Modified Senning operation for treatment of transposition of the great arteries.

Since February, 1978, 42 infants ranging in age from 15 days to 16 months (mean age 6 months) and weighing between 2.0 and 9.0 kg (mean weight 5.8 kg) underwent a modified Senning I operation. Eleven (26%) underwent operation during the first 3 months of life. Twenty-nine patients had dextro-transposition of the great arteries (d-TGA) and an intact ventricular septum (Group I), and 13 patients had d-TGA and a large ventricular septal defect (VSD) (Group 2). In addition to the Senning I procedure, 13 patients had transatrial closure of their VSD, eight had ligation of a patient ductus arterioses, two had removal of a pulmonary artery band, and four had trans-pulmonary artery resection of short-segment subpulmonary stenosis. Modification of the original Senning operation included (1) patch augmentation (pericardium or Gore-Tex) of the atrial septal flap and (2) pericardial patch enlargement of the pulmonary venous pathway. One patient in Group 1 (3%) and two patients in Group 2 (15%) died after operation. A 2-week-old infant (Group 1) was treated with prostaglandin E1 (PGE) for 2 weeks before operation. The other hospital deaths (Group 2) occurred in a 2-month-old infant with advanced ischemic damage to the right ventricle and a 4-month-old child with multiple VSDs and Grade IV pulmonary vascular disease. No caval gradients were found after modification of the right atrial incision. Two patients died later from pulmonary venous obstruction, one during attempted recatheterization and the other after repair of the pulmonary venous obstruction. One patient had transient complete heart block, and four were discharged in junctional rhythm. Thirty-four patients (87%) were in regular sinus rhythm when released from the hospital. Postoperative catheterizations in eight patients showed no significant gradients in six and severe pulmonary venous obstruction in two (late deaths). More late postoperative results are required, including postoperative catheterization and electrophysiological studies, before the relative merits of the Senning versus the Mustard operation can be assessed.