A Case of Aortopulmonary Artery Fistula

Abstract

Acute aortopulmonary artery fistula is a rare but potentially fatal disorder. We encountered a case in which this disorder was successfully treated by urgent total arch graft replacement and repair of the left pulmonary artery. A 74-year-old man was referred to Shizuoka City Hospital with a 2-day history of worsening dyspnea and thoracic aortic aneurysm. The patient had a history of hypertension and dyslipidemia. Physical examination showed diastolic hypotension, marked peripheral coldness, and systolic murmur. Arterial blood gas analysis showed severe metabolic acidosis with base excess of −16 mmol/l. Contrast-enhanced computed tomography (CT) revealed an aortic arch aneurysm on the lesser curvature, almost obstructing the left pulmonary artery. A Swan-Ganz catheter study confirmed severe low-output syndrome and uncompensated congestive heart failure. After amelioration of critically ill conditions with dopamine, milrinone, and carperitide, oxymetry revealed significant left-to-right shunt with Qp/Qs＝3.2 at the pulmonary artery level. Acute aortopulmonary artery fistula was diagnosed and urgent surgery was planned. Transesophageal echocardiography showed systolic shunt flow from the aneurysm into the left pulmonary artery. Surgery was performed through a median sternotomy. Aortic arch graft replacement with a 24-mm Dacron graft and repair of the left pulmonary artery with an equine pericardial patch were accomplished under hypothermic circulatory arrest and selective antegrade cerebral perfusion. Flooding of pulmonary circulation until circulatory arrest was prevented by manual control through the main pulmonary artery incision. Postoperative recovery was uneventful, and the patient is doing well at one year postoperatively.