Normothermic Machine Perfusion Enhances Intraoperative Hepatocellular Synthetic Capacity: A Propensity Score-matched Analysis

Abstract

Background. Normothermic machine perfusion (NMP) of liver grafts is increasingly being incorporated in clinical practice. Current evidence has shown NMP plays a role in reconditioning the synthetic and energy capabilities of grafts. Intraoperative coagulation profile is a surrogate of graft quality and preservation status; however, to date this aspect has not been documented. Methods. The liver transplantation recipients who received NMP liver grafts in the QEHB between 2013 and 2016 were compared in terms of intraoperative thromboelastography characteristics (R time, K time, α-angle, maximum amplitude, G value, and LY30) to a propensity score-matched control group, where the grafts were preserved by traditional static cold storage (SCS). Results. After propensity matching, none of the thromboelastography characteristics were found to differ significantly between the 72 pairs of SCS and NMP organs when measured preimplantation. However, postimplantation, NMP organs had significantly shorter K time (median: 2.8 vs 3.6 min, P = 0.010) and R + K time (11.4 vs 13.7 min, P = 0.016), as well as significantly larger α-angle (55.9° vs 44.8°, P = 0.002), maximum amplitude (53.5 