Determinants of successful balloon valvotomy in infants with critical pulmonary stenosis or membranous pulmonary atresi with intact ventricular septum

Objectives. This study reviewed our experience with percutaneous balloon valvotomy in infants with critical pulmonary stenosis or membranous pulmonary atresi with intact ventricular septum and defined the anatomic and hemodynamic characteristics of infants in whom this procedure is successful and provides definitive therapy. Background. Unlike children with valvular pulmonary stenosis, the follow-up of infants with critical pulmonary stenosis undergoing percutaneous balloon valvotomy is limited. Methods. Between December 1987 and August 1992, percutaneous balloon valvotomy was attempted in 12 infants with critical pulmonary stenosis (n = 10) or pulmonary atresi with intact ventricular septum (n = 2). Two outcome groups were identified: Group patients are acyanotic, have mild residual pulmonary stenosis and have not required operation; Group B patients have required operation. Results. Of the 12 infants, 11 had successful balloon valvotomy procedure. Group patients (n = 7) have residual gradient of 22 ± 18.7 mm Hg (mean ± SD) at follow-up of 3.2 years (range 1.2 to 5.0). In Group B (n = 5), operation was required for inability to cross the pulmonary valve (n = 1) or persistent severe hypoxemi for 2 weeks after valvotomy (n = 4). Significant differences (p ≤0.01) between the two groups (Group vs. Group B) were identified in pulmonary valve annulus (Z value) 8.1 mm (−1.1) versus 5.5 mm (−3.4); tricuspid valve annulus (Z value) 14.0 mm (0.8) versus 8.8 mm (−1.8); right ventricular volume 65 versus 29 ml/m2; and Lewis index 10.9 versus 8.9. Conclusions. Percutaneous balloon valvotomy is effective and likely to provide definitive therapy in infants with critical pulmonary stenosis or membranous pulmonary atresi with intact ventricular septum who have tricuspid valve annulus >11 mm, pulmonary valve annulus 7 mm and right ventricular volume >30 ml/m2.