Corrected transposition and repair of associated intracardiac defects.

From August 1974 through April 1981, 23 patients, ages 5 months to 40 years (median 11 years) with corrected transposition of the great arteries (C-TGA), underwent repair of associated intracardiac defects: 20 for ventricular septal defect (VSD), 19 for pulmonary outflow tract obstruction, and five for anatomic tricuspid valve regurgitation. Segmental anatomy was [S,L,L] in 18 or [I,D,D] in 5. Pulmonary outflow tract obstruction was resected in 10 and bypassed with a left ventricle-to-main pulmonary artery conduit in nine patients. Hospital mortality was 9% (two of 23). One patient died from arrhythmia and one from sepsis and arrhythmia. The late mortality rate was 14% (three patients). Two patients died from severe pulmonary vascular obstructive disease (5 months and 2 years postoperatively) and one from arrhythmia (2 months postoperatively). Fourteen have undergone cardiac catheterization 3 days to 4 years (mean 12 months) postoperatively. Three had a small residual VDS (Qp/Qs less than 1.5). Five had residual pulmonary outflow tract obstruction (peak systolic ejection gradient 30-130 mm Hg) after resection or pulmonary valvotomy. One patient had reresection and four had placement of a secondary left ventricular-pulmonary artery conduit. Anatomic tricuspid valve regurgitation became severe in three patients after VSD closure, two of whom required valve replacement; the other died of coexisting pulmonary vascular obstructive disease. Five with [S,L,L] segmental anatomy had complete atrioventricular block preoperatively and six developed complete atrioventricular block at surgery. Eleven of 18 patients with [S,L,L] anatomy had atrioventricular spontaneous or iatrogenic complete block; none of the five patients with [I,D,D] anatomy had atrioventricular block. Pulmonary outflow tract obstruction in [S,L,L] segmental anatomy required conduit interposition in 12 of 14 of our patients to significantly decompress the ventricle. Postoperative development or exacerbation of anatomic tricuspid valve regurgitation occurs in TGA [S,L,L] and may be causally related to surgical complete atrioventricular block.