Unlike more invasive procedures that surgically strip veins from the leg, venous ablation surgery uses a catheter, which is inserted through a single and very small incision. The skin is sterilized, local numbing anesthesia is administered, and a small needle is inserted into the vein to be treated using ultrasound for guidance. An external ultrasound transducer is used to study the vein and track its path. It is also used to guide the insertion of the catheter and gauge effectiveness of the procedure.