Results of Norwood stage I operation: Comparison of hypoplastic left heart syndrome with other malformations

Abstract

Objective: We compared the Norwood stage I operation for hypoplastic left heart syndrome and other complex malformations with ductus-dependent systemic circulation. Methods: A retrospective study of 194 patients who underwent a Norwood stage I palliation between 1990 and 1998 was conducted. Malformations in 131 patients were classified as hypoplastic left heart syndrome, defined as aortic and mitral atresia or severe stenosis, normal segmental anatomy, intact ventricular septum, and hypoplasia of the left ventricle. Sixtythree patients had other lesions: hypoplastic left ventricle with ventricular septal defect (n = 18), unbalanced complete atrioventricular canal (n = 9), complex double-outlet right ventricle (n = 14), double-inlet left ventricle (n = 11), tricuspid atresia with transposition of the great arteries (n = 6), and others (n = 5), including heterotaxia. Results: Operative (>30 days) and 1-year survivals were lower for patients with hypoplastic left heart syndrome than for those with other lesions (63.4% vs 81%, P = .008, and 51.2% vs 71.4%, P = .02, respectively). The presence of a nonhypoplastic left ventricle (n = 27) was associated with higher operative and 1-year survivals (96.3% vs 64.7%, P = .002; 88.9% vs 52.7%, P < .001). A restrictive atrial septal defect and prematurity tended to increase mortality across both groups. Cox proportional hazards regression indicated that a single right ventricle was the most important independent predictor of death (P < .001). Operative mortality for all patients undergoing the stage I procedure decreased from 38.5% (1990-1994) to 21.4% after 1994 (P = .02). Conclusions: The survival of patients with malformations other than hypoplastic left heart syndrome after the Norwood procedure is greater than for those with hypoplastic left heart syndrome. Staged palliation is valid surgical therapy in these patients, with good results in intermediate follow- up.