Spontaneous aortocaval fistula: CT findings with pathologic correlation

Abstract

We present a case of aortocaval fistula (ACF) secondary to spontaneous rupture of an atherosclerotic infrarenal aortic aneurysm into the inferior vena cava that was initially diagnosed with computed tomography (CT). This is believed to be the first report of this condition with CT demonstration of the exact site of fistula and CT-pathologic correlation. We retrospectively reviewed the CT findings of another two cases of ACF and the previous literature.

Aortocaval fistula: diagnosis with carbon dioxide angiography

“…The fistula site may also be identified [4 -6, 8]. Secondary signs described include dilatation of the IVC at the level of the porta hepatis [5,6], dilatation of retroperitoneal and pelvic veins, and dilated enhancing renal veins equivalent to the aorta despite poor enhancement of the kidneys. Potential limitations of this modality are inconsistency in demonstration of the fistula site and inability to use contrast in patients with marked hypersensitivity or, as in our case, renal impairment.…”

“…Diagnosis of ACF with magnetic resonance (MR) imaging and MR angiography have also been described [3][4][5][6][7][8]. As noted in prior reports, patients presenting with ACF often have oliguric renal insufficiency, which discourages the use of iodinated contrast material.…”

Arteriovenous fistula secondary to iliac mycotic aneurysm: helical CT findings

“…Other possible related CT findings include distention of the venous structures (IVC, renal veins, iliac veins) and retrograde flow to the renal and iliac veins [13,14,17]. If an arteriovenous fistula is present, prompt surgery is necessary to prevent fatal cardiac failure.…”

“…If an arteriovenous fistula is present, prompt surgery is necessary to prevent fatal cardiac failure. Preoperative diagnosis of arteriovenous fistula is also important for the surgeon because paradoxical pulmonary embolism and massive venous bleeding are known complications if the aneurysm is manipulated before the fistula is closed [8,13,15,18].…”

“…The clinical signs of arteriovenous fistula include a continuous abdominal bruit, high-output cardiac failure, renal failure because of reduced arterial perfusion and venous engorgement, hepatomegaly due to hepatic venous congestion, and edema of the lower limbs [12][13][14][15].…”