['Neoaortic arch obstruction after stage I palliation is an important risk factor affecting interstage mortality in patients with hypoplastic left heart syndrome, with no accepted standard surgical approach. We sought to determine the efficacy of different techniques for aortic arch reconstruction to reduce the incidence of postoperative neoaortic arch obstruction.', 'From January 2000 through June 2005, 210 patients underwent stage I palliation. To enlarge the aortic arch, 12 (6%) patients had a direct connection, 115 (55%) patients had an aortic homograft, 53 (25%) patients had a pulmonary homograft patch, and 30 (14%) patients had autologous pericardium. Independent of the technique for aortic enlargement, 55 (26%) children had coarctectomy.', 'Eighty patients had a significant arch gradient, as determined by means of echocardiography, and of these, 50 required balloon angioplasty, surgical arch augmentation, or both. Preoperative aortic coarctation was consistently linked to neoaortic arch obstruction (P = .032). Patients having aortic arch enlargement by means of direct connection or with autologous pericardium were less likely to have neoaortic arch obstruction (P = .049). Coarctectomy resulted in a lower incidence of neoaortic arch obstruction, as determined by means of echocardiography (P = .015), or need for reintervention (P = .01).'] Does coarctectomy reduce neoaortic arch obstruction in hypoplastic left heart syndrome?