Heart 100:775-780 doi:10.1136/heartjnl-2013-304759
  • Congenital heart disease
  • Original research

Analysis of preoperative condition and interstage mortality in Norwood and hybrid procedures for hypoplastic left heart syndrome using the Aristotle scoring system

  1. Thomas Krasemann
  1. Evelina London Children's Hospital, Guy's & St Thomas NHS Foundation Trust, London, UK
  1. Correspondence to Dr Thomas Krasemann, Evelina London Children's Hospital, Department of Paediatric Cardiology, Guy's & St Thomas NHS Foundation Trust, Westminster Bridge Road, London SE1 7EH, UK; thomas.krasemann{at}
  • Received 31 July 2013
  • Revised 3 December 2013
  • Accepted 11 December 2013
  • Published Online First 10 January 2014


Objective The ‘hybrid procedure’, consisting of surgical banding of the pulmonary arteries with intraoperative stenting of the arterial duct, was developed as primary palliation in hypoplastic left heart syndrome (HLHS), avoiding the risks of cardiopulmonary bypass. In many centres, it is reserved for low birth weight, premature or unstable neonates; however, its role in such high risk cases of HLHS has yet to be defined.

Methods The preoperative condition of all patients with HLHS who underwent either the hybrid or the Norwood procedure for HLHS between 2005–2011 was analysed retrospectively, using a modified comprehensive Aristotle score. We then compared operative, interstage and 1 year mortalities between the groups after Aristotle adjustment via Cox proportional hazards analyses.

Results Of 138 patients with HLHS, 27 had hybrid and 111 Norwood procedures. The hybrid group had significantly higher Aristotle scores (mean 4.1 vs 1.8; p<0.001); however, there was no significant difference in mortality at any stage. At 1 year, the overall unadjusted survival among Norwood and hybrid patients was 58.6% and 51.9%, respectively, yielding an Aristotle adjusted hazard ratio for mortality among hybrid patients of 1.09 (95% CI 0.56 to 2.11, p=0.80).

Conclusions Applying a hybrid approach to high risk patients with HLHS produces a comparable early and interstage mortality risk to lower risk patients undergoing the Norwood procedure. Prospective studies are needed to establish whether the hybrid procedure is a viable alternative to the Norwood procedure in all HLHS patients in terms of both mortality and long term morbidity.

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