The hemodynamic impact of the bidirectional flow within calf perforators and conductive veins in varicose vein disease

Abstract

The hemodynamic assessment of the bidirectional flow within calf perforators and in the conductive veins in varicose vein disease is presented. The bidirectional streaming within calf perforators is induced by the changing polarity of the systolic and diastolic pressure gradients arising during calf pump activity between the deep veins and the saphenous system of the lower leg, as documented by simultaneous pressure measurements in the posterior tibial vein and the great saphenous vein. This bidirectional flow makes the deep and superficial veins of the lower leg conjoined vessels. The vector of the bidirectional streaming in varicose vein patients is oriented inward, into the deep veins. The enlarged calf perforators are the consequence of the saphenous reflux; after elimination of saphenous reflux the diameter of calf perforators diminishes significantly. Results of venous pressure, plethysmographic and electromagnetic flow measurements rebut the still prevalent opinion that the outward flow within calf perforators is a reflux. There is an up-and-down flow in the conductive veins during calf pump activity with a prevailing systolic centripetal (orthograde) flow in the popliteal/femoral axis and a diastolic centrifugal (retrograde) flow in the incompetent great saphenous vein. The popliteal vein represents actually the drain pipe of the calf muscle pump. The ambulatory venous pressure gradient arising during the diastolic phase of the calf pump activity resembles the diastolic pressure difference between the aorta and the left ventricle.