Weakening and enlargement of the veins that return blood from the leg to the heart can occur. This may be due to abnormal valves inside the veins. Valves are one-way flaps that keep blood from moving backward. When the valves are diseased, the blood moves backwards in a phenomenon known as reflux. The abnormal veins can be ablated permanently using a minimally invasive procedure. Using ultrasound, the surgeon positions a catheter into the diseased vein through a small incision. The catheter delivers radiofrequency energy to the vein wall. As the catheter is withdrawn, the vein wall is heated causing collagen in the wall to shrink and the vein to close. Outcomes are positive: 90 percent of treated veins have remained reflux free at two years. Patient benefits include less postoperative pain and bruising, return to normal activity within one day and return to work more than a week earlier than patients who undergo vein stripping.