Outcomes after primary transcatheter therapy in infants and young children with severe bilateral peripheral pulmonary artery stenosis.

Background: Angioplasty and stent implantation have become accepted therapies for isolated peripheral pulmonary stenosis, and have been shown to increase vessel diameter and reduce right ventricular (RV) pressure acutely in patients with pulmonary artery (PA) stenosis. The purpose of this study was to assess long-term outcomes after primary transcatheter therapy for peripheral pulmonary stenosis.
Methods and Results: We studied 69 patients who underwent primary transcatheter intervention for severe isolated peripheral pulmonary stenosis at ≤ 5 years of age. Genetic/syndromic diagnoses included Williams syndrome (n=23), non-Williams familial arteriopathy (n=12), and Alagille syndrome (n=3). At the initial PA intervention, median RV:aortic pressure ratio decreased from 1.00 to 0.88 (median decrease, 0.18; P<0.001). Patients with a higher preintervention RV:aortic pressure ratio had a greater reduction (P<0.001). During follow-up (median, 8.5 years), 10 patients died, 5 from complications of PA catheterization (all before 1998). Thirteen patients underwent surgical PA intervention, most within 1 year and along with repair of supravalvar aortic stenosis. Freedom from any PA reintervention was 38 ± 6% at 1 year and 22 ± 6% at 5 years. The median RV:aortic pressure ratio decreased from 1.0 at baseline to 0.53 at the most recent catheterization (P<0.001), and 82% of patients with available clinical follow-up were asymptomatic.
Conclusions: Transcatheter therapy for infants with severe peripheral pulmonary stenosis has become safer, regardless of genetic condition. Coupled with reintervention and surgical relief in selected cases, RV:aortic pressure ratios decrease substantially and most patients are asymptomatic at late follow-up.