Aorto-caval fistula

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)
  • haematuria
  • 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.

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. 

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Article information

rID: 25602
System: Vascular
Section: Pathology
Synonyms or Alternate Spellings:
  • Intracaval aortic fistula
  • Aorto-caval fistulation
  • Aortocaval fistula
  • Aortocaval fistulation

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