter of 1999, the Company entered into a five-year
distribution agreement with Guidant Corporation. Under the terms of the
agreement, Guidant receives exclusive worldwide marketing and distribution
rights to the Company's Vectra vascular access graft product line, except in
Japan. In exchange for these rights, Guidant made a $1.5 million non-refundable
payment, and will pay up to an additional $2 million when the Vectra product
line receives FDA approval for use in the U.S. Guidant also agreed to provide a
four-year, unsecured line of credit in the amount of $10 million to the Company,
which may be used, if needed, for a variety of business purposes. The Company is
recognizing the $1.5 million contract payment received in the first quarter of
1999 as revenue ratably over the five-year life of the contract. Other operating
income in 1999 included approximately $285,000 of such payment amortization.

     With the proceeds available from this line of credit, the Company believes
that it has sufficient funds to increase its marketing efforts, to conduct
clinical trials on its new products, and to develop new sources of revenue,
including new products, for at least the next year. However, the Company expects
that its operating expenses will increase in future periods as the Company
expends increased amounts on product manufacturing, marketing, and research and
development of new product lines. There can be no assurance that the Company
will achieve profitability or positive cash flow.

3. SHORT-TERM INVESTMENTS

     Short term investments available-for-sale are summarized as follows:

<TABLE>
<CAPTION>
                                                          GROSS         GROSS
                                          AMORTIZED     UNREALIZED    UNREALIZED       FAIR
                                             COST         GAINS         LOSSES        VALUE
                                          ----------    ----------    ----------    ----------
<S>                                       <C>           <C>           <C>           <C>
Fiscal 1998
  Corporate debt instruments............  $1,025,220       $79           $  0       $1,025,299
  Federal government agency.............   1,006,879         0            (71)       1,006,808
                                          ----------       ---           ----       ----------
     Total..............................  $2,032,099       $79           $(71)      $2,032,107
                                          ==========       ===           ====       ==========
Fiscal 1999
  Corporate debt instruments............  $  276,464       $ 0           $  0       $  276,464
                                          ==========       ===           ====       ==========
</TABLE>

     The Company classifies those investments which mature in less than one year
as short-term investments.

                                      F-10
<PAGE>   65
                THORATEC LABORATORIES CORPORATION AND SUBSIDIARY

             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)

 4. INVENTORIES

     Inventories consist of the following:

<TABLE>
<CAPTION>
                                                              FISCAL YEAR
                                                       --------------------------
                                                          1998           1999
                                                       -----------    -----------
<S>                                                    <C>            <C>
Finished goods.....................................    $ 2,712,543    $ 3,163,055
Work-in-process....................................      1,456,784      2,033,194
Raw materials......................................      1,121,418      1,415,238
                                                       -----------    -----------
          Total....................................    $ 5,290,745    $ 6,611,487
                                                       ===========    ===========
</TABLE>

     Included in finished goods for 1998 and 1999 is rental product inventory of
approximately $819,000 and $951,000, respectively.

 5. EQUIPMENT AND IMPROVEMENTS

     Equipment and improvements consist of the following:

<TABLE>
<CAPTION>
                                                              FISCAL YEAR
                                                       --------------------------
                                                          1998           1999
                                                       -----------    -----------
<S>                                                    <C>            <C>
Equipment..........................................    $ 3,458,804    $ 4,568,466
Leasehold Improvements.............................      4,875,339      7,540,866
Construction in Progress...........................      4,126,612        119,473
                                                       -----------    -----------
          Total....................................     12,460,755     12,228,805
Accumulated depreciation and amortization..........     (2,835,365)    (2,667,991)
                                                       -----------    -----------
                                                       $ 9,625,390    $ 9,560,814
                                                       ===========    ===========
</TABLE>

     Included in equipment for 1998 and 1999 is product used in the Company's
rental program of approximately $381,000 and $647,000 of cost, respectively, and
$120,000 and $261,000, of accumulated amortization, respectively.

 6. LEASES

     The Company leases offices, laboratory and manufacturing space under
noncancelable operating leases. In 1996 the Company entered into a lease
agreement for a new facility located in Pleasanton, California, which
accommodates all of the Company's manufacturing, engineering and administrative
activities. The administrative and engineering portion of the building was
completed and occupied in late 1997. The manufacturing portion was completed in
1998 and occupied in 1999 after receiving clearance from the FDA. The Company
has invested approximately $9 million in equipment and leasehold improvements to
the building. Annual payments under the amended lease are approximately $751,000
for a lease term of 15 years and commenced in August 1997. The lease includes
provisions, among others, for annual cost of living adjustments to the lease
payments, two five-year renewal options, a purchase option, and a security
deposit of $885,600 which is included in other assets. A significant portion
($750,000) of the remaining security deposit can be reduced or eliminated before

                                      F-11
<PAGE>   66
                THORATEC LABORATORIES CORPORATION AND SUBSIDIARY

             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)

the end of the initial lease term if the Company meets certain criteria as
specified by the contract. Future minimum lease payments as of the end of fiscal
year 1999 are noted below:

<TABLE>
<CAPTION>
                        FISCAL YEAR:
                        ------------
<S>                                                           <C>
  2000......................................................  $  774,899
  2001......................................................     774,899
  2002......................................................     774,899
  2003......................................................     774,899
  2004......................................................     774,899
  Thereafter................................................   5,796,372
                                                              ----------
     Total..................................................  $9,670,867
                                                              ==========
</TABLE>

     Rent expense for all operating leases was $473,237 in 1997, $911,609 in
1998, and $871,162 in 1999.

 7. COMMON AND PREFERRED STOCK AND WARRANTS

     The Company has authorized 100,000,000 no par common shares, and 2,500,000
shares of preferred stock, of which 540,541 shares have been designated Series A
and 500,000 shares designated Series B.

     The Series A preferred stock is entitled to cumulative annual dividends of
$1.30 per share and has a liquidation preference of $9.25 plus cumulative unpaid
dividends. The Company may redeem the Series A preferred stock at any time for
its liquidation preference. Each share of preferred stock is convertible into
one-third of a share of common stock, after adjusting for earned but unpaid
dividends. At January 1, 2000, no shares of Series A preferred stock were
outstanding.

     Series B preferred stock is senior to Series A in all preferences. Series B
is entitled to cumulative annual dividends of $.96 per share and has a
liquidation preference of $8.00 plus cumulative unpaid dividends. The Series B
preferred stock is redeemable by the Company five years after issuance for $8.00
per share plus cumulative unpaid dividends. Each share of Series B preferred
stock is convertible at any time into three and one-third shares of common stock
and has certain anti-dilution provisions. Series B preferred votes on an
as-converted basis. At January 1, 2000, no shares of the Series B preferred
stock were outstanding.

     In November 1997, the Company sold through a public offering 2,000,000
shares of common stock at $5.00 per share. Net cash proceeds received by the
Company related to this offering were approximately $8,809,000 after placement
agents' fees and approximately $491,000 of other costs.

     In July 1996, the Company sold, through an underwritten public offering,
1,644,000 shares of common stock at $12.00 per share. In connection with the
public offering the underwriters were issued five-year warrants to purchase
164,400 shares of the Company's common stock at $14.40 per share. The warrants
are currently exercisable and include a net exercise provision. Net cash
proceeds received by the Company related to this offering were approximately
$17,591,000. Underwriters' commissions, the fair value of warrants issued to the
underwriters, and approximately $1,050,000 of other estimated costs have been
recorded as a deduction to the proceeds received from the sale of the common
stock.

                                      F-12
<PAGE>   67
                THORATEC LABORATORIES CORPORATION AND SUBSIDIARY

             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)

 8. OPTIONS

     In 1993, the Directors approved the 1993 Stock Option Plan ("1993 SOP"),
which permits the Company to grant options to purchase up to 666,667 shares of
common stock. During 1998, 52,500 options were granted under this plan. No
options were granted under this plan in 1999 or 1997.

     In 1996, the Directors adopted the 1996 Stock Option Plan ("1996 SOP") and
the 1996 Nonemployee Directors Stock Option Plan ("Directors Option Plan"). The
1996 SOP consists of two parts. Part One permits the Company to grant options to
purchase up to 500,000 shares of common stock. During 1999, 1998 and 1997,
6,000, 132,500 and 319,833 options, respectively, were granted at fair market
value under this Part of the Plan. Part Two related to the Chief Executive
Officer (CEO) and permits the Company to grant non-qualified options to the CEO
to purchase up to 333,333 shares of common stock. During 1996, 333,333 options
were granted at fair market value under this Part of the Plan. In November 1997,
these options were repriced to the then fair market value of $5.00 per share.
All other options of the CEO were canceled in conjunction with the repricing.
The Directors Option Plan was amended by approval by a vote of the Company's
shareholders in May 1999. The amendments include increasing the number of shares
granted to the Board of Directors in the initial grants from 10,000 to 15,000
shares (granted in four equal installments, once when elected to the Board then
quarterly thereafter), and the annual grants from 5,000 to 7,500 shares (granted
in four equal installments after re-election). Provisions were also made for
immediate vesting of both initial and annual grants, and for changing the term
of the options from ten to five years. In addition, the number of shares
reserved for issuance under The Director's Option Plan was increased from
150,000 to 350,000 and the plan administrator has been provided with the
discretion to impose any repurchase rights in favor of the Company on any
optionee. The Company currently has seven non-employee directors who are
eligible to participate in the Directors Option Plan. During 1999, 1998 and
1997, 39,375, 35,000 and 45,000 options, respectively, were granted at fair
market value under this plan.

     In 1997, the Directors adopted the 1997 Stock Option Plan ("1997 SOP"). The
1997 SOP was amended by approval of a vote of the Company's shareholders in May
1999. The 1997 SOP, as amended, permits the Company to grant options to purchase
up to 2,800,000 shares of common stock. During 1999, 1998, and 1997, 1,038,276,
718,960 and 294,834 options, respectively, were granted at fair market value
under this plan.

     Including the 1993 SOP, the 1996 SOP, the Directors Option Plan, the 1997
SOP, and several older plans, the Company had eight common stock option plans.
Options may be granted by the Board of Directors at fair market value at the
date of grant. Options under plans generally become exercisable within six
months to five years of grant and expire between five and ten years from date of
grant. At January 1, 2000, 1,310,153 common shares remain available for grant
under all the plans.

     Agreements have been entered into with selected consultants whereby options
to purchase the Company's common stock were accepted by these consultants as
full or partial payment for the services rendered to the Company. The fair
market value of the consulting service is the basis for recording the fair
market value of the transaction in the Company's financial records and is
recognized as the related services are performed. Options issued under these
agreements totaled 17,341 in 1999 and are included in the grant activity
previously discussed.

     The Company applies APB Opinion 25 and related Interpretations in
accounting for its employee stock-based compensation plans. Accordingly, no
compensation cost has been recognized for its stock

                                      F-13
<PAGE>   68
                THORATEC LABORATORIES CORPORATION AND SUBSIDIARY

             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)

option plans. Had compensation cost for the Company's stock-based plans been
determined based on the fair value at the grant dates for awards under those
plans consistent with the method of FASB Statement 123, the Company's net loss
and net loss per share would have been increased to the proforma amounts
indicated in the following table. As 1996 was the initial phase-in period for
applying this Statement, the proforma results indicated are not necessarily
representative of the effects on proforma disclosures of net income for future
periods as they exclude options that were granted prior to January 1, 1995, with
vesting periods in 1995 and later.

<TABLE>
<CAPTION>
                                                                FISCAL YEAR
                                                 -----------------------------------------
                                                    1997           1998           1999
                                                 -----------    -----------    -----------
<S>                                              <C>            <C>            <C>
Net Loss
  As reported..................................  $(4,402,359)   $(2,320,552)   $(1,789,110)
  Pro forma....................................   (6,582,359)    (4,565,552)    (5,230,110)
Basic and diluted loss per share
  As reported..................................  $     (0.24)   $     (0.11)   $     (0.09)
  Pro forma....................................        (0.36)         (0.22)         (0.26)
</TABLE>

     The fair value of each option grant is estimated at the date of grant using
the Black-Scholes option-pricing model with the following weighted-average
assumptions used for grants made in 1999, 1998, and 1997: risk-free interest
rates of 5.71% in 1999, 5.09% in 1998, and 6.32% in 1997; expected volatility of
77% for 1999, 81% for 1998, and 88% for 1997; expected lives in all years of two
years beyond each incremental vesting period (total life of 2 1/2 to 7 years,
depending upon each grant's individual vesting schedule). No dividends are
assumed for any plan in any year.

                                      F-14
<PAGE>   69
                THORATEC LABORATORIES CORPORATION AND SUBSIDIARY

             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)

     Option activity is summarized as follows:

<TABLE>
<CAPTION>
                                                      NUMBER OF    WEIGHTED AVERAGE
                                                       OPTIONS      EXERCISE PRICE
                                                      ---------    ----------------
<S>                                                   <C>          <C>
Outstanding at fiscal year end 1996 (783,396
  exercisable at $2.18 weighted average exercise
  price per share)..................................  1,575,191         $ 6.18
  Granted ($3.59 weighted average fair value per
     share).........................................    993,000           6.06
  Canceled and expired..............................   (531,135)         12.02
  Exercised(1)......................................   (241,937)          1.81
                                                      ---------
Outstanding at fiscal year end 1997 (844,747
  exercisable at $3.56 weighted average exercise
  price per share)..................................  1,795,119         $ 4.98
  Granted ($4.08 weighted average fair value per
     share).........................................    938,960           6.44
  Canceled and expired..............................   (143,288)          4.45
  Exercised(2)......................................   (292,535)          1.50
                                                      ---------
Outstanding at fiscal year end 1998 (790,934
  exercisable at $5.60 weighted average exercise
  price per share)..................................  2,298,256         $ 6.05
  Granted ($5.01 weighted average fair value per
     share).........................................  1,083,651           8.11
  Canceled and expired..............................   (192,967)          6.44
  Exercised(3)......................................    (49,116)          3.11
                                                      ---------
Outstanding at fiscal year end 1999 (1,220,699
  exercisable at $6.09 weighted average exercise
  price per share)..................................  3,139,824         $ 6.78
                                                      =========
</TABLE>

- -------------------------
(1) Includes 193,371 options exercised for $335,681 cash and 48,566 options
    exercised by exchange for 11,609 shares of common stock, which were
    canceled.

(2) Includes 68,893 options exercised for $146,343 cash and 223,642 options
    exercised by exchange for 42,028 shares of common stock, which were
    canceled.

(3) Includes 36,402 options exercised for $101,188 cash and 12,714 options
    exercised by exchange for 5,742 shares of common stock, which were canceled.

     The status of options outstanding as of the end of fiscal 1999 is
summarized as follows:

<TABLE>
<CAPTION>
                                     OPTIONS OUTSTANDING                       OPTIONS EXERCISABLE
                      -------------------------------------------------   ------------------------------
                                    WEIGHTED AVERAGE
                        NUMBER         REMAINING       WEIGHTED AVERAGE     NUMBER      WEIGHTED AVERAGE
   PRICE CATEGORY     OUTSTANDING   CONTRACTUAL LIFE    EXERCISE PRICE    OUTSTANDING    EXERCISE PRICE
- --------------------  -----------   ----------------   ----------------   -----------   ----------------
<S>      <C>  <C>     <C>           <C>                <C>                <C>           <C>
$ 0.75                    39,447       1.25 years           $ 0.75            38,076         $ 0.75
$ 1.14   to   $ 2.25     230,233       3.57 years             2.18           230,233           2.18
$ 4.38   to   $ 5.88     697,996       7.70 years             5.23           379,251           5.20
$ 6.00   to   $ 7.81     960,415       8.13 years             6.41           309,848           6.43
$ 8.00   to   $ 9.75   1,011,708       9.03 years             8.38           119,783           8.74
$10.00   to   $12.00     158,668       6.79 years            10.37           103,401          10.34
$15.00   to   $15.75      28,025       6.16 years            15.62            26,775          15.65
$30.00                    13,332       6.42 years            30.00            13,332          30.00
                       ---------                                           ---------
$ 0.75   to   $30.00   3,139,824       7.81 years           $ 6.78         1,220,699         $ 6.09
                       =========                                           =========
</TABLE>

                                      F-15
<PAGE>   70
                THORATEC LABORATORIES CORPORATION AND SUBSIDIARY

             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)

 9. RELATED PARTIES

     In 1992 the Company entered into an agreement to sell common stock,
representing 26% of the Company, to COBE Laboratories, Inc., "COBE" which
included several provisions including a standstill agreement. The Company and
COBE also finalized a licensing, manufacturing, and distribution agreement which
provides for a royalty-bearing license to the Company's biomaterial technology
for use in certain of COBE's products, among other items. The licensing
agreement was amended in 1999 to split the license into two separate agreements
at the time of the sale of a portion of COBE's cardiovascular business. In 1997,
the Company's obligation to manufacture biomaterials and distribute products
through COBE terminated.

     Sales to COBE and its affiliates for 1997, 1998 and 1999 were $312,000,
$145,000 and $167,000, respectively. Receivables from COBE and its affiliates
were nil and $17,100 at the end of fiscal years 1998 and 1999, respectively.

     For other related party transactions, see Note 12.

10. TAXES ON INCOME

     Deferred income taxes reflect the net tax effects of (a) temporary
differences between the carrying amounts of assets and liabilities for financial
reporting purposes and the amounts used for income tax purposes, and (b)
operating loss and tax credit carryforwards.

