Background: Pulmonary valve (PV) balloon valvotomy (BV) is considered the treatment of choice for isolated pulmonary valve stenosis (IPVS). While immediate and long-term results of PVBV are usually excellent, the reported results in dysplastic valves are variable. High-pressure (HP) PVBV in dysplastic valves that fail low-pressure (LP) PVBV may increase success rate, reducing the need for surgical interventions.
Methods: We reviewed all cases of IPVS in patients <3 years old, who underwent PVBV between August 1999 and March 2004. Study outcomes were initial success rate (gradient post PVBV < 30 mm Hg) and freedom from reintervention. Possible predictors of failure to LP-PVBV were explored (age, hemodynamic data, PV leaflet maximal thickness, diameter/z-scores for PV annulus, sinotubular junction, and subvalvar area).
Results: All 35 patients (16 neonates, 5 with critical IPVS) underwent LP-PVBV with immediate success in 27 (80%). All eight patients who failed LP-PVBV successfully underwent HP-PVBV. Upon follow-up (27 +/- 24 months), two patients (6.9%) required reintervention after LP-PVBV (LP-PVBV at 3 months, HP-PVBV at 2 months with success, both reintervention free thereafter), and one patient (12.5%) after HP-PVBV (surgical right ventricular outflow tract patch at 33 months) (Fisher's exact test = 0.5). There were no major immediate or long-term complications. After nonparametric median regression, age (2 vs. 11 months, P < .001) and PV maximal thickness (0.13 vs. 0.24 cm, P= .026) were the only predictors of failure to LP-PVBV.
Conclusion: HP-PVBV can be performed safely in patients with IPVS that fail LP-PVBV, with high success rate and acceptable long-term results. Failure to LP-PVBV is difficult to predict.