Comparison of nylon and polypropylene sutures in a microvenous thrombosis model.

Thrombosis rates of femoral end-to-end microvenous anastomoses with nylon and polypropylene sutures (9-0 suture, 70 mu needle) were compared in a microvenous thrombosis model. The vessel injuries were produced during anastomosis by using a suture with a knot 1 cm from the needle. Anastomotic thrombosis rates were assessed by visual inspection and strip test at 24 hr postoperatively. Low thrombosis rates (0% and 20%, respectively) of anastomoses with both unknotted nylon and unknotted polypropylene sutures were obtained. Anastomoses with knotted nylon and polypropylene sutures resulted in 65% and 45% thrombosis rates, respectively. Statistical analyses showed that there were no significant differences between thrombosis rates, both in anastomosis performance with unknotted nylon and polypropylene sutures (P > 0.05) and with knotted nylon and polypropylene sutures (P > 0.05), while there were significant differences between the thrombosis rate using unknotted sutures and knotted sutures (P < 0.01). It was concluded that vascular injury, not suture material, is the main factor leading to thrombosis in this model.