     Significant components of the Company's net deferred taxes are as follows:

<TABLE>
<CAPTION>
                                                              FISCAL YEAR
                                                      ---------------------------
                                                         1998            1999
                                                      -----------    ------------
<S>                                                   <C>            <C>
Deferred tax assets:
  Federal tax loss carryforward (as adjusted for the
     limitation on change in ownership).............  $ 7,400,000    $  6,920,000
  State tax loss carryforward.......................      425,000         375,000
  Deferred revenue..................................           --         450,000
  Foreign...........................................      410,000         750,000
  Credits (research and manufacturing)..............      750,000         970,000
  Other, net........................................      440,000         685,000
                                                      -----------    ------------
          Total.....................................    9,425,000      10,150,000
  Less: Valuation allowance.........................   (9,425,000)    (10,150,000)
                                                      -----------    ------------
                                                      $        --    $         --
                                                      ===========    ============
</TABLE>

     At the end of fiscal 1999, the Company had net operating loss ("NOL")
carryforwards of approximately $20.5 million. The majority of such carryforwards
expire from 2003 through 2018. Use of the $7.4 million NOL which arose prior to
the greater than 50% change in ownership which occurred in 1992 is limited to
approximately $440,000 per year due to such change.

     Due to these limitations and due to the fact that the Company has sustained
cumulative losses, the potential future benefit from these deferred assets are
fully reserved by means of a valuation allowance and will therefore produce a
financial statement benefit if and when utilized.

                                      F-16
<PAGE>   71
                THORATEC LABORATORIES CORPORATION AND SUBSIDIARY

             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)

     A reconciliation between the effective tax rate and the statutory federal
rate follows:

<TABLE>
<CAPTION>
                                                             FISCAL YEAR
                                     -----------------------------------------------------------
                                            1997                 1998                1999
                                     ------------------    ----------------    -----------------
<S>                                  <C>           <C>     <C>         <C>     <C>          <C>
Income tax benefit at statutory
  rate.............................  $(1,496,000)  (34.0)% $(789,000)  (34.0)% $(608,000)   (34.0)%
State taxes........................      (91,000)  (2.1)     (70,000)  (3.0)     (98,000)   (5.5)
Increase in tax credit
  carryforwards....................     (855,000)  (19.4)    (96,000)  (4.1)    (115,000)   (6.4)
Increase in valuation allowance....    2,665,000   60.6      975,000   42.0      725,000    40.5
Other, net.........................     (223,000)  (5.1)     (20,000)   (.9)      96,000     5.4
                                     -----------   ----    ---------   ----    ---------    ----
                                     $        --     --    $      --     --    $      --      --
                                     ===========   ====    =========   ====    =========    ====
</TABLE>

11. ENTERPRISE AND RELATED GEOGRAPHIC INFORMATION

     The Company manages its business on the basis of one reportable operating
segment. (See Note 1 for a brief description of the Company's business.) Net
sales by geographic area are presented by attributing revenues from external
customers or distributors on the basis of where the products are sold.
Long-lived assets by geographic area and information about products and services
are included as enterprise-wide disclosures.

     In 1997, one domestic customer accounted for slightly over 10% of total
product sales. No receivable was outstanding from this customer at the end of
fiscal 1997. No customer accounted for greater than 10% of product sales or
receivables in 1998 or 1999.

                                GEOGRAPHIC AREAS

<TABLE>
<CAPTION>
                                                        FISCAL YEAR
                                          ----------------------------------------
                                             1997          1998           1999
                                          ----------    -----------    -----------
<S>                                       <C>           <C>            <C>
Product Sales:
  International
     Europe.............................  $1,094,516    $ 2,718,794    $ 3,597,973
     All Other..........................     793,339      1,497,584      1,606,447
                                          ----------    -----------    -----------
       Subtotal.........................   1,887,855      4,216,378      5,204,420
     Domestic...........................   7,553,447     12,103,153     17,303,464
                                          ----------    -----------    -----------
       Total............................  $9,441,302    $16,319,531    $22,507,884
                                          ==========    ===========    ===========
</TABLE>

<TABLE>
<CAPTION>
                                                               FISCAL YEAR
                                                         ------------------------
                                                            1998          1999
                                                         ----------    ----------
<S>                                                      <C>           <C>
Long-lived assets:
  International -- Europe..............................  $  318,310    $  377,958
  Domestic.............................................   9,307,080     9,182,856
                                                         ----------    ----------
       Total...........................................  $9,625,390    $9,560,814
                                                         ==========    ==========
</TABLE>

                                      F-17
<PAGE>   72
                THORATEC LABORATORIES CORPORATION AND SUBSIDIARY

             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)

                          CLASSES OF SIMILAR PRODUCTS

<TABLE>
<CAPTION>
                                                        FISCAL YEAR
                                          ----------------------------------------
                                             1997          1998           1999
                                          ----------    -----------    -----------
<S>                                       <C>           <C>            <C>
Product Sales:
  Circulatory Support...................  $8,831,455    $15,637,756    $21,768,089
  Vascular Graft........................     300,120        681,775        739,795
  Biomaterial Manufacturing.............     309,727             --             --
                                          ----------    -----------    -----------
       Total............................  $9,441,302    $16,319,531    $22,507,884
                                          ==========    ===========    ===========
</TABLE>

See Note 9 for discussion of Biomaterial Manufacturing.

12. COMMITMENTS

     In October 1997, the Company executed a four-year agreement with Arrow
International, Inc. ("Arrow") to supply the mechanical valves for the VAD system
used in the Company's VAD system. As of January 1, 2000, the remaining long-term
purchase commitment associated with this agreement was approximately $1.8
million.

     In July 1998, the Company established an Executive Officer Severance
Benefits Plan and an Employee Severance Benefits Plan as part of the employee
benefits package. The plans provide severance benefits to certain employees
whose employment is terminated, other than for cause. An Executive Officer's
standard severance pay benefit is equal to one times annualized base salary. An
employee's severance pay benefit is equal to an amount based on job level and
length of service.

     In January 2000, the Company entered into a four-year employment agreement
with a key executive officer. This employment agreement provides for, among
other provisions, a minimum base salary, an annual bonus based on performance,
and a severance package.

     The Company is not party to any legal proceedings other than ordinary
routine litigation incidental to the Company's business. The Company believes
that the ultimate resolution of these matters will not have a material adverse
effect on the Company's consolidated financial statements taken as a whole.

     See Notes 6 and 9 for additional commitments.

13. RETIREMENT SAVINGS PLAN

     Effective January 1997, the Company implemented a 401(k) Plan (the "Plan")
covering all employees who have met certain eligibility requirements. Under the
Plan, employees may elect to contribute up to 18% of their eligible compensation
to the Plan, subject to certain limitations. The Company matches employee
contributions at 25% up to the first 6% of employees' compensation. Employees
vest at the rate of 25% per year with full vesting after four years of service
with the Company. For fiscal years 1997, 1998 and 1999, the Company made
contributions to the Plan of approximately nil, $54,000 and $91,000,
respectively.

                                      F-18
<PAGE>   73

[Picture of Mr. Carr, the first recipient of a
prototype Aria coronary artery bypass graft]

[Angiogram of Aria coronary artery bypass
graft implanted in patient]


Mr. Carr was the first recipient of a prototype Aria CABG graft in 1993. The
Aria was used to complete the revascularization of Mr. Carr's heart in his
second coronary artery bypass surgery. He is symptom-free and doing well to this
day. Shown above is an image, or angiogram, of the Aria that was taken nine
months after his surgery, showing the graft to be open and functional.


[Illustration of Thoratec's Aria coronary artery
bypass graft showing placement in the heart.]

Thoratec's Aria Coronary Artery Bypass Graft.


[Illustration of Thoratec's Vectra Vascular
Access Graft showing placement in the arm.]

The Vectra Vascular Access Graft.

We have developed unique technology to manufacture small diameter vascular
grafts, or prosthetic blood vessels. These devices are designed to address those
pressing clinical needs in which current, large diameter vascular graft
materials have to date been unsuccessful.



<PAGE>   74

                                4,500,000 Shares

                                      LOGO

                                  Common Stock

                           -------------------------
                                   PROSPECTUS
                                           , 2000
                           -------------------------

                                LEHMAN BROTHERS
                            BEAR, STEARNS & CO. INC.
                          ADAMS, HARKNESS & HILL, INC.
                            FIDELITY CAPITAL MARKETS
             a division of National Financial Services Corporation

                                      LOGO
<PAGE>   75

                                    PART II

                     INFORMATION NOT REQUIRED IN PROSPECTUS

ITEM 14. OTHER EXPENSES OF ISSUANCE AND DISTRIBUTION

<TABLE>
<S>                                                           <C>
SEC Registration Fee........................................  $ 21,518
NASD Filing Fee.............................................     8,651
Nasdaq National Market Listing Fee..........................    17,500
Transfer Agent and Registrant Fees..........................    25,000
Accounting Fees and Expenses................................   150,000
Legal Fees and Expenses.....................................   150,000
Printing and Engraving......................................   110,000
Miscellaneous...............................................   167,331
                                                              --------
  TOTAL.....................................................  $650,000
                                                              ========
</TABLE>

ITEM 15. INDEMNIFICATION OF DIRECTORS AND OFFICERS

     Our certificate of incorporation provides that, to the fullest extent
permitted by California law, none of our directors shall be personally liable to
us or our shareholders for monetary damages for breach of fiduciary duty as a
director, notwithstanding any other provision of law. However, a director shall
be liable to the extent required by law (a) for any breach of the director's
duty of loyalty to us or our shareholders, (b) for acts or omissions not in good
faith or which involve intentional misconduct or a knowing violation of law, (c)
in respect of certain unlawful dividend payments or stock redemptions or
repurchases, or (d) for any transaction from which the director derived an
improper personal benefit.

     We entered into indemnification agreements with each of our directors and
anticipate that we will enter into similar agreements with any future director.
Generally, these agreements attempt to provide the maximum protection permitted
by California law with respect to indemnification. The indemnification
agreements provide that we will pay certain amounts incurred by a director in
connection with any civil or criminal action or proceeding, specifically
including actions by us or in our name (derivative suits) where the individual's
involvement is by reason of the fact that he is or was a director or officer.
For directors, such amounts include, to the maximum extent permitted by law,
attorney's fees, judgments, civil or criminal fines, settlement amounts and
other expenses customarily incurred in connection with legal proceedings. Under
the indemnification agreements, a director will not receive indemnification if
the director is found not to have acted in good faith and in a manner he
reasonably believed to be in or not opposed to our best interests. We have also
entered into similar agreements with certain of our officers and top management
personnel who are not also directors. Generally, the indemnification agreements
attempt to provide the maximum protection permitted by California law with
respect to indemnification of directors and officers.

     The effect of these provisions would be to permit such indemnification by
us for liabilities arising under the Securities Act of 1933, as amended.

     Reference is hereby made to Section 10 of the Underwriting Agreement among
the underwriters, the selling shareholder and us, a form of which is filed as
Exhibit 1.1 to this Registration Statement, for a description of indemnification
arrangements between and the underwriters and us.

                                      II-1
<PAGE>   76

ITEM 16. EXHIBITS

(a) EXHIBITS AND INDEX OF EXHIBITS

<TABLE>
<CAPTION>
    EXHIBIT
    NUMBER                              EXHIBIT
    -------                             -------
    <C>       <S>
     1.1      Underwriters Agreement among the Underwriters named therein,
              the selling shareholder and us.
     4.1      Form of Convertible Secured Promissory Note.(1)
     5.1      Opinion of Heller Ehrman White & McAuliffe LLP.
    10.1      Our amended 1984 Incentive Stock Option Plan.(2)
    10.2      Our 1993 Stock Option Plan.(3)
    10.3      Agreement for the acquisition of Th. Goldschmidt AG of
              Certain of the Assets of Thoratec Laboratories Corporation
              dated March 29, 1989.(4)
    10.4      Common Stock Purchase Agreement between COBE Laboratories,
              Inc. dated November 23, 1992(5)
    10.5      License Agreement between COBE Laboratories, Inc. and us
              dated November 23, 1992.(5)
    10.6      Lease Agreement dated July 25, 1996, between Main Street
              Associates and us, as amended.(6)
    10.7      Our 1996 Stock Option Plan.(7)
    10.8      Our amended 1996 Nonemployee Directors Stock Option Plan.(8)
    10.9      First Amendment to Lease Agreement originally between
              Mainstreet Associates and us dated July 25, 1996.(9)
    10.10     Our 1997 Stock Option Plan.(8)
    10.11     Second Amendment to Lease Agreement originally between
              Mainstreet Associates and us dated July 25, 1996.(10)
    10.12     Distribution Agreement between Guidant Corporation and us
              dated January 13, 1999.(11)
    10.13     Credit Agreement between us as Borrower, and Guidant
              Corporation as Lender dated January 13, 1999.(11)
    23.1      Independent Auditors' Consent -- Deloitte & Touche LLP.
    23.2      Fish & Richardson P.C. Consent
    23.3      Heller Ehrman White & McAuliffe LLP Consent (contained in
              Exhibit 5.1)
    24        Power of Attorney (included at pages II-5 and II-6 hereof).
    27        Financial Data Schedule.
</TABLE>

- -------------------------
 (1) Filed as an Exhibit to our Annual Report on Form 10-K for the fiscal year
     ended December 31, 1994 filed with the SEC on April 3, 1995, and
     incorporated herein by reference.

 (2) Filed as an Exhibit to our Annual Report on Form 10-K for the fiscal year
     ended December 29, 1990 filed with the SEC on March 28, 1991, and
     incorporated herein by reference.

 (3) Filed as an Exhibit to our Annual Report on Form 10-K for the fiscal year
     ended January 1, 1994 filed with the SEC on March 22, 1994, and
     incorporated herein by reference.

 (4) Filed as an Exhibit to our Annual Report on Form 10-K for the fiscal year
     ended December 30, 1989 filed with the SEC on March 30, 1990, and
     incorporated herein by reference.

                                      II-2
<PAGE>   77

 (5) Filed as an Exhibit to our Annual Report on Form 10-K for the fiscal year
     ended January 2, 1993 filed with the SEC on March 22, 1993, and
     incorporated herein by reference.

 (6) Filed as an Exhibit to our Quarterly Report on Form 10-Q for the fiscal
     quarter ended June 29, 1996, filed with the SEC on August 13, 1996, and
     incorporated herein by reference.

 (7) Filed as an Exhibit to our Registration Statement on Form S-8 filed with
     the SEC on September 12, 1996, (Registration No. 333-11883) and
     incorporated herein by reference.

 (8) Filed as an Exhibit to our Registration Statement on Form S-8 filed with
     the SEC on June 16, 1999 (Registration No. 333-80807), and incorporated
     herein by reference.

 (9) Filed as an Exhibit to our Quarterly Report on Form 10-Q for the fiscal
     quarter ended June 28, 1997, filed with the SEC on July 30, 1997, and
     incorporated herein by reference.

(10) Filed as an Exhibit to our Quarterly Report on Form 10-Q for the fiscal
     quarter ended September 27, 1997 filed with the SEC on November 12, 1997,
     and incorporated herein by reference.

(11) Filed as an Exhibit to our Annual Report on Form 10-K, for the fiscal year
     ended January 2, 1999, filed with the SEC on March 24, 1999, and
     incorporated herein by reference.

ITEM 17. UNDERTAKINGS

     The undersigned registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, each filing of the
registrant's annual report pursuant to Section 13(a) or 15(d) of the Securities
Exchange Act of 1934 that is incorporated by reference in the registration
statement shall be deemed to be a new registration statement relating to the
securities offered therein, and the offering of such securities at that time
shall be deemed to be the initial bona fide offering thereof.

     Insofar as indemnification for liabilities arising under the Securities Act
may be permitted to directors, officers and controlling persons of the
registrant pursuant to the foregoing provisions, or otherwise, the registrant
has been advised that in the opinion of the Securities and Exchange Commission
such indemnification is against public policy as expressed in the Securities Act
and is, therefore, unenforceable. In the event that a claim for indemnification
against such liabilities (other than the payment by the registrant of expenses
incurred or paid by a director, officer or controlling person of the registrant
in the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the Securities Act and will be governed by the final
adjudication of such issue.

     The undersigned registrant hereby undertakes that:

          (1) For purposes of determining any liability under the Securities
     Act, the information omitted from the form of prospectus filed as part of
     this registration statement in reliance upon Rule 430A and contained in a
     form of prospectus filed by the registrant pursuant to Rule 424(b)(1) or
     (4) or 497(h) under the Securities Act shall be deemed to be part of this
     registration statement as of the time it was declared effective.

          (2) For the purpose of determining any liability under the Securities
     Act, each post-effective amendment that contains a form of prospectus shall
     be deemed to be a new registration statement relating to the securities
     offered therein, and the offering of such securities at that time shall be
     deemed to be the initial bona fide offering thereof.

                                      II-3
<PAGE>   78

                                   SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933, the registrant
certifies that it has grounds to believe that it meets all of the requirements
for filing on Form S-3 and has duly caused this registration statement to be
signed on its behalf by the undersigned, thereunto duly authorized, in the City
of Pleasanton, State of California, on March 16, 2000.

                                          Thoratec Laboratories Corporation

                                          By:     /s/ D. KEITH GROSSMAN
                                            ------------------------------------
                                                     D. Keith Grossman
                                               President and Chief Executive
                                                           Officer

                               POWER OF ATTORNEY

     KNOW ALL PERSONS BY THESE PRESENTS that each person whose signature appears
below constitutes and appoints D. Keith Grossman and Cheryl D. Hess, and each of
them, his true and lawful attorney-in-fact, with full power of substitution and
resubstitution, to act for him and in his name, place and stead, in any and all
capacities to sign any and all pre- or post-effective amendments to this
registration statement, any subsequent registration statement for the same
offering which may be filed under Rule 462(b) under the Securities Act (a "Rule
462(b) registration statement") and any and all pre- or post-effective
amendments thereto, and to file the same, with all exhibits thereto, and all
documents in connection therewith, with the Securities and Exchange Commission,
granting unto said attorneys-in-fact and agents, and each of them, full power
and authority to do and perform each and every act and thing which they, or any
of them, may deem necessary or advisable to be done in connection with this
registration statement or any Rule 462(b) registration statement, as fully to
all intents and purposes as he might or could do in person, hereby ratifying and
confirming all that said attorneys-in-fact and agents or any of them, or any
substitute or substitutes for any or all of them, may lawfully do or cause to be
done by virtue hereof.

