Venous wall function in the pathogenesis of varicose veins.

Three theories have been proposed to explain the cause of varicose veins, citing three different factors as the primary cause: valvular incompetence, a weakness of the vein wall, and increased arterial inflow associated with multiple arteriovenous communications. This study was designed to determine the cause of varicose veins with respect to these three factors. Duplex scanning techniques were used to assess the venous valves, and simultaneous measurements of calf volume (strain-gauge plethysmography) and venous pressure made during venous occlusion plethysmography were used to determine the elasticity of the venous wall and the rate of arterial inflow. Fifty-one control legs and 36 legs with superficial venous insufficiency were examined. Risk factors were used to divide the control legs into two groups: low risk or normal (23 legs) and high risk (28 legs). The results obtained in the high-risk limbs demonstrated a significantly reduced vein wall elasticity (p less than 0.001) and increased arterial inflow (p less than 0.005) compared with the normal limbs, with no corresponding increase in the incidence of valvular incompetence. These results clearly suggest that the role of the venous valves in the development of varicose veins is secondary to changes in the elastic properties of the vein wall and the rate of arterial inflow.