Aorto-caval fistula is a rare and devastating complication of abdominal aortic aneurysm (AAA), wherein the aneurysm erodes into the inferior vena cava.
Spontaneous rupture of an AAA into the adjacent vena cava occurs in <1% of all aneurysms and in ~3% of ruptured aortic aneurysms 1.
The features can be very atypical leading to a delay in diagnosis. The various factors that influence the clinical presentations are the origin, size, location and duration of the fistula:
- high output cardiac failure
- bilateral pedal oedema (venous hypertension in the lower half of body)
- renal insufficiency (reduced renal blood flow)
- continuous bruit
Aortography is the modality of choice. Colour Doppler, CT and MRI may also demonstrate the same non-invasively. At times, the presence of a mural thrombus may obstruct the fistula.
Treatment and prognosis
Surgical exploration and repair is urgent. Operative mortality of spontaneous aortocaval fistula is about 20 to 55%, the deaths being predominantly due to delayed or mis-diagnosis.
- acute aortic syndrome
- thoracic aortic aneurysm
- abdominal aortic aneurysm
- endovascular aneurysm repair (EVAR)
- reporting tips for aortic aneurysms
- aortic coarctation
- aortic pseudocoarctation
- cervical aortic arch
- interrupted aortic arch
- transposition of the great arteries
- variant anatomy of the aortic arch
- traumatic aortic injuries
- 1. Erratum. Therap Adv Gastroenterol. 2000;5 (3): 371. Therap Adv Gastroenterol (full text) - doi:10.1177/021849230000800321 - Free text at pubmed - Pubmed citation
- 2. Baker WH, Sharzer LA, Ehrenhaft JL. Aortocaval fistula as a complication of abdominal aortic aneurysms. Surgery. 1973;72 (6): 933-8. Pubmed citation
- 3. Steinke TM, Reber PU, Hakki H et-al. Haematuria and an abdominal aortic aneurysm-warning of an aortocaval fistula. Eur J Vasc Endovasc Surg. 1999;18 (6): 530-1. doi:10.1053/ejvs.1999.0940 - Pubmed citation