Significance of the residual aortic obstruction in multistage repair of hypoplastic left heart syndrome.

OBJECTIVE: The population of children who received right ventricle-to-pulmonary artery shunt (RV-PA) at Norwood procedure (NP) is growing, but limited data are available regarding the long-term outcome. The aim of this study was to present operative outcomes and mid-term hemodynamics and to assess the impact of the residual aortic obstruction on the results in patients undergoing three-staged surgery with RV-PA application at NP.

METHODS: Between June 2001 and June 2009, 229 children with hypoplastic left heart syndrome (HLHS) and variants underwent NP with RV-PA; 172 have proceeded to stage II and 95 to stage III. The medical records (clinical data, echocardiographic records, cardiac catheterization reports, electrocardiograms, and surgical notes) were retrospectively reviewed.

RESULTS: The later era of NP was associated with significantly better outcome (2001-2004: 1- and 5-years' survival were 64.3% and 59.8%, respectively; 2005-2009: 1- and 4-years' survival were 93.1% and 86.9%, respectively) (p<0.001). There was no association between long-term survival and diagnosis (HLHS/HLHS variant) (p=0.39). The incidence of depressed ventricular function and moderate or severe systemic atrioventricular valve regurgitation among the children who required balloon aortoplasty (BA) before stage II surgery was significantly higher than in children without aortic arch obstruction (p=0.027, p=0.008, respectively). In midterm follow-up, BA had no significant influence on the actuarial survival (p=0.089). No ventricular arrhythmias were noticed at any stage.

CONCLUSIONS: The RV-PA shunt is a safe technique that does not seem to impair systolic or electrical ventricular function; its outcomes continue to improve with growing experience. Combined cardiologic interventional and surgical procedures are required to optimize the outcomes.