The veins in the lower limbs are classified into two systems:
• Superficial Veins (including saphenous)
• Deep Veins
The two systems are connected by perforating veins that pass through the deep fascia
Three factors influence the return of blood back to the heart:
What are the Greater and Lesser Saphenous Veins?
The greater saphenous vein is a large superficial leg vein running from the foot to the groin, roughly in parallel with the short or lesser saphenous vein, which runs up the back of the leg from the ankle to the knee. These are the principal vessels of the superficial venous system in the leg.
The greater saphenous vein delivers oxygen-depleted blood from the ankle, lower leg and thigh vessels to the femoral vein, the primary deep vein in the leg. The propulsion of blood up such a significant length of the body is heavily dependent on the function of the one-way valves that prevent backflow down the vein. When those valves fail, the resultant venous reflux causes blood to back up into the smaller veins closer to the skin, distending them and initiating the condition known as varicose veins
Venous insufficiency, also known medically as venous reflux disease, in the greater saphenous vein is a primary underlying cause of varicose veins. The great saphenous is also therefore the superficial vein most frequently treated with endovenous ablation to restore healthy circulation and eliminate varicose veins.
Perforator Veins What are Perforator Veins?
Perforator veins serve as connections between the two networks of veins in the extremities, the superficial venous system and the deep venous system. Perforators connect the two parallel systems, somewhat like the rungs of a ladder connect the side rails, and normally drain blood from the superficial veins to the deep veins as part of the process of returning oxygen-depleted blood to the heart.
To view perforator video with Windows Media Player click here.
Perforator veins have one-way valves designed to prevent backflow of blood down towards the superficial veins. When those valves no longer function properly and reflux occurs, the buildup of blood and pressure can cause not only the superficial veins but the perforators themselves to become incompetent. Perforator veins in the lower leg and ankle are particularly vulnerable to distention and incompetence, and the resultant circulatory problems create an increased likelihood of edema, skin discoloration, dermatitis and skin ulcers in the immediate area.
The video above is about perforator veins. Click on the arrow to view.
Like primary superficial veins that become incompetent, perforator veins can be treated. The ClosureRFS™ Stylet is the only endovenous device FDA specifically cleared for treatment of incompetent perforators.
Whereas superficial veins are close to the skin and often visible, the deep veins tend to run under the muscular fascia deep within the limb. The most important deep veins of the lower limbs are the femoral and popliteal veins. The deep veins begin on the plantar aspect of the foot and accompany the arteries which bring oxygenated blood to the legs. Arteries do not contain valves, but many valves are present in healthy deep veins. Most of the blood from the lower limbs is returned to the heart by way of the deep veins. The superficial veins can be obliterated or removed without seriously affecting the circulation, provided that the deep veins remain intact.
When the one-way valves are functioning properly, blood flows from superficial veins into the deep veins either directly or through perforating veins. Muscular contraction pumps blood through the veins, and venous return is reduced while standing or sitting. Prolonged sitting, such as occurs during long plane flights, may contribute to clot formation in the deep veins (Deep Venous Thrombosis--DVT)