Superficial Veins
Superficial veins of the lower limbs are those located between the deep fascia, covering the muscles of the limb, and the skin. The main superficial veins are the great saphenous vein (GSV) and the small saphenous vein (SSV). All previous names used to describe these vessels (greater, long, lesser) should be abandoned. The GSV originates from the medial superficial veins of the dorsum of the foot and ascends in front of the medial malleolus along the medial border of the tibia, next to the saphenous nerve (Fig 1). There are posterior and anterior accessory saphenous veins in the calf and the thigh. The saphenofemoral junction (SFJ) is the confluence of superficial inguinal veins, comprising the GSV and the superficial circumflex iliac, superficial epigastric, and external pudendal veins. The GSV in the thigh lies in the saphenous subcompartment of the superficial compartment, between the saphenous fascia and the deep fascia.
The SSV is the most important posterior superficial vein of the leg (Fig 2). It originates from the lateral side of the foot and drains blood into the popliteal vein, joining it usually just proximal to the knee crease. The intersaphenous vein (vein of Giacomini), which runs in the posterior thigh, connects the SSV with the GSV.
Deep veins
Deep veins accompany the main arteries of the limb and pelvis. The deep veins of the calf (anterior, posterior tibial, and peroneal veins) are paired structures, and the popliteal and femoral veins may also be paired. The gastrocnemius and soleal veins are important deep tributaries. The old term superficial femoral vein has been replaced by the new term femoral vein. The femoral vein connects the popliteal to the common femoral vein.
The pelvic veins include the external, internal, and common iliac veins, which drain into the inferior vena cava (IVC). Large gonadal veins drain into the IVC on the right and the left renal vein on the left.
Perforating veins
Perforating veins connect the superficial to the deep venous system (Fig 1). They pass through the deep fascia that separates the superficial compartment from the deep. Communicating veins connect veins within the same system. The most important leg perforating veins are the medial calf perforators. The posterior tibial perforating veins (Cockett perforators in the old nomenclature) connect the posterior accessory GSV of the calf (the posterior arch vein in the old nomenclature) with the posterior tibial veins and form the lower, middle, and upper groups. They are located just behind the medial malleolus (lower) at 7 to 9 cm (middle) and at 10 to 12 cm (upper) from the lower edge of the malleolus. The distance between these perforators and the medial edge of the tibia is 2 to 4 cm (Fig 1). Paratibial perforators connect the main GSV trunk with the posterior tibial veins. In the distal thigh, perforators of the femoral canal usually connect directly the GSV to the femoral vein.
Venous valves
Bicuspid venous valves are important structures assisting unidirectional flow in the normal venous system. The GSV usually has at least 6 valves (range, 4-25), with a constant valve present within 2 to 3 cm of the SFJ in 85% of cases and the SSV has a median of 7 to 10 valves (range, 4-13).There are valves in the deep veins of the lower limb, but the common femoral or external iliac vein has only one valve in about 63% of cases. In 37%, there is no valve in the common femoral or external iliac veins. The internal iliac vein has a valve in 10%; its tributaries have valves in 9%.