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

Objective: We compared the Norwood stage I operation for hypoplastic left h eart syndrome and other complex malformations with ductus-dependent systemi c circulation. Methods: A retrospective study of 194 patients who underwent a Norwood stage I palliation between 1990 and 1998 was conducted. Malforma tions in 131 patients were classified as hypoplastic left heart syndrome, d efined as aortic and mitral atresia or severe stenosis, normal segmental an atomy, intact ventricular septum, and hypoplasia of the left ventricle, Six tythree patients had of her lesions: hypoplastic left ventricle with ventri cular septal defect (n = 18), unbalanced complete atrioventricular canal (n = 9), complex double-outlet right ventricle (n = 14), double-inlet left ve ntricle (n = 11), tricuspid atresia with transposition of the great arterie s (n = 6), and of hers (n = 5), including heterotaxia, Results: Operative ( >30 days) and 1-year survivals were lower for patients with hypoplastic lef t 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 nonhypoplast ic left ventricle (n = 27) was associated with higher operative and I-year survivals (96.3% vs 64.7%, P = .002; 88.9% vs 52.7%, P < .001). A restricti ve 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 procedur e decreased from 38.5% (1990-1994) to 21.4% after 1994 (P = .02), Conclusio ns: 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 thera py in these patients, with good results in intermediate follow-up.