title: Lowering Perfusate Temperature From 37°C to 32°C Diminishes Function in a Porcine Model of Ex Vivo Kidney Perfusion.
abstract: BACKGROUND
  Ex vivo perfusion (EVP) is a novel method of preservation. However, optimal perfusion conditions remain undetermined. Reducing the temperature of the perfusate to subnormothermia may be beneficial during EVP and improve early graft function. The aim of this study was to investigate whether subnormothermia would influence the conditioning effect of EVP when compared with normothermic perfusion, and standard cold static storage (CS).
  
  
  METHODS
  Porcine kidneys underwent static CS for 23 hours followed by 1 hour of EVP using leukocyte-depleted blood at a mean temperature of 32°C or 37°C. After this, kidneys were reperfused with whole autologous blood at 37°C for 3 hours to assess renal function and injury. These were compared with a control group that underwent 24 hours CS.
  
  
  RESULTS
  During EVP, kidneys perfused at 37°C had a higher level of renal blood flow and oxygen consumption compared with EVP at 32°C (P= 0.001, 0.002). During reperfusion, 32°C EVP kidneys had lower creatinine clearance and urine output than control (P= 0.023, 0.011) and a higher fractional excretion of sodium, serum potassium, and serum aspartate transaminase than 37°C EVP kidneys (P= 0.01, 0.023, 0.009).
  
  
  CONCLUSIONS
  Tubular and renal functions were better preserved by a near-physiological temperature of 37°C during 1 hour of EVP, when compared to EVP at 32°C or cold storage.
authors.affiliation: Division of Transplantation, Department of Surgery, Cambridge University, Addenbrookes Hospital, Cambridge, United Kingdom.
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Adams
authors.affiliation: Department Infection, Immunity and Inflammation, Transplant Group, University of Leicester, Leicester General Hospital, Leicester, United Kingdom.
authors.forename: Meeta
authors.initials: M
authors.lastname: Patel
authors.affiliation: Division of Transplantation, Department of Surgery, Cambridge University, Addenbrookes Hospital, Cambridge, United Kingdom.; Department Infection, Immunity and Inflammation, Transplant Group, University of Leicester, Leicester General Hospital, Leicester, United Kingdom.
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Hosgood
authors.affiliation: Division of Transplantation, Department of Surgery, Cambridge University, Addenbrookes Hospital, Cambridge, United Kingdom.; Department Infection, Immunity and Inflammation, Transplant Group, University of Leicester, Leicester General Hospital, Leicester, United Kingdom.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Nicholson