Ilio-Iliac Arteriovenous Fistula Secondary to a Ruptured Right Common Iliac Artery Aneurysm and Anomalous Anatomy of Inferior Vena Cava Resulting in an Arteriovenous Shunt Formation with Right-sided Cardiac Failure: A Case Report.

Introduction: An ilio-iliac arteriovenous fistula (IIAVF) secondary to the rupture of a common iliac artery aneurysm (CIAA) is rare. Sudden arteriovenous shunting and subsequent fistula enlargement can result in acute cardiac failure. Immediate diagnosis and treatment are required; however, the clinical symptoms differ from those of a free wall rupture of an aortic aneurysm, making a quick diagnosis difficult. Thus, we reported the case of a patient with severe right-sided cardiac failure, due to an arteriovenous shunt formation secondary to an IIAVF who underwent an artificial blood vessel replacement with favorable results.
Case Presentation: A 71-year-old male patient presented to our hospital with polypnea and palpitations. Initial early-phase computed tomography (CT) revealed a 60-mm-in-diameter right CIAA and an inferior vena cava (IVC) dilatation. Severe congestive heart failure, due to an arteriovenous shunt formation secondary to an IIAVF was diagnosed. The massive shunt of blood flowed from the right common iliac artery (CIA) to the right common iliac vein (CIV). He underwent an emergency open abdominal aortic replacement. The IVC ran anomalously anterior to the giant right CIAA and strongly adhered to the IVC and right CIV. Two guidewires were inserted from the bilateral femoral veins into the IVC intraoperatively. Moreover, an occlusion balloon was inserted into the right CIV. Thus, bleeding from the fistula was well-controlled by the time of aneurysm opening. The proximal side of the artificial graft was anastomosed to the abdominal aorta, while the right and left peripheral branches of the prosthesis were anastomosed to the right external iliac artery and left CIA, respectively.
Conclusions: We reported the case of a giant right CIAA that directly created a shunt into the right CIV. Contrast-enhanced CT is a useful method for confirming the working diagnosis of an IIAVF. In particular, in cases of IVC anomalies or strong perivenous tissue adhesions, bleeding can be controlled using devices, such as occlusion balloons and a meticulous surgical plan.
Competing Interests: The authors declare that they have no competing interests.
(© 2025 The Author(s). Published by Japan Surgical Society.)