title: Early mortality and concomitant procedures related to Fontan conversion: Quantitative analysis.
abstract: BACKGROUND
  The Fontan palliation is associated with numerous complications during long-term. The Fontan conversion operation has been advocated as an option to avoid some of these problems by converting classical Fontan types to modern forms of the circulation. Early mortality of Fontan conversion, however, remains unclear as available reports include limited numbers of patients and the results are heterogeneous.
  
  
  METHODS
  We reviewed all original articles from 1994 to 2016 reporting Fontan conversion operations. Reports were analysed with specific reference to patient demographics, patient number, concomitant arrhythmia surgery, pacemaker implantation and early mortality.
  
  
  RESULTS
  Overall, 37 Fontan conversion studies with a total of 1182 patients were analysed, including 35 single-centre studies and 2 registers. In the 35 single-centre studies the average age at the time of conversion was 21.6years (range 10.2-30.9years). Concomitant arrhythmia operation was performed in 71.6% of patients and concomitant pacemaker implantation procedure was performed in 59.3% of patients. Early mortality varied greatly between publications ranging from 0 to 21%. Based on a random and a fixed effect model mean mortality was 5.3% and 6.2%, respectively. Lower mortality was observed in series including younger patients at the time of conversion (average age<20years, 4.6%) and in the highest volume centre (1.4%).
  
  
  CONCLUSIONS
  Fontan conversion carries a substantial mortality risk. However, results vary between centres. Overall, the combination with arrhythmia surgery seems to be associated with lower early mortality especially when patients are referred at an earlier age and are treated at highly experienced centres.
authors.affiliation: Division of Adult Congenital and Valvular Heart Disease, Department of Cardiovascular Medicine, University Hospital Muenster, Muenster, Germany; Adult Congenital Heart Centre and Centre for Pulmonary Hypertension, NIHR Cardiovascular and Respiratory Biomedical Research Unit, Royal Brompton Hospital, London, UK; Division of Valvular Heart Disease and Adult Congenital Heart Disease, Department of Cardiovascular Medicine, University Hospital Centre Zagreb, Zagreb, Croatia. Electronic address: margarita.brida@icloud.com.
authors.forename: Margarita
authors.initials: M
authors.lastname: Brida
authors.affiliation: Division of Adult Congenital and Valvular Heart Disease, Department of Cardiovascular Medicine, University Hospital Muenster, Muenster, Germany.
authors.forename: Helmut
authors.initials: H
authors.lastname: Baumgartner
authors.affiliation: Adult Congenital Heart Centre and Centre for Pulmonary Hypertension, NIHR Cardiovascular and Respiratory Biomedical Research Unit, Royal Brompton Hospital, London, UK; National Heart and Lung Institute, Imperial College London, London, UK.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Gatzoulis
authors.affiliation: Division of Adult Congenital and Valvular Heart Disease, Department of Cardiovascular Medicine, University Hospital Muenster, Muenster, Germany; Adult Congenital Heart Centre and Centre for Pulmonary Hypertension, NIHR Cardiovascular and Respiratory Biomedical Research Unit, Royal Brompton Hospital, London, UK; National Heart and Lung Institute, Imperial College London, London, UK.
authors.forename: Gerhard-Paul
authors.initials: GP
authors.lastname: Diller
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D018729:Fontan Procedure / Q000401:mortality* / Q000639:trends*; D061847:Hospitals, High-Volume / Q000639:trends*; D061846:Hospitals, Low-Volume / Q000639:trends*; D006801:Humans; D008297:Male; D009026:Mortality / Q000639:trends; D016896:Treatment Outcome; D055815:Young Adult
keywords: Arrhythmia surgery; Fontan conversion; Fontan procedure; Mortality