Currently, sclerotherapy is the treatment of choice for eliminating most unwanted leg spider veins and small to medium-sized varicose veins. Sclerotherapy is performed as an in-office procedure. Salt water or a chemical solution is injected directly into the abnormal veins with a small needle. The vein hardens and disappears. Following this 15 to 20-minute treatment, you can resume all activities. A support stocking should be worn during the daytime for a few days after the procedure to aid in the closure of the veins.