Pharmacological vasodilation during reconstructive vascular surgery.

The effect on graft blood flow of two vasodilatory drugs, papaverine and bamethane (Vasculat), was infestigated by electromagnetic flowmetry intra-operatively in 31 patients following vascular reconstruction with a femoro-popliteal reversed saphenous vein bypass graft. With both drugs, graft flow augmentation was dose dependent (p less than 0.01) with increasing flow rates up to the injection into the popliteal artery of 40 mg of papaverine and 100 mg of bamethane respectively. The increase in graft flow rate was significantly more pronounced during vasodilation with 40 mg of papaverine than when 100 mg of bamethane was injected (p less than 0.001). Furthermore, 40 mg of papaverine and 100 mg of bamethane respectively induced a significantly larger increase in graft blood flow when injected into the popliteal artery than into the common femoral artery (p less than 0.01). The interpretation of these findings is discussed, and the augmented graft flow values presented are compared to those previously reported. From the present results, it is recommended that, for 'maximal' intra-operative flow augmentation, papaverine should be used, the dose being 40 mg injected into the popliteal artery or into the graft, but not into the common femoral artery or elsewhere intra-arterially.