Primary repair of complete atrioventricular septal defect in infancy.

Forty infants with complete atrioventricular septal defect have undergone primary repair within their 1st year of life. The mean age at time of surgery was 4 months (range 1-12 months) and the mean weight 4.2 kg (range 2.9-7.0 kg). Either the one- or the two-patch method was used. Four patients died (10%). There were no late deaths. Three patients needed reoperation due to mitral valve insufficiency. Postoperative complications were: 1 total atrioventricular block in an infant with an absent ventricular septum 3 weeks after surgery, 9 complete right bundle branch blocks, 3 small residual ventricular septal defects. Mean follow-up of the 36 survivors is 22 months (3-46 months). Thirty (83%) are in NYHA functional class I, 4 (11%) in NYHA class II and 2 (6%) in NYHA class III. No atrioventricular valve regurgitation is detectable by the color Doppler technique in 19 (53%) patients. Mitral incompetence is mild in 13 cases (36%) and moderate in 4 (11%). In ten recatheterized patients the average systolic pulmonary to systemic artery pressure ratio dropped from 1.0 to 0.42 and the average pulmonary arteriolar resistance was reduced from 5.5 to 3.9 U/m2. All but one patient gained weight and underwent adequate statomotoric development. Primary repair should be performed at the age of 5-6 months or even earlier, if pulmonary arteriolar resistance exceeds 5 U/m2.