Abstract
A 27-year-old male patient presented 3 years ago with a fistula between the right common iliac artery and the left common iliac vein which developed after lumbar disk surgery. The fistula was successfully treated with placement of an endovascular stentgraft in the proximal right common iliac artery at that time. Annual follow-up abdominal computed tomography (CT) was performed. Three years after treatment an arterial phase CT demonstrated redevelopment of the fistula (Fig. A). A small outpouching (4 mm) from the right common iliac artery is evident extending towards the left common iliac vein at the site of fistula formation which was at the mid level of the stentgraft with contrast opacifying the inferior vena cava (IVC) and extending down a distended left common iliac vein consistent with arteriovenous fistula (AVF). Axial CT (Fig. B) shows contrast enhancement of the infrahepatic IVC (straight arrow) which should not occur during arterial phase unless there is an AVF. The patient’s conventional angiogram performed at the time of initial diagnosis three years earlier is presented for comparison (Fig. C). This image demonstrates contrast traversing from the right common iliac artery to the left common iliac vein with distension of the IVC typical of an AVF.