Ruptured Infrarenal Abdominal Aortic Aneurysm with Aortocaval Fistula: Open Surgical Repair and Clinical Outcome

Background: Aortocaval fistula (ACF) is a rare but life-threatening complication of abdominal aortic aneurysm (AAA), occurring in approximately 1% of all AAAs and up to 6% of ruptured cases. It results from progressive erosion of the aneurysmal wall into the inferior vena cava, creating a pathological arteriovenous communication that may lead to high-output cardiac failure, venous hypertension, and renal dysfunction. Because clinical manifestations are highly variable, diagnosis is often delayed. Computed tomography angiography remains the diagnostic modality of choice, allowing visualization of early venous opacification and characterization of aneurysm morphology. Case Presentation: We report the case of a 65-year-old woman presenting with acute abdominal pain and exertional dyspnea. CT angiography demonstrated a 68-mm infrarenal ruptured AAA with early opacification of the inferior vena cava, confirming an ACF. Despite the rupture, the patient remained hemodynamically stable, with preserved renal function and normal laboratory parameters. Management: Emergency open surgical repair was performed through a midline laparotomy. After proximal and distal vascular control, the aneurysm sac was opened, revealing a large fistulous defect on the right posterolateral aortic wall. The venous defect was closed with interrupted sutures, followed by an aortobi-iliac bypass using a bifurcated prosthetic graft. Postoperative recovery was uneventful, and the patient was discharged on postoperative day 8. At 30-day follow-up, she remained asymptomatic, and Doppler ultrasound confirmed graft patency without residual arteriovenous communication. Conclusion: Aortocaval fistula remains an uncommon but severe complication of infrarenal AAA. Early recognition and prompt surgical intervention are essential to reduce morbidity and mortality. While endovascular repair is an emerging alternative in selected patients, open repair continues to be the standard approach in many settings, particularly where endovascular resources are limited or when the fistula is large or anatomically complex.