The arterial duct is tied off, and the venous cannula is removed. The septum primum is resected. This is generally first attempted through the venous purse-string. If the atrial septum is deviated far posteriorly so that its exposure is difficult, then a small atriotomy can be made along the right atrioventricular groove, and the septum resected through the atriotomy. The coronary sinus may be cut back into the left atrium at this time.
Attention is directed towards reconstruction of the ventricular outflow tract.
The pulmonary trunk is divided at it s bifurcation, the ductus arteriosus is doubly ligated and divided, and all residual ductal tissue is removed from the aortic side. The spoon-shaped clamp is replaced on the distal descending aorta, and the distal aorta is incised 1 cm past the ductus insertion site. The underside of the transverse and ascending arch are incised to the point where the aorta exactly meets the facing commissure of the divided pulmonary artery. The reverse-bite Potts scissors are best for opening the undersurface of the aorta. The incision starts distally at the ductus insertion site, and proceeds proximally, The first-assistant gently retracts the divided lip of the aorta to aid in exposure.