Morphologic effects of percutaneous balloon pulmonary valvuloplasty.

Five patients with pulmonary valve stenosis and other cardiac anomalies had elective operative repair after percutaneous balloon pulmonary valvuloplasty. Four had reduction in pulmonary valve gradients from 67 +/- 9 mm Hg to 39 +/- 9 mm Hg (P less than .01), whereas one patient with a dysplastic pulmonary valve did not. Operative evaluation of the pulmonary valves revealed the morphologic effects of the balloon forces on the stenotic valves to be commissure splitting in one patient, cusp tear in one patient, and a combination of commissure splitting and cusp avulsion in two patients. There were no deaths. Patients with combined infundibular and pulmonary valve stenosis have a high potential for cusp avulsion due to fixation of the balloon in the infundibulum and retraction of the balloon into the ventricle during systole. Echocardiography, cardiac catheterization pressure gradients, and cineangiography should be used to assess infundibular stenosis and avoid percutaneous balloon angioplasty in patients who have combined pulmonary valve stenosis and infundibular pulmonary stenosis.