Failure to obtain long-term patency after implantation of fibrous polyurethane prostheses in the carotid arteries of rabbits.

Fibrous polyurethane prostheses were implanted in the carotid arteries and aortae of New Zealand white (NZW) and Chinchilla (CHIN) rabbits. No immediate post-implantation patency was obtained after implantation in the carotid arteries in NZW rabbits. In CHIN rabbits patency up to 1 week was obtained after carotid implantation. Attempts to increase patency rates by administration of 20 mg/kg body weight/day of both dipyridamol (DIP) and acetyl-salicylic acid (ASA) p.o., starting the week before implantation, had an adverse effect; prostheses became occluded within a few hours after implantation. Coagulation tests (Lee and White, Am J Med Sci 145:495-503, 1913) carried out with blood drawn from CHIN rabbits revealed hypercoaguability after administration of either 10 or 20 mg/kg body weight/day of both DIP and ASA compared to pre-medication values. Prostheses implanted in the aortae of both strains remained patent without anti-platelet-aggregation therapy for a 3-month observation period. It is concluded that in the NZW rabbit carotid implantation was not successful due to severe spasmic reactions and that in CHIN rabbits only very short-term patency could be obtained both with and without administration of 10 or 20 mg/kg body weight/day medication DIP and ASA.