     Pursuant to the requirements of the Securities Act of 1933, this
registration statement has been signed by the following persons in the
capacities and on the dates indicated.

<TABLE>
<CAPTION>
                      SIGNATURE                                    TITLE                   DATE
                      ---------                                    -----                   ----
<C>                                                    <C>                            <S>
                /s/ D. KEITH GROSSMAN                    Chief Executive Officer,     March 16, 2000
- -----------------------------------------------------     President and Director
                  D. Keith Grossman

                 /s/ HOWARD E. CHASE                             Director             March 16, 2000
- -----------------------------------------------------
                   Howard E. Chase

                 /s/ J. DANIEL COLE                              Director             March 16, 2000
- -----------------------------------------------------
                   J. Daniel Cole

                 /s/ J. DONALD HILL                      Director and Chairman of     March 16, 2000
- -----------------------------------------------------     the Board of Directors
                   J. Donald Hill
</TABLE>

                                      II-4
<PAGE>   79

<TABLE>
<CAPTION>
                      SIGNATURE                                    TITLE                   DATE
                      ---------                                    -----                   ----
<C>                                                    <C>                            <S>
              /s/ WILLIAM M. HITCHCOCK                           Director             March 16, 2000
- -----------------------------------------------------
                William M. Hitchcock

             /s/ GEORGE W. HOLBROOK, JR.                         Director             March 16, 2000
- -----------------------------------------------------
               George W. Holbrook, Jr.

                /s/ DANIEL M. MULVENA                            Director             March 16, 2000
- -----------------------------------------------------
                  Daniel M. Mulvena

                 /s/ CHERYL D. HESS                     Vice President -- Finance,    March 16, 2000
- -----------------------------------------------------   Chief Financial Officer and
                   Cheryl D. Hess                          Secretary (Principal
                                                         Financial and Accounting
                                                                 Officer)
</TABLE>

                                      II-5
<PAGE>   80

                                 EXHIBIT INDEX

<TABLE>
<CAPTION>
    EXHIBIT
    NUMBER                              EXHIBIT
    -------                             -------
    <C>       <S>
     1.1      Underwriters Agreement among the Underwriters named therein,
              the selling shareholder and us.
     4.1      Form of Convertible Secured Promissory Note.(1)
     5.1      Opinion of Heller Ehrman White & McAuliffe LLP.
    10.1      Our amended 1984 Incentive Stock Option Plan.(2)
    10.2      Our 1993 Stock Option Plan.(3)
    10.3      Agreement for the acquisition of Th. Goldschmidt AG of
              Certain of the Assets of Thoratec Laboratories Corporation
              dated March 29, 1989.(4)
    10.4      Common Stock Purchase Agreement between COBE Laboratories,
              Inc. dated November 23, 1992(5)
    10.5      License Agreement between COBE Laboratories, Inc. and us
              dated November 23, 1992.(5)
    10.6      Lease Agreement dated July 25, 1996, between Main Street
              Associates and us, as amended.(6)
    10.7      Our 1996 Stock Option Plan.(7)
    10.8      Our amended 1996 Nonemployee Directors Stock Option Plan.(8)
    10.9      First Amendment to Lease Agreement originally between
              Mainstreet Associates and us dated July 25, 1996.(9)
    10.10     Our 1997 Stock Option Plan.(8)
    10.11     Second Amendment to Lease Agreement originally between
              Mainstreet Associates and us dated July 25, 1996.(10)
    10.12     Distribution Agreement between Guidant Corporation and us
              dated January 13, 1999.(11)
    10.13     Credit Agreement between us as Borrower, and Guidant
              Corporation as Lender dated January 13, 1999.(11)
    23.1      Independent Auditors' Consent -- Deloitte & Touche LLP.
    23.2      Fish & Richardson P.C. Consent
    23.3      Heller Ehrman White & McAuliffe LLP Consent (contained in
              Exhibit 5.1)
    24        Power of Attorney (included at pages II-5 and II-6 hereof).
    27        Financial Data Schedule.
</TABLE>

- -------------------------
 (1) Filed as an Exhibit to our Annual Report on Form 10-K for the fiscal year
     ended December 31, 1994 filed with the SEC on April 3, 1995, and
     incorporated herein by reference.

 (2) Filed as an Exhibit to our Annual Report on Form 10-K for the fiscal year
     ended December 29, 1990 filed with the SEC on March 28, 1991, and
     incorporated herein by reference.

 (3) Filed as an Exhibit to our Annual Report on Form 10-K for the fiscal year
     ended January 1, 1994 filed with the SEC on March 22, 1994, and
     incorporated herein by reference.

 (4) Filed as an Exhibit to our Annual Report on Form 10-K for the fiscal year
     ended December 30, 1989 filed with the SEC on March 30, 1990, and
     incorporated herein by reference.
<PAGE>   81

 (5) Filed as an Exhibit to our Annual Report on Form 10-K for the fiscal year
     ended January 2, 1993 filed with the SEC on March 22, 1993, and
     incorporated herein by reference.

 (6) Filed as an Exhibit to our Quarterly Report on Form 10-Q for the fiscal
     quarter ended June 29, 1996, filed with the SEC on August 13, 1996, and
     incorporated herein by reference.

 (7) Filed as an Exhibit to our Registration Statement on Form S-8 filed with
     the SEC on September 12, 1996, (Registration No. 333-11883) and
     incorporated herein by reference.

 (8) Filed as an Exhibit to our Registration Statement on Form S-8 filed with
     the SEC on June 16, 1999 (Registration No. 333-80807), and incorporated
     herein by reference.

 (9) Filed as an Exhibit to our Quarterly Report on Form 10-Q for the fiscal
     quarter ended June 28, 1997, filed with the SEC on July 30, 1997, and
     incorporated herein by reference.

(10) Filed as an Exhibit to our Quarterly Report on Form 10-Q for the fiscal
     quarter ended September 27, 1997 filed with the SEC on November 12, 1997,
     and incorporated herein by reference.

(11) Filed as an Exhibit to our Annual Report on Form 10-K, for the fiscal year
     ended January 2, 1999, filed with the SEC on March 24, 1999, and
     incorporated herein by reference.

<PAGE>   1
                                                                     EXHIBIT 1.1

                         FORM OF UNDERWRITING AGREEMENT

                                4,500,000 SHARES

                        THORATEC LABORATORIES CORPORATION

                                  COMMON STOCK

                             UNDERWRITING AGREEMENT


                                                                  March __, 2000

LEHMAN BROTHERS INC.,
As Representative of the several
  Underwriters named in Schedule 1,
Three World Financial Center
New York, New York 10285

Dear Sirs:

               Thoratec Laboratories Corporation, a California corporation (the
"Company"), and Gambro, Inc. (the "Selling Stockholder"), propose to sell an
aggregate of 4,500,000 shares (the "Firm Stock") of the Company's Common Stock,
no par value per share (the "Common Stock"). Of the 4,500,000 shares of the Firm
Stock, 3,000,000 are being sold by the Company and 1,500,000 by the Selling
Stockholder. In addition, the Selling Stockholder proposes to grant to the
Underwriters named in Schedule 1 hereto (the "Underwriters") an option to
purchase up to an additional 675,000 shares of the Common Stock on the terms and
for the purposes set forth in Section 3 (the "Option Stock"). The Firm Stock and
the Option Stock, if purchased, are hereinafter collectively called the "Stock."
This is to confirm the agreement concerning the purchase of the Stock from the
Company and the Selling Stockholder by the Underwriters.

               1. Representations, Warranties and Agreements of the Company. The
Company represents, warrants and agrees that:

               (a) A registration statement on Form S-3 (including any
amendments thereto, if any) with respect to the Stock has (i) been prepared by
the Company in conformity with the requirements of the United States Securities
Act of 1933 (the "Securities Act") and the rules and regulations (the "Rules and
Regulations") of the United States Securities and Exchange Commission (the
"Commission") thereunder, (ii) been filed with the Commission under the
Securities Act and (iii) become effective under the Securities Act. Copies of
such registration statement and any amendment thereto have been delivered by the
Company to you as the representative (the "Representative") of the Underwriters.
As used in this Agreement, "Effective Time" means the date and the time as of
which such registration statement, or the most recent post-effective amendment
thereto, if any, was declared effective by the Commission; "Effective Date"
means the date of the Effective Time; "Preliminary Prospectus" means each
prospectus


<PAGE>   2
included in such registration statement, or amendments thereof, before it became
effective under the Securities Act and any prospectus filed with the Commission
by the Company with the consent of the Representative pursuant to Rule 424(a) of
the Rules and Regulations; "Registration Statement" means such registration
statement, as amended at the Effective Time, including any documents
incorporated by reference therein at such time and all information contained in
the final prospectus filed with the Commission pursuant to Rule 424(b) of the
Rules and Regulations in accordance with Section 5 hereof and deemed to be a
part of the registration statement as of the Effective Time pursuant to
paragraph (b) of Rule 430A of the Rules and Regulations; and "Prospectus" means
such final prospectus, as first filed with the Commission pursuant to paragraph
(1) or (4) of Rule 424(b) of the Rules and Regulations. Reference made herein to
any Preliminary Prospectus or to the Prospectus shall be deemed to refer to and
include any documents incorporated by reference therein pursuant to Item 12 of
Form S-3 under the Securities Act, as of the date of such Preliminary Prospectus
or the Prospectus, as the case may be, and any reference to any amendment or
supplement to any Preliminary Prospectus or the Prospectus shall be deemed to
refer to and include any document filed under the United States Securities
Exchange Act of 1934 (the "Exchange Act") after the date of such Preliminary
Prospectus or the Prospectus, as the case may be, and incorporated by reference
in such Preliminary Prospectus or the Prospectus, as the case may be; and any
reference to any amendment to the Registration Statement shall be deemed to
include any annual report of the Company filed with the Commission pursuant to
Section 13(a) or 15(d) of the Exchange Act after the Effective Time that is
incorporated by reference in the Registration Statement. The Commission has not
issued any order preventing or suspending the use of any Preliminary Prospectus.

               (b) The Registration Statement conforms, and the Prospectus and
any further amendments or supplements to the Registration Statement or the
Prospectus will, when they become effective or are filed with the Commission, as
the case may be, conform in all respects to the requirements of the Securities
Act and the Rules and Regulations and do not and will not, as of the applicable
effective date (as to the Registration Statement and any amendment thereto) and
as of the applicable filing date (as to the Prospectus and any amendment or
supplement thereto) contain an untrue statement of a material fact or omit to
state a material fact required to be stated therein or necessary to make the
statements therein not misleading; provided that no representation or warranty
is made as to information contained in or omitted from the Registration
Statement or the Prospectus in reliance upon and in conformity with written
information furnished to the Company through the Representative by or on behalf
of any Underwriter specifically for inclusion therein.

               (c) The documents incorporated by reference in the Prospectus,
when they became effective or were filed with the Commission, as the case may
be, conformed in all material respects to the requirements of the Securities Act
or the Exchange Act, as applicable, and the rules and regulations of the
Commission thereunder, and none of such documents contained an untrue statement
of a material fact or omitted to state a material fact required to be stated
therein or necessary to make the statements therein not misleading; and any
further documents so filed and incorporated by reference in the Prospectus, when
such documents become effective or are filed with Commission, as the case may
be, will conform in all material respects to the requirements of the Securities
Act or the Exchange Act, as applicable, and the rules and regulations of the
Commission thereunder and will not contain an untrue statement of a material
fact or omit to state a material fact required to be stated therein or necessary
to make the statements therein not misleading.

               (d) The Company and each of its subsidiaries (as defined in
Section 17) have been duly incorporated and are validly existing as corporations
in good standing under the laws of their respective jurisdictions of
incorporation, are duly qualified to do business and are in good


                                       2


<PAGE>   3
standing as foreign corporations in each jurisdiction in which their respective
ownership or lease of property or the conduct of their respective businesses
requires such qualification, and have all power and authority necessary to own
or hold their respective properties and to conduct the businesses in which they
are engaged; and none of the subsidiaries of the Company is a "significant
subsidiary," as such term is defined in Rule 405 of the Rules and Regulations.

               (e) The Company has an authorized capitalization as set forth in
the Prospectus, and all of the issued shares of capital stock of the Company
have been duly and validly authorized and issued, are fully paid and
non-assessable and conform to the description thereof contained in the
Prospectus; and all of the issued shares of capital stock of each subsidiary of
the Company have been duly and validly authorized and issued and are fully paid
and non-assessable and are owned directly or indirectly by the Company, free and
clear of all liens, encumbrances, equities or claims.

               (f) The unissued shares of the Stock to be issued and sold by the
Company to the Underwriters hereunder have been duly and validly authorized and,
when issued and delivered against payment therefor as provided herein, will be
duly and validly issued, fully paid and non-assessable; and the Stock will
conform to the description thereof contained in the Prospectus.

               (g) This Agreement has been duly authorized, executed and
delivered by the Company and each of the documents relating to this Agreement to
which the Company is a party has been duly authorized, executed and delivered by
the Company.

               (h) The execution, delivery and performance of this Agreement by
the Company and the consummation of the transactions contemplated hereby and in
the Registration Statement and Prospectus will not conflict with or result in a
breach or violation of any of the terms or provisions of, or constitute a
default under, any indenture, mortgage, deed of trust, loan agreement or other
agreement or instrument to which the Company or any of its subsidiaries is a
party or by which the Company or any of its subsidiaries is bound or to which
any of the property or assets of the Company or any of its subsidiaries is
subject, nor will such actions result in any violation of the provisions of the
charter or by-laws of the Company or any of its subsidiaries or any statute or
any order, rule or regulation of any court or governmental agency or body having
jurisdiction over the Company or any of its subsidiaries or any of their
properties or assets; and except for the registration of the Stock under the
Securities Act and such consents, approvals, authorizations, registrations or
qualifications as may be required under the Exchange Act and applicable state or
foreign securities laws in connection with the purchase and distribution of the
Stock by the Underwriters, no consent, approval, authorization or order of, or
filing or registration with, any such court or governmental agency or body is
required for the execution, delivery and performance of this Agreement by the
Company and the consummation of the transactions contemplated hereby.

               (i) Except as described in the Prospectus, there are no
contracts, agreements or understandings between the Company and any person
granting such person the right (other than rights which have been waived or
satisfied) with respect to any securities of the Company owned by such person,
to require the Company to file a registration statement under the Securities Act
with respect to any securities of the Company owned or to be owned by such
person or to require the Company to include such securities in the securities
registered pursuant to the Registration Statement or in any securities being
registered pursuant to any other registration statement filed by the Company
under the Securities Act.

               (j) Except as described in the Prospectus, the Company has not
sold or issued any shares of Common Stock during the six-month period preceding
the date of the


                                       3


<PAGE>   4
Prospectus, including any sales pursuant to Rule 144A under, or Regulations D or
S of, the Securities Act, other than shares issued pursuant to employee benefit
plans, qualified stock options plans or other employee compensation plans or
pursuant to outstanding options, rights or warrants.

               (k) Neither the Company nor any of its subsidiaries has
sustained, since the date of the latest audited financial statements included in
the Prospectus, any material loss or interference with its business from fire,
explosion, flood or other calamity, whether or not covered by insurance, or from
any labor dispute or court or governmental action, order or decree, otherwise
than as set forth or contemplated in the Prospectus; and, since such date, there
has not been any change in the capital stock or long-term debt of the Company or
any of its subsidiaries or any material adverse change, or any development
involving a prospective material adverse change, in or affecting the general
affairs, management, financial position, stockholders' equity or results of
operations of the Company and its subsidiaries, otherwise than as set forth or
contemplated in the Prospectus.

               (l) The financial statements (including the related notes and
supporting schedules) filed as part of the Registration Statement or included in
the Prospectus present fairly the financial condition and results of operations
of the entities purported to be shown thereby, at the dates and for the periods
indicated, and have been prepared in conformity with generally accepted
accounting principles applied on a consistent basis throughout the periods
involved.

               (m) Deloitte & Touche LLP, who have certified certain financial
statements of the Company, whose report appears in the Prospectus and who have
delivered the initial letter referred to in Section 9(j) hereof, are independent
public accountants as required by the Securities Act and the Rules and
Regulations.

               (n) Neither the Company or any of its subsidiaries owns any real
property. The Company and each of its subsidiaries have good and marketable
title to all personal property owned by them, in each case free and clear of all
liens, encumbrances and defects except such as are described in the Prospectus
or such as do not materially affect the value of such property and do not
materially interfere with the use made and proposed to be made of such property
by the Company and its subsidiaries; and all real property and buildings held
under lease by the Company and its subsidiaries are held by them under valid,
subsisting and enforceable leases, with such exceptions as are not material and
do not interfere with the use made and proposed to be made of such property and
buildings by the Company and its subsidiaries.

               (o) The Company and each of its subsidiaries carry, or are
covered by, insurance in such amounts and covering such risks as is adequate for
the conduct of their respective businesses and the value of their respective
properties and as is customary for companies engaged in similar businesses in
similar industries.

