Kohinur, 60yrs woman,has a left femoral venous thrombosis during a pregnancy 30 year ago.The left greater saphenous vein had been stripped at age 21.She now presents with a large non healing ulceration over the medical left calf,which has continuously progressed despite bedrest,elevation,and use of a support stocking.Descending phlebography of the left leg demonstrates a patent deep venous system,with free flow of dye from the groin to foot.The first profunda femoris valve is competent.Which of the following is appropriate management?

• A. Ligated illiofemoral venous thrombectomy with creation of the temporary arteriovenous fistula
• B. Subfascial ligation of perforating veins in the left calf
• C. Division of the superficial femoral vein in the groin and transposition of its distal end onto the profunda femoris vein below the level of the competent profunda valve
• D. Saphenous venous crossover graft with asastomosis of the end of the right saphenous vein onto the side of competent femoral vein