Evaluation of compliant and noncompliant PTFE vascular prostheses.

Four chronic implants of 6 mm diameter grafts compare a new longitudinally compliant PTFE-composite vascular prosthesis (ULTRAFLEX PTFE-PLUS) with clinical grade microporous expanded polytetrafluoroethylene (PTFE). Implants were carried out in the ovine carotid-jugular position as A-V fistulae. All four grafts were subjected to sham dialysis punctures in identical fashion with 14-gauge needles. After 60 days the grafts were explanted and submitted for histologic evaluation. All four grafts were patent at explant. The compliant PTFE (ULTRAFLX PTFE-PLUS) lumen surface was thrombus free. Neointima lining at the proximal and distal anastomoses was similar in both test and controls. Tissue ingrowth and outer capsule formation were virtually identical. Foreign body reaction was minimal. Superior handling and self-sealing properties distinguished test from controls. Long term animal studies are in progress for vascular access and peripheral applications.