A 1:3 foam of 3% STD will be produced as described for FS. At this point the patient will be repositioned into a Trendelenburg position (head up). The Unifuse® Self-Occluding ball wire will be inserted and the tip correctly positioned at 2cm from the junction under ultrasound guidance. As the internal diameter of the Unifuse® catheter is 1mm (3F) approximately 0.35ml of foam in the 45cm catheter or 0.7ml of form for the 90cm catheter will be injected to fill the dead-space. The appropriate volume of foam will be then be infused through the Unifuse® catheter during withdrawal under ultra-sound guidance. The catheter will be withdrawn the length of the infusion pattern following each injection. The surgeon will endeavour to prevent propagation of fresh foam beyond the perforators and junctions into the deep venous system. The maximum volume of foam used in one sitting is again limited to 12 ml, although the dead space in the catheter will be added to this. Once the varicose vein is treated the total volume of foam used is noted. After ensuring that the axial varicose vein is treated the surgeon can then progress to the treating the tributaries and application of the dressings, as detailed below.