title: Importance of left atrial pressure during ex vivo lung perfusion.
abstract: Ex vivo lung perfusion (EVLP) allows for the evaluation and treatment of donor lungs before transplant. Different EVLP strategies have been described using either an open left atrium (LA) (pressure of 0 mm Hg) or closed LA (pressure of 5 mm Hg). We hypothesized that maintaining a physiologic positive LA pressure during EVLP is protective to the lung.
  
  
  
  Pig lungs were flushed with Perfadex, retrieved and stored at 4°C for 4 hours [short cold ischemic time (CIT), n = 10] or 18 hours (prolonged CIT, n = 8). Subsequently, lungs underwent normothermic EVLP for 12 hours using either an open or closed LA technique. A linear mixed effect model was used to compare functional parameters between the 2 groups.
  
  
  
  After short CIT, 12-hour EVLP could not be completed in 4 of 5 open atrium cases due to significant pulmonary edema. Lung injury was evident in this group after 7 hours of EVLP, demonstrating an increase in pulmonary vascular resistance (p < 0.001) and peak inspiratory pressure (p = 0.001), and a decrease in lung compliance (p < 0.001) and perfusate oxygenation (p = 0.04). In contrast, in the closed atrium group, all lungs completed 12 hours of EVLP with stable functional parameters. At the end of the experiment, the wet/dry ratio (p = 0.015) and lung edema score (p = 0.02) were significantly worse in the open LA group compared with the closed LA EVLP group. Similar findings were observed in the prolonged CIT group.
  
  
  
  The use of a closed atrial technique to create a controlled positive LA during EVLP leads to significantly less edema and superior lung physiology.
authors.affiliation: Latner Thoracic Surgery Laboratories, The Toronto Lung Transplant Program, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Virginia
authors.initials: V
authors.lastname: Linacre
authors.affiliation: Latner Thoracic Surgery Laboratories, The Toronto Lung Transplant Program, University of Toronto, Toronto, Ontario, Canada. Electronic address: marcelo.cypel@uhn.ca.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Cypel
authors.affiliation: Latner Thoracic Surgery Laboratories, The Toronto Lung Transplant Program, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Tiago
authors.initials: T
authors.lastname: Machuca
authors.affiliation: Latner Thoracic Surgery Laboratories, The Toronto Lung Transplant Program, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Nakajima
authors.affiliation: Latner Thoracic Surgery Laboratories, The Toronto Lung Transplant Program, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Kohei
authors.initials: K
authors.lastname: Hashimoto
authors.affiliation: Latner Thoracic Surgery Laboratories, The Toronto Lung Transplant Program, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Zamel
authors.affiliation: Latner Thoracic Surgery Laboratories, The Toronto Lung Transplant Program, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Manyin
authors.initials: M
authors.lastname: Chen
authors.affiliation: Latner Thoracic Surgery Laboratories, The Toronto Lung Transplant Program, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Ilker
authors.initials: I
authors.lastname: Iskender
authors.affiliation: Latner Thoracic Surgery Laboratories, The Toronto Lung Transplant Program, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Pedro
authors.initials: P
authors.lastname: Dos Santos
authors.affiliation: Latner Thoracic Surgery Laboratories, The Toronto Lung Transplant Program, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Thomas K
authors.initials: TK
authors.lastname: Waddell
authors.affiliation: Latner Thoracic Surgery Laboratories, The Toronto Lung Transplant Program, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Mingyao
authors.initials: M
authors.lastname: Liu
authors.affiliation: Latner Thoracic Surgery Laboratories, The Toronto Lung Transplant Program, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Shaf
authors.initials: S
authors.lastname: Keshavjee
mesh_terms: D000818:Animals; D062185:Atrial Pressure; D005112:Extracorporeal Circulation; D008168:Lung; D016040:Lung Transplantation; D010477:Perfusion; D013552:Swine
keywords: donor lungs; ex vivo lung perfusion; left atrium pressure; lung transplantation; pulmonary edema