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 Fallot. METHODS AND RESULTS: Balloon dilatation of the pulmonary valve was performed in 19 infants with tetralogy of Fallot. Its effects on the severity of cyanosis, the growth of the pulmonary valve and pulmonary arteries, and the need for transannular patching were evaluated. Clinical, echographic, angiographic, hemodynamic, and operative data were analyzed. The procedure was safe in all, without significant complications. After balloon dilatation, systemic oxygen saturation increased from 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. Balloon dilatation increased pulmonary annulus size in each case, from a mean 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 immediately after the procedure, and -2.7 SD at preoperative catheterization (P < .001). Pulmonary artery dimensions remained unchanged immediately after balloon dilatation but increased at follow-up from a Z score mean value of -2.5 to -0.06 SD and from -2.2 to 0.04 SD for right and left pulmonary arteries, respectively (P < .001). At the time of corrective surgery, the pulmonary annulus was considered large enough to avoid a transannular patch in 69% of the infants. This represented a 30% to 40% reduction in the need for a transannular patch compared with the incidence of transannular patch expected before balloon dilatation. CONCLUSIONS: Pulmonary valve dilatation in infants with tetralogy of Fallot is a relatively safe procedure and appears to produce adequate palliation in most patients. It allowed the growth of the pulmonary annulus and of the pulmonary arteries, resulting in a mean gain of 2 SD for those structures.