Pulmonary regurgitation after percutaneous balloon valvoplasty for isolated pulmonary valvar stenosis in childhood

OBJECTIVES: A retrospective study was undertaken to determine the degree of pulmonary regurgitation following percutaneous balloon valvoplasty for isolated pulmonary valvar stenosis. BACKGROUND: Percutaneous balloon valvoplasty is the recognised treatment of choice in pulmonary valvar stenosis with effective relief of gradient. Few studies have reviewed the degree of pulmonary regurgitation after the balloon valvoplasty. METHODS: We reviewed all patients with isolated pulmonary valvar stenosis undergoing percutaneous balloon valvoplasty at a tertiary centre between December 1984 and August 1996. Those with an associated haemodynamically insignificant atrial septal defect or patent oval foramen were also included. Their medical records, echocardiograms and angiograms were studied. Colour flow Doppler was used as a semi-quantitative way of assessing the pulmonary incompetence. RESULTS: Over the period of review, 57 procedures had been performed in 49 patients. The median age at the time of the procedure was 1.08 years, with a range from 0.01 to 13.3 years. The median period of follow-up was 5.64 years, with a range from 3.00 to 14.26 years. Immediately following the dilation of the pulmonary valve, the peak-to-peak instantaneous systolic pressure gradient was significantly reduced. Seven patients required a second dilation of the valve. Their median age at the first valvoplasty, at 0.49 year, was significantly lower than those who required only one procedure, at a median of 1.50 years. Following the valvoplasty, mild pulmonary incompetence was noted in 26 out of 42 patients the day after the procedure, but only 7% had moderate incompetence. On follow-up, there was an increase in the number of patients with moderate to severe pulmonary incompetence, from 7% to 29%. Those patients in whom the procedure was performed at a younger age had more significant pulmonary incompetence. Neither the initial gradient across the pulmonary valve, nor the size of the balloon used, were related with statistical significance to the subsequent development of pulmonary incompetence. CONCLUSIONS: The majority of the patients with congenital isolated pulmonary valvar stenosis had only a mild increase in the degree of pulmonary incompetence following a single pulmonary valvoplasty. Patients who required the procedure early in life were more likely to develop significant pulmonary incompetence. The ratio of the size of the balloon to the diameter of the valve did not significantly affect the outcome. We suggest that those patients who had more severe stenosis because of a more abnormal pulmonary valve, and hence required early intervention, were more likely to develop greater pulmonary incompetence after the valvoplasty.