The Effects of Purification Perfusate during Subnormothermic Machine Perfusion for Porcine Liver Donated after Cardiac Death
Masahide Otani1,2, Naoto Matsuno1,2, Hiromichi Obara3, Yo Ishihara2, Tatsuya Shonaka1, Mikako Gochi1, Mizuho Ohara1, Hiroyuki Takahashi1, Yuji Nishikawa4, Hiroyuki Furukawa1.
1Gastroenterology and Transplantation, Asahikawa Medical University, Asahikawa, Japan; 2Transplantation technology, Asahikawa Medical University, Asahikawa, Japan; 3Mechanical Engineering, Metropolitan University of Tokyo, Tokyo, Japan; 4Pathology, Asahikawa Medical University, Asahikawa, Japan
Background: Subnormothermic machine perfusion (SNMP) shows some advantages for the preservation of the DCD grafts. Further improvement of perfusion technologies are require to enhance the quality of the organ for transplantation. There are some improvement ideas of installing a filter or a dialyzer into a perfusion circuit to maintain perfusate contamination. The aim of this study was to investigate the effects of the purification perfusate imitated installing a filter or a dialyzer during the SNMP to consider the improved perfusion technology.
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=4) ; Group 2; grafts were perfused with SNMP with a modified university of Wisconsin solution(n=6); Group3; liver grafts were perfused with purified subnormothermic machine perfusion (PSNMP)(n=5). The vascular pressures, the oxygen consumption and enzyme release rate of AST and LDH during reperfusion were analyzed to consider purification effect in SNMP. Preserved grafts were reperfused with autologous blood at 37°C for 2 hours to access the organ functions.
Results: Pressure of the hepatic artery of preserved grafts by PSNMP at reperfusion 2 hours was decreased in comparison of the preserved grafts by CS or SNMP. In addition, oxygen consumption of the grafts after PSNMP were higher than that of the grafts after CS or SNMP. The release of the effluent enzyme levels in blood reperfusion were decreased by purifying perfusate in MP preservation compared to CS or SNMP. The average PV resistance of IRM after CS, SNMP, and PSNMP were 0.0091±0.0075, 0.0042±0.0030, and 0.0048±0.0035 mmHg/ml/min/100 g liver, respectively. The average HA resistance of IRM after CS, SNMP, and PSNMP were 0.296±0.051, 0.189±0.087, and 0.086±0.033 mmHg/ml/min/100 g liver, respectively (*p<0.05, ※※p<0.01). The final HA resistance of IRM after PSNMP was the lowest of the three preservation groups significantly.
Conclusions: In summary, this study demonstrates that purifying perfusate under subnormothermic condition offered several advantages over CS or simple SNMP for DCD liver grafts preservation and decreased reperfusion injury.
