SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                  SCHEDULE TO/A
                                (AMENDMENT NO. 4)

        TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR SECTION 13(E)(1)
                     OF THE SECURITIES EXCHANGE ACT OF 1934

                    INTEGRA LIFESCIENCES HOLDINGS CORPORATION
                                (Name of Issuer)

               INTEGRA LIFESCIENCES HOLDINGS CORPORATION (ISSUER)
 (Name of Filing Person (Identifying Status as Offeror, Issuer or Other Person))

            2 1/2% CONTINGENT CONVERTIBLE SUBORDINATED NOTES DUE 2008
                         (Title of Class of Securities)

                      (CUSIP NOS. 457985AA7 AND 457985AB5)
                      (CUSIP Number of Class of Securities)

                              MAUREEN B. BELLANTONI
              EXECUTIVE VICE PRESIDENT AND CHIEF FINANCIAL OFFICER
                    INTEGRA LIFESCIENCES HOLDINGS CORPORATION
                              311 ENTERPRISE DRIVE
                          PLAINSBORO, NEW JERSEY 08536
                                 (609) 275-0500

       (Name, Address and Telephone Number of Person Authorized to Receive
          Notices and Communications on Behalf of the Filing Person(s))

                                    COPY TO:
                              PETER LABONSKI, ESQ.
                              LATHAM & WATKINS LLP
                                885 THIRD AVENUE
                               NEW YORK, NY 10022
                                 (212) 906-1200


                            CALCULATION OF FILING FEE

         TRANSACTION VALUATION*                         AMOUNT OF FILING FEE**
              $120,000,000                                     $12,840

*    Calculated  solely for the purpose of determining  the amount of the filing
     fee, based upon the exchange of $120,000,000  aggregate principal amount of
     the Issuer's 2 1/2% Contingent  Convertible  Subordinated Notes due 2008 in
     exchange for Integra LifeSciences Holdings  Corporation's 2 1/2% Contingent
     Convertible Subordinated Notes due 2008.


**   Previously paid.


[ ]  Check box if any part of the fee is offset as provided by Rule 0-11(a)(2)
     and identify the filing with which the offsetting fee was previously  paid.
     Identify the previous filing by registration  statement number, or the form
     or schedule and the date of its filing.

     Amount Previously Paid: Not applicable.       Filing party: Not applicable.
     Form or Registration No.: Not applicable.     Date Filed: Not applicable.

[ ]  Check the box if  the filing relates solely  to  preliminary communications
     made before the commencement of a tender offer.

Check the  appropriate  boxes below to designate any  transactions  to which the
statement relates:

         [ ]  third-party tender offer subject to Rule 14d-1

         [x]  issuer tender offer subject to Rule 13e-4

         [ ]  going private transaction subject to Rule 13e-3

         [ ]  amendment to Schedule 13D under Rule 13d-2


Check the following box if the filing is a final amendment reporting the results
of the tender offer [x]


                                       2

This Amendment No. 4 to Schedule TO (this "Amendment") amends and supplements the Tender Offer Statement on Schedule TO filed by Integra LifeSciences Holdings Corporation, a Delaware corporation, (the "Issuer") on July 17, 2006, and amended by Amendment No. 1 thereto filed on July 31, 2006, Amendment No. 2 thereto filed on August 15, 2006 and Amendment No. 3 thereto filed on August 28, 2006 (as so amended, the "Schedule TO"). This Amendment relates to the offer by the Issuer (i) to exchange $1,000 in principal amount of 2 1/2% Contingent Convertible Subordinated Notes due 2008 (the "New Notes") and (ii) a one time cash payment (an "Exchange Fee") equal to $2.50 for each $1,000 in principal amount of the Issuer's outstanding 2 1/2% Contingent Convertible Subordinated Notes due 2008 (the "Old Notes" and together with the New Notes, the "Notes") that is properly tendered and accepted for exchange upon the terms and subject to the conditions set forth in the Offer to Exchange (this "Offer to Exchange") and in the related Letter of Transmittal (the "Letter of Transmittal"), as each may be amended from time to time. The offer to exchange the Notes (including the payment of an Exchange Fee) pursuant to the Offer to Exchange is referred to herein as an "Offer." This Amendment amends and supplements Schedule TO as set forth below. This Amendment is filed to satisfy the reporting requirements of Rule 13e-4 under the Securities Exchange Act of 1934, as amended. The information in the Offer to Exchange and the related Letter of Transmittal, copies of which were previously filed on Schedule TO as exhibits (a)(1)(i) and (a)(1)(ii) thereto, is incorporated in this Amendment by reference, except that such information is hereby amended and supplemented to the extent specifically provided herein. ITEM 11. ADDITIONAL INFORMATION Item 11 of the Schedule TO is hereby amended and supplemented by adding the following language: On October 2, 2006, the Company issued a press release announcing the results of the exchange offer, which expired on September 26, 2006. A copy of this press release is filed as Exhibit (a)(5)(v) to the Schedule TO and is incorporated herein by reference. ITEM 12. EXHIBITS. Item 12 of the Schedule TO is hereby amended and supplemented by adding the following exhibits: (a)(5)(v) Press Release, dated October 2, 2006. 3