               (p) The Company and each of its subsidiaries own or possess
adequate licenses or other rights to use all patents, patent applications,
inventions, trademarks, trade names, applications for registration of
trademarks, service marks, service mark applications, copyrights, know-how,
manufacturing processes, formulae, trade secrets, licenses and rights in any
thereof and any other intangible property and assets (herein called the
"Proprietary Rights") necessary to conduct its business in the manner described
in the Prospectus, except where the failure to so own or possess such
Proprietary Rights would not, singularly or in the aggregate, have a material
adverse effect on the financial position, stockholders' equity, results of
operations, business or prospects of the Company. The Company and each of its
subsidiaries take security measures to provide adequate trade secret protection
in its non-patented technology. Except as disclosed in the Prospectus, neither
the Company nor any of its subsidiaries has received any notice of


                                       4


<PAGE>   5
infringement or conflict with asserted rights of others with respect to any
Proprietary Rights which could result in any material adverse effect on the
Company, or any of its subsidiaries, as the case may be, and, except as
specifically identified and described in the Prospectus, no action, suit,
arbitration or legal, administrative or other proceeding, or investigation is
pending, or, to the knowledge of the Company, threatened, which involves any
Proprietary Rights. Except as disclosed in the Prospectus, the Proprietary
Rights of the Company and its subsidiaries referred to in the Prospectus do not,
to the knowledge of the Company, infringe or conflict with any right or valid
and enforceable patent of any third party, or any discovery, invention, product
or process which is the subject of a patent application filed by any third
party, known to the Company which could have a material adverse effect on the
Company or any of its subsidiaries. Neither the Company nor any of its
subsidiaries is subject to any judgment, order, writ, injunction or decree of
any court or any Federal, state, local, foreign or other governmental
department, commission, board, bureau, agency or instrumentality, domestic or
foreign, or any arbitrator, nor, except as described in the Prospectus, has it
entered into or is a party to any contract which restricts or impairs the use of
any such Proprietary Rights in a manner which would have a material adverse
effect on the use of any of the Proprietary Rights. The Company and each of its
subsidiaries have complied, in all material respects, with its respective
contractual obligations relating to the protection of the Proprietary Rights
used pursuant to licenses. To the knowledge of the Company, no person is
infringing on or violating the Proprietary Rights owned or used by the Company
or any of its subsidiaries.

               (q) There are no legal or governmental proceedings pending to
which the Company or any of its subsidiaries is a party or of which any property
or assets of the Company or any of its subsidiaries is the subject which, if
determined adversely to the Company or any of its subsidiaries, might have a
material adverse effect on the consolidated financial position, stockholders'
equity, results of operations, business or prospects of the Company and its
subsidiaries; and to the best of the Company's knowledge, no such proceedings
are threatened or contemplated by governmental authorities or threatened by
others.

               (r) The conditions for use of Form S-3, as set forth in the
General Instructions thereto, have been satisfied.

               (s) There are no contracts or other documents which are required
to be described in the Prospectus or filed as exhibits to the Registration
Statement by the Securities Act or by the Rules and Regulations which have not
been described in the Prospectus or filed as exhibits to the Registration
Statement or incorporated therein by reference as permitted by the Rules and
Regulations.

               (t) No relationship, direct or indirect, exists between or among
the Company on the one hand, and the directors, officers, stockholders,
customers or suppliers of the Company on the other hand, which is required to be
described in the Prospectus which is not so described.

               (u) No labor disturbance by the employees of the Company exists
or, to the knowledge of the Company, is imminent which might be expected to have
a material adverse effect on the consolidated financial position, stockholders'
equity, results of operations, business or prospects of the Company and its
subsidiaries.

               (v) The Company is in compliance in all material respects with
all presently applicable provisions of the Employee Retirement Income Security
Act of 1974, as amended, including the regulations and published interpretations
thereunder ("ERISA"); no "reportable event" (as defined in ERISA) has occurred
with respect to any "pension plan" (as defined in ERISA) for which the Company
would have any liability; the Company has not incurred and does not expect to
incur liability under (i) Title IV of ERISA with respect to termination of, or


                                       5


<PAGE>   6
withdrawal from, any "pension plan" or (ii) Sections 412 or 4971 of the Internal
Revenue Code of 1986, as amended, including the regulations and published
interpretations thereunder (the "Code"); and each "pension plan" for which the
Company would have any liability that is intended to be qualified under Section
401(a) of the Code is so qualified in all material respects and nothing has
occurred, whether by action or by failure to act, which would cause the loss of
such qualification.

               (w) The Company and each of its subsidiaries has filed all
federal, state and local income and franchise tax returns required to be filed
through the date hereof and has paid all taxes due thereon, and no tax
deficiency has been determined adversely to the Company or any of its
subsidiaries which has had (nor does the Company have any knowledge of any tax
deficiency which, if determined adversely to the Company or any of its
subsidiaries, might have) a material adverse effect on the consolidated
financial position, stockholders' equity, results of operations, business or
prospects of the Company and its subsidiaries.

               (x) Since the date as of which information is given in the
Prospectus through the date hereof, and except as may otherwise be disclosed in
the Prospectus, the Company has not (i) issued or granted any securities, (ii)
incurred any liability or obligation, direct or contingent, other than
liabilities and obligations which were incurred in the ordinary course of
business, (iii) entered into any transaction not in the ordinary course of
business or (iv) declared or paid any dividend on its capital stock.

               (y) The Company and each of its subsidiaries (i) makes and keeps
accurate books and records and (ii) maintains internal accounting controls which
provide reasonable assurance that (A) transactions are executed in accordance
with management's authorization, (B) transactions are recorded as necessary to
permit preparation of its financial statements and to maintain accountability
for its assets, (C) access to its assets is permitted only in accordance with
management's authorization and (D) the reported accountability for its assets is
compared with existing assets at reasonable intervals.

               (z) Neither the Company nor any of its subsidiaries (i) is in
violation of its charter or by-laws or similar governing document, (ii) is in
default in any material respect, and no event has occurred which, with notice or
lapse of time or both, would constitute such a default, in the due performance
or observance of any term, covenant or condition contained in any material
indenture, mortgage, deed of trust, loan agreement or other agreement or
instrument to which it is a party or by which it is bound or to which any of its
properties or assets is subject or (iii) is in violation in any material respect
of any law, ordinance, governmental rule, regulation or court decree to which it
or its property or assets may be subject or has failed to obtain any material
license, permit, certificate, franchise or other governmental authorization or
permit necessary to the ownership of its property or to the conduct of its
business.

               (aa) Neither the Company nor any of its subsidiaries, nor any
director, officer, agent, employee or other person associated with or acting on
behalf of the Company or any of its subsidiaries, has used any corporate funds
for any unlawful contribution, gift, entertainment or other unlawful expense
relating to political activity; made any direct or indirect unlawful payment to
any foreign or domestic government official or employee from corporate funds;
violated or is in violation of any provision of the Foreign Corrupt Practices
Act of 1977; or made any bribe, rebate, payoff, influence payment, kickback or
other unlawful payment.

               (ab) There has been no storage, disposal, generation,
manufacture, refinement, transportation, handling or treatment of toxic wastes,
medical wastes, hazardous wastes or hazardous substances by the Company or any
of its subsidiaries (or, to the knowledge of the Company, any of their
predecessors in interest) at, upon or from any of the property now or


                                       6


<PAGE>   7
previously owned or leased by the Company or its subsidiaries in violation of
any applicable law, ordinance, rule, regulation, order, judgment, decree or
permit or which would require remedial action under any applicable law,
ordinance, rule, regulation, order, judgment, decree or permit, except for any
violation or remedial action which would not have, or could not be reasonably
likely to have, singularly or in the aggregate with all such violations and
remedial actions, a material adverse effect on the general affairs, management,
financial position, stockholders' equity or results of operations of the Company
and its subsidiaries; there has been no material spill, discharge, leak,
emission, injection, escape, dumping or release of any kind onto such property
or into the environment surrounding such property of any toxic wastes, medical
wastes, solid wastes, hazardous wastes or hazardous substances due to or caused
by the Company or any of its subsidiaries or with respect to which the Company
or any of its subsidiaries have knowledge, except for any such spill, discharge,
leak, emission, injection, escape, dumping or release which would not have or
would not be reasonably likely to have, singularly or in the aggregate with all
such spills, discharges, leaks, emissions, injections, escapes, dumpings and
releases, a material adverse effect on the general affairs, management,
financial position, stockholders' equity or results of operations of the Company
and its subsidiaries; and the terms "hazardous wastes," "toxic wastes,"
"hazardous substances" and "medical wastes" shall have the meanings specified in
any applicable local, state, federal and foreign laws or regulations with
respect to environmental protection.

               (ac) Neither the Company nor any subsidiary is an "investment
company" within the meaning of such term under the Investment Company Act of
1940 and the rules and regulations of the Commission thereunder.

               (ad) The Company and each of its subsidiaries has such permits,
licenses, franchises, authorizations and clearances (collectively, "Permits") of
governmental or regulatory authorities, including, without limitation, the Food
and Drug Administration and/or any committee thereof, as are reasonably
necessary to own, lease and operate its properties and to conduct its business
in the manner described in the Prospectus, subject to such qualifications as may
be set forth in the Prospectus, except where such failure to receive such
Permits would not, individually or in the aggregate, be reasonably expected to
have a material adverse effect on the operations, business or prospects of the
Company; subject to such qualifications as may be set forth in the Prospectus,
the Company and each of its subsidiaries has fulfilled and performed all its
material obligations with respect to the Permits, and no event has occurred that
allows, or after notice or lapse of time would allow, revocation or termination
thereof or results in any other material impairment of the rights of the holder
of any Permit, subject in each case to such qualification as may be set forth in
the Prospectus. Except as described in the Prospectus, none of the Permits
contains any restriction that is materially burdensome to the Company or any of
its subsidiaries.

               (ae) Except to the extent disclosed in the Registration Statement
and the Prospectus, the clinical, pre-clinical and other studies and tests
conducted by or on behalf of or sponsored by the Company or any of its
subsidiaries or in which the Company or any of its subsidiaries or the Company's
or any of its subsidiaries' products under development have participated that
are described in the Prospectus were and, if still pending, are being conducted
in accordance with standard medical and scientific research procedures. The
descriptions of the results of such studies and tests are accurate and complete
in all material respects and fairly present the data derived from such studies
and tests, and the Company has no knowledge of any other studies or tests the
results of which are inconsistent with or otherwise call into question the
results described or referred to in the Prospectus. Except to the extent
disclosed in the Registration Statement and the Prospectus, the Company has
operated and currently is in compliance in all material respects with all
applicable FDA rules, regulations and policies.


                                       7


<PAGE>   8
Except to the extent disclosed in the Registration Statement and the Prospectus,
neither the Company nor any of its subsidiaries has received any notices or
other correspondence from the Food and Drug Administration or any other
governmental agency requiring the termination, suspension or modification of any
clinical or pre-clinical studies or tests that are described in the Prospectus
or the results of which are referred to therein.

               2. Representations, Warranties and Agreements of the Selling
Stockholder. The Selling Stockholder represents, warrants and agrees that:

               (a) The Selling Stockholder has, and immediately prior to the
First Delivery Date (as defined in Section 5 hereof) the Selling Stockholder
will have good and valid title to the shares of Stock to be sold by the Selling
Stockholder hereunder on such date, free and clear of all liens, encumbrances,
equities or claims; and upon delivery of such shares and payment therefor
pursuant hereto, good and valid title to such shares, free and clear of all
liens, encumbrances, equities or claims, will pass to the several Underwriters.

               (b) The Selling Stockholder has placed in custody under a custody
agreement (the "Custody Agreement") with American Securities Transfer and Trust,
Inc., as custodian (the "Custodian"), for delivery under this Agreement,
certificates in negotiable form (with signature guaranteed by a commercial bank
or trust company having an office or correspondent in the United States or a
member firm of the New York or American Stock Exchanges) representing the shares
of Stock to be sold by the Selling Stockholder hereunder.

               (c) The Selling Stockholder has duly and irrevocably executed and
delivered a power of attorney (the "Power of Attorney") appointing D. Keith
Grossman and Cheryl D. Hess, as attorneys-in-fact, with full power of
substitution, and with full authority (exercisable by any one or more of them)
to execute and deliver this Agreement and to take such other action as may be
necessary or desirable to carry out the provisions hereof on behalf of the
Selling Stockholder.

               (d) The Selling Stockholder has full right, power and authority
to enter into this Agreement, the Power of Attorney and the Custody Agreement;
the execution, delivery and performance of this Agreement, the Power of Attorney
and the Custody Agreement by the Selling Stockholder and the consummation by the
Selling Stockholder of the transactions contemplated hereby and thereby will not
conflict with or result in a breach or violation of any of the terms or
provisions of, or constitute a default under, any indenture, mortgage, deed of
trust, loan agreement or other agreement or instrument to which the Selling
Stockholder is a party or by which the Selling Stockholder is bound or to which
any of the property or assets of the Selling Stockholder is subject, nor will
such actions result in any violation of the provisions of the charter or by-laws
or similar governing document of the Selling Stockholder or any statute or any
order, rule or regulation of any court or governmental agency or body having
jurisdiction over the Selling Stockholder or the property or assets of the
Selling Stockholder; and, except for the registration of the Stock under the
Securities Act and such consents, approvals, authorizations, registrations or
qualifications as may be required under the Exchange Act and applicable state or
foreign securities laws in connection with the purchase and distribution of the
Stock by the Underwriters, no consent, approval, authorization or order of, or
filing or registration with, any such court or governmental agency or body is
required for the execution, delivery and performance of this Agreement, the
Power of Attorney or the Custody Agreement by the Selling Stockholder and the
consummation by the Selling Stockholder of the transactions contemplated hereby
and thereby.

               (e) All information relating to the Selling Stockholder in the
Registration Statement and the Prospectus and any further amendments or
supplements to the Registration


                                       8


<PAGE>   9
Statement or the Prospectus will, when they become effective or are filed with
the Commission, as the case may be, does not and will not, as of the applicable
effective date (as to the Registration Statement and any amendment thereto) and
as of the applicable filing date (as to the Prospectus and any amendment or
supplement thereto) contain an untrue statement of a material fact or omit to
state a material fact required to be stated therein or necessary to make the
statements therein not misleading; provided that no representation or warranty
is made as to information contained in or omitted from the Registration
Statement or the Prospectus in reliance upon and in conformity with written
information furnished to the Company through the Representative by or on behalf
of any Underwriter specifically for inclusion therein.

               (f) The Selling Stockholder has not taken and will not take,
directly or indirectly, any action which is designed to or which has constituted
or which might reasonably be expected to cause or result in the stabilization or
manipulation of the price of any security of the Company to facilitate the sale
or resale of the shares of the Stock.

               (g) The Selling Stockholder is not prompted to sell shares of
Stock by any information concerning the Company that is not set forth in the
Registration Statement and the Prospectus.

               3. Purchase of the Stock by the Underwriters. On the basis of the
representations and warranties contained in, and subject to the terms and
conditions of, this Agreement, the Company agrees to sell 3,000,000 shares of
the Firm Stock and the Selling Stockholder hereby agrees to sell 1,500,000
shares of the Firm Stock, to the several Underwriters and each of the
Underwriters, severally and not jointly, agrees to purchase the number of shares
of the Firm Stock set opposite that Underwriter's name in Schedule 1 hereto.
Each Underwriter shall be obligated to purchase from the Company, and from the
Selling Stockholder, that number of shares of the Firm Stock which represents
the same proportion of the number of shares of the Firm Stock to be sold by the
Company, and by the Selling Stockholder, as the number of shares of the Firm
Stock set forth opposite the name of such Underwriter in Schedule 1 represents
of the total number of shares of the Firm Stock to be purchased by all of the
Underwriters pursuant to this Agreement. The respective purchase obligations of
the Underwriters with respect to the Firm Stock shall be rounded among the
Underwriters to avoid fractional shares, as the Representative may determine.

               In addition, the Selling Stockholder grants to the Underwriters
an option to purchase up to 675,000 shares of Option Stock. Such option is
granted solely for the purpose of covering over-allotments in the sale of Firm
Stock and is exercisable as provided in Section 5 hereof. Shares of Option Stock
shall be purchased severally for the account of the Underwriters in proportion
to the number of shares of Firm Stock set opposite the name of such Underwriters
in Schedule 1 hereto. The respective purchase obligations of each Underwriter
with respect to the Option Stock shall be adjusted by the Representative so that
no Underwriter shall be obligated to purchase Option Stock other than in 100
share amounts.

               The price of both the Firm Stock and any Option Stock shall be
$_____ per share.

               The Company and the Selling Stockholder shall not be obligated to
deliver any of the Stock to be delivered on any Delivery Date (as hereinafter
defined), as the case may be, except upon payment for all the Stock to be
purchased on such Delivery Date as provided herein.


                                       9


<PAGE>   10
               4. Offering of Stock by the Underwriters.

               Upon authorization by the Representative of the release of the
Firm Stock, the several Underwriters propose to offer the Firm Stock for sale
upon the terms and conditions set forth in the Prospectus.

               5. Delivery of and Payment for the Stock. Delivery of and payment
for the Firm Stock shall be made at the offices of Clifford Chance Rogers &
Wells LLP, 200 Park Avenue, New York, New York 10166, at 10:00 A.M., New York
City time, on the fourth full business day following the date of this Agreement
or at such other date or place as shall be determined by agreement between the
Representative and the Company. This date and time are sometimes referred to as
the "First Delivery Date." On the First Delivery Date, the Company and the
Selling Stockholder shall deliver or cause to be delivered certificates
representing the Firm Stock to the Representative for the account of each
Underwriter against payment to or upon the order of the Company and the Selling
Stockholder of the purchase price by wire transfer in immediately available
funds. Time shall be of the essence, and delivery at the time and place
specified pursuant to this Agreement is a further condition of the obligation of
each Underwriter hereunder. Upon delivery, the Firm Stock shall be registered in
such names and in such denominations as the Representative shall request in
writing not less than two full business days prior to the First Delivery Date.
For the purpose of expediting the checking and packaging of the certificates for
the Firm Stock, the Company and the Selling Stockholder shall make the
certificates representing the Firm Stock available for inspection by the
Representative in New York, New York, not later than 2:00 P.M., New York City
time, on the business day prior to the First Delivery Date.

