Panels I and II (separate patients): reformatted oblique axial images (A) and oblique coronal images (B) and a volume rendered image in a right anterior oblique projection (C) show high drainage of the tributary draining the apical segment of the right upper lobe into the superior caval vein while the tributaries draining the anterior and posterior segments of the right upper lobe and right middle lobe are seen draining into the superior vena cava close to the superior vena cava–right atrial junction, straddling the sinus venosus septal defect. A volume rendered image in a posterior projection (D) shows normal drainage of the left-sided pulmonary veins and the right inferior pulmonary veins into the left atrium. Panel III: schematic drawings of the surgical repair of a superior sinus venosus defect with rechannelling of anomalous right superior and middle pulmonary veins using the double-barrel technique. LA: left atrium; PV: pulmonary vein; RA: right atrium; RIPV: right inferior pulmonary vein; RSPV: right superior pulmonary vein; SVC: superior vena cava; SVSD: sinus venosus septal defect. (1A) High cannulation of superior caval vein or brachiocephalic vein or left superior caval vein (if present, not shown). The right atrial appendage is left untouched. Cardiopulmonary bypass is initiated using aortoinferior caval venous cannulation. Two separate atriotomy and cavotomy incisions are made between the stay sutures 1 cm above and below the superior cavoatrial junction, taking care to avoid injury to the sinoatrial nodal artery and the sinus node. (1B) After measuring the length and width of the sinus venosus defect at the superior and inferior locations, an appropriately sized dome-shaped Dacron patch was selected for the intracaval pulmonary venous baffle. (1C and 1D) After excising the excess trabeculae within the right atrial appendage, the systemic venous pathway is reconstructed by atriocavoplasty. Suturing starts from the lower end of the atriotomy appendage to the corresponding margin of the cavotomy using polypropylene suture. (1E and 1F) The completed operation with the right atrial appendage augmenting the superior venocavotomy with a preserved cavoatrial junction and creating a double outlet of the superior caval vein. RAA: right atrial appendage.