Chronic venous insufficiency: assessment with descending venography.

Six hundred forty-four legs were examined by means of descending venography in patients with chronic venous insufficiency. Three patient positions (supine, 30 degrees semierect, and 60 degrees semierect) were used with a standard angiographic technique. Patients were also studied during either normal respiration or a Valsalva maneuver. The deep venous valvular system was incompetent more often than the superficial (saphenous) venous system. Positive venograms revealed that reflux occurred into the deep venous system alone in 82%, the superficial venous system alone in only 2%, and a combination of deep and superficial systems in 16%. The authors conclude that descending venography is best performed at the more physiologic 60 degrees semierect position and with the Valsalva maneuver, which enables evaluation of the competence of valves in the closed position.