Great saphenous vein

Vena saphena magna

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What it is

The longest vein in the body. It starts at the medial end of the dorsal venous arch of the foot, passes in front of the medial malleolus, climbs the medial side of the leg, passes a hand's breadth behind the patella at the knee, and ascends the medial thigh to join the femoral vein at the saphenous opening just below the groin.

Function

Drains the skin and superficial tissues of the foot, leg and thigh into the deep system via perforating veins and the saphenofemoral junction.

Size

~3–5 mm diameter, ~1 m long; 10–20 valves.

Clinical note

Failure of its valves causes varicose veins; it is the vein most often harvested for coronary artery bypass grafts, and its position in front of the medial malleolus makes it reliable for emergency cut-down.