A compliant vascular graft fabricated from a unique polyurethane material has been developed and tested as a 4-mm-diameter prosthesis. The material used is unique because its bulk and surface requirements have been separated and developed independently in two distinct materials. The final polymer possesses overall optimized characteristics by blending optimized surface-active copolymers into the optimized bulk material.Using a patented process for fabrication of multilayered tubing, 6-mm-diameter vascular grafts will be produced. These grafts will be tested both in vivo and in vitro. In vitro testing will include compliance, burst strength, kink radius, elongation, and suture pullout strength. In vivo evaluation will be accomplished using 30-cm-long conduitsto create an arteriovenous (AV) fistula between the external carotid artery and ipsilateral external jugular vein. Direct AV fistulas will also be constructed. Polytetrafluoroethylene (PTFE) conduits will serve as comparisons. Some conduits will be punctured 6 times weekly for 12 weeks. Explanted grafts will be resubjected to the in vitro test protocol as well as standard microscopic examination. It is expected that these grafts will heal into the vascular system and prove more durable than PTFE conduits as well as providing features such as selfsealing, decreased thrombus formation, and less intimal hyperplasia.
Anticipated Results:Approximately 40,000 to 50,000 people per year require the construction of an AV fistula for vascular access. Currently available products have not been optimized for this use. The proposed product addresses the specific needs of these patients. Significant sales can be expected in this market, as well as saving millions of dollars in health-care costs by decreasing the need for repair or reconstruction of failed shunts.National Institute Of Diabetes And Digestive And Kidney Diseases (NIDDK)
