Ductus-associated proximal pulmonary artery stenosis in patients with right heart obstruction

Proximal pulmonary artery stenosis is a common acquired lesion in infants treated for congenital heart disease. We hypothesized that a large number of stenoses develop at the site of ductal insertion in patients with right ventricular outflow tract obstruction (RVOTO) and that these patients are at risk for developing hypoplasia of the ipsilateral pulmonary artery. The surgical and cardiac catheterization databases at our institution during the years 1988–2000 were searched for all patients under 1 year of age carrying a diagnosis of pulmonary atresia with intact ventricular septum (PA), tetralogy of Fallot (TOF) or pulmonary stenosis (PS), yielding 700 patients (62 PA, 373 TOF, 265 PS). The cardiac catheterization database was also searched for all patients with any diagnosis under 1 year of age found at catheterization to have proximal pulmonary artery stenosis. Proximal pulmonary artery stenosis associated with the ductal insertion site was diagnosed at catheterization in 33 infants (18 with PA, 5 with TOF, 6 with PS, 4 other diagnoses). This represents 29% of patients with PA, 1% with TOF and 2% with PS. Among patients with RVOTO and ductal insertion site-associated stenosis, there was a high prevalence (59%) of associated distal pulmonary arterial hypoplasia, defined as diameter of the stenosed vessel at first distal branch ≤ 80% the diameter of the contralateral vessel. Symptomatology failed to identify this lesion; therefore, a high index of suspicion is necessary if proximal pulmonary artery stenosis is to be detected early in these patients.