EXPANDED POLYTETRAFLUOROETHYLENE ARTERIAL PROSTHESES IN HUMANS - HISTOPATHOLOGICAL STUDY OF 298 SURGICALLY EXCISED GRAFTS

The expanded polytetrafluoroethylene vascular prosthesis is considered to be the best synthetic alternative for peripheral arterial reconstr uction. Most studies on the healing characteristics Of expanded polyte trafluoroethylene prostheses have been carried out on animals, and ver y few data are available on prostheses implanted in humans long term. We implanted 298 expanded polytetrafluoroethylene grafts as arterial s ubstitutes in humans. The mean duration of implantation was 523 d and the grafts were implanted mainly for infrainguinal or axillofemoral by pass. The cellular and collagen infiltration of the microporous expand ed polytetrafluoroethylene structure was generally poor. Infiltration occurred mainly in the external region of the prosthetic wall and incr eased with the duration of implantation. The external reinforcement wa s not a major factor in limiting tissue infiltration. The luminal surf aces were covered with a thin, irregular layer of organized fibrin, in terspersed with exposed expanded polytetrafluoroethylene areas. Minera l deposits were observed in five cases. Despite poor healing, the clin ical performance of expanded polytetrafluoroethylene vascular prosthes es is relatively good. Since the chief advantage of this material is g ood mechanical stability in vivo, any modifications of the graft to im prove healing characteristics or thrombogenic properties should not be made at the expense of stability in vivo.