Pulmonary stenosis in infants and young children.

Twenty-four patients less than 3 years old underwent operation for pulmonary stenosis. Pulmonary dysplasia was diagnosed preoperatively in only 4 patients; in 20 patients the lesion was categorized simply as pulmonary stenosis. At operation, more severe valve deformities were often present in patients less than 2 years of age. Preoperative evaluation did not reveal the extent of the deformity in 7 additional patients. The deformities included not only valvular dysplasia (thickened redundant valve cusps) but also supravalvular and annular abnormalities. Relief of obstruction was obtained only when all components of the obstructive abnormality were relieved. Patch angioplasty of the right ventricular outflow tract was necessary in 13 patients with complex morphology. Valvotomy was effective only for pulmonary stenosis due to pure commissural fusion. A spectrum of the morphology of pulmonary stenosis is recognized, with more complex lesions than simple commissural fusion identified in younger children. The more complex lesions may require more extensive operations (outflow tract patch) to completely relieve the obstructive pathological condition in the outflow tract.