title: Size of the right ventricle-to-pulmonary artery conduit impacts mid-term outcome after the Norwood procedure in patients weighing less than 3 kg.
abstract: OBJECTIVE
  The optimal shunt size for patients who have the Norwood operation with a right ventricle-to-pulmonary artery conduit is controversial. The goal of this study is to compare outcomes of 2 shunt sizes in this population.
  
  
  METHODS
  Between 2002 and 2010, 75 consecutive patients diagnosed with hypoplastic left heart syndrome and its variants underwent the Norwood procedure with a right ventricle-to-pulmonary artery conduit. The outcomes of 20 neonates weighing <3 kg were analyzed.
  
  
  RESULTS
  The cumulative 30-day stage 1 survival [corrected] was 97% (95% confidence interval, 88%-99%) for all patients (73/75), 20 of whom weighed <3 kg. Nine patients had a 6-mm (group 1) and 11 patients had a 5-mm (group 2) right ventricle-to-pulmonary artery conduit. Thirty-day stage 1 survival was 88% (8/9) in group 1 and 90% (10/11) in group 2 (P = .88). The central pulmonary artery confluence size at prebidirectional cavopulmonary shunt catheterization was 4.5 ± 1.2 mm in group 1 and 2.5 ± 1.0 mm in group 2 (P = .009). The mean transpulmonary gradient was higher in group 2 (7.8 ± 3.1 mm Hg vs 4.2 ± 1.9 mm Hg; P = .036). The incidence of pulmonary artery intervention was 16% (1/7) in group 1 and 75% (6/8) in group 2 (P = .030). Survival rate at 6 months was 66% (6/9) in group 1 and 70% (7/10) in group 2 (P = .89).
  
  
  CONCLUSIONS
  Use of a 6-mm right ventricle-to-pulmonary artery conduit showed better central pulmonary artery growth and less need for pulmonary artery intervention in the authors' experience.
authors.affiliation: Division of Pediatric Cardiothoracic Surgery, University of California San Francisco, San Francisco, CA, USA.
authors.forename: Naruhito
authors.initials: N
authors.lastname: Watanabe
authors.forename: Petros V
authors.initials: PV
authors.lastname: Anagnostopoulos
authors.forename: Takeshi
authors.initials: T
authors.lastname: Shinkawa
authors.forename: Natalie
authors.initials: N
authors.lastname: Johnson
authors.forename: Anthony
authors.initials: A
authors.lastname: Azakie
mesh_terms: D001835:Body Weight; D016009:Chi-Square Distribution; D005260:Female; D006352:Heart Ventricles / Q000503:physiopathology / Q000601:surgery*; D006439:Hemodynamics; D017052:Hospital Mortality; D006801:Humans; D018636:Hypoplastic Left Heart Syndrome / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D007226:Infant Mortality; D007231:Infant, Newborn; D008297:Male; D058327:Norwood Procedures / Q000009:adverse effects / Q000401:mortality; D011651:Pulmonary Artery / Q000254:growth & development / Q000503:physiopathology / Q000601:surgery*; D012086:Reoperation; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012495:San Francisco; D016019:Survival Analysis; D013997:Time Factors; D016896:Treatment Outcome