The lower extremity venous system includes the deep, superficial, and perforating veins, which work in concert to return blood to the heart (Fig. 97–1).1 Unlike the arterial system, the venous system has low resistance and must overcome gravitational and hydrostatic pressure forces to achieve blood return to the heart. The venules and veins have very thin walls and low resting basal tone, which allows for enormous distensibility. As a result, small changes in hydrostatic forces, central pressure, and/or external forces result in changes of the vein diameter. Venous blood flow is reliant upon muscular leg contraction, historically referred to as “the peripheral heart,”2 as well as bicuspid venous valves that open and close to prevent backflow. Together, muscular leg contraction and venous valves help to overcome hydrostatic forces within the vein itself. Venous disease results from degeneration and dysfunction of the veins and/or valves, which may occur following an obstruction such as deep vein thrombosis or in the setting of increased central pressures, as in congestive heart failure. Venous disease is associated with a wide array of clinical manifestations caused by complex hemodynamic and anatomic failures. A basic understanding of these complexities is essential in the evaluation, diagnosis, and appropriate treatment of venous disease.
Peripheral Venous Anatomy.
The veins of the lower extremities are divided into three main subgroups, which are interconnected and together ultimately drain into the external and common iliac veins to the inferior vena cava: (1) perforator veins, (2) superficial veins, and (3) deep veins. The fascia muscularis divides the deep and superficial vein compartments; the perforator veins cross the fascial plane to connect the deep and superficial venous systems.3 A network of bicuspid venous valves exists in the deep and superficial veins to assist in venous return and prevent backflow. In the lower extremity, the deep veins accompany the corresponding arteries and their branches.4 The popliteal vein is formed by the confluence of the calf veins, which include the gastrocnemius vein draining into the popliteal vein and the soleal veins emptying into the tibial and then popliteal veins. Subsequently, the popliteal vein empties into the femoral vein (previously called superficial femoral vein), common femoral and iliac veins. The common femoral and external iliac vein each have one venous valve approximately 63% of the time; in 37% of patients, there is no valve present in this location.5,6
The largest of the superficial veins, the great saphenous vein (GSV), is also the longest vein in the human body. It courses from the ankle medially up the calf and into the thigh to ultimately confluence with the common femoral vein at the saphenofemoral junction (see Fig. 97–1). Normal GSV caliber ranges from 3 to 4 mm in diameter, and 10 to 20 valves ...