Reduced anastomotic bleeding using new sutures with a needle-suture diameter ratio of one.

Reduction of blood loss from a vascular anastomosis, especially when one is using a polytetrafluoroethylene (PTFE) graft, is of great interest; even when a technically perfect anastomosis has been performed, there can still be significant and often bothersome bleeding from the needle holes. Currently, sutures have a needle-to-suture ratio of 2:1 or 3:1. Two new sutures, one made of PTFE and the other of polypropylene, were designed to have a needle-to-suture diameter ratio of 1:1. Theoretically, this allows the suture to completely fill the graft needle hole and control bleeding. These sutures were evaluated in a heparin-treated canine in vivo model to measure graft needle-hole bleeding. The materials were also tested by an independent laboratory to compare the basic physical characteristics. Twenty centimeters of 6 mm PTFE graft was interposed in an end-to-end fashion to the infrarenal canine aorta. The graft was then transected at its midpoint and a series of end-to-end, graft-to-graft anastomoses were performed with alternate experimental and control sutures. The experimental PTFE suture bled a mean of 12.46 ml per anastomosis. The experimental polypropylene bled 4.32 ml per anastomosis, while a control suture of polypropelene with a needle-to-suture ratio of 1.94 (5-0 prolene with a C-1 needle), produced a mean blood loss of 33.35 ml per anastomosis. These data are based on a total of 82 anastomoses. The results were analyzed with a two-tailed paired t test. As the data indicate, both experimental sutures allowed significantly less bleeding than the controls (p = .05). The testing of physical properties of the suture included diameter, tensile strength, needle pull-off strength, and elongation percent and were performed by an independent laboratory. These findings are included along with subjective evaluations of the sutures' handling qualities. We believe that sutures produced with needle-to-suture ratios of 1:1 greatly reduce graft needle-hole bleeding and will be a useful addition to the vascular surgeon's armamentarium.