Great Saphenous Vein
The great saphenous vein (GSV), also long saphenous vein, is the large (subcutaneous) superficial vein of the leg and thigh. The GSV originates from where the dorsal vein of the first digit (the large toe) merges with the dorsal venous arch of the foot. After passing anterior to the medial malleolus (where it often can be visualized and palpated), it runs up the medial side of the leg. At the knee, it runs over the posterior border of the medial epicondyle of the femur bone. The great saphenous vein then courses laterally to lie on the anterior surface of the thigh before entering an opening in the fascia lata called the saphenous opening. It joins with the femoral vein in the region of the femoral triangle at the saphenofemoral junction.