Congenital malformations of the mitral valve in children. Pathology and surgical treatment.

A systematic study of congenital mitral valve malformations was undertaken on a surgical basis in an attempt to develop techniques of valvular reconstruction adapted to the various lesions. Forty-seven children between the ages of 4 months and 12 years (average 6 years, 4 months) have been operated upon between January, 1970, and March, 1976. Valvular lesions were classified into four group: Group I, mitral insufficiency owing to valvular lesions: Group II mitral insufficiency with subvalvular lesions; Group III, mitral insufficiency and stenosis; Group IV, stenosis. Associated lesions (ventricular or atrial septal defects, coarctation, or aortic valve stenosis) were present in 31 patients (65 per cent) and were corrected during the same operation. Valve reconsruction was possible in 38 patients whereas valve replacement was necessary in 9 patients. In the valve repair group there were three operative deaths (8 per cent), no late deaths, one reoperation for residual ventricular septal defect, and one myocardial infarction. In the valve replacement group of 9 patients, there were three operative deaths, three late deaths, and one case of repeated embolization. Thirty-one of 38 patients in the valve repair group were classified into Functional Class I after the operation (86 per cent), 2 were in Class II, and one in Class III. Minimal or moderate regurgitation and cardiomegaly persisted in the majority of the patients. Pulmonary artery pressure significantly decreased, however, as demonstrated by postoperative catheterization in 17 patients.