Asymptomatic vena caval fistulization complicating abdominal aortic aneurysm.

Aortocaval fistulization is usually manifested by signs of rupture of an aneurysm or of the large fistula. Absence of symptoms is unusual with this rare complication. Two cases of asymptomatic aortocaval fistula are presented. An awareness of this possibility should facilitate management when unexpected venous bleeding is encountered.