Congenital Pulmonary Stenosis Resulting from Dysplasia of Valve

A distinctive type of pulmonary valvular stenosis, termed "pulmonary valvular dysplasia," is described from six necropsies and 10 living children. The anatomic features of the stenotic pulmonary valve are unique in that there are three distinct cusps and no commissural fusion. The obstructive mechanism is related to markedly thickened, immobile cusps, characterized by the presence of disorganized myxomatous tissue. Several clinical features tend to distinguish this form of pulmonary stenosis. In each of 16 patients studied, a pulmonary ejection murmur was present, but this was not associated with an ejection click. Other features suggestive of this type of pulmonary stenosis were slow body growth, abnormal facies, and a positive family history of pulmonary stenosis. The electrocardiogram showed a greater degree of right axis deviation than is found in most cases of dome-shaped pulmonary stenosis. Right ventriculography revealed distinctive features of the pulmonary valve which were characterized by lack of typical dome-shaped deformity and by the presence of thick cusps. Experience with simple incision-valvulotomy was associated with a high (38%) operative mortality and significant residual stenosis in survivors. The suggested operative procedures include excision of a valve cusp, placement of a right ventricular outflow patch, or replacement of the pulmonary valve.