Radiofrequency ablation is a minimally invasive procedure which uses heat energy to seal off varicose veins. The procedure involves inserting a catheter into the problem vein in the leg and uses ultrasound to guide the catheter. Once in place, an electrode on the catheter uses radiofrequency, or heat, energy to close the vein. Blood flow is then automatically directed to other healthy veins. The procedure lasts about an hour and requires no hospital stay. Use of compression stockings are usually recommended for at least one week afterwards.