Technical and anatomical factors affecting the size of the branch pulmonary arteries following first stage Norwood palliation for HLHS

Background Evidence suggests that the anatomical characteristics of the Fontan circulation, in particular the size of the pulmonary arteries, play a key role in the hemodynamic efficiency of the circulation and consequently, patient outcome. Understanding and optimizing early growth of the pulmonary arteries is crucial to avoid later increase in pulmonary vascular resistance, a major risk factor for failure of the Fontan circulation. We sought to elucidate the factors that may account for central pulmonary artery stenosis and a small left pulmonary artery (LPA) following the first Norwood operation for Hypoplastic Left Heart Syndrome (HLHS).