IDENTIFICATION OF AN ARTERIOVENOUS-FISTULA DURING FREE TISSUE TRANSFER DESPITE NEGATIVE PREOPERATIVE ANGIOGRAPHY - A POTENTIALLY CORRECTABLE CAUSE OF VENOUS THROMBOSIS

Although refinements in microvascular technique have resulted in great success with free tissue transfer, long-term anastomotic patency, par ticularly venous, is less predictable in patients with a history of in travenous drug abuse or other causes of intimal damage and/or venous h ypertension. We report an unusual case in which an arteriovenous fistu la was identified intraoperatively as the cause of pulsatile venous ba ckflow despite a normal preoperative angiogram. A flow disturbance at the site of venous anastomosis and subsequent development of a venous thrombosis prompted more proximal venous exposure and the identificati on of an arteriovenous fistula. Once ligated, pulsatile venous backflo w resolved and successful revision of the venous anastomosis was perfo rmed. This case illustrates that an anomalous arteriovenous communicat ion must be considered when high-pressure venous backflow is observed intraoperatively, despite no evidence of an arteriovenous fistula on p reoperative angiography, because, if identified and ligated, an arteri ovenous fistula may represent a treatable cause of venous thrombosis. (C) 1998 Wiley-Liss, Inc.