Collateral circulation secondary to upper extremity venous thrombosis visualized during excretory urography.

Unsuspected upper extremity venous thrombosis was observed in three patients undergoing excretory urography. Thoraco-abdominal collateral vessels were readily visible following an intravenous bolus injection of contrast material into a vein in the affected extremity. The increased incidence of upper extremity venous thrombosis is probably due to the frequent use of subclavian vein catheterization for parenteral nutrition, central venous monitoring, and cardiac pacing. The collateral pathways are characteristic and can easily be recognized.