Background: One of the rare forms of abdominal aortic aneurysm (AAA) rupture is the rupture into great abdominal veins such as the inferior vein cava (IVC), the iliac veins, or the left renal vein, with the formation of direct or indirect aorto-caval fistula (ACF). The purpose of the present study was to summarize 20 years of experience at a single referral center for vascular surgery in a developing country, and to discuss the clinical presentation, diagnosis, treatment options, and outcome of patients with spontaneous aorto-venous fistulas (AVF) caused by ruptured aortic aneurysms.
Materials and methods: Retrospective database review identified 50 patients treated in our institution for aorto-venous fistulas (AVF) caused by spontaneous AAA rupture in the 20 years 1991-2010. Pulsating abdominal mass and low back pain were the leading symptoms on admission in our patients. Signs of shock, congestive heart failure, or pelvic and lower extremity venous hypertension were present in 48%, 26%, and 75% of the patients, respectively. Diagnosis of AVF was based on physical examination, duplex ultrasonography, conventional angiography, or multislice computed tomography (MSCT). In 40% of the patients the presence of AVF has not been recognized before surgery. All patients were treated with open surgery.
Results: After proximal and distal bleeding control the fistula was closed with direct suture (92%) or patch angioplasty (8%). Aortic reconstruction followed with tubular (22%) or bifurcated (78%) synthetic graft. Six (12%) patients died. The causes of death were excessive intraoperative blood loss, myocardial infarction, left colon gangrene and multiple organ failure.
Conclusions: Spontaneous AVFs caused by aneurysmal rupture are not uncommon, and they require prompt surgical or endovascular treatment. Routine use of multislice CT in patients with acute aortic syndrome is probably the best way to the correct diagnosis of aorto-venous fistulas and planning of the optimal treatment.