Outcomes of the Modified Norwood Procedure: Hypoplastic Left Heart Syndrome Versus Other Single-Ventricle Malformations

Abstract

Recent studies have suggested that survival after the modified Norwood procedure is influenced by anatomy and is worse for patients with hypoplastic left heart syndrome (HLHS) than for patients with other forms of functional single ventricle. This study aimed to compare the outcomes of the modified Norwood procedure for these two groups at a single center. A retrospective chart review compared modified Norwood procedure outcomes between children with HLHS (n=40) and children with other single-ventricle malformations (n=19) from January 2002 to August 2012. The HLHS patients had a lower mean age (10.0±13.2days) at the time of operation than the non-HLHS patients (16.5±18.5days). The difference was not significant. The number of patients with a Sano modification was significantly higher in the HLHS group (HLHS 85% vs non-HLHS 32%; p<0.001). The follow-up data did not differ between the groups (HLHS 3.6±3.2years vs non-HLHS 4.8±3.3years, nonsignificant difference). The overall operative survival was 85%: 83% for the patients with HLHS and 89% for the patients with non-HLHS (nonsignificant difference). The Kaplan-Meier transplant-free survival estimate at 10years was 73% and did not differ between the HLHS patients (67%) and the non-HLHS patients (84%, nonsignificant difference). The timing of stages 2 and 3 palliation (bidirectional Glenn and external conduit Fontan) did not differ significantly (HLHS, 7.0±2.8months and 3.0±0.5years vs non-HLHS 6.1±1.7months and 2.8±0.8years). The two groups were similar with respect to the need for post-Norwood extracorporeal membrane oxygenation support, aortic arch reinterventions, atrioventricular valve repair, pulmonary artery reconstruction, pacemaker implantation, and progression to bidirectional Glenn and Fontan completion. The modified Norwood reconstruction provides good palliation for HLHS as well as other forms of functional single-ventricle anatomy. Survival, postoperative morbidity, and progression to Glenn and Fontan are not significantly different.