title: Influence of oxygen concentration during hypothermic machine perfusion on porcine kidneys from donation after circulatory death.
abstract: BACKGROUND
  Hypothermic machine perfusion (HMP) for preservation led to compelling success for outcomes of renal transplantation. Application of different concentrations of oxygen during renal HMP has not been systematically analyzed. This study investigates the aspects of renal function and morphology in dependence of oxygen concentrations during HMP in a porcine donation after circulatory death model.
  
  
  METHODS
  After 30 min of warm ischemia, porcine kidneys were randomly assigned to preservation for 21 hr by HMP without oxygenation (HMPnoox), oxygenated HMP with air (HMPair), or 100% oxygen (HMPox100%). Afterward, kidneys were reperfused for 2 hr in an ex vivo model for assessment of function and integrity.
  
  
  RESULTS
  Application of HMPox100% led to significantly increased blood flow during reperfusion compared to HMPnoox. Preservation by HMPox100% led to a doubling of creatinine clearance after 90 and 120 min of reperfusion (13.4 and 12.0 mL/min) compared to preservation by HMPnoox (7.3 and 7.7 mL/min; P=0.01). Oxygenated HMP with air led to results between the two other groups. Fractional excretion of sodium demonstrated a strong tendency of higher values after HMPnoox compared to HMPox100% (P=0.096) and HMPair (P=0.09). Analysis of structural integrity during reperfusion demonstrated significantly higher values of lactate dehydrogenase resembling cell damage (P=0.02), higher values of gamma-glutamyl-transferase (gGT) resembling tubulus injury (P=0.048), and more pronounced tubular dilatation (P=0.02) after HMPnoox compared to HMPox100%.
  
  
  CONCLUSIONS
  The present study demonstrates that application of HMPox100% for kidneys from donations after circulatory death results in better renal function during early reperfusion compared to HMPnoox.
authors.affiliation: 1 Department of General, Visceral and Transplantation Surgery, University Hospital Essen, Germany. 2 Institute of Pathology and Neuropathology, University Hospital Essen, Germany. 3 Institute of Physiological Chemistry, University Hospital Essen, Germany. 4 Surgical Research Division, University Hospital Bonn, Germany. 5 Address correspondence to: Dieter P. Hoyer, M.D., University Hospital Essen, Department of General, Visceral and Transplantation Surgery, Hufelandstr. 55, 45127 Essen, Germany.
authors.forename: Dieter P
authors.initials: DP
authors.lastname: Hoyer
authors.forename: Anja
authors.initials: A
authors.lastname: Gallinat
authors.forename: Sandra
authors.initials: S
authors.lastname: Swoboda
authors.forename: Jeremias
authors.initials: J
authors.lastname: Wohlschlaeger
authors.forename: Ursula
authors.initials: U
authors.lastname: Rauen
authors.forename: Andreas
authors.initials: A
authors.lastname: Paul
authors.forename: Thomas
authors.initials: T
authors.lastname: Minor
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity; D003404:Creatinine / Q000097:blood; D003643:Death; D005260:Female; D007036:Hypothermia, Induced / Q000379:methods; D007668:Kidney / Q000098:blood supply / Q000378:metabolism / Q000473:pathology*; D007684:Kidney Tubules / Q000473:pathology; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D015227:Lipid Peroxidation; D009926:Organ Preservation / Q000379:methods; D019188:Organ Preservation Solutions; D010100:Oxygen / Q000378:metabolism*; D010477:Perfusion; D017382:Reactive Oxygen Species / Q000378:metabolism; D015424:Reperfusion; D012964:Sodium / Q000378:metabolism; D013552:Swine; D013997:Time Factors; D005723:gamma-Glutamyltransferase / Q000378:metabolism
chemical_list: D019188:Organ Preservation Solutions; D017382:Reactive Oxygen Species; D012964:Sodium; D003404:Creatinine; D007770:L-Lactate Dehydrogenase; D005723:gamma-Glutamyltransferase; D010100:Oxygen