Custodiol-MP in Rewarming Machine Perfusion Up to Normothermia for Porcine Kidney Grafts.

OBJECTIVES: Controlled oxygenated rewarming is an effective strategy to minimize tissue alterations upon reperfusion after cold preservation and ensures better graft function after transplant. Custodiol-MP, a modification of the classical HTK solution, has been further developed specifically for use in machine perfusion of organs with the intention to meet clinical standards. Here, we compared Custodiol-MP with AQIX RS-I solution for rewarming machine perfusion from hypo- up to normothermic temperature. MATERIALS AND METHODS: Porcine kidney grafts that were ischemically predamaged were cold stored for 18 hours in HTK solution. Kidneys were then connected to a machine perfusion device and treated with controlled oxygenated rewarming from 8 to 35 °C using either AQIX RS-I or Custodiol-MP solution. Kidneys were then evaluated using an established ex vivo reperfusion model. RESULTS: Controlled rewarming with either AQIX RS-I or Custodiol-MP solution resulted in an overall improved kidney performance compared with simply cold storage of kidneys in terms of glomerular capacity, tubular function, and cellular damage. No major differences between rewarming with AQIX RS-I or Custodiol-MP were noted. However, controlled oxyge-nated rewarming with Custodiol-MP resulted in slight improvements in urine production, protein urea, and efficiency of oxygen utilization. CONCLUSIONS: Custodiol-MP seems to be at least equally suitable for controlled oxygenated rewarming up to normothermia versus AQIX RS-I solution, with a tendency to improved support of glomerular function and mitochondrial recovery.