Comparison Between Terminal or Preterminal Conditioning of Donor Livers by Ex Situ Machine Perfusion

Abstract

Background. The successful implementation of end-ischemic normothermic machine perfusion (NMP) into clinical practice comes along with unusual demands for trained personnel and technical facilities in the implantation clinic. This creates an interest to bundle expertise and professional equipment for execution of MP at regional pump centers at the disadvantage of adding a second short period of cold preservation while sending the reconditioned grafts to the actual implant clinic. Differences of liver recovery upon reperfusion either immediately after NMP or after 3 h of cold storage subsequent to NMP should therefore be evaluated. Methods. Rat livers were cold stored for 18 h, subjected to 2 h of NMP, and then either directly evaluated by ex vivo reperfusion or exposed to a second cold storage period of 3 h to simulate transport from the hub center to the implant clinic. Livers stored for 18 h by cold storage only served as controls. Results. Both MP regimens significantly reduced hepatic enzyme release and improved bile production, clearance of lactate, and energetic recovery compared with the controls. However, no differences were seen between the 2 MP groups. Conclusions. The study provides first evidence that machine perfusion at regional perfusion centers may be a safe and economical alternative to the widespread individual efforts in the respective implantation clinics.