               The option granted in Section 3 will expire 30 days after the
date of this Agreement and may be exercised in whole or in part from time to
time by written notice being given to the Selling Stockholder and the Company by
the Representative. If the Option is exercised in part, the Underwriters shall
purchase on a pro rata basis from the Selling Stockholder that number of shares
of Option Stock offered by the Selling Stockholder pursuant to Section 3 hereof.
Such notice shall set forth the aggregate number of shares of Option Stock as to
which the option is being exercised, the names in which the shares of Option
Stock are to be registered, the denominations in which the shares of Option
Stock are to be issued and the date and time, as determined by the
Representative, when the shares of Option Stock are to be delivered; provided,
however, that this date and time shall not be earlier than the First Delivery
Date nor earlier than the second business day after the date on which the option
shall have been exercised nor later than the fifth business day after the date
on which the option shall have been exercised. The date and time the shares of
Option Stock are delivered are sometimes referred to as a "Second Delivery Date"
and the First Delivery Date and any Second Delivery Date are sometimes each
referred to as a "Delivery Date."

               Delivery of and payment for the Option Stock shall be made at the
place specified in the first sentence of the first paragraph of this Section 5
(or at such other place as shall be determined by agreement between the
Representative and the Selling Stockholder) at 10:00 A.M., New York City time,
on the such Second Delivery Date. On the such Second Delivery Date, the Selling
Stockholder shall deliver or cause to be delivered the certificates representing
the Option Stock to the Representative for the account of each Underwriter
against payment to or upon the order of the Selling Stockholder of the purchase
price by wire transfer in immediately available funds. Time shall be of the
essence, and delivery at the time and place specified pursuant to this Agreement
is a further condition of the obligation of each Underwriter hereunder. Upon
delivery, the Option Stock shall be registered in such names and in such
denominations as the Representative shall request in the aforesaid written
notice. For the purpose of expediting the checking and packaging of the
certificates for the Option Stock, the Selling


                                       10


<PAGE>   11
Stockholder shall make the certificates representing the Option Stock available
for inspection by the Representative in New York, New York, not later than 2:00
P.M., New York City time, on the business day prior to the such Second Delivery
Date.

               6. Further Agreements of the Company. The Company agrees:

               (a) To prepare the Prospectus in a form approved by the
Representative and to file such Prospectus pursuant to Rule 424(b) under the
Securities Act not later than Commission's close of business on the second
business day following the execution and delivery of this Agreement or, if
applicable, such earlier time as may be required by Rule 430A(a)(3) under the
Securities Act; to make no further amendment or any supplement to the
Registration Statement or to the Prospectus prior to the last Delivery Date
except as permitted herein; to advise the Representative, promptly after it
receives notice thereof, of the time when any amendment to the Registration
Statement has been filed or becomes effective or any supplement to the
Prospectus or any amended Prospectus has been filed and to furnish the
Representative with copies thereof; to file promptly all reports and any
definitive proxy or information statements required to be filed by the Company
with the Commission pursuant to Section 13(a), 13(c), 14 or 15(d) of the
Exchange Act subsequent to the date of the Prospectus and for so long as the
delivery of a prospectus is required in connection with the offering or sale of
the Stock; to advise the Representative, promptly after it receives notice
thereof, of the issuance by the Commission of any stop order or of any order
preventing or suspending the use of any Preliminary Prospectus or the
Prospectus, of the suspension of the qualification of the Stock for offering or
sale in any jurisdiction, of the initiation or threatening of any proceeding for
any such purpose, or of any request by the Commission for the amending or
supplementing of the Registration Statement or the Prospectus or for additional
information; and, in the event of the issuance of any stop order or of any order
preventing or suspending the use of any Preliminary Prospectus or the Prospectus
or suspending any such qualification, to use promptly its best efforts to obtain
its withdrawal;

               (b) To furnish promptly to the Representative and to counsel for
the Underwriters a signed copy of the Registration Statement as originally filed
with the Commission, and each amendment thereto filed with the Commission,
including all consents and exhibits filed therewith;

               (c) To deliver promptly to the Representative such number of the
following documents as the Representative shall reasonably request: (i)
conformed copies of the Registration Statement as originally filed with the
Commission and each amendment thereto (in each case excluding exhibits other
than this Agreement and the computation of per share earnings), (ii) each
Preliminary Prospectus, the Prospectus and any amended or supplemented
Prospectus and (iii) any document incorporated by reference in the Prospectus
(excluding exhibits thereto) and, if the delivery of a prospectus is required at
any time after the Effective Time in connection with the offering or sale of the
Stock or any other securities relating thereto and if at such time any events
shall have occurred as a result of which the Prospectus as then amended or
supplemented would include an untrue statement of a material fact or omit to
state any material fact necessary in order to make the statements therein, in
the light of the circumstances under which they were made when such Prospectus
is delivered, not misleading, or, if for any other reason it shall be necessary
to amend or supplement the Prospectus or to file under the Exchange Act any
document incorporated by reference in the Prospectus in order to comply with the
Securities Act or the Exchange Act, to notify the Representative and, upon its
request, to file such document and to prepare and furnish without charge to each
Underwriter and to any dealer in securities as many copies as the Representative
may from time to time reasonably request of an amended or supplemented
Prospectus which will correct such statement or omission or effect such
compliance;


                                       11


<PAGE>   12
               (d) To file promptly with the Commission any amendment to the
Registration Statement or the Prospectus or any supplement to the Prospectus
that may, in the judgment of the Company or the Representative, be required by
the Securities Act or requested by the Commission;

               (e) Prior to filing with the Commission any amendment to the
Registration Statement or supplement to the Prospectus, any document
incorporated by reference in the Prospectus or any Prospectus pursuant to Rule
424 of the Rules and Regulations, to furnish a copy thereof to the
Representative and counsel for the Underwriters and obtain the consent of the
Representative to the filing;

               (f) As soon as practicable after the Effective Date, to make
generally available to the Company's security holders and to deliver to the
Representative an earnings statement of the Company and its subsidiaries (which
need not be audited) complying with Section 11(a) of the Securities Act and the
Rules and Regulations (including, at the option of the Company, Rule 158);

               (g) For a period of five years following the Effective Date, to
furnish to the Representative copies of all materials furnished by the Company
to its shareholders and all public reports and all reports and financial
statements furnished by the Company to the principal national securities
exchange upon which the Common Stock may be listed pursuant to requirements of
or agreements with such exchange or to the Commission pursuant to the Exchange
Act or any rule or regulation of the Commission thereunder;

               (h) Promptly from time to time to take such action as the
Representative may reasonably request to qualify the Stock for offering and sale
under the securities laws of such jurisdictions as the Representative may
request and to comply with such laws so as to permit the continuance of sales
and dealings therein in such jurisdictions for as long as may be necessary to
complete the distribution of the Stock; provided that in connection therewith
the Company shall not be required to qualify as a foreign corporation or to file
a general consent to service of process in any jurisdiction;

               (i) For a period of 90 days from the date of the Prospectus, not
to, directly or indirectly, (1) offer for sale, sell, pledge or otherwise
dispose of (or enter into any transaction or device which is designed to, or
could be expected to, result in the disposition by any person at any time in the
future of) any shares of Common Stock or securities convertible into or
exchangeable for Common Stock (other than the Stock and shares issued pursuant
to employee benefit plans, qualified stock option plans or other employee
compensation plans existing on the date hereof or pursuant to currently
outstanding options, warrants or rights), or sell or grant options, rights or
warrants with respect to any shares of Common Stock or securities convertible
into or exchangeable for Common Stock (other than the grant of options pursuant
to option plans existing on the date hereof), or (2) enter into any swap or
other derivatives transaction that transfers to another, in whole or in part,
any of the economic benefits or risks of ownership of such shares of Common
Stock, whether any such transaction described in clause (1) or (2) above is to
be settled by delivery of Common Stock or other securities, in cash or
otherwise, in each case without the prior written consent of Lehman Brothers
Inc. on behalf of the Underwriters;

               (j) Prior to the Effective Date, to apply for the listing of the
Stock on the Nasdaq National Market System and to use its best efforts to
complete that listing, subject only to official notice of issuance and evidence
of satisfactory distribution, prior to the First Delivery Date;


                                       12


<PAGE>   13
               (k) To apply the net proceeds from the sale of the Stock being
sold by the Company as set forth in the Prospectus; and

               (l) To take such steps as shall be necessary to ensure that
neither the Company nor any subsidiary shall become an "investment company"
within the meaning of such term under the Investment Company Act of 1940 and the
rules and regulations of the Commission thereunder.

               7. Further Agreements of the Selling Stockholder. The Selling
Stockholder agrees:

               (a) For a period of 90 days from the date of the Prospectus, not
to, directly or indirectly, (1) offer for sale, sell, pledge or otherwise
dispose of (or enter into any transaction or device which is designed to, or
could be expected to, result in the disposition by any person at any time in the
future of) any shares of Common Stock or securities convertible into or
exchangeable for Common Stock (other than the Stock) or (2) enter into any swap
or other derivatives transaction that transfers to another, in whole or in part,
any of the economic benefits or risks of ownership of such shares of Common
Stock, whether any such transaction described in clause (1) or (2) above is to
be settled by delivery of Common Stock or other securities, in cash or
otherwise, in each case without the prior written consent of Lehman Brothers
Inc.

               (b) That the Stock to be sold by the Selling Stockholder
hereunder, which is represented by the certificates held in custody for the
Selling Stockholder, is subject to the interest of the Underwriters, that the
arrangements made by the Selling Stockholder for such custody are to that extent
irrevocable, and that the obligations of the Selling Stockholder hereunder shall
not be terminated by any act of the Selling Stockholder, by operation of law, by
the death or incapacity of the individual Selling Stockholder or, in the case of
a trust, by the death or incapacity of any executor or trustee or the
termination of such trust, or the occurrence of any other event.

               (c) To deliver to the Representative prior to the First Delivery
Date a properly completed and executed United States Treasury Department Form
W-8 (if the Selling Stockholder is a non-United States person) or Form W-9 (if
the Selling Stockholder is a United States person).

               8. Expenses. The Company agrees to pay (a) the costs incident to
the authorization, issuance, sale and delivery of the Stock and any taxes
payable in that connection; (b) the costs incident to the preparation, printing
and filing under the Securities Act of the Registration Statement and any
amendments and exhibits thereto; (c) the costs of distributing the Registration
Statement as originally filed and each amendment thereto and any post-effective
amendments thereof (including, in each case, exhibits), any Preliminary
Prospectus, the Prospectus and any amendment or supplement to the Prospectus or
any document incorporated by reference therein, all as provided in this
Agreement; (d) the costs of producing and distributing this Agreement and any
other related documents in connection with the offering, purchase, sale and
delivery of the stock; (e) the costs of delivering and distributing the Custody
Agreement and the Power of Attorney; (f) the filing fees incident to securing
any required review by the National Association of Securities Dealers, Inc. of
the terms of sale of the Stock; (g) any applicable listing or other fees; (h)
the fees and expenses of qualifying the Stock under the securities laws of the
several jurisdictions as provided in Section 6(h) preparing, printing and
distributing a Blue Sky Memorandum (including related fees and expenses of
counsel to the Underwriters); and (i) all other costs and expenses incident to
the performance of the obligations of the Company and the Selling Stockholder
under this Agreement; provided that, except as provided in this Section 8 and in
Section 13, the Underwriters shall pay their own costs and expenses, including
the costs and


                                       13


<PAGE>   14
expenses of their counsel, any transfer taxes on the Stock which they may sell
and the expenses of advertising any offering of the Stock made by the
Underwriters, and the Selling Stockholder shall pay the fees and expenses of its
counsel, the Custodian (and any other attorney-in-fact), and any transfer taxes
payable in connection with its sale of Stock to the Underwriters.

               9. Conditions of Underwriters' Obligations. The respective
obligations of the Underwriters hereunder are subject to the accuracy, when made
and on each Delivery Date, of the representations and warranties of the Company
and the Selling Stockholder contained herein, to the performance by the Company
and the Selling Stockholder of their respective obligations hereunder, and to
each of the following additional terms and conditions:

               (a) The Prospectus shall have been timely filed with the
Commission in accordance with Section 6(a); no stop order suspending the
effectiveness of the Registration Statement or any part thereof shall have been
issued and no proceeding for that purpose shall have been initiated or
threatened by the Commission; and any request of the Commission for inclusion of
additional information in the Registration Statement or the Prospectus or
otherwise shall have been complied with.

               (b) No Underwriter shall have discovered and disclosed to the
Company on or prior to such Delivery Date that the Registration Statement or the
Prospectus or any amendment or supplement thereto contains an untrue statement
of a fact which, in the opinion of Clifford Chance Rogers & Wells LLP, counsel
for the Underwriters, is material or omits to state a fact which, in the opinion
of such counsel, is material and is required to be stated therein or is
necessary to make the statements therein not misleading.

               (c) All corporate proceedings and other legal matters incident to
the authorization, form and validity of this Agreement, the Custody Agreement,
the Power of Attorney, the Stock, the Registration Statement and the Prospectus,
and all other legal matters relating to this Agreement and the transactions
contemplated hereby shall be reasonably satisfactory in all material respects to
counsel for the Underwriters, and the Company and the Selling Stockholder shall
have furnished to such counsel all documents and information that they may
reasonably request to enable them to pass upon such matters.

               (d) Heller Ehrman McAuliffe & White shall have furnished to the
Representative its written opinion, as counsel to the Company, addressed to the
Underwriters and dated such Delivery Date, in form and substance reasonably
satisfactory to the Representative, to the effect that:

                      (i) The Company has been duly incorporated and is validly
existing as a corporation in good standing under the laws of its jurisdiction of
incorporation, is duly qualified to do business and is in good standing as a
foreign corporation in each jurisdiction in which its ownership or lease of
property or the conduct of its businesses requires such qualification and has
all power and authority necessary to own or hold its properties and conduct the
businesses in which it is engaged;

                      (ii) The Company has an authorized capitalization as set
forth in the Prospectus, and all of the issued shares of capital stock of the
Company (including the shares of Stock being delivered on such Delivery Date)
have been duly and validly authorized and issued, are fully paid and
non-assessable and conform to the description thereof contained in the
Prospectus; and all of the issued shares of capital stock of each of the
subsidiaries of the


                                       14


<PAGE>   15
Company owned by the Company are owned by the Company, free and clear of all
liens, encumbrances, equities or claims;

                      (iii) There are no preemptive or other rights to subscribe
for or to purchase, nor any restriction upon the voting or transfer of, any
shares of the Stock pursuant to the Company's charter or by-laws or any
agreement or other instrument known to such counsel;

                      (iv) The real property and buildings held under lease by
the Company are held by it under valid, subsisting and enforceable leases, with
such exceptions as are not material and do not interfere with the use made and
proposed to be made of such property and buildings by the Company;

                      (v) To the best of such counsel's knowledge, there are no
legal or governmental proceedings pending to which the Company is a party or of
which any property or assets of the Company is the subject which, if determined
adversely to the Company, might have a material adverse effect on the
consolidated financial position, stockholders' equity, results of operations,
business or prospects of the Company except as described in the Prospectus; and,
to the best of such counsel's knowledge, no such proceedings are threatened or
contemplated by governmental authorities or threatened by others;

                      (vi) The Registration Statement was declared effective
under the Securities Act as of the date and time specified in such opinion, the
Prospectus was filed with the Commission pursuant to the subparagraph of Rule
424(b) of the Rules and Regulations specified in such opinion on the date
specified therein and no stop order suspending the effectiveness of the
Registration Statement has been issued and, to the knowledge of such counsel, no
proceeding for that purpose is pending or threatened by the Commission;

                      (vii) The Registration Statement and the Prospectus and
any further amendments or supplements thereto made by the Company prior to such
Delivery Date (other than the financial statements and related schedules
therein, as to which such counsel need express no opinion) comply as to form in
all material respects with the requirements of the Securities Act and the Rules
and Regulations; the documents incorporated by reference in the Prospectus and
any further amendment or supplement to any such incorporated document made by
the Company prior to such Delivery Date (other than the financial statements and
related schedules therein, as to which such counsel need express no opinion),
when they became effective or were filed with the Commission, as the case may
be, complied as to form in all material respects with the requirements of the
Securities Act or the Exchange Act, as applicable, and the rules and regulations
of the Commission thereunder;

                      (viii) To the best of such counsel's knowledge, there are
no contracts or other documents which are required to be described in the
Prospectus or filed as exhibits to the Registration Statement by the Securities
Act or by the Rules and Regulations which have not been described or filed as
exhibits to the Registration Statement or incorporated therein by reference as
permitted by the Rules and Regulations;

                      (ix) This Agreement has been duly authorized, executed and
delivered by the Company; and each of the other documents relating to this
Agreement to which the Company is a party has been duly authorized, executed and
delivered by the Company;


                                       15


<PAGE>   16
                      (x) The issue and sale of the shares of Stock being
delivered on such Delivery Date by the Company and the compliance by the Company
with all of the provisions of this Agreement and each of the other documents to
be entered into in connection with the consummation of the transactions
contemplated hereby and in the Registration Statement and the Prospectus
(including the issuance and sale of the Stock and the use of proceeds from the
sale of the Stock as described under the caption "Use of Proceeds") will not
conflict with or result in a breach or violation of any of the terms or
provisions of, or constitute a default under, any indenture, mortgage, deed of
trust, loan agreement or other agreement, license or instrument known to such
counsel to which the Company or any of its subsidiaries is a party or by which
the Company or any of its subsidiaries is bound or to which any of the property
or assets of the Company or any of its subsidiaries is subject, nor will such
actions result in any violation of the provisions of the charter or by-laws or
similar governing document of the Company or any of its subsidiaries or any
statute or any order, rule or regulation (including the United States Food and
Drug Administration and any similar foreign governing body) known to such
counsel of any court or governmental agency or body having jurisdiction over the
Company or any of it subsidiaries or any of their properties or assets; and,
except for the registration of the Stock under the Securities Act and such
consents, approvals, authorizations, registrations or qualifications as may be
required under the Exchange Act and applicable state or foreign securities laws
in connection with the purchase and distribution of the Stock by the
Underwriters, no consent, approval, authorization or order of, or filing or
registration with, any such court or governmental agency or body is required for
the execution, delivery and performance of this Agreement by the Company and the
consummation of the transactions contemplated hereby;

                      (xi) To the best of such counsel's knowledge, there are no
contracts, agreements or understandings between the Company and any person
granting such person the right (other than rights which have been waived or
satisfied) to require the Company to file a registration statement under the
Securities Act with respect to any securities of the Company owned or to be
owned by such person or to require the Company to include such securities in the
securities registered pursuant to the Registration Statement or in any
securities being registered pursuant to any other registration statement filed
by the Company under the Securities Act;

                      (xii) Neither the Company nor any subsidiary is an
"investment company" as defined in the Investment Company Act of 1940, as
amended; and

                      (xiii) Each of the Power-of-Attorney and Custody Agreement
constitutes a valid and binding agreement of the Selling Stockholder enforceable
in accordance with its terms.

