Great saphenous vein
Vena saphena magna
Also known as: long saphenous vein, GSV
The great saphenous vein is the longest vein in the body. It runs from in front of the medial malleolus up the medial side of the leg and thigh and drains into the femoral vein at the saphenofemoral junction in the groin.
Overview
Course. The vein begins at the medial end of the dorsal venous arch of the foot. It passes in front of the medial malleolus, where it is very constant, and ascends along the medial side of the leg with the saphenous nerve. It passes about a hand's breadth behind the medial border of the patella, behind the medial condyle of the femur. It then runs up the medial and front of the thigh. It passes through the saphenous opening in the fascia lata, about 3–4 cm below and lateral to the pubic tubercle, and drains into the femoral vein.
Valves and perforators. The vein contains about 10–20 valves. Perforating veins link it to the deep veins. Their valves normally allow blood to flow only from superficial to deep, so the calf muscle pump can empty the superficial system.
Junction tributaries. Near the saphenofemoral junction it receives the superficial epigastric, superficial circumflex iliac and superficial external pudendal veins.
Anatomy
- Tributaries
The dorsal venous arch, medial marginal vein, posterior arch vein, anterior and posterior accessory saphenous veins, and the superficial epigastric, superficial circumflex iliac and superficial external pudendal veins. Perforating veins connect it to the deep system.
Function
- Drains the superficial tissues of the medial foot, leg and thigh into the deep veins.
Clinical significance
Varicose veins
When the valves at the saphenofemoral junction or in the perforating veins fail, blood refluxes downward. The superficial veins become dilated and tortuous (varicose). Long-standing venous hypertension causes swelling, brown skin pigmentation from haemosiderin, hardening of the skin and fat (lipodermatosclerosis) and ulcers above the medial malleolus. Treatment options include compression, endovenous thermal ablation, foam sclerotherapy and surgical ligation and stripping.
Conduit for bypass grafting
The great saphenous vein is harvested for coronary bypass and leg bypass grafts. It is reversed so that its valves do not block arterial flow, or the valves are cut (in-situ bypass). Fewer vein grafts than internal thoracic artery grafts remain open in the long term.
Saphenous cut-down and nerve injury
Because the vein lies so constantly in front of the medial malleolus, it can be exposed surgically for emergency venous access (cut-down). The saphenous nerve runs alongside and can be damaged, leaving numbness along the medial foot.
Test yourself
Where is the great saphenous vein most reliably found at the ankle?
- Anterior to the medial malleolus
- Posterior to the lateral malleolus
- Posterior to the medial malleolus
- Anterior to the lateral malleolus
Answer: Anterior to the medial malleolus
The great saphenous vein lies in front of the medial malleolus, with the saphenous nerve beside it. This is the classic site for an emergency venous cut-down. The small saphenous vein passes behind the lateral malleolus with the sural nerve.
Compiled from standard anatomy and physiology references — see the Cardiovascular System sources. For education only; not medical advice.