Iliofemoral venous obstruction without thrombosis.

Nonthrombotic iliofemoral venous obstruction, masquerading as deep vein thrombosis, was diagnosed in four patients. In each instance the patient was hospitalized and intravenous heparin therapy was started. Phlebography demonstrated venous outflow obstruction without thrombosis; subsequent CT scanning revealed an obstructing lesion in each case. At surgical exploration, (1) endoaneurysmorrhaphy of a hypogastric artery aneurysm decompressed an obstructed right iliac vein; (2) a primary iliac vein leiomyosarcoma was extirpated; (3) a synovial cyst arising from the right hip joint, which obstructed the femoral vein, was excised; and, (4) a postherniorrhaphy inflammatory mass obstructing the left iliofemoral vein junction was confirmed with biopsy results. Improved diagnostic accuracy with its attendant specific therapy is achieved in suspected cases of iliofemoral vein thrombosis if, in addition to noninvasive venous studies or phlebography, CT scanning of the abdomen and pelvis is performed.