               In rendering such opinion, such counsel may state that its
opinion is limited to matters governed by the Federal laws of the United States
of America, the laws of the State of California and the General Corporation Law
of the State of California. Such counsel shall also have furnished to the
Representative a written statement, addressed to the Underwriters and dated such
Delivery Date, in form and substance satisfactory to the Representative, to the
effect that (x) such counsel has acted as counsel to the Company on a regular
basis and has acted as counsel to the Company in connection with the preparation
of the Registration Statement, and (y) based on the foregoing, no facts have
come to the attention of such counsel which lead it to believe that (I) the
Registration Statement, as of the Effective Date, contained any untrue statement
of a material fact or omitted to state a material fact required to be stated
therein or necessary in order to make the statements therein not misleading, or
that the Prospectus contains any untrue statement of a material fact or omits to
state a material fact required to be stated therein or necessary in order to
make the statements therein, in light of the circumstances under which they were
made, not misleading or (II) any document incorporated by reference in the
Prospectus or


                                       16


<PAGE>   17
any further amendment or supplement to any such incorporated document made by
the Company prior to such Delivery Date, when they became effective or were
filed with the Commission, as the case may be, contained, in the case of a
registration statement which became effective under the Securities Act, any
untrue statement of a material fact or omitted to state a material fact required
to be stated therein or necessary in order to make the statements therein not
misleading, or, in the case of other documents which were filed under the
Exchange Act with the Commission, an untrue statement of a material fact or
omitted to state a material fact necessary in order to make the statements
therein, in light of the circumstances under which they were made, not
misleading.

               (e) Fish & Richardson P.C. shall have furnished to the
Representative its written opinion, as patent counsel to the Company, addressed
to the Underwriters and dated such Delivery Date, in form and substance
reasonably satisfactory to the Representative, to the effect that it serves as
special patent counsel to the Company with respect to the Proprietary Rights,
and that:

                      (i) The information in the Prospectus contained under the
headings "Risk Factors--Our inability to protect our proprietary technologies
could harm our competitive position," "Business--General," "Business--Thoratec
Circulatory Support Products," "Business--Advantages of the Thoratec VAD
System--Thoratec Biomaterials," "Business--Thoratec Biomaterials--Thoralon,"
"Business--Thoratec Vascular Graft Products," "Business--Patents and Proprietary
Rights" and "Business--Competition," to the extent that it constitutes
description of legal matters or summaries of legal matters, documents or
proceedings, has been reviewed by such counsel and is correct in all material
respects and it fairly and correctly presents the information presented therein;

                      (ii) To such counsel's knowledge, there are no pending
legal or governmental proceedings, or allegations on the part of any person of
infringement by the Company of patents, trade secrets, trademarks, service
marks, or copyrights of others, nor to such counsel's knowledge, has the Company
been advised that such proceedings are threatened or contemplated. To such
counsel's knowledge, the Company is not infringing any patents, trademarks,
service marks, copyrights or violating any trade secrets of others. Such counsel
has conducted an infringement search of the United States Patent and Trademark
Office (the "PTO") patent records in the subject matter areas of biomaterials
and arterial grafts, and has reviewed the patents uncovered in the search. Such
counsel has not reviewed the prosecution files and makes no opinion as to such
files. To such counsel's knowledge, no person is infringing or otherwise
violating any of the Company's patents, trade secrets, trademarks, service
marks, copyrights or other proprietary information or know-how of the Company in
any way which could materially affect the use thereof by the Company;

                      (iii) To such counsel's knowledge, the Company owns or
possesses sufficient licenses or other rights to use all patents, trade secrets,
trademarks, service marks or other proprietary information or know-how described
in the above-identified headings of the Prospectus necessary to conduct the
business now being or proposed to be conducted by the Company as described in
the Prospectus;

                      (iv) With respect to the United States patents and patent
applications relating to biomaterials, ventricular assist devices and grafts
identified in the above-identified headings in the Prospectus, the Company is
listed in the records of the PTO as the sole assignee of record in each of the
relevant patents and applications listed in Schedule I attached to its opinion,
except that U.S. Patent No. 5,443,504 is assigned to Donald Hill. Additionally,
U.S. Patent Nos. 5,235,003 and 4,731,073 are solely assigned to the Company by
virtue of assignments recorded in their


                                       17


<PAGE>   18
respective parent applications, therefore there are no assignments in the PTO
recorded on these patents. To such counsel's knowledge, there are no asserted
claims of any person relating to the scope of or to the ownership of the patents
or applications, nor to such counsel's knowledge has any unasserted claim
relating to such scope or ownership been communicated to the Company. To such
counsel's knowledge, there are no outstanding liens which have been filed in the
PTO against the patents or applications in Schedule I, except as listed. There
are no material defects of form in the preparation or filing of the applications
which such counsel has reviewed. A list of the applications which such counsel
has reviewed is attached to its opinion as Schedule II. These applications are
being diligently prosecuted and no application has been finally rejected. None
of these applications is abandoned;

                      (v) To such counsel's knowledge, according to its files of
the foreign patents listed in Schedule I, the Company is listed as the sole
assignee of record;

                      (vi) To such counsel's knowledge, there are no asserted
claims of any persons relating to the scope or ownership of the foreign patents
in Schedule I nor, to such counsel's knowledge, has any unasserted claim
relating to such scope or ownership been communicated to the Company. To such
counsel's knowledge, there are no material defects of form in the preparation or
filing of the foreign applications. The foreign applications have completed
prosecution, and issued as patents indicated in Schedule I;

                      (vii) The Company is the exclusive licensee in fields of
use respectively specified in the license with Goldschmidt AG dated March 29,
1989, of the United States patent and foreign patent and patent applications in
Schedule III attached to its opinion. With the Underwriters' permission, such
counsel assumes the validity of the signatures and proper authorization of the
signatures to such licenses. To such counsel's knowledge, such licenses are duly
executed, validly binding and enforceable in accordance with their terms and the
Company is not in default of any material provision of such license. To such
counsel's knowledge, there are no asserted claims of any persons relating to the
scope or ownership of the foreign patents or foreign applications in Schedule
III;

                      (viii) To such counsel's knowledge, and upon inquiry of
the Company, all relevant prior art references known to the Company or its
counsel in the prosecution of the U.S. patents and applications in Schedules I
and II as "prosecuted by us" were disclosed to the PTO and to such counsel's
knowledge and upon inquiry of the Company, neither such counsel nor the Company
made any misrepresentation to or concealed any material fact from the PTO during
such prosecution;

                      (ix) Upon inquiry of the Company, the Company takes
security measures adequate to assert trade secret protection in its non-patented
technology. Upon inquiry of the Company, the agreements executed by the
Company's employees, consultants and other advisors respecting trade secrets,
confidentiality, or intellectual property rights appear to be valid, binding and
enforceable in accordance with their terms; and

                      (x) Such counsel is not aware of any other matter that
leads it to believe that, with respect to licenses, patents, trade secrets,
copyrights or other proprietary information or know-how owned or used by the
Company which are the subject of the foregoing opinion, the registration
statement, at the time it became effective, contained an untrue statement of
material fact or omitted to state a material fact required to be stated therein
or necessary to make the statements therein not misleading or that the
Prospectus, included or includes an untrue statement of a material fact or
omitted or omits to state a material fact necessary in order to make the
statements therein, in the light of circumstances under which they were made,
not misleading.


                                       18


<PAGE>   19
               (f) Hyman, Phelps & McNamara, P.C. shall have furnished to the
Representative its written opinion, as regulatory counsel to the Company,
addressed to the Underwriters and dated such Delivery Date, in form and
substance reasonably satisfactory to the Representative, to the effect that it
serves as special patent counsel to the Company with respect to the Proprietary
Rights, and that:

                      (i) The information in the Prospectus under the headings
"Risk Factors--We have a history of net losses, and we may not achieve or
maintain profitability," "Risk Factors--Physicians may not accept or continue to
accept our products under development," "Risk Factors--We rely on single source
suppliers. Our business will be harmed if our suppliers interrupt the sale of
materials to us," "Risk factors--If we fail to obtain approval from the FDA and
from foreign regulatory authorities, we cannot market and sell our products
under development in the United States and in other countries,"
"Business--Strategy--Obtain U.S. Approval and Support European and U.S. Market
Launch of Vectra VAG," "Business--Thoratec Circulatory Support Products,"
"Business--Thoratec Vascular Graft Products," "Business--Manufacturing."
"Business--Government Regulation" and "Business--Facilities," insofar as they
constitute summaries of Food and Drug Administration regulatory provisions in
general, have been reviewed by such counsel and are correct in all material
respects and fairly and correctly present the material information called for
with respect thereto; and

                      (ii) Such counsel has reviewed the Registration Statement,
and nothing has come to its attention that leads it to believe that, with
respect to matters pending before the FDA, the Registration Statement, at the
time it became effective, contained an untrue statement of a material fact or
omitted to state a material fact required to be stated therein or necessary to
make the statements therein not misleading or that the Prospectus, as of its
date (unless the term "Prospectus" refers to a prospectus which has been
provided to the Underwriters by the Company for use in connection with the
offering which differs from the Prospectus on file at the Commission at the time
the Registration Statement becomes effective, in which case at the time it is
first provided to the Underwriters for such use) or at the First Delivery Date
or the Second Delivery Date, as the case may be, included or includes an untrue
statement of a material fact or omitted or omits to state a material fact
relating to matters pending before the FDA necessary in order to make the
statements therein, in the light of the circumstances under which they were
made, not misleading.

               (g) [Clifford, Chance Limited Liability Partnership], shall have
furnished to the Representative its written opinion, as special U.K. counsel to
the Company, addressed to the Underwriters and dated such Delivery Date, in form
and substance reasonably satisfactory to the representative to the effect that:

                      (i) Thoratec Europe Limited has been duly incorporated and
is validly existing as a corporation in good standing under the laws of the
jurisdiction of its incorporation;

                      (ii) All of the issued shares of capital stock of Thoratec
Europe Limited have been duly and validly authorized and issued and are fully
paid, non-assessable and are owned by the Company, free and clear of all liens,
encumbrances, equities or claims and none of such shares of capital stock was
issued in violation of preemptive or other similar rights arising by operation
of law or under the charter and by-laws or similar governing document of the
Thoratec Europe Limited;

                      (iii) The issue and sale of the shares of Stock being
delivered on such Delivery Date by the Company and the compliance by the Company
with all of the provisions of this Agreement and each of the other documents to
be entered into in connection with the


                                       19


<PAGE>   20
consummation of the transactions contemplated hereby and in the Registration
Statement and the Prospectus (including the issuance and sale of the Stock and
the use of proceeds from the sale of the Stock as described under the caption
"Use of Proceeds"), will result in any violation of the provisions of the
charter or by-laws or similar governing document of Thoratec Europe Limited or
any statute or any order, rule or regulation known to such counsel of any court
or governmental agency or body having jurisdiction over Thoratec Europe Limited
or any of its properties or assets; and

                      (iv) No governmental consents, approval, authorizations,
registrations, declarations or filings are required by the Company or Thoratec
Europe Limited for the execution and delivery of this Agreement by the Company
and consummation of the transactions contemplated herein.

               (h) Counsel for the Selling Stockholder shall have furnished to
the Representative its written opinion, as counsel to the Selling Stockholder
for whom it is acting as counsel, addressed to the Underwriters and dated such
Delivery Date, in form and substance reasonably satisfactory to the
Representative, to the effect that:

                      (i) The Selling Stockholder has full right, power and
authority to enter into this Agreement, the Power of Attorney and the Custody
Agreement; the execution, delivery and performance of this Agreement, the Power
of Attorney and the Custody Agreement by the Selling Stockholder and the
consummation by the Selling Stockholder of the transactions contemplated hereby
and thereby will not conflict with or result in a breach or violation of any of
the terms or provisions of, or constitute a default under, any statute, any
indenture, mortgage, deed of trust, loan agreement or other agreement or
instrument known to such counsel to which the Selling Stockholder is a party or
by which the Selling Stockholder is bound or to which any of the property or
assets of the Selling Stockholder is subject, nor will such actions result in
any violation of the provisions of the charter or by-laws or similar governing
document of the Selling Stockholder or any statute or any order, rule or
regulation known to such counsel of any court or governmental agency or body
having jurisdiction over the Selling Stockholder or the property or assets of
the Selling Stockholder; and, except for the registration of the Stock under the
Securities Act and such consents, approvals, authorizations, registrations or
qualifications as may be required under the Exchange Act and applicable state or
foreign securities laws in connection with the purchase and distribution of the
Stock by the Underwriters, no consent, approval, authorization or order of, or
filing or registration with, any such court or governmental agency or body is
required for the execution, delivery and performance of this Agreement, the
Power of Attorney or the Custody Agreement by the Selling Stockholder and the
consummation by the Selling Stockholder of the transactions contemplated hereby
and thereby;

                      (ii) This Agreement has been duly authorized, executed and
delivered by or on behalf of the Selling Stockholder;

                      (iii) A Power-of-Attorney and a Custody Agreement have
been duly authorized, executed and delivered by the Selling Stockholder;

                      (iv) Immediately prior to such Delivery Date, the Selling
Stockholder had good and valid title to the shares of Stock to be sold by the
Selling Stockholder under this Agreement, free and clear of all liens,
encumbrances, equities or claims, and full right, power and authority to sell,
assign, transfer and deliver such shares to be sold by such Selling Stockholder
hereunder; and


                                       20


<PAGE>   21
                      (v) Good and valid title to the shares of Stock to be sold
by the Selling Stockholder under this Agreement, free and clear of all liens,
encumbrances, equities or claims, has been transferred to each of the several
Underwriters.

               In rendering such opinion, such counsel may (i) state that its
opinion is limited to matters governed by the Federal laws of the United States
of America, the laws of the State of Colorado and the General Corporation Law of
the State of Delaware and (ii) in rendering the opinion in Section 9(e)(iv)
above, rely upon a certificate of the Selling Stockholder in respect of matters
of fact as to ownership of and liens, encumbrances, equities or claims on the
shares of Stock sold by the Selling Stockholder, provided that such counsel
shall furnish copies thereof to the Representative and state that it believes
that both the Underwriters and it are justified in relying upon such
certificate. Such counsel shall also have furnished to the Representative a
written statement, addressed to the Underwriters and dated such Delivery Date,
in form and substance satisfactory to the Representative, to the effect that (x)
such counsel has acted as counsel to the Selling Stockholder on a regular basis
and has acted as counsel to the Selling Stockholder in connection with the
preparation of the Registration Statement, and (y) based on the foregoing, no
facts have come to the attention of such counsel that lead it to believe that
the Registration Statement, as of the Effective Date, contained any untrue
statement of a material fact relating to the Selling Stockholder or omitted to
state such a material fact required to be stated therein or necessary in order
to make the statements therein not misleading, or that the Prospectus contains
any untrue statement of a material fact relating to the Selling Stockholder or
omits to state such a material fact required to be stated therein or necessary
in order to make the statements therein, in light of the circumstances under
which they were made, not misleading. The foregoing opinion and statement may be
qualified by a statement to the effect that such counsel does not assume any
responsibility for the accuracy, completeness or fairness of the statements
contained in the Registration Statement or the Prospectus.

               (i) Clifford Chance Rogers & Wells LLP shall have furnished to
the Representative its written opinion, as counsel for the Underwriters,
addressed to the Underwriters and dated such Delivery Date, with respect to the
issuance and sale of the Stock, the Registration Statement, the Prospectus and
other related matters as the Representative may reasonably require, and the
Company shall have furnished to such counsel such documents as they reasonably
request for the purpose of enabling them to pass upon such matters.

               (j) At the time of execution of this Agreement, the
Representative shall have received from Deloitte & Touche LLP a letter, in form
and substance satisfactory to the Representatives, addressed to the Underwriters
and dated the date hereof (i) confirming that they are independent public
accountants within the meaning of the Securities Act and are in compliance with
the applicable requirements relating to the qualification of accountants under
Rule 2-01 of Regulation S-X of the Commission, (ii) stating, as of the date
hereof (or, with respect to matters involving changes or developments since the
respective dates as of which specified financial information is given in the
Prospectus, as of a date not more than five days prior to the date hereof), the
conclusions and findings of such firm with respect to the financial information
and other matters ordinarily covered by accountants' "comfort letters" to
underwriters in connection with registered public offerings.

