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                                                                    EXHIBIT 2.13

                   FIRST AMENDMENT TO ASSET PURCHASE AGREEMENT

      This FIRST AMENDMENT TO ASSET PURCHASE AGREEMENT (this "AMENDMENT") is
made and entered into, to be effective as of ___________, 2004 (the "EFFECTIVE
DATE"), by and between ENDOCARE, INC., a Delaware corporation (the "COMPANY"),
and GARY ONIK, M.D., an individual and any person or entity that directly, or
indirectly through one or more intermediaries, controls or is controlled by or
is under common control with Dr. Onik (collectively, "ASSIGNOR") (each a "PARTY"
and together, the "PARTIES"). Capitalized terms used in this Amendment shall
have the meanings set forth in the Asset Purchase Agreement dated February 6,
2002, by and between the Company and Assignor (the "AGREEMENT"), or elsewhere in
the text of this Amendment.

WITNESSETH:

      WHEREAS, the Company is a medical device company, which provides medical
devices and related supplies and services used in connection with cryosurgical
procedures, and

      WHEREAS, Assignor is a radiologist who has developed intellectual property
used in connection with cryosurgery procedures as a byproduct of his urology
practice, and

      WHEREAS, the Company and Assignor entered into the Agreement pursuant to
which the Company acquired the Rights (as defined in Section 1 of the Agreement)
to the Technology (as defined in Section 1 of the Agreement) as used in the
Business (as defined in Section 16 of the Agreement) and also engaged Assignor
to perform certain consulting services (the "CONSULTING SERVICES"); and

      WHEREAS, each Party acknowledges Assignor's continuing obligation to
provide the Consulting Services under the terms set forth in the Agreement; and

      WHEREAS, the Parties desire to amend the Agreement to clarify that the
Rights do not include any right, title or interest to Assignor's ideas,
developments and other intellectual property directly related to percutaneous
cryoablation techniques, procedures, equipment and supplies for the treatment of
liver, lung, kidney, bone and other conditions unrelated to the prostate that
Assignor has developed or will develop in the future (collectively,
"NON-PROSTATE-RELATED INTELLECTUAL PROPERTY"), and

      WHEREAS, the Company desires to obtain from Assignor a right of first
refusal option to purchase Assignor's entire interest in any
Non-Prostate-Related Intellectual Property, and

      WHEREAS, Assignor is willing to grant such a right of first refusal option
to the Company under the terms and conditions of this Amendment,

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      NOW, THEREFORE, in consideration of the mutual agreements, covenants,
terms and conditions herein contained, Assignor and the Company agree as
follows:

      1. The Parties acknowledge and agree that the Agreement is now in full
force and effect, and no event has occurred which, with the passage of time or
the sending of notice, or both, would constitute grounds for termination of the
Agreement.

      2. Without amending any other term or condition contained in the
Agreement, the Parties agree to amend Section 1 of the Agreement, to add the
following sentence to the end of the Section:

            Notwithstanding the foregoing, the Technology and the Rights thereto
      acquired by the Company pursuant to this Agreement shall not include
      Assignor's ideas, developments and other intellectual property directly
      related to percutaneous cryoablation techniques, procedures, equipment and
      supplies for the treatment of liver, lung, kidney, bone and other
      conditions unrelated to the prostate that Assignor has developed or will
      develop in the future (collectively, "Non-Prostate-Related Intellectual
      Property") and any right, title or interest to the Non-Prostate-Related
      Intellectual Property.

      3. Without amending any other term or condition contained in the
Agreement, the Parties agree to amend the Agreement to add a new Section 28, to
read as follows:

            28. Grant of Right of First Refusal. Assignor hereby grants to the
      Company the right to purchase any Non-Prostate-Related Intellectual
      Property at the same price offered to Assignor in an arms-length
      negotiation with a third party under the following terms ("Right of First
      Refusal"):

                  (a) In the event that Assignor receives an offer for any
      Non-Prostate-Related Intellectual Property from a third party (a
      "Third-Party Offer"), Assignor shall forward a copy of such Third-Party
      Offer (or a written term sheet summarizing any oral Third-Party Offer) to
      the Company within three (3) days of Assignor's receipt of the Third-Party
      Offer and prior to accepting the Third-Party Offer.

                  (b) Following receipt of a copy of a Third-Party Offer (or
      written term sheet summarizing any oral Third-Party Offer), the Company
      shall have twenty one (21) days to review the Third-Party Offer.

                  (c) If the Company desires to purchase the
      Non-Prostate-Related Intellectual Property which is the subject of the
      Third-Party Offer on the same terms as set forth in the Third-Party Offer,
      then the Company shall deliver written notice of its decision to exercise
      its Right of First Refusal to Assignor prior to the expiration of the
      three-week review period.

                  (d) Promptly after the Company's exercise of its Right of
      First Refusal, the Parties shall take any and all actions necessary to
      close the transfer of the Non-Prostate-Related Intellectual Property to
      the Company on a timely basis.

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      4. Counterparts: Facsimile Signatures. This Amendment may be executed in
two counterparts, each of which shall be deemed an original, but both of which
together shall constitute one and the same instrument. Copies of signatures sent
by facsimile transmission shall be deemed to be originals for purposes of
execution and proof of this Amendment.

      IN WITNESS WHEREOF, the Parties have duly executed this Amendment as of
the day and year first set forth above.

                                                         /s/ GARY ONIK, M.D.
                                                      -------------------------
                                                           Gary Onik, M.D.

                                                          /s/ WILLIAM NYDAM
                                                      -------------------------
                                                            William Nydam
                                                              President