Acute renal impairment due to a primary aortocaval fistula is normalised after a successful operation

Objectives: to study renal function in patients with aortocaval fistula, before and after surgery. Design: Retrospective study. Material and methods: during the last 22 years nine male patients (median age 67, age range 50-72) with spontaneous aortocaval fistula in combination with AAA were operated upon. This constitutes 4% of the patients with ruptured AAA and 1.5% of all patients with AAA. Results: a preoperative diagnosis of aortocaval fistula was established in three of the nine cases. The medium duration of symptoms prior to surgery was 5 days (range 4 h-14 days). The fistula was combined with an extravasating ruptured AAA in only three patients. Seven of the patients had acute renal insufficiency, with creatinine levels of in median 292 mu mol (IQR 218-342). Creatinine declined to 172 mu mol/l (IQR 170-313) on the fifth postoperative day in uncomplicated cases and to 86 mu mol at discharge. One patient died due to multi-organ failure, whereas the other left hospital well and alive with normal renal function. Conclusion: acute preoperative renal insufficiency due to an aortocaval fistula in patients with AAA is often due to venous congestion, and is normalised after successful surgery.