The radiofrequency ablation system (or RF ablation) by VNUS™, also known as Venefit™ (formerly called the VNUS Closure™ procedure) is a minimally invasive varicose vein treatment procedure that uses targeted radiofrequency energy (electricity) to heat, collapse and seal off the targeted blood vessels. After using ultrasound to determine the course of the vein to be treated, the physician guides a catheter through a small incision into the diseased vein, threading it through the blood vessel into the groin area. Electricity is delivered, heating and contracting the collagen within the walls of the vein until they shrink and shut down. This process is called ablation. The vein is treated in segments as the catheter is gradually inched back down towards the incision. When the entire vein has been ablated, the blood flow is automatically rerouted through healthier adjacent veins, restoring healthy circulation and reducing swelling. The ablated vein becomes scar tissue and is absorbed by the body. Venefit radiofrequency treatment is an alternative to more invasive leg stripping surgery or endovenous laser treatment. It is used primarily to treat the great saphenous vein (GSV), small saphenous vein (SSV), and other superficial veins in the legs.