Aberrant Aortopulmonary Venous Fistula: An Intraoperative Surprise.

An isolated systemic artery to pulmonary vein arteriovenous fistula is a rare clinical entity. We report a 20-year-old woman diagnosed with myxomatous mitral valve prolapse with severe mitral regurgitation and planned for mitral valve repair. An aberrant aortopulmonary venous fistula was suspected intraoperatively due to flooding of the left atrium with blood from the left inferior pulmonary vein on cardiopulmonary bypass. The mitral valve was repaired successfully. A postoperative computed tomography angiogram revealed an anomalous fistula between the descending thoracic aorta and left inferior pulmonary vein. The patient underwent successful percutaneous device closure of the fistula.