SIGNATURE After due inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct. Dated: October 3, 2006 INTEGRA LIFESCIENCES HOLDINGS CORPORATION By: /s/ MAUREEN B. BELLANTONI --------------------------------------- Name: Maureen B. Bellantoni Title: Executive Vice President and Chief Financial Officer 4

EXHIBIT INDEX EXHIBIT NUMBER DESCRIPTION - ------ ----------- (a)(1)(i) Offer to Exchange, dated July 17, 2006.* (a)(1)(ii) Letter of Transmittal.* (a)(1)(iii) Notice of Guaranteed Delivery.* (a)(1)(iv) Letter to Brokers, Dealers, Commercial Banks, Trust Companies and Other Nominees.* (a)(1)(v) Letter to Clients for use by Brokers, Dealers, Commercial Banks, Trust Companies and Other Nominees.* (a)(1)(vi) Supplement to Offer to Exchange, dated July 31, 2006.* (a)(1)(vii) Supplement No. 2 to Offer to Exchange, dated August 28, 2006.* (a)(5)(i) Press Release, dated July 17, 2006.* (a)(5)(ii) Press Release, dated July 31, 2006.* (a)(5)(iii) Press Release, dated August 14, 2006.* (a)(5)(iv) Press Release, dated August 28, 2006.* (a)(5)(v) Press Release, dated October 2, 2006. * Previously filed. 5

                                                                 EXHIBIT a(5)(v)

NEWS RELEASE

Contacts:

Integra LifeSciences Holdings Corporation

Maureen B. Bellantoni                    John Bostjancic
Executive Vice President                 Vice President, Corporate Development
and Chief Financial Officer              and Investor Relations
(609) 936-6822                           (609) 936-2239
maureen.bellantoni@Integra-LS.com        jbostjancic@Integra-LS.com


       INTEGRA LIFESCIENCES ANNOUNCES COMPLETION OF EXCHANGE OFFER FOR ITS
           2 1/2% CONTINGENT CONVERTIBLE SUBORDINATED NOTES DUE 2008


Plainsboro,  New  Jersey,  October  2,  2006  -  Integra  LifeSciences  Holdings
Corporation  (NASDAQ: IART)  announced  today  that  it  completed  its offer to
exchange  up to $120  million  principal  amount of new notes  with a "net share
settlement"   mechanism   for  its  currently   outstanding  2 1/2%   Contingent
Convertible Subordinated Notes due 2008.

The exchange  offer  expired at 5:00 p.m.,  New York City time, on September 26,
2006. As of the expiration  date, an aggregate  principal amount of $115,205,000
of old notes had been  tendered.  All old notes that were properly  tendered and
not withdrawn have been accepted and exchanged for an equal amount of new notes.

The terms of the new notes are substantially  similar to those of the old notes,
except that the new notes have a net share  settlement  feature and will include
"takeover protection," whereby Integra will pay a premium to holders who convert
their notes upon the  occurrence  of  designated  events,  including a change in
control.  The net share settlement  feature of the new notes requires that, upon
conversion  of the new  notes,  Integra  will pay  holders in cash for up to the
principal  amount of the converted new notes,  with any amounts in excess of the
cash amount  settled,  at the election of Integra,  in cash or shares of Integra
common  stock.  Holders  who  exchanged  their old notes in the  exchange  offer
received  an  exchange  fee of $2.50 per  $1,000  principal  amount of their old
notes.

This press release is for informational purposes only and is not an offer to buy
or the solicitation of an offer to sell securities of Integra.  The solicitation
of offers to exchange the 2 1/2% Contingent  Convertible  Subordinated Notes was
made only  pursuant to the  exchange  offer  documents,  including  the Offer to
Exchange (as  supplemented)  and the related Letter of Transmittal  that Integra
distributed  to its  noteholders  and filed  with the  Securities  and  Exchange
Commission.  Noteholders  and  investors  may obtain a free copy of the Offer to
Exchange and other  documents  filed by Integra with the Securities and Exchange
Commission at the Securities and Exchange Commission's website at www.sec.gov or
from the  information  agent,  Georgeson  Inc.,  at (212) 440-9800   (banks  and
brokers) or (866) 482-4943 (all others).

This  announcement is neither an offer to sell nor a solicitation of an offer to
buy any securities and shall not  constitute an offer,  solicitation  or sale in
any jurisdiction in which such offer,  solicitation or sale is unlawful. The new
notes were not registered  under the Securities Act of 1933, as amended,  or any
state securities  laws, and unless so registered,  may not be offered or sold in
the United States

except pursuant to an exemption from the registration requirements of the Securities Act of 1933, as amended and applicable state laws. Integra LifeSciences Holdings Corporation is a diversified medical technology company that develops, manufactures, and markets medical devices for use in a variety of applications. The primary applications for our products are neurosurgery, reconstructive surgery and general surgery. Integra is a leader in applying the principles of biotechnology to medical devices that improve patients' quality of life. Our corporate headquarters are in Plainsboro, New Jersey, and we have manufacturing and research facilities located throughout the world. Please visit our website at (http://www.Integra-LS.com). SOURCE: INTEGRA LIFESCIENCES HOLDINGS CORPORATION