Superficial Veins
The superficial veins of the lower extremity are the greater and lesser saphenous veins.
The greater saphenous vein (GSV) runs from the top of the foot and the inside of the ankle towards the groin, where it joins the deep system. It courses along the inner calf, across the inside of the knee and up the inside of the thigh. The GSV is the most common source of leg vein failure.
The lesser saphenous vein (LSV) or short saphenous vein (SSV) runs from the back of the foot and ankle, up the back of the calf and joins the deep system behind the knee. It may also give off a branch that continues up the back of the thigh to communicate with the greater saphenous vein.
When these veins of the leg fail, or become incompetent, the smaller tributary veins that empty into them can become dilated from increased pressure. With time these branch veins may become visible varicose veins.
