Acute aortocaval fistula in association with ruptured aortic aneurysm.

Eight cases of aortocaval fistula are described. In all of them operation was performed with repair of the fistula and replacement of the aneurysm by a prosthetic graft. In seven cases the cause was rupture of an atherosclerotic aneurysm but one case followed rupture of a re-entrant dissecting aortic aneurysm. A fistula is most easily recognized by the sensation of a palpable thrill over the aorta during operation together with systemic venous congestion and a high central venous pressure before aortic clamps are applied. Diagnosis of the fistula before surgery or its recognition during operation and before opening the aorta usually leads to a successful outcome.