Donald J Lyman, 979202 Autumn Line Loop SE, Olympia, WA 98513

4334327, Jun 15, 1982

Dec 21, 1979

6/106175

Donald J. Lyman - Salt Lake City UT
Richard G. Middleton - Salt Lake City UT

University of Utah - Salt Lake City UT

A61F 124

3 1

A ureter prosthesis fabricated from copolyurethane materials which are non-reactive in the urinary environment and adapted for fixation within a patient to avoid adverse migration. This ureter prosthesis can be adapted for intermediate location along a ureter or can be constructed with one-way valve means appropriate for implantation into the bladder lumen without a resulting vesico-ureteral reflux. The ureter prosthesis includes an elongate duct having a lumen whose interior surface is ultrasmooth based on microscopic inspection. An exterior cuff with terminal and intermediate sewing projections is formed around a portion of the elongate duct to enable its fixation by suturing to appropriate muscular tissue. The utility and success of this ureter prosthesis has been confirmed in multiple testing of dogs which have survived more than a year with the prosthetic ureter in place.

4173689, Nov 6, 1979

Feb 3, 1976

5/654831

Donald J. Lyman - Salt Lake City UT
Frank J. Fazzio - Salt Lake City UT

University of Utah - Salt Lake City UT

C08G 1814
A61F 124

521 64

A blood and body-tissue compatible synthetic polymer having mechanical compliance properties matching that of body tissue, useful in prosthesis as vascular grafts, skin covering, small diameter body duct work, and similar tissue replacement materials. A block copolymer having suitable body and blood compatibility characteristics is dissolved in a solvent, yielding a solution having an approximate relative viscosity between the range of 100 to 1000. A clean mandrel is slowly dipped into the solution and slowly withdrawn, leaving a uniform coating of polymer solution over the forming surface of the mandrel. The coated mandrel is then immersed into a second, nonsolvent solution which is miscible with the first solvent. The resulting transfer of the nonsolvent solution into the polymer network, displacing the first solvent molecules, acts to precipitate the polymer in a physical form containing a uniform dispersion of voids throughout the polymer structure. Such voids provide a mechanical response to the final polymer material which parallels that of natural arterial tissue, while at the same time retaining the necessary compatibility characteristics for prosthesis.