Neonatal repair of left atrial diverticulum with gigantic thrombus without cardiopulmonary bypass.

A 5-day-old neonate with coarctation of the aorta, hypoplastic aortic arch, large apical muscular ventricular septal defect, and patent ductus arteriosus developed pulmonary over-circulation and systemic hypoperfusion underwent bilateral pulmonary artery banding through median sternotomy as a part of hybrid stage I palliation. At operation, left atrial diverticulum with gigantic thrombus formation at the base of the left atrial appendage was incidentally detected by intraoperative direct echocardiography, and therefore, was successfully resected with the whole thrombus inside it without use of cardiopulmonary bypass. Histopathological finding was compatible with diverticulum. The patient was free from atrial arrhythmia and recurrent thrombus formation.