Effect of bipolar coagulation and occlusion clamping on the patency rate in microvascular anastomosis.

Even with extremely high output from a bipolar coagulator applied close to a vessel, the patency in the femoral arteries and veins of 20 rats was found to be excellent. Scanning electron microscopy and histopathologic studies showed minimal disturbances within the intima. When the extremely high pressure (350 gramforce/mm2) of the Ikuta microvascular occlusion clamp was applied to the rat femoral veins for 1 hour, only one out of six veins became nonpatent. Lower pressures had no detrimental effects on the other 33 veins. When high clamping pressure and high output bipolar coagulation were applied together in 20 femoral veins of the rat, patency rate was 80 percent. From the results, it appears that bipolar coagulation is extremely safe, while clamping can be harmful to patency in microvascular anastomoses.