Protection of the sinus node in Mustard's operation.

The occurrence of dysrhythmias after the Mustard operation for transposition of the great arteries was compared in 70 patients operated upon before and 58 patients operated upon after January 1972 when surgical modifications aimed at preserving the sino-atrial node and its arterial supply were initiated. The surgical modifications included changing the site of the superior vena cava (SVC) cannulation away from the SVC-right atrial junction, incision into the right atrial wall anterior to the sulcus terminalis, and sewing of the superior part of the baffle patch away from the sino-atrial node area. A significant decrease in the incidence of dysrhythmias occurred in the group of patients operated upon after the surgical modifications. The modifications in surgical technique have reduced but not avoided dysrhythmias.