A Case of Surgical Treatment for a Large Pulmonary Artery Aneurysm with a Quadricuspid Pulmonary Valve.

A 65-year-old man was referred to our hospital for the annual assessment of the diameter and dilation of a pulmonary artery (PA) aneurysm. He had a small ventricular septal defect (VSD) that had closed naturally. Echocardiography revealed a dilated main PA, mild pulmonary regurgitation and no VSD. Computed tomography confirmed the dilation of the main PA (66.7×47.8 mm), right PA (37.1×32.9 mm), and left PA (36.7×34.0 mm). The patient underwent pulmonary artery replacement using a prosthetic vascular graft. A quadricuspid pulmonary valve was identified intraoperatively. Early surgical intervention could help to prevent rupture and dissection of PA aneurysms.