Great Saphenous vein
The venous drainage of the lower limb is capable of returning blood back to the heart against gravity. There is a special pumping mechanism and the presence of valves which ensure venous return. The venous system of the body is divided into a superficial and deep system. The superficial system is visible on the surface of our skin, if a tourniquet is applied. These veins are commonly used to sample blood for blood tests. The superficial veins drain into deep veins (which share the same names as the arteries they run along). These deep veins return blood to the inferior and superior vena cava, and then to the right atrium of the heart.
In this article we will discuss the anatomy and clinical relevance of the great saphenous vein. The great saphenous vein is also known as long saphenous vein. It is the longest vein in the body and runs superficially along the length of the lower limb. In the end we will conclude with a summary and some review questions to test the reader’s understanding of the article content.
The great saphenous vein is a large superficial vein of the lower limb. It drains into the femoral vein, which is the medial most structure in the femoral triangle. The lateral border of the femoral triangle is formed by the medial border of sartorius, the medial border of the femoral triangle is formed by the medial border of adductor longus and the inguinal ligament forms the base of the triangle. The point at which it drains into the femoral vein is known as the saphenofemoral junction.
The great saphenous vein originates from the dorsal vein of the hallux, which merges with the dorsal venous arch of the foot. The vein then runs anterior to the medial malleolus (a relatively easy area to locate the vein). The vein ascends up the medial surface of the leg, and then runs posterior to the medial epicondyle of the femur. It then runs upward in the thigh and passes over the medial surface of the thigh. In the thigh it is accompanied by branches of the medial femoral cutaneous nerves , and at the knee, in the leg and the foot the vein is closely related to the saphenous artery (a branch of the descending genicular artery). The great saphenous vein then passes through an opening in the fascia lata i.e. the saphenous opening. It continues as an arch to join the femoral vein within the medial region of the femoral triangle.
The great saphenous vein is the medial most structure in the femoral triangle. Lateral to it, is a space that allows for expansion of the vein during increases venous return. Situated on the lateral side of the great saphenous vein is the femoral artery. The most lateral structure is the femoral nerve (posterior divisions of the ventral rami of L2-L4), which runs close to the anterior superior iliac spine, and runs beneath the inguinal ligament. There are numerous valves in this vein, that ensure blood flows in the correct direction.
There is a valve covering the saphenofemoral junction (where the saphenous vein joins the femoral vein), and separates the superficial and deep venous system.
The greater saphenous vein receives smaller veins from the ankle and foot. These include the medial marginal vein (drains the sole of the foot), the small saphenous vein (it has numerous connections with its smaller counterpart in the lower region of the leg). In leg it is connected to short saphenous vein and with deep veins through perforating veins. Close to knee it receives three large tributaries, in thigh it receives many tributaries that are posteromedial i.e accessory saphenous vein, anterolateral i.e anterior femoral cutaneous vein and peri-inguinal which are superficial epigastric, superficial circumflex iliac and superficial external pudendal veins. It also receives connecting branches from the popliteal vein via another perforator. As the vein ascends in the thigh it receives branches from the common femoral vein.
- The greater saphenous vein is a superficial vein of the lower limb
- It drains the superficial structures of the medial thigh and leg
- It drains into the common femoral vein at the saphenofemoral junction
- It receives blood from the small saphenous vein, medial marginal vein of the ankle, as well as named perforators from the veins of the thigh and knee region
- It is harvested for use in CABG procedures
- The popliteal vein connects to the greater saphenous vein via the Boyd perforator
- The Dodd perforator connects the common femoral vein to the greater saphenous vein
Coronary Artery Bypass graft (CABG)- Coronary artery disease is the biggest killer in the Western world. It is a complication of hypertension, diabetes and high cholesterol. The saphenous vein can be removed from the leg, and sutured into the heart to bypass a blockage of the coronary arteries. This procedure is known as a heart bypass, and the patient is put on cardiopulmonary bypass during the procedure.
Thrombophlebitis- This condition is characterised by the formation of a thrombus along with inflammation in the superficial veins and involves great saphenous vein in many cases. There is a wide range of predisposing factors including prolonged immobilisation, trauma, malignancies like pancreatic cancer etc. Patients usually present with tender erythematous area overlying the superficial vein, a distended vein may be visible proximal to the thrombus. The occurrence of associated deep venous thrombosis and pulmonary embolism is variable.
Varicose veins- The greater saphenous vein is a superficial vein. The deep veins (posterior tibial, anterior tibial, fibular, popliteal, femoral) are separated from the superficial veins by a series of valves. These valves ensure blood flows from the superficial system to the deep system i.e. prevents backflow. The incompetence of these valves results in varicose veins, which are engorged tortuous veins, that can be tender to the touch. Causes include genetic inheritance, pregnancy, chronic heart disease, obesity and prolonged standing.