               (k) With respect to the letter of Deloitte & Touche LLP referred
to in the preceding paragraph and delivered to the Representative concurrently
with the execution of this Agreement (the "initial letter"), the Company shall
have furnished to the Representative a letter (the "bring-down letter") of such
accountants, addressed to the Underwriters and dated such Delivery Date (i)
confirming that they are independent public accountants within the meaning of
the Securities Act and are in compliance with the applicable requirements
relating to the


                                       21


<PAGE>   22
qualification of accountants under Rule 2-01 of Regulation S-X of the
Commission, (ii) stating, as of the date of the bring-down letter (or, with
respect to matters involving changes or developments since the respective dates
as of which specified financial information is given in the Prospectus, as of a
date not more than five days prior to the date of the bring-down letter), the
conclusions and findings of such firm with respect to the financial information
and other matters covered by the initial letter and (iii) confirming in all
material respects the conclusions and findings set forth in the initial letter.

               (l) The Company shall have furnished to the Representative a
certificate, dated such Delivery Date, of its Chairman of the Board, its
President or a Vice President and its chief financial officer stating that:

                      (i) The representations, warranties and agreements of the
Company in Section 1 are true and correct as of such Delivery Date; the Company
has complied with all its agreements contained herein; and the conditions set
forth in Sections 9(a) or 9(o) have been fulfilled; and

                      (ii) They have carefully examined the Registration
Statement and the Prospectus and, in their opinion (A) as of the Effective Date,
the Registration Statement and the Prospectus did not include any untrue
statement of a material fact and did not omit to state a material fact required
to be stated therein or necessary to make the statements therein not misleading,
and (B) since the Effective Date no event has occurred which should have been
set forth in a supplement or amendment to the Registration Statement or the
Prospectus.

               (m) The Selling Stockholder (or the Custodian or one or more
attorneys-in-fact on behalf of the Selling Stockholder) shall have furnished to
the Representative on such Delivery Date a certificate, dated such Delivery
Date, signed by, or on behalf of, the Selling Stockholder (or the Custodian or
one or more attorneys-in-fact) stating that the representations, warranties and
agreements of the Selling Stockholder contained herein are true and correct as
of the First Delivery Date and that the Selling Stockholder has complied with
all agreements contained herein to be performed by the Selling Stockholder at or
prior to the such Delivery Date.

               (n) (i) Neither the Company nor any of its subsidiaries shall
have sustained since the date of the latest audited financial statements
included or incorporated by reference in the Prospectus any loss or interference
with its business from fire, explosion, flood or other calamity, whether or not
covered by insurance, or from any labor dispute or court or governmental action,
order or decree, otherwise than as set forth or contemplated in the Prospectus
or (ii) since such date there shall not have been any change in the capital
stock or long-term debt of the Company or any of its subsidiaries or any change,
or any development involving a prospective change, in or affecting the general
affairs, management, financial position, stockholders' equity or results of
operations of the Company and its subsidiaries, otherwise than as set forth or
contemplated in the Prospectus, the effect of which, in any such case described
in clause (i) or (ii), is, in the judgment of the Representative, so material
and adverse as to make it impracticable or inadvisable to proceed with the
public offering or the delivery of the Stock being delivered on such Delivery
Date on the terms and in the manner contemplated in the Prospectus.

               (o) Subsequent to the execution and delivery of this Agreement
there shall not have occurred any of the following: (i) trading in securities
generally on the New York Stock Exchange, the American Stock Exchange, the
Nasdaq National Market or in the over-the-counter market, or trading in any
securities of the Company on any exchange or in the over-the-counter market,
shall have been suspended or minimum prices shall have been established on any
such exchange or such market by the Commission, by such exchange or by any other
regulatory body


                                       22


<PAGE>   23
or governmental authority having jurisdiction, (ii) a banking moratorium shall
have been declared by Federal or state authorities, (iii) the United States
shall have become engaged in hostilities, there shall have been an escalation in
hostilities involving the United States or there shall have been a declaration
of a national emergency or war by the United States or (iv) there shall have
occurred such a material adverse change in general economic, political or
financial conditions (or the effect of international conditions on the financial
markets in the United States shall be such) as to make it, in the judgment of a
majority in interest of the several Underwriters, impracticable or inadvisable
to proceed with the public offering or delivery of the Stock being delivered on
such Delivery Date on the terms and in the manner contemplated in the
Prospectus.

               (p) The Nasdaq National Market shall have approved the Stock for
listing, subject only to official notice of issuance and evidence of
satisfactory distribution.

               All opinions, letters, evidence and certificates mentioned above
or elsewhere in this Agreement shall be deemed to be in compliance with the
provisions hereof only if they are in form and substance reasonably satisfactory
to counsel for the Underwriters.

               10. Indemnification and Contribution.

               (a) The Company shall indemnify and hold harmless each
Underwriter, its officers and employees and each person, if any, who controls
any Underwriter within the meaning of the Securities Act, from and against any
loss, claim, damage or liability, joint or several, or any action in respect
thereof (including, but not limited to, any loss, claim, damage, liability or
action relating to purchases and sales of Stock), to which that Underwriter,
officer, employee or controlling person may become subject, under the Securities
Act or otherwise, insofar as such loss, claim, damage, liability or action
arises out of, or is based upon, (i) any untrue statement or alleged untrue
statement of a material fact contained in (A) any Preliminary Prospectus, the
Registration Statement or the Prospectus or in any amendment or supplement
thereto, or (B) in any materials or information provided to investors by, or
with the approval of, the Company in connection with the marketing of the
offering of the Stock ("Marketing Materials"), including any roadshow or
investor presentations made to investors by the Company (whether in person or
electronically), (ii) the omission or alleged omission to state in any
Preliminary Prospectus, the Registration Statement or the Prospectus, or in any
amendment or supplement thereto, or in any Marketing Materials, any material
fact required to be stated therein or necessary to make the statements therein
not misleading or (iii) any act or failure to act or any alleged act or failure
to act by any Underwriter in connection with, or relating in any manner to, the
Stock or the offering contemplated hereby, and which is included as part of or
referred to in any loss, claim, damage, liability or action arising out of or
based upon matters covered by clause (i) or (ii) above (provided that the
Company shall not be liable under this clause (iii) to the extent that it is
determined in a final judgment by a court of competent jurisdiction that such
loss, claim, damage, liability or action resulted directly from any such acts or
failures to act undertaken or omitted to be taken by such Underwriter through
its gross negligence or willful misconduct), and shall reimburse each
Underwriter and each such officer, employee or controlling person promptly upon
demand for any legal or other expenses reasonably incurred by that Underwriter,
officer, employee or controlling person in connection with investigating or
defending or preparing to defend against any such loss, claim, damage, liability
or action as such expenses are incurred; provided, however, that the Company
shall not be liable in any such case to the extent that any such loss, claim,
damage, liability or action arises out of, or is based upon, any untrue
statement or alleged untrue statement or omission or alleged omission made in
any Preliminary Prospectus, the Registration Statement or the Prospectus, or in
any such amendment or supplement, in reliance upon and in conformity with
written information concerning such Underwriter furnished to the Company through
the Representative by or on behalf of any Underwriter specifically for


                                       23


<PAGE>   24
inclusion therein which information consists solely of the information specified
in Section 10(f). The foregoing indemnity agreement is in addition to any
liability which the Company may otherwise have to any Underwriter or to any
officer, employee or controlling person of that Underwriter.

               (b) [The Selling Stockholder shall indemnify and hold harmless
each Underwriter, its officers and employees, and each person, if any, who
controls any Underwriter within the meaning of the Securities Act, from and
against any loss, claim, damage or liability, joint or several, or any action in
respect thereof (including, but not limited to, any loss, claim, damage,
liability or action relating to purchases and sales of Stock), to which that
Underwriter, officer, employee or controlling person may become subject, under
the Securities Act or otherwise, insofar as such loss, claim, damage, liability
or action arises out of, or is based upon, (i) any untrue statement or alleged
untrue statement of a material fact contained in any Preliminary Prospectus, the
Registration Statement or the Prospectus or in any amendment or supplement
thereto, but only to the extent that the untrue statement or alleged untrue
statement was made in reliance upon and in conformity with information furnished
to the Company by the Selling Stockholder, (ii) the omission or alleged omission
to state in any Preliminary Prospectus, Registration Statement or the
Prospectus, or in any amendment or supplement thereto, any material fact
required to be stated therein or necessary to make the statements therein not
misleading, but only to the extent that the omission or alleged omission was
made in reliance upon and in conformity with information furnished to the
Company by the Selling Stockholder or (iii) any act or failure to act or any
alleged act or failure to act by any Underwriter in connection with, or relating
in any manner to, the Stock, or the Offering contemplated hereby, and which is
included as part of or referred to in any loss, claim, damage, liability or
action arising out or based upon matters covered by clause (i) or (ii) above
(provided that the Selling Stockholder shall not be liable under this clause
(iii) to the extent that it is determined in a final judgment by a court of
competent jurisdiction that such loss, claim, damage, liability or action
resulted directly from any such acts or failures to act undertaken or omitted to
be taken by such Underwriter through its gross negligence or willful
misconduct), and shall reimburse each Underwriter, its officers and employees
and each such controlling person for any legal or other expenses reasonably
incurred by that Underwriter, its officers and employees or controlling person
in connection with investigating or defending or preparing to defend against any
such loss, claim, damage, liability or action as such expenses are incurred;
provided, however, that the Selling Stockholder shall not be liable in any such
case to the extent that any such loss, claim, damage, liability or action arises
out of, or is based upon, any untrue statement or alleged untrue statement or
omission or alleged omission made in any Preliminary Prospectus, the
Registration Statement or the Prospectus or in any such amendment or supplement
in reliance upon and in conformity with written information concerning such
Underwriter furnished to the Company through the Representative by or on behalf
of any Underwriter specifically for inclusion therein which information consists
solely of the information specified in Section 10(f). The foregoing indemnity
agreement is in addition to any liability which the Selling Stockholder may
otherwise have to any Underwriter or any officer, employee or controlling person
of that Underwriter.]

               (c) Each Underwriter, severally and not jointly, shall indemnify
and hold harmless the Company, its officers and employees, each of its directors
and each person, if any, who controls the Company within the meaning of the
Securities Act, from and against any loss, claim, damage or liability, joint or
several, or any action in respect thereof, to which the Company or any such
director, officer or controlling person may become subject, under the Securities
Act or otherwise, insofar as such loss, claim, damage, liability or action
arises out of, or is based upon, (i) any untrue statement or alleged untrue
statement of a material fact contained in any Preliminary Prospectus, the
Registration Statement or the Prospectus or in any amendment or


                                       24


<PAGE>   25
supplement thereto, or (ii) the omission or alleged omission to state in any
Preliminary Prospectus, the Registration Statement or the Prospectus, or in any
amendment or supplement thereto, any material fact required to be stated therein
or necessary to make the statements therein not misleading, but in each case
only to the extent that the untrue statement or alleged untrue statement or
omission or alleged omission was made in reliance upon and in conformity with
written information concerning such Underwriter furnished to the Company through
the Representative by or on behalf of that Underwriter specifically for
inclusion therein, and shall reimburse the Company and any such director,
officer or controlling person for any legal or other expenses reasonably
incurred by the Company or any such director, officer or controlling person in
connection with investigating or defending or preparing to defend against any
such loss, claim, damage, liability or action as such expenses are incurred. The
foregoing indemnity agreement is in addition to any liability which any
Underwriter may otherwise have to the Company or any such director, officer,
employee or controlling person.

               (d) Promptly after receipt by an indemnified party under this
Section 10 of notice of any claim or the commencement of any action, the
indemnified party shall, if a claim in respect thereof is to be made against the
indemnifying party under this Section 10, notify the indemnifying party in
writing of the claim or the commencement of that action; provided, however, that
the failure to notify the indemnifying party shall not relieve it from any
liability which it may have under this Section 10 except to the extent it has
been materially prejudiced by such failure and, provided further, that the
failure to notify the indemnifying party shall not relieve it from any liability
which it may have to an indemnified party otherwise than under this Section 10.
If any such claim or action shall be brought against an indemnified party, and
it shall notify the indemnifying party thereof, the indemnifying party shall be
entitled to participate therein and, to the extent that it wishes, jointly with
any other similarly notified indemnifying party, to assume the defense thereof
with counsel reasonably satisfactory to the indemnified party. After notice from
the indemnifying party to the indemnified party of its election to assume the
defense of such claim or action, the indemnifying party shall not be liable to
the indemnified party under this Section 10 for any legal or other expenses
subsequently incurred by the indemnified party in connection with the defense
thereof other than reasonable costs of investigation; provided, however, that
the Representative shall have the right to employ counsel to represent jointly
the Representative and those other Underwriters and their respective officers,
employees and controlling persons who may be subject to liability arising out of
any claim in respect of which indemnity may be sought by the Underwriters
against the Company or the Selling Stockholder under this Section 10 if, in the
reasonable judgment of the Representative, it is advisable for the
Representative and those Underwriters, officers, employees and controlling
persons to be jointly represented by separate counsel, and in that event the
fees and expenses of such separate counsel shall be paid by the Company or the
Selling Stockholder. No indemnifying party shall (i) without the prior written
consent of the indemnified parties (which consent shall not be unreasonably
withheld), settle or compromise or consent to the entry of any judgment with
respect to any pending or threatened claim, action, suit or proceeding in
respect of which indemnification or contribution may be sought hereunder
(whether or not the indemnified parties are actual or potential parties to such
claim or action) unless such settlement, compromise or consent includes an
unconditional release of each indemnified party from all liability arising out
of such claim, action, suit or proceeding, or (ii) be liable for any settlement
of any such action effected without its written consent (which consent shall not
be unreasonably withheld), but if settled with the consent of the indemnifying
party or if there be a final judgment of the plaintiff in any such action, the
indemnifying party agrees to indemnify and hold harmless any indemnified party
from and against any loss or liability by reason of such settlement or judgment.


                                       25


<PAGE>   26
               (e) If the indemnification provided for in this Section 10 shall
for any reason be unavailable to or insufficient to hold harmless an indemnified
party under Section 10(a), 10(b) or 10(c) in respect of any loss, claim, damage
or liability, or any action in respect thereof, referred to therein, then each
indemnifying party shall, in lieu of indemnifying such indemnified party,
contribute to the amount paid or payable by such indemnified party as a result
of such loss, claim, damage or liability, or action in respect thereof, (i) in
such proportion as shall be appropriate to reflect the relative benefits
received by the Company and the Selling Stockholder on the one hand and the
Underwriters on the other from the offering of the Stock or (ii) if the
allocation provided by clause (i) above is not permitted by applicable law, in
such proportion as is appropriate to reflect not only the relative benefits
referred to in clause (i) above but also the relative fault of the Company and
the Selling Stockholder on the one hand and the Underwriters on the other with
respect to the statements or omissions which resulted in such loss, claim,
damage or liability, or action in respect thereof, as well as any other relevant
equitable considerations. The relative benefits received by the Company and the
Selling Stockholder on the one hand and the Underwriters on the other with
respect to such offering shall be deemed to be in the same proportion as the
total net proceeds from the offering of the Stock purchased under this Agreement
(before deducting expenses) received by the Company and the Selling Stockholder,
on the one hand, and the total underwriting discounts and commissions received
by the Underwriters with respect to the shares of the Stock purchased under this
Agreement, on the other hand, bear to the total gross proceeds from the offering
of the shares of the Stock under this Agreement, in each case as set forth in
the table on the cover page of the Prospectus. The relative fault shall be
determined by reference to whether the untrue or alleged untrue statement of a
material fact or omission or alleged omission to state a material fact relates
to information supplied by the Company, the Selling Stockholder or the
Underwriters, the intent of the parties and their relative knowledge, access to
information and opportunity to correct or prevent such statement or omission.
The Company, the Selling Stockholder and the Underwriters agree that it would
not be just and equitable if contributions pursuant to this Section 10(e) were
to be determined by pro rata allocation (even if the Underwriters were treated
as one entity for such purpose) or by any other method of allocation which does
not take into account the equitable considerations referred to herein. The
amount paid or payable by an indemnified party as a result of the loss, claim,
damage or liability, or action in respect thereof, referred to above in this
Section shall be deemed to include, for purposes of this Section 10(e), any
legal or other expenses reasonably incurred by such indemnified party in
connection with investigating or defending any such action or claim.
Notwithstanding the provisions of this Section 10(e), no Underwriter shall be
required to contribute any amount in excess of the amount by which the total
price at which the Stock underwritten by it and distributed to the public was
offered to the public exceeds the amount of any damages which such Underwriter
has otherwise paid or become liable to pay by reason of any untrue or alleged
untrue statement or omission or alleged omission. No person guilty of fraudulent
misrepresentation (within the meaning of Section 11(f) of the Securities Act)
shall be entitled to contribution from any person who was not guilty of such
fraudulent misrepresentation. The Underwriters' obligations to contribute as
provided in this Section 10(e) are several in proportion to their respective
underwriting obligations and not joint.

               (f) The Underwriters severally confirm and the Company
acknowledges that the statements with respect to the public offering of the
Stock by the Underwriters set forth on the cover page of, and the concession and
reallowance figures appearing under the caption "Underwriting" in, the
Prospectus are correct and constitute the only information concerning such
Underwriters furnished in writing to the Company by or on behalf of the
Underwriters specifically for inclusion in the Registration Statement and the
Prospectus.

