Aortocaval fistula in ruptured inflammatory abdominal aortic aneurysm. A report of two cases and literature review.

Inflammatory abdominal aortic aneurysms (IAAA) occur infrequently in clinical practice. The reported incidence varies from 2.5-15% of all abdominal aortic aneurysms (AAA). Four percent of all AAA rupture into the vena cava. IAAA rupturing into the vena cava is exceedingly rare. To date, four such cases have been reported. IAAA are associated with a thick, rigid aortic wall which may be thin posteriorly and posterolaterally, where they are likely to rupture. A dense, fibrotic, desmoplastic reaction is found in the periaortic tissues often involving the duodenum, the inferior vena cava, the left renal vein, and ureters. IAAA may present with abdominal, back, or flank pain even in the absence of rupture. The diagnosis of IAAA can be made preoperatively by CT scan and at the time of laparotomy. Aortocaval fistula (ACF) can occur as a complication of AAA. The triad of low back pain, a palpable AAA, and a machinery murmur is diagnostic. ACF in association with IAAA is even more rare. It is amenable to surgical correction using a standard technique of fistula repair from within the aneurysm and prosthetic aortic graft replacement. Two cases of AAA with aortocaval fistula (ACF) are presented. In both, the diagnosis of ACF was made preoperatively. Repair of ACF was performed from within the aneurysm, with subsequent graft replacement. Despite complicated postoperative courses, both patients survived.