Which superficial vein is NOT commonly used as a bypass graft?

The superficial femoral vein is not commonly used as a bypass graft because it is classified as a deep vein rather than a superficial vein. Bypass grafts typically utilize superficial veins, which are more accessible during surgical procedures and often have better long-term patency when used in arterial bypass. In contrast, the superficial femoral vein is part of the deep venous system and is primarily involved in the drainage of the leg's deep structures, making it less suitable for bypass grafting.

The other veins mentioned, such as the greater saphenous vein, cephalic vein, and basilic vein, are frequently harvested for grafting procedures due to their superficial location, ease of removal, and favorable characteristics for arterial reconstruction.