Current treatments for varicose veins and spider veins have very high success rates compared to traditional surgical treatments. Over a period of years, however, more abnormal veins can develop. The major reason for this is that there is no cure for weak vein valves. So with time, pressure gradually builds up in the leg veins. Ultrasound can be used to keep track of how badly the valves are leaking (venous insufficiency). Ongoing treatment can help keep this problem under control.