The veins that can be treated are in the superficial venous system. These veins are located in the subcutaneous tissue and are only responsible for a very small amount of blood return from the legs. All of the diseased superficial veins can be treated because once these veins are closed, the blood is re-routed into the deep veins. The deep system is a more competent system and can accommodate all of the blood from the superficial veins. So, every last problematic superficial vein can be treated with great success.