title: Aggressive Patch Augmentation May Reduce Growth Potential of Hypoplastic Branch Pulmonary Arteries After Tetralogy of Fallot Repair.
abstract: BACKGROUND
  Potential surgical strategies for hypoplastic branch pulmonary arteries (BPAs) during tetralogy of Fallot repair include (1) extensive patch augmentation to the hilum (PATCH), (2) limited extension arterioplasty to the proximal pulmonary artery (EXTENSION), or (3) leaving the native vessels unaugmented (NATIVE). We explored the effect of these strategies on reintervention and BPA growth.
  
  
  METHODS
  From 2000 to 2012, 434 children underwent complete tetralogy of Fallot repair. Risk-adjusted parametric models were used to analyze the risk of BPA reintervention for (1) all children, (2) children with BPAs of 4 mm or smaller, and (3) children with BPAs of 3 mm or smaller. Repeated-measures analysis of more than 2,000 echocardiograms was used to characterize postoperative BPA growth and right ventricular pressure by using nonlinear mixed models.
  
  
  RESULTS
  Overall survival (99% [3 deaths]) was excellent. The 10-year freedom from BPA reintervention was 84%. In risk-adjusted models (including baseline BPA z-score), PATCH had a decreased freedom from reintervention (73%; p < 0.01) vs EXTENSION (87%) or NATIVE (91%). For children with BPAs of 4 mm or smaller (28 PATCH, 60 EXTENSION, 75 NATIVE), baseline characteristics were similar. The risk-adjusted 5-year freedom from reintervention was 68% for PATCH, 76% for EXTENSION, and 85% for NATIVE. PATCH trended toward an increased risk of reintervention (p = 0.07). For children with BPAs of 4 mm or smaller left in their NATIVE state, only ∼15% required reintervention. After adjustment for baseline BPA z-score, the time-related BPA growth was decreased (p < 0.014) and right ventricular pressure was increased (p = 0.03) for the PATCH group.
  
  
  CONCLUSIONS
  Aggressive PATCH augmentation of hypoplastic BPAs improves the short-term geometry but may lead to late stenosis and higher rates of reintervention. Hypoplastic BPAs in tetralogy of Fallot tend (∼85%) to grow well without instrumentation.
authors.affiliation: Division of Cardiovascular Surgery, Department of Surgery, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Travis J
authors.initials: TJ
authors.lastname: Wilder
authors.affiliation: Division of Cardiovascular Surgery, Department of Surgery, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Glen S
authors.initials: GS
authors.lastname: Van Arsdell
authors.affiliation: Division of Cardiology, Department of Pediatrics, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada; Division of Cardiology, Department of Medicine, University of Toronto, Toronto General Hospital, Toronto, Ontario, Canada.
authors.forename: Eric
authors.initials: E
authors.lastname: Pham-Hung
authors.affiliation: Division of Cardiovascular Surgery, Department of Surgery, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Gritti
authors.affiliation: Division of Cardiovascular Surgery, Department of Surgery, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Sara
authors.initials: S
authors.lastname: Hussain
authors.affiliation: Division of Cardiology, Department of Pediatrics, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada; Division of Cardiology, Department of Medicine, University of Toronto, Toronto General Hospital, Toronto, Ontario, Canada.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Caldarone
authors.affiliation: Department of Pediatric Cardiology, the Heart Institute at Cincinnati Children's Hospital, Cincinnati, Ohio.
authors.forename: Andrew
authors.initials: A
authors.lastname: Redington
authors.affiliation: Division of Cardiovascular Surgery, Department of Surgery, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada. Electronic address: edward.hickey@sickkids.ca.
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Hickey
mesh_terms: D000015:Abnormalities, Multiple; D000293:Adolescent; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009864:Ontario / Q000453:epidemiology; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology / Q000601:surgery*; D011651:Pulmonary Artery / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000601:surgery; D012086:Reoperation; D012189:Retrospective Studies; D013524:Surgical Flaps; D015996:Survival Rate / Q000639:trends; D013771:Tetralogy of Fallot / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome; D014656:Vascular Surgical Procedures / Q000379:methods*