Hematuria as a sign of aorto-caval fistula.

An aorto-caval fistula is a rare complication of an abdominal aortic aneurysm (AAA). Typical features, including congestive heart failure and a loud abdominal bruit, may be present and allow prompt diagnosis, but not infrequently they are absent or overlooked and the diagnosis not made preoperatively. Four patients with an AAA and an aorto-caval fistula are described, each of whom presented with hematuria. We believe the presence of hematuria in a patient with a symptomatic AAA should suggest the diagnosis of an aorto-caval fistula. A correct preoperative diagnosis may contribute to better planning of the operative procedure, reduced blood loss, and avoidance of possible pulmonary embolization.