Exhibit 3 SECOND AMENDED AND RESTATED JOINT FILING AGREEMENT THIS SECOND AMENDED AND RESTATED JOINT FILING AGREEMENT is entered into as of April 4, 2005, by and among the parties signatories hereto. This Second Amended and Restated Joint Filing...

                                                                       Exhibit 3

               SECOND AMENDED AND RESTATED JOINT FILING AGREEMENT

     THIS SECOND AMENDED AND RESTATED JOINT FILING AGREEMENT is entered into as
of April 4, 2005, by and among the parties signatories hereto. This Second
Amended and Restated Joint Filing Agreement amends and restates the Amended and
Restated Joint Filing Agreement, dated August 29, 2003, filed as Exhibit A to
Amendment No. 6 of the Schedule 13D filed on September 3, 2003 (the "Statement
on Schedule 13D").

     The undersigned hereby agree that the Statement on Schedule 13D with
respect to the shares of common stock, par value $0.001 per share, of Micro
Therapeutics, Inc., a Delaware corporation, is, and any amendment thereafter
signed by each of the undersigned shall be, filed on behalf of each undersigned
pursuant to and in accordance with the provisions of 13d-1(k) under the
Securities Exchange Act of 1934, as amended.


Dated:  April 4, 2005                   EV3 LLC

                                        By:     /s/ Xxxxx X. Xxxxxxx
                                               --------------------------------
                                               Name:  Xxxxx X. Xxxxxxx
                                               Title: President and Chief
                                                      Executive Officer


Dated:  April 4, 2005                   MICRO INVESTMENT, LLC

                                               By:  ev3 LLC, Managing Member

                                        By:     /s/ Xxxxx X. Xxxxxxx
                                               --------------------------------
                                               Name:  Xxxxx X. Xxxxxxx
                                               Title: President and Chief
                                                      Executive Officer



Dated:  April 4, 2005                   WARBURG, XXXXXX EQUITY PARTNERS, L.P.

                                               By:  Warburg Pincus Partners LLC,
                                                    its General Partner

                                               By:  Warburg Pincus & Co.,
                                                    its Managing Member

                                        By:     /s/ Xxxx X. Xxxxxx
                                               --------------------------------
                                               Name:  Xxxx X. Xxxxxx
                                               Title: Partner


Dated:  April 4, 2005                   WARBURG PINCUS & CO.

                                        By:     /s/ Xxxx X. Xxxxxx
                                               --------------------------------
                                               Name:  Xxxx X. Xxxxxx
                                               Title: Partner


Dated:  Xxxxx 0, 0000                   XXXXXXX PINCUS LLC

                                        By:     /s/ Xxxx X. Xxxxxx
                                               --------------------------------
                                               Name:  Xxxx X. Xxxxxx
                                               Title: Member


Dated:  April 4, 2005                   WARBURG PINCUS PARTNERS LLC

                                             By:  Warburg Pincus & Co.,
                                                  its Managing Member

                                        By:     /s/ Xxxx X. Xxxxxx
                                               --------------------------------
                                               Name:  Xxxx X. Xxxxxx
                                               Title: Partner