Chronic iliac vein obstruction as a cause of venous claudication. A plethysmographic and isotope phlebographic study.

Chronic obstruction of the iliac vein may be followed by severe pain, tense swelling and cyanosis of the affected lower limb on exercise (venous claudication). Four patients with venous claudication were examined by strain gauge plethysmography and isotope phlebography. One patient had earlier undergone vein by-pass surgery and one caval ligation. All patients had anatomically abundant, but functionally insufficient cross-over and collateral circulation as the cause of the venous claudication symptom. The venous emptying rate was below normal in all the affected limbs; the venous capacity was low in both limbs in 2 of the 4 patients. It is concluded that in venous claudication isotope phlebography confirms occlusion of the iliac vein and the presence of abundant cross-over veins. The pathologically slow venous return demonstrated by plethysmography in the affected and occasionally also in the unaffected limb, results from the fixed resistance of the cross-over veins.