title: Double lung transplants have significantly improved survival compared with single lung transplants in high lung allocation score patients.
abstract: BACKGROUND
  Historically, double lung transplantation survival rates are higher than those of single lung transplantation, but in critically ill patients a single lung transplant, with less associated operative morbidity, could afford a better outcome. This article evaluates how survival is affected in patients who have a high lung allocation score (LAS) and receive a single versus a double lung transplant.
  
  
  METHODS
  The UNOS Thoracic Transplant Database for lung transplants from January 2005 to June 2012 was used for analysis. Propensity matching was used to minimize differences between the high and low LAS groups and between single and double lung transplants in the high LAS group.
  
  
  RESULTS
  Within this database, there were 8,778 patients, of whom 8,050 had an LAS less than 75 and 728 had an LAS greater than or equal to 75. Kaplan-Meier survival curves stratified by high and low LAS, and by single versus double lung transplants, showed a marked decrease in survival (p<0.001) in those with a high LAS who received a single lung transplant when compared with those with a high LAS who received a double lung transplant. This was a much greater difference in survival than was present in the low LAS patient population.
  
  
  CONCLUSIONS
  Despite a higher operative morbidity, patients who had a high LAS did substantially better in terms of survival if two lungs were transplanted rather than only one, with a larger difference in survival than for patients with a lower LAS.
authors.affiliation: Department of Surgery, University of Louisville School of Medicine, Louisville, Kentucky.
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Black
authors.affiliation: Department of Cardiothoracic Surgery, University of Louisville School of Medicine, Louisville, Kentucky.
authors.forename: Jaimin
authors.initials: J
authors.lastname: Trivedi
authors.affiliation: Department of Surgery, University of Louisville School of Medicine, Louisville, Kentucky.
authors.forename: Erin M
authors.initials: EM
authors.lastname: Schumer
authors.affiliation: Department of Cardiothoracic Surgery, University of Louisville School of Medicine, Louisville, Kentucky.
authors.forename: Michael
authors.initials: M
authors.lastname: Bousamra
authors.affiliation: Department of Cardiothoracic Surgery, University of Louisville School of Medicine, Louisville, Kentucky. Electronic address: victor.vanberkel@louisville.edu.
authors.forename: Victor
authors.initials: V
authors.lastname: van Berkel
mesh_terms: D005260:Female; D005500:Follow-Up Studies; D015276:Health Care Rationing / Q000379:methods*; D006801:Humans; D053208:Kaplan-Meier Estimate; D007629:Kentucky / Q000453:epidemiology; D008171:Lung Diseases / Q000401:mortality / Q000601:surgery*; D016040:Lung Transplantation / Q000379:methods / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D012189:Retrospective Studies; D015996:Survival Rate / Q000639:trends; D013997:Time Factors; D009927:Tissue and Organ Procurement / Q000458:organization & administration*; D014850:Waiting Lists