A great saphenous vein that needs treatment is not functioning properly. When a vein is diseased, the walls become weak and the vessel can dilate or grow triple its’ normal size. This is not the type of vessel that would be ideal to place in a diseased heart. While the saphenous vein is a common vein that is harvested for bypass grafts, there are other options such as the internal thoracic artery in the chest and the radial artery which is in the arm. With these options, an artery replaces an artery and the removal of the valves inside the veins is not necessary. It is important for the entire circulatory system to be functioning properly, together.