CASE 6932 Published on 04.11.2009

Aorto-caval fistula

Section

Cardiovascular

Case Type

Clinical Cases

Authors

Sathyanarayana R, Rajendran P,
Belfast City Hospital, Belfast

Patient

63 years, female

Clinical History
63-year-old lady presented with sudden onset of abdominal pain radiating to the back.
Imaging Findings
A 63-year-old lady presented to A&E with sudden onset of epigastric pain radiating to the back. She was tachycardic and hypotensive. On examination, a tender pulsatile epigastric mass was noted. CT of the abdominal aorta demonstrated an infrarenal abdominal aortic aneurysm (AAA) complicated by an aorto-caval fistula just above the caval bifurcation. The AAA was deemed unsuitable for an endovascular stent graft and an emergency surgical repair was carried out.
Discussion
Aorto-caval fistula is a rare complication of abdominal aortic aneurysm (0.2-0.9%). Because of the rarity of the condition, clinical diagnosis is difficult unless the classic clinical triad is present. The clinical triad of abdominal pain, palpable aneurysm and continuous bruit are reported to be present in 80-90% of cases. The resulting arterio-venous fistula may produce high-output cardiac failure, systemic arterial hypotension leading to shock syndrome and/or systemic venous hypertension producing lower limb edema and cyanosis. The fistula, as in our case, is reported to commonly occur between the right postero-lateral aspect of AAA and the inferior vena cava (IVC) at or immediately above its bifurcation. Modern multi-detector CTs are better in demonstrating the actual site of fistula however this may be missed if attention is not paid to the key finding which is early/simultaneous contrast opacification of IVC. Prompt diagnosis and treatment are essential to prevent the invariably fatal outcome. Endovascular stent graft or open surgical repair are the treatment options.
Differential Diagnosis List
Abdominal aortic aneurysm complicated by Aorto-caval fistula.
Final Diagnosis
Abdominal aortic aneurysm complicated by Aorto-caval fistula.
Case information
URL: https://www.eurorad.org/case/6932
DOI: 10.1594/EURORAD/CASE.6932
ISSN: 1563-4086