Spontaneous aortocaval fistula: CT findings with pathologic correlation

Spontaneous ilio-iliac arteriovenous fistula: A rare complication of aorto-iliac aneurysm

Ilio-iliac arteriovenous fistula is an unusual complication of aorto-iliac aneurysms that can occur spontaneously, traumatically or iatrogenically. The typical clinical presentation includes the characteristic triad of high-output heart failure, a pulsatile abdominal mass with unilateral limb ischemia, or signs of venous congestion. We describe a rare case of spontaneous rupture of an aortoiliac aneurysm into the left common iliac vein of a 65-year-old man, easily diagnosed by angiography. We highlight here the angiographic findings of the ilio-iliac fistula, which was the means of diagnosis in this presentation, especially in patients with atypical clinical features at the outset, and we report the difficulties in choosing the optimal vascular approach.

Images in medicine: Spontaneous aortocaval fistula complicating abdominal aortic aneurysm

Aortocaval fistula represents a rare, life-threatening complication of abdominal aortic aneurysm that needs emergency surgical treatment. The presentation couples that of a rupturing aneurysm with other more characteristic features resulting from the massive arteriovenous shunt. Early recognition and emergency surgical treatment are essential in reducing mortality and morbidity. Prompt investigation with multidetector computed tomography (CT) angiography quickly and accurately establishes a precise preoperative diagnosis, thereby enabling proper planning of operative treatment.

Iliocaval arteriovenous fistula presenting with multiple organ failure

Iliac arteriovenous fistulas are an uncommon condition, which may be spontaneous or traumatic in nature. Such fistulas classically present with a triad of high-output cardiac failure, pulsatile abdominal mass with a bruit and unilateral leg ischaemia or venous congestion. We describe a case of an iliocaval fistula secondary to rupture of a common iliac artery aneurysm, with an unusual presentation of multiple organ failure, masquerading as sepsis. We describe the CT findings of iliocaval fistula, which was the means of diagnosis in this study.

CT of acute abdominal aortic disorders

Aortic aneurysm rupture, aortic dissection, PAU, acute aortic occlusion, traumatic aortic injury, and aortic fistula represent acute abdominal aortic conditions. Because of its speed and proximity to the emergency department, helical CT is the imaging test of choice for these conditions. MR imaging also plays an important role in the imaging of aortic dissection and PAU, particularly when the patient is unable to receive intravenous contrast material. In this era of MDCT, conventional angiography is used as a secondary diagnostic tool to clarify equivocal findings on cross-sectional imaging. Ultrasound is helpful when CT is not readily available and the patient is unable or too unstable to undergo MR imaging.

Acute aortic abnormalities

Aneurysm and type B dissections account for most acute abdominal aortic abnormalities. The postsurgical aorta deserves special attention owing to the risk of complications. Most aortic abnormalities presenting acutely are emergencies that carry a high risk of mortality, and imaging plays a critical role in patient evaluation. Modern helical CT scanners provide excellent spatial resolution, are readily available, and allow for rapid imaging. For these reasons, helical CT angiography is the imaging modality of choice for initial evaluation of the acute aorta.