High-Output Heart Failure Caused by Abdominal Aortic Aneurysm-Inferior Vena Cava Fistula Due to Blunt Trauma

A 73-year-old man suffered abdominal bruising from the airbag in a vehicle accident 1 month prior to his admission to our hospital. The day after the accident, he noted dyspnea on exertion. The symptom gradually progressed in the absence of abdominal pain. A physical examination revealed significant bilateral lower extremity pitting edema and a fist-sized pulsatile abdominal mass. Chest X-rays showed cardiomegaly and bilateral pleural effusion. Echocardiography showed hyperdynamic left ventricular systolic function (ejection fraction 70%) and enlarged right heart cavities. Abdominal ultrasound revealed an approximately 8-cm-diameter abdominal aortic aneurysm (AAA) with an aortocaval fistula (ACF), as evidenced by a jet effect of aortic blood flow into the inferior vena cava (IVC; Figure A,B). Contrast-enhanced computed tomography revealed the large fusiform AAA and IVC enhancement almost concurrent with the arterial phase through the ACF (Figure C–E). The IVC was compressed by the AAA. The patient was diagnosed with high-output heart failure due to the ACF. On Day 15 of admission, the patient underwent endovascular stent-graft treatment for the large AAA with ACF (Figure F,G). Three days after the procedure, his heart failure symptoms were significantly improved.

Figure.

(A) Abdominal ultrasound showing abdominal aortic aneurysm (AAA). IVC, inferior vena cava. (B) Color Doppler imaging revealed continuous flow from the AAA into the IVC. (C–E) Contrast-enhanced computed tomography revealed the large fusiform AAA and IVC through the aortocaval fistula (arrows). 3-D, 3-dimensional. (F,G) Aortography after endovascular stent-graft treatment demonstrating no leakage from the aortocaval fistula.

ACF is one of the causes of high-output heart failure. Less commonly, ACFs are caused by trauma. The majority of acute ACF cases are caused by sharp trauma, and ACFs caused by blunt trauma are extremely rare. Pressure and tension from large aneurysms produce necrosis of the aortic wall, and the diseased aorta adheres to the adjacent IVC.¹ We speculate that the indirect impact due to blunt trauma to the vulnerable site in pre-existing AAA caused the ACF and that the ACF location close to the heart may have caused heart failure.

Disclosures

None.

Reference

• 1.   Brightwell RE, Pegna V, Boyne N. Aortocaval fistula: Current management strategies. ANZ J Surg 2013; 83: 31–35, doi:10.1111/j.1445-2197.2012.06294.x.