Patency and healing of 10-cm long microarterial polytetrafluoroethylene prostheses in the rat abdominal aorta.

Many studies have been undertaken on the experimental evaluation of microarterial polytetrafluoroethylene (PTFE) prostheses of short length. This study was undertaken to obtain insight into the performance of longer microvascular PTFE prostheses, which would be of more clinical utility. Microvascular PTFE prostheses of 10 cm in length (n = 8) were implanted into the rat abdominal aorta, fixed in a loop, and were compared regarding patency and healing with microvascular PTFE prostheses of 1 cm in length (n = 8) at three months after implantation (all prostheses: I.D.--1.5 mm, fibril length--30 microns). At three months, all prostheses, except one 10-cm prosthesis, were patent. In all PTFE microarterial prostheses, healing was observed only at the anastomotic sites with ingrowth of endothelial cells for a few millimeters into the lumen. There was no evidence of healing in the central areas of the prostheses. It was concluded that microvascular PTFE prostheses of useful clinical length show encouraging patency rates in the rat, despite poor endothelial cover. For possible clinical application of microvascular PTFE prostheses, further experimental studies should be undertaken to improve their healing capabilities.