AORTOCAVAL FISTULAS PRESENTING WITH RENAL-FAILURE - CT DIAGNOSIS

We describe two patients who presented with acute renal failure second ary to aortocaval fistulae, which were demonstrated by computed tomogr aphy (CT) and confirmed at surgery. Renal function rapidly returned to normal following appropriate surgery. In addition to the expected CT findings of early equal enhancement of the inferior vena cava and aort a and dilation of the inferior vena cava, there was early enhancement of dilated renal veins despite poor contrast enhancement of the kidney s. It is postulated that retrograde flow of blood from the aortocaval fistula may cause renal impairment secondary to renal venous hypertens ion.