EARLY BALLOON DILATATION OF THE PULMONARY VALVE IN INFANTS WITH TETRALOGY OF FALLOT - RISKS AND BENEFITS

Background Balloon dilatation, an established treatment for pulmonary valve stenosis, remains a controversial procedure in tetralogy of Fall ot. Methods and Results Balloon dilatation of the pulmonary valve was performed in 19 infants with tetralogy of Fallot. Its effects on the s everity of cyanosis, the growth of the pulmonary valve and pulmonary a rteries, and the need for transannular patching were evaluated. Clinic al, echographic, angiographic, hemodynamic, and operative data were an alyzed. The procedure was safe in all, without significant complicatio ns. After balloon dilatation, systemic oxygen saturation increased fro m a mean value of 79% to 90%. This increase proved to be short-lasting in 4 patients, who required surgery before the age of 6 months. Ballo on dilatation increased pulmonary annulus size in each case, from a me an value of 4.9 to 6.9 mm (P<.001). This gain in size remained stable over time, with a mean Z score of -4.8 SD before dilatation, -3.1 SD i mmediately after the procedure, and -2.7 SD at preoperative catheteriz ation (P<.001). Pulmonary artery dimensions remained unchanged immedia tely after balloon dilatation but increased at follow-up from a Z scor e mean value of -2.5 to -0.06 SD and from -2.2 to 0.04 SD for right an d left pulmonary arteries, respectively (P<.001). At the time of corre ctive surgery, the pulmonary annulus was considered large enough to av oid a transannular patch in 69% of the infants. This represented a 30% to 40% reduction in the need for a transannular patch compared with t he incidence of transannular patch expected before balloon dilatation. Conclusions Pulmonary valve dilatation in infants with tetralogy of F allot is a relatively safe procedure and appears to produce adequate p alliation in most patients. It allowed the growth of the pulmonary ann ulus and of the pulmonary arteries, resulting in a mean gain of 2 SD f or those structures.