               11. Defaulting Underwriters.


                                       26


<PAGE>   27
               If, on either Delivery Date, any Underwriter defaults in the
performance of its obligations under this Agreement, the remaining
non-defaulting Underwriters shall be obligated to purchase the Stock which the
defaulting Underwriter agreed but failed to purchase on such Delivery Date in
the respective proportions which the number of shares of the Firm Stock set
opposite the name of each remaining non-defaulting Underwriter in Schedule 1
hereto bears to the total number of shares of the Firm Stock set opposite the
names of all the remaining non-defaulting Underwriters in Schedule 1 hereto;
provided, however, that the remaining non-defaulting Underwriters shall not be
obligated to purchase any of the Stock on such Delivery Date if the total number
of shares of the Stock which the defaulting Underwriter or Underwriters agreed
but failed to purchase on such date exceeds 9.09% of the total number of shares
of the Stock to be purchased on such Delivery Date, and any remaining
non-defaulting Underwriter shall not be obligated to purchase more than 110% of
the number of shares of the Stock which it agreed to purchase on such Delivery
Date pursuant to the terms of Section 3. If the foregoing maximums are exceeded,
the remaining non-defaulting Underwriters, or those other underwriters
satisfactory to the Representative who so agree, shall have the right, but shall
not be obligated, to purchase, in such proportion as may be agreed upon among
them, all the Stock to be purchased on such Delivery Date. If the remaining
Underwriters or other underwriters satisfactory to the Representative do not
elect to purchase the shares which the defaulting Underwriter or Underwriters
agreed but failed to purchase on such Delivery Date, this Agreement (or, with
respect to the Second Delivery Date, the obligation of the Underwriters to
purchase, and of the Company to sell, the Option Stock) shall terminate without
liability on the part of any non-defaulting Underwriter or the Company or the
Selling Stockholder, except that the Company will continue to be liable for the
payment of expenses to the extent set forth in Section 8 and Section 13. As used
in this Agreement, the term "Underwriter" includes, for all purposes of this
Agreement unless the context requires otherwise, any party not listed in
Schedule 1 hereto who, pursuant to this Section 11, purchases Stock which a
defaulting Underwriter agreed but failed to purchase.

               Nothing contained herein shall relieve a defaulting Underwriter
of any liability it may have to the Company and the Selling Stockholder for
damages caused by its default. If other underwriters are obligated or agree to
purchase the Stock of a defaulting or withdrawing Underwriter, either the
Representative or the Company may postpone the Delivery Date for up to seven
full business days in order to effect any changes that in the opinion of counsel
for the Company or counsel for the Underwriters may be necessary in the
Registration Statement, the Prospectus or in any other document or arrangement.

               12. Termination. The obligations of the Underwriters hereunder
may be terminated by the Representative by notice given to and received by the
Company and the Selling Stockholder prior to delivery of and payment for the
Firm Stock if, prior to that time, any of the events described in Sections 9(m),
9(n) or 9(o), shall have occurred or if the Underwriters shall decline to
purchase the Stock for any reason permitted under this Agreement.

               13. Reimbursement of Underwriters' Expenses. If the Company or
the Selling Stockholder shall fail to tender the Stock for delivery to the
Underwriters by reason of any failure, refusal or inability on the part of the
Company or the Selling Stockholder to perform any agreement on its part to be
performed, or because any other condition of the Underwriters' obligations
hereunder required to be fulfilled by the Company or the Selling Stockholder is
not fulfilled, the Company and the Selling Stockholder will reimburse the
Underwriters for all reasonable out-of-pocket expenses (including fees and
disbursements of counsel) incurred by the Underwriters in connection with this
Agreement and the proposed purchase of the Stock, and upon demand the Company
and the Selling Stockholder shall pay the full amount thereof to the
Representative. If this Agreement is terminated pursuant to Section 12 by reason
of the default of


                                       27


<PAGE>   28
one or more Underwriters, neither the Company nor the Selling Stockholder shall
be obligated to reimburse any defaulting Underwriter on account of those
expenses.

               14. Notices, etc. All statements, requests, notices and
agreements hereunder shall be in writing, and:

               (a) if to the Underwriters, shall be delivered or sent by mail,
telex or facsimile transmission to Lehman Brothers Inc., Three World Financial
Center, New York, New York 10285, Attention: Syndicate Department (Fax:
212-526-6588), with a copy, in the case of any notice pursuant to Section 10(d),
to the Director of Litigation, Office of the General Counsel, Lehman Brothers
Inc., 3 World Financial Center, 10th Floor, New York, New York 10285;

               (b) if to the Company, shall be delivered or sent by mail, telex
or facsimile transmission to the address of the Company set forth in the
Registration Statement, Attention: D. Keith Grossman (Fax: 925-847-8574);

               (c) if to the Selling Stockholder, shall be delivered or sent by
mail, telex or facsimile transmission to the Selling Stockholder at Gambro,
Inc., 225 Union Boulevard, Suite 600, Lakewood, Colorado 80228, Attention: Kevin
M. Smith, President and Chief Financial Officer (Fax: 303-231-4915);

provided, however, that any notice to an Underwriter pursuant to Section 10(d)
shall be delivered or sent by mail, telex or facsimile transmission to such
Underwriter at its address set forth in its acceptance telex to the
Representative, which address will be supplied to any other party hereto by the
Representative upon request. Any such statements, requests, notices or
agreements shall take effect at the time of receipt thereof. The Company and the
Selling Stockholder shall be entitled to act and rely upon any request, consent,
notice or agreement given or made on behalf of the Underwriters by Lehman
Brothers Inc. and the Company and the Underwriters shall be entitled to act and
rely upon any request, consent, notice or agreement given or made on behalf of
the Selling Stockholder by the Custodian or the attorney-in-fact appointed
pursuant to the Power of Attorney.

               15. Persons Entitled to Benefit of Agreement. This Agreement
shall inure to the benefit of and be binding upon the Underwriters, the Company,
the Selling Stockholder and their respective successors. This Agreement and the
terms and provisions hereof are for the sole benefit of only those persons,
except that (A) the representations, warranties, indemnities and agreements of
the Company and the Selling Stockholder contained in this Agreement shall also
be deemed to be for the benefit of the person or persons, if any, who control
any Underwriter within the meaning of Section 15 of the Securities Act and (B)
the indemnity agreement of the Underwriters contained in Section 10(c) of this
Agreement shall be deemed to be for the benefit of directors of the Company,
officers of the Company who have signed the Registration Statement and any
person controlling the Company within the meaning of Section 15 of the
Securities Act. Nothing in this Agreement is intended or shall be construed to
give any person, other than the persons referred to in this Section 15, any
legal or equitable right, remedy or claim under or in respect of this Agreement
or any provision contained herein.

               16. Survival. The respective indemnities, representations,
warranties and agreements of the Company, the Selling Stockholder and the
Underwriters contained in this Agreement or made by or on behalf on them,
respectively, pursuant to this Agreement, shall survive the delivery of and
payment for the Stock and shall remain in full force and effect, regardless of
any investigation made by or on behalf of any of them or any person controlling
any of them.



                                       28
<PAGE>   29
               17. Definition of the Terms "Business Day" and "subsidiary." For
purposes of this Agreement, (a) "business day" each Monday, Tuesday, Wednesday,
Thursday or Friday which is not a day on which banking institutions in New York
are generally authorized or obligated by law or executive order to close and (b)
"subsidiary" has the meaning set forth in Rule 405 of the Rules and Regulations.

               18. Governing Law. This Agreement shall be governed by and
construed in accordance with the laws of New York.

               19. Consent to Jurisdiction. Each party irrevocably agrees that
any legal suit, action or proceeding arising out of or based upon this Agreement
or the transactions contemplated hereby ("Related Proceedings") may be
instituted in the federal courts of the United States of America located in the
City of New York or the courts of the State of New York in each case located in
the Borough of Manhattan in the City of New York (collectively, the "Specified
Courts"), and irrevocably submits to the exclusive jurisdiction (except for
proceedings instituted in regard to the enforcement of a judgment of any such
court (a "Related Judgment"), as to which such jurisdiction is non-exclusive) of
such courts in any such suit, action or proceeding. The parties further agree
that service of any process, summons, notice or document by mail to such party's
address set forth above shall be effective service of process for any lawsuit,
action or other proceeding brought in any such court. The parties hereby
irrevocably and unconditionally waive any objection to the laying of venue of
any lawsuit, action or other proceeding in the Specified Courts, and hereby
further irrevocably and unconditionally waive and agree not to plead or claim in
any such court that any such lawsuit, action or other proceeding brought in any
such court has been brought in an inconvenient forum. Each party not located in
the United States hereby irrevocably appoints CT Corporation System, which
currently maintains a New York City office at 111 Eighth Avenue, New York, New
York 10011, United States of America, as its agent to receive service of process
or other legal summons for purposes of any such action or proceeding that may be
instituted in any state or federal court in the City and State of New York.

               20. Waiver of Immunity. With respect to any Related Proceeding,
each party irrevocably waives, to the fullest extent permitted by applicable
law, all immunity (whether on the basis of sovereignty or otherwise) from
jurisdiction, service of process, attachment (both before and after judgment)
and execution to which it might otherwise be entitled in the Specified Courts,
and with respect to any Related Judgment, each party waives any such immunity in
the Specified Courts or any other court of competent jurisdiction, and will not
raise or claim or cause to be pleaded any such immunity at or in respect of any
such Related Proceeding or Related Judgment, including, without limitation, any
immunity pursuant to the United States Foreign Sovereign Immunities Act of 1976,
as amended.

               21. Counterparts. This Agreement may be executed in one or more
counterparts and, if executed in more than one counterpart, the executed
counterparts shall each be deemed to be an original but all such counterparts
shall together constitute one and the same instrument.

               22. Headings. The headings herein are inserted for convenience of
reference only and are not intended to be part of, or to affect the meaning or
interpretation of, this Agreement.

                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]


                                       29


<PAGE>   30
               If the foregoing correctly sets forth the agreement among the
Company, the Selling Stockholder and the Underwriters, please indicate your
acceptance in the space provided for that purpose below.


                                Very truly yours,

                                THORATEC LABORATORIES CORPORATION,
                                as the Company

                                By:
                                   -------------------------------
                                   Name:
                                   Title:

                                GAMBRO, INC., as the Selling Stockholder


                                By:
                                   -------------------------------
                                   Name:
                                   Title: Attorney-in-Fact


Accepted:

LEHMAN BROTHERS INC.

For itself and as Representative of the
several Underwriters named in Schedule 1
hereto

By: LEHMAN BROTHERS INC.



By:
   -------------------------------
      Authorized Representative


<PAGE>   31
                                   SCHEDULE 1


<TABLE>
<CAPTION>
                                                                    Number of Shares
  Underwriters                                                       of Firm Stock
  ------------                                                       -------------
<S>                                                                 <C>
  Lehman Brothers Inc.......................................
  Bear, Stearns & Co. Inc...................................
  Adams, Harkness & Hill, Inc...............................
  Fidelity Capital Markets, a division of National
    Financial Services Corporation..........................
                                                                     -------------
                                 Total                                  3,000,000.
</TABLE>



<PAGE>   1
                                                                     EXHIBIT 5.1


                                 March 16, 2000

                                                                      18103-1000

Thoratec Laboratories Corporation
6035 Stoneridge Drive
Pleasanton, California 94588

                       REGISTRATION STATEMENT ON FORM S-3

     Ladies and Gentlemen:

     We have acted as counsel to Thoratec Laboratories Corporation, a California
corporation (the "Company"), in connection with the Registration Statement on
Form S-3 to be filed with the Securities and Exchange Commission on or about
March 17, 2000, (as may be further amended or supplemented, the "Registration
Statement") for the purpose of registering under the Securities Act of 1933, as
amended, 5,175,000 shares of its Common Stock, par value $.0001 per share. The
shares to be registered include 3,000,000 currently unissued shares of Common
Stock to be issued by the Company (the "Shares") and 1,500,000 shares of
outstanding Common Stock held by an existing shareholder of the Company. The
Shares are to be sold among the Company and Lehman Brothers, Bear, Stearns & Co.
Inc., Adams Harkness & Hill, Inc. and Fidelity Capital Markets, as
representatives of the several underwriters.

     We have assumed the authenticity of all records, documents and instruments
submitted to us as originals, the genuineness of all signatures, the legal
capacity of natural persons and the conformity to the originals of all records,
documents and instruments submitted to us as copies.

     In rendering our opinion, we have examined the following records, documents
and instruments:

(a)  The Amended and Restated Articles of Incorporation of the Company, filed
     with the California Secretary of State, and certified to us by an officer
     of the Company as being complete and in full form and effect as of the date
     of this opinion;

(b)  The Amended and Restated Bylaws of the Company certified to us by an
     officer of the Company as being complete and in full force and effect as of
     the date of this opinion;

(c)  A Certificate of an officer of the Company (i) attaching records certified
     to us as constituting all records of proceedings and actions of the Board
     of Directors, including any committee thereof, and shareholders of the
     Company relating to the Shares, and the Registration Statement, and (ii)
     certifying as to certain factual matters;
<PAGE>   2
Thoratec Laboratories Corporation
March 16, 1999


(d)     The Registration Statement; and

(e)     The draft of the Underwriting Agreement filed as Exhibit 1.1 to the
Registration Statement.

        This opinion is limited to the federal law of the United States of
America and the General Corporation Law of the State of California, and we
disclaim any opinion as to the laws of any other jurisdiction. We further
disclaim any opinion as to any other statute, rule, regulation, ordinance, order
or other promulgation of any other jurisdiction or any regional or local
governmental body or as to any related judicial or administrative opinion. Our
opinion to the effect that all issued and outstanding Shares are fully paid and
nonassessable is based on the certification obtained from the Company identified
in item (c) above to the effect that the consideration of such Shares recited in
the Board of Directors' resolutions for such Shares will be received.

        Based upon the foregoing and our examination of such questions of law as
we have deemed necessary or appropriate for the purpose of this opinion, and
assuming that (i) the Registration Statement becomes and remains effective
during the period when the Shares are offered and sold, (ii) the currently
unissued Shares to be sold by the Company are issued, delivered and paid for,
(iii) appropriate certificates evidencing the Shares will be executed and
delivered by the Company, and (iv) all applicable securities laws are complied
with, it is our opinion that, when issued by the Company, the currently unissued
Shares covered by the Registration Statement will be legally issued, fully paid
and nonassessable.

        This opinion is rendered to you in connection with the Registration
Statement and is solely for your benefit. This opinion may not be relied upon by
you for any other purpose, or relied upon by any other person, firm, corporation
or other entity for any purpose, without our prior written consent. We disclaim
any obligation to advise you of any change of law that occurs, or any facts of
which we may become aware, after the date of this opinion.

        We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement.


                                        Very truly yours,


                                        /s/ Heller Ehrman White & McAuliffe LLP
                                        ---------------------------------------
                                        Heller Ehrman White & McAuliffe LLP


<PAGE>   1
                                                                    Exhibit 23.1


INDEPENDENT AUDITORS' CONSENT


     We consent to the use in this Registration Statement of Thoratec
Laboratories Corporation on Form S-3 of our report dated February 18, 2000,
appearing in the Prospectus, which is part of this Registration Statement.

     We also consent to the reference to us under the heading "Experts" in such
Prospectus.


/s/ DELOITTE & TOUCHE LLP


San Francisco, CA
March 16, 2000


<PAGE>   1
                                                                    EXHIBIT 23.2

                       CONSENT OF FISH & RICHARDSON P.C.

      We hereby consent to the reference to our name under the caption
"Experts" in the Prospectus included in the Registration Statement on Form S-3
(Registration No. 333-    ) of Thoratec Laboratories Corporation.


Dated March 16, 2000

                                          /s/ FISH & RICHARDSON
                                          -------------------------------------
                                          Fish & Richardson P.C.


<TABLE> <S> <C>

<ARTICLE> 5
<LEGEND>
This schedule contains summary financial information extracted from (A) the
balance sheets and consolidated statements of operations of Thoratec
Laboratories Corporation and is qualified in its entirety by reference to such
(B) Registration Statement filed with the SEC on Form S-3 pursuant to the
Securities Act of 1933.
</LEGEND>
<MULTIPLIER> 1
<CURRENCY> U.S. DOLLARS

<S>                             <C>
<PERIOD-TYPE>                   YEAR
<FISCAL-YEAR-END>                          JAN-01-2000
<PERIOD-START>                             JAN-03-1999
<PERIOD-END>                               JAN-01-2000
<EXCHANGE-RATE>                                      1
<CASH>                                       1,696,522
<SECURITIES>                                   276,464
<RECEIVABLES>                                5,485,982
<ALLOWANCES>                                  (32,795)
<INVENTORY>                                  6,611,487
<CURRENT-ASSETS>                            14,462,977
<PP&E>                                      12,228,805
<DEPRECIATION>                               2,667,991
<TOTAL-ASSETS>                              25,060,438
<CURRENT-LIABILITIES>                        3,929,871
<BONDS>                                              0
                                0
                                          0
<COMMON>                                    72,911,638
<OTHER-SE>                                (52,635,365)
<TOTAL-LIABILITY-AND-EQUITY>                25,060,438
<SALES>                                     22,507,884
<TOTAL-REVENUES>                            23,199,779
<CGS>                                        9,738,946
<TOTAL-COSTS>                                9,738,946
<OTHER-EXPENSES>                            15,249,943
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                                   0
<INCOME-PRETAX>                            (1,789,110)
<INCOME-TAX>                                         0
<INCOME-CONTINUING>                        (1,789,110)
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                               (1,789,110)
<EPS-BASIC>                                     (0.09)
<EPS-DILUTED>                                   (0.09)


</TABLE>


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