Exhibit 10.45

STS Biopolymers

an STS company

336 Summit Point Dr.. Henrietta, New York 14467  Tel: 716-321-1130  Fax:
716-321-1575

May 16, 1998

Mike McLain

V.P. Operations

Micro Therapeutics, Inc.

1062-F Calle Negocio

San Clemente, CA 92673

Dear Mr. McLain:

This letter confirms our discussion of Tuesday, May 5, 1998.  STS agrees to
reduce the royalty rate specified in section 3.2 of the two license agreements,
dated November 18, 1996, by and between STS Biopolymers, Inc. and Micro
Therapeutics, Inc. from four percent (4%) to three percent (3%), effective
immediately.

We also discussed adding a .010” guidewire (similar to a wire previously offered
to the market by MIS) to the agreements. After our discussion I reread the
agreements; both include “...any device used in vascular access procedures...”
in the definition (section 1.5) of COATED PRODUCTS and the license grant is
defined in terms of COATED PRODUCTS. Therefore, I conclude that the guidewire is
already included in the license.

If you agree with the royalty rate change and my interpretation that the wires
are already included in the license, would you please countersign one original
of this letter and return it to me for our file?

Sincerely,

/s/Richard D. Richmond

 

Richard D. Richmond

President

 

RDR/mac

xc:  R. Goodwin, M. Lydon, R. Whitbourne

Agreed for Micro Therapeutics

/s/ H.A. Hurwitz

 

 

Chief Financial Officer

 

(title)

 

5/21/98

 

(date)

 

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