The Effects of Preservation Temperature During Machine Perfusion Preservation for Porcine Liver Donated after Cardiac Death Evaluated by Isolated Liver Perfusion Model

Background Because of difficulty of evaluation for the graft function during perfusion preservation, exvivo isolated liver perfusion model was developed and assessed DCD livergraft at different preservation temperature. Enough number of animal are necessary to conduct detailed experiment to evaluate preservation results. And also reduction and replacement of animal experiments should be considering to design experiments. In this study, ex vivo perfusion model using autologous. blood under normothermic perfusion condition was established to evaluate availability of machine preservation for liver donated after cardiac death (DCD). In particular, results of the subnormothermic machine perfusion for DCD porcine livers were evaluated using ex vivo reperfusion model. Materials and Methods Porcine liver grafts were procured under warm ischemia time of 60 minutes imitated the DCD graft condition. The liver grafts were preserved under three conditions for 4 hours. Group 1; liver grafts were preserved with simple cold storage (CS)(n=3); Group 2; grafts were perfused with hypothermic machine preservation(HMP)with a modified university of Wisconsin solution(n=3); Group3; liver grafts were perfused with subnormothermic machine perfusion (SMP)(n=3) Preserved grafts were perfused with autologous blood at 37°C for 2 hours to access the organ functions. The vascular pressures, the oxygen consumption and enzyme release rate of AST and LDH during reperfusion were analyzed. Results Vascular resistance of portal vein and hepatic artery after reperfusion were remarkablyhigher in Group 3 compared than Group 2 and 3. In addition, portal and hepatic artery resistance in early phase was more higher in Group 2 rather than Group 3 AST, LDH, ALP and hyaluronic acid were remarkably higher in Group 1 rather than Group 2 and 3.(P<0.05) The changes of AST and LDH at 0 ~30min after reperfusion was lower in Group 3 Historical findings showed severe hepatocyte necrosis in Group 1 rather than Group 2. Conclusions In summary, this study demonstrates that ex vivo isolated reperfusion model haspossibility of applying to evaluate for liver graft function.