Prevention of thrombosis in arterial and venous microanastomoses by using topical agents.

A replantation model, using the rat's foot severed at the ankle and replanted on an extended vascular pedicle, was used to study the effect of topical vasodilators in preventing microvascular thrombosis. Magnesium sulfate, Xylocaine, and papaverine gave arterial patency rates of 89% or more, compared to 65% for saline alone. There was no appreciable effect on the venous patency rates. The possible mechanisms of action for the various drugs are discussed.