Ambulatory pressure gradient in the veins of the lower extremity

Neovascularization is an important cause of venous reflux recurrence after high ligation of the long saphenous vein. The pathogenesis of this phenomenon is so far obscure. It is possible that a hemodynamic factor--a pressure gradient between the femoral vein and the residual long saphenous vein--could be the trigger initiating the process of neovascularization.

Venous pressure measurements on eight patients with primary varicose veins were performed in the erect position in the insufficient long saphenous vein on the thigh. Mean pressures in the quiet standing position and ambulatory pressures were considered. By interrupting the saphenous reflux either distally or proximally to the point of measurement the pressure conditions either in the femoral or in the crural veins were simulated.

With the tourniquet placed distally to the point of measurement, the venous pressure in the upper interrupted segment of the long saphenous vein (equivalent to the pressure in the femoral vein) remained uninfluenced during ambulation. In contrast, by interrupting the reflux proximally to the point of measurement, a marked decrease of the ambulatory pressure in the lower part of the long saphenous vein (equivalent to the pressure in the crural veins) was noted.

A pressure difference occurs between the veins of the thigh and the lower leg during the activation of the muscle venous pump. This fact may explain the tendency of recurrencies of varicose veins after high ligation of the long saphenous vein as well as the initiation of reflux.