Balloon dilation of critical pulmonary stenosis in the first week of life.

Although balloon dilation of valvular pulmonary stenosis is established in infants and children, the techniques for and results of balloon dilation in neonates with critical pulmonary stenosis remain largely unreported. Since January 1, 1985, six successive neonates with critical pulmonary stenosis (aged 1 to 6 days) underwent attempted balloon dilation. Each was cyanotic and three of the six were on prostaglandin E1 therapy and three required tracheal intubation and ventilation. All had suprasystemic right ventricular pressures (mean 122.8 +/- 6.8 mm Hg). After hemodynamic evaluation and right ventricular angiography, the valve was crossed in five patients, and was first dilated with a low profile, 5 or 6 mm diameter, 2 cm long balloon. At least one more balloon was used in each patient, the largest being 95 to 133% of the diameter of the pulmonary valve anulus. The anulus size was 6.8 +/- 1.1 mm and the largest balloon size used was 6 to 10 mm. Right ventricular pressure decreased to nearly systemic level or less in five of five patients (58.8 +/- 6.7 mm Hg). Pressure gradients, measured in four infants, were 7, 12, 16 and 35 mm Hg, respectively, but were unreliable indicators of obstruction because of a patent ductus arteriosus. The five patients were discharged 3 to 8 days after balloon dilation. All are currently symptom free 10.6 +/- 11.7 months later, and all but one are believed clinically to have mild obstruction. Complications included iliac vein occlusion (n = 1) and complete right bundle branch block (n = 1). Although follow-up has been brief, neonates with critical pulmonary stenosis can safely undergo balloon dilation, usually with good short-term results.