title: The effect of morphologic subtype on outcomes following the Sano-Norwood procedure.
abstract: OBJECTIVE
  Controversy exists concerning outcomes of patients with different morphologic subtypes of hypoplastic left heart syndrome undergoing the Norwood procedure, in particular, aortic atresia-mitral stenosis (AA-MS) patients receiving a systemic-pulmonary modified Blalock-Taussig (mBT) shunt. We sought to determine the influence of known risk factors and morphology on early survival in our cohort of Sano-Norwood patients with right ventricle-pulmonary artery (RV-PA) conduits as the source of pulmonary blood flow.
  
  
  METHODS
  We studied early survival in patients with Sano-modified Norwood procedures from 2002 to 2010 and included both typical and atypical (including unbalanced atrioventricular canal defect) morphologic variants. We included a comparison group composed of classical Norwood patients with mBT shunts.
  
  
  RESULTS
  Of 264 Sano-Norwood patients, 49 had AA-MS and 30 had atypical morphologies. Weight ≤ 2.5 kg was associated with a poorer 1-year survival (P = 0.0007), though ascending aorta (AscAo) size <2.0 mm was not. We did not observe a difference in 30-day or 1-year Kaplan-Meier (K-M) survival across typical morphologic variants for either a Sano or mBTS group. Atypical variants exhibited a trend towards lower 30-day and 1-year survival in both Sano and mBTS groups though this was not significant. Direct comparison of 30-day K-M survival for Sano versus mBTS in AA-MS patients showed similar outcomes (P = NS).
  
  
  CONCLUSIONS
  Use of the RV-PA conduit results in good early survival, even in those with a small AscAo size. Atypical morphologic variants seem to do worse irrespective of the Sano or mBTS group. Further studies will be required to determine conclusively whether the RV-PA shunt confers protective effects in the AA-MS subgroup compared with the mBTS.
authors.affiliation: Department of Paediatric Cardiac Surgery,  Birmingham Children's Hospital, Birmingham,  UK.
authors.forename: Bari
authors.initials: B
authors.lastname: Murtuza
authors.forename: Oliver
authors.initials: O
authors.lastname: Stumper
authors.forename: Douglas
authors.initials: D
authors.lastname: Wall
authors.forename: John
authors.initials: J
authors.lastname: Stickley
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Jones
authors.forename: David J
authors.initials: DJ
authors.lastname: Barron
authors.forename: William J
authors.initials: WJ
authors.lastname: Brawn
mesh_terms: D001011:Aorta / Q000033:anatomy & histology; D001021:Aortic Valve / Q000002:abnormalities; D058366:Blalock-Taussig Procedure / Q000401:mortality; D001835:Body Weight; D005260:Female; D005500:Follow-Up Studies; D006352:Heart Ventricles / Q000601:surgery; D006801:Humans; D018636:Hypoplastic Left Heart Syndrome / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D007223:Infant; D007231:Infant, Newborn; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008297:Male; D008943:Mitral Valve / Q000002:abnormalities; D015999:Multivariate Analysis; D058327:Norwood Procedures / Q000379:methods* / Q000401:mortality; D011651:Pulmonary Artery / Q000601:surgery; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome