title: The Role of Echocardiography and Intracardiac Exploration in the Evaluation of Candidacy for Biventricular Repair in Patients With Borderline Left Heart Structures.
abstract: BACKGROUND
  Predictors for single ventricle palliation (SVP) or successful biventricular repair (BVR) in patients with borderline left-side heart structures are not well defined. The goal was to evaluate the role of echocardiography and intracardiac exploration in determining feasibility of BVR.
  
  
  METHODS
  All neonates surgically treated from 1995 to 2015 with mitral valve (MV), aortic valve, or left ventricle end-diastolic dimension z score of -2 or less for whom management was controversial were included. Data were analyzed using Fisher's exact test, Kruskal-Wallis test, and Kaplan-Meier analysis.
  
  
  RESULTS
  The cohort consisted of 42 patients: 7 SVP (17%) and 35 BVR (83%). Median follow-up was 7 years (range, 6 months to 18 years). Intracardiac exploration was performed in 29 patients (69%). There was poor correlation between echocardiographic and intraoperative MV measurements (intraclass correlation coefficient 0.14). Preoperative echocardiography significantly underestimated MV size in 14 patients (54%). Two BVR patients were converted to SVP, and 4 (including 1 converted patient) had cardiac-related deaths. All patients with MV greater than 8 mm on preoperative echocardiography had successful BVR. An intraoperative MV less than 8 mm and an abnormal subvalvar apparatus was present in 5 of 6 SVP (83%) and 3 of 3 (100%) failed BVR patients who had intracardiac exploration, and in only 1 of 20 successful BVR patients (5%) who had an intracardiac exploration.
  
  
  CONCLUSIONS
  The decision to proceed to BVR in patients with borderline left-side heart structures should not rely strictly on echocardiographic measurements. Intracardiac exploration of the MV and subvalvar apparatus is useful before committing a patient to SVP. Patients with low MV z scores, especially those with a normal subvalvar apparatus, may undergo BVR with good outcomes.
authors.affiliation: Division of Congenital Heart Surgery, Michael E. DeBakey Department of Surgery, Texas Children's Hospital and Baylor College of Medicine, Houston, Texas. Electronic address: cmmery@texaschildrens.org.
authors.forename: Carlos M
authors.initials: CM
authors.lastname: Mery
authors.affiliation: Division of Congenital Heart Surgery, Michael E. DeBakey Department of Surgery, Texas Children's Hospital and Baylor College of Medicine, Houston, Texas.
authors.forename: R Michael
authors.initials: RM
authors.lastname: Nieto
authors.affiliation: Division of Congenital Heart Surgery, Michael E. DeBakey Department of Surgery, Texas Children's Hospital and Baylor College of Medicine, Houston, Texas.
authors.forename: Luis E
authors.initials: LE
authors.lastname: De León
authors.affiliation: Division of Pediatric Cardiology, Department of Pediatrics, Texas Children's Hospital and Baylor College of Medicine, Houston, Texas.
authors.forename: Shaine A
authors.initials: SA
authors.lastname: Morris
authors.affiliation: Outcomes and Impact Service, Texas Children's Hospital, Houston, Texas.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Division of Pediatric Cardiology, Department of Pediatrics, Texas Children's Hospital and Baylor College of Medicine, Houston, Texas.
authors.forename: John L
authors.initials: JL
authors.lastname: Colquitt
authors.affiliation: Division of Congenital Heart Surgery, Michael E. DeBakey Department of Surgery, Texas Children's Hospital and Baylor College of Medicine, Houston, Texas.
authors.forename: Iki
authors.initials: I
authors.lastname: Adachi
authors.affiliation: Division of Congenital Heart Surgery, Michael E. DeBakey Department of Surgery, Texas Children's Hospital and Baylor College of Medicine, Houston, Texas.
authors.forename: Lauren C
authors.initials: LC
authors.lastname: Kane
authors.affiliation: Division of Congenital Heart Surgery, Michael E. DeBakey Department of Surgery, Texas Children's Hospital and Baylor College of Medicine, Houston, Texas.
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Heinle
authors.affiliation: Division of Congenital Heart Surgery, Michael E. DeBakey Department of Surgery, Texas Children's Hospital and Baylor College of Medicine, Houston, Texas.
authors.forename: E Dean
authors.initials: ED
authors.lastname: McKenzie
authors.affiliation: Division of Congenital Heart Surgery, Michael E. DeBakey Department of Surgery, Texas Children's Hospital and Baylor College of Medicine, Houston, Texas.
authors.forename: Charles D
authors.initials: CD
authors.lastname: Fraser
mesh_terms: D004452:Echocardiography / Q000379:methods*; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D018636:Hypoplastic Left Heart Syndrome / Q000000981:diagnostic imaging / Q000601:surgery*; D007231:Infant, Newborn; D008297:Male