Congenital aortic stenosis. Experience with 43 patients.

Between September, 1967, and January, 1975, 43 patients underwent intracardiac repair for congenital aortic stenosis at the Buffalo Children's Hospital. The patients ranged in age from 2 days to 24 years, 6 of them being below one year of age. Valvular aortic stenosis was found in 21 cases (4 infants [Group I-A] and 17 older patients [Group I-B]), discrete subaortic membranous diaphragm in 11 (Group II); diffuse subvalvular muscular obstruction in 3 (Group III), supravalvular stenosis in 4 (Group IV), and multiple-level obstruction in 4 (2 infants [Group V-A] and 2 older patients [Group V-B]). Preoperatively, 58 per cent of the patients were symptomatic and 67 per cent had abnormal electrocardiograms. Associated congenital cardiac defects were found in 28 per cent of the cases. The over-all hospital mortality rate was 9 per cent (3 patients in Group I-A and one in Group V-A), with no deaths occurring in patients older than 3 months of age at the time of operation. Two late deaths occurred (Groups I-B and V-B). A complete heart block developed in one patient (Group III). The average intraoperative peak systolic left ventricular-aortic gradient decreased in all groups after repair but progressively increased in the late hemodynamic studies obtained in symptomatic patients. Six patients were reoperated upon for recurrent obstruction. Late results were evaluated on the basis of symptoms, electrocardiographic findings, valve function, and hemodynamic data. They showed excellent or satisfactory results in 59 per cent of the patients in Group I-B, in 45 per cent in Group II, in 66 per cent in Group III, and in 25 per cent in Group I-V. Results were fair or poor in Groups, I-A, V-A, and V-B. In children and adolescents, effective relief of the obstruction and of the symptoms can be obtained with minimal operative risk and minimal morbidity. In symptomatic infants, despite the high operative mortality rate, surgical intervention is indicated because of the poor prognosis.