Growth of diminutive central pulmonary arteries after right ventricle to pulmonary artery homograft implantation

Background The management of tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collateral arteries is controversial because of the wide variability of pulmonary artery (PA) and major aortopulmonary collateral arteries morphology. Several different staged strategies have been used to promote growth of diminutive PA branches. We have preferred a right ventricular (RV)-PA homograft for symmetrical growth of the central PA branches. In this study we evaluated the success of this strategy. Methods Between 2006 and 2012, 23 patients with pulmonary atresia and diminutive PAs underwent RV-PA homograft implantation. Median age was 2 months (range, 4 days to 18 months), and median body weight was 5.1 kg (range, 1.7 to 8.5 kg). The type of homograft was aortic in 8, pulmonary in 6, and femoral vein in 9. The mean diameter of the homograft was 10.5 mm (range, 6 to 16 mm). All procedures were performed on cardiopulmonary bypass. The PA diameter was measured at the time of the operation and subsequent catheterization. Results The median size of the branch PA was 2.1 mm. In the 18 patients who had serial assessment of PA size, the right PA increased by 307% ± 184%, the left PA increased by 283% ± 139%, and the Nakata index increased from 28.8 ± 20.1 mm ²/m² to 253 ± 96 mm²/m² during a median period of 347 days (range, 44 to 1,520 days). The PA growth ratio (PA growth in mm/mo) was similar between the right PA (0.42 ± 0.46 mm/mo) and the left PA (0.43 ± 0.47 mm/mo). There was no acute conduit failure. Seventeen patients required 28 percutaneous interventions for embolization of an aortopulmonary collateral or stenosis of the conduit or PA. There were no hospital deaths. Three patients died late after other procedures during a mean follow-up of 44.7 months. Twenty patients (87%) have undergone complete repair to date. Conclusions RV-PA homograft implantation can be performed in neonates and infants with minimal risk of acute occlusion. The RV-PA homograft promotes rapid and balanced growth of central pulmonary arteries leading to complete repair in most patients.