Absent right superior vena cava with persistent left superior vena cava which drains to unroofed coronary sinus in a child with atrioventricular septal defect and cor triatriatum sinister: preop correct diagnosis and successful surgery in a single session.

We report a unique case of a 4-year-old boy with intermediate-type atrioventricular septal defect, cor triatriatum sinister, persistent left superior vena cava, unroofed coronary sinus, and absent right superior vena cava. Persistent left vena cava draining into the unroofed coronary sinus was demonstrated easily using the agitated saline-contrast echocardiography. After conformation with angiographic evaluation, surgery was performed at a single session. Roofing of the coronary sinus with polytetrafluoroethylene patch, mitral cleft repair, tricuspid annuloplasty, atrioventricular defect repair with pericardial patch, and resection of the membrane in the left atrium was succeeded without complication.