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Surgery for chronic vein insufficiency.

1. Although varicose veins are the most prevalent form of venous insufficiency, obstruction or valvular incompetence of the deep system produces the most severe forms of lower extremity venous insufficiency and is responsible for most cases of leg ulceration of venous etiology. 2. With careful patient selection, surgery for varicose veins can be successful. Deep venous surgery, however, has limited indications and still carries a high failure rate; it should only be indicated in selected patients after conservative therapy has failed. 3. The main causes for failure of deep venous surgery are the low pressure and low velocity flow characteristics of the venous system that favor thrombosis.