Radio Frequency Ablation Greater saphenous vein (GSV) reflux is the most important pathophysiologic component of primary venous insufficiency. Radiofrequency ablation (RFA) is a minimally invasive percutaneous technique using thermal energy to ablate incompetent veins. This technique is used primarily to treat insufficiency of the axial veins (great, small, or accessory saphenous veins). Intersaphenous veins or perforator veins can also be treated with specialized probes. It is similar in effect to endovenous laser ablation.