RESUMEN
Percutaneous valvuloplasty with a balloon catheter was attempted in 41 young patients with pulmonary valve stenosis. There were 9 neonates (1 to 7 days), 6 infants (1.5 to 7 months) and 26 children (16 months to 17 years). The attempt failed in 8 cases, either because the balloon could not be inserted due to intravenous progression problems or to quasi-atresia of the orifice, or because serious accidents (air embolism in one patient, perforation of the infundibulum in another) forced us to abandon the procedure before dilatation. Failures mostly occurred in very young children: 7 out of 15 aged less than 1 year, 1 out of 26 older than 1 year. Dilatation was effective in 33 cases. Among 13 patients who had moderate stenosis with infra- or iso-systemic right ventricular systolic pressure (RVP) (mean: 70 +/- 13 mmHg) and modest ventriculo-pulmonary gradient (49 +/- 12 mmHg), there was only 1 failure due to coexistent biventricular myocardiopathy; success was immediate and complete in 8 cases, partial in 4 cases. Among 20 children presenting with tight stenosis with supra-systemic RVP (164 +/- 39 mmHg) and high ventriculo-pulmonary gradient (140 +/- 43 mmHg), there were 5 failures; success was partial in 8 cases, complete and immediate in 7 cases. Accentuation of the infundibular stenosis after dilatation was a frequent cause of failure, as we have shown by calculating the infundibular "reactivity index" on pre- and post-operative angiocardiograms. In such cases one may hope for spontaneous improvement, as was indeed subsequently observed in 2 of our patients.(ABSTRACT TRUNCATED AT 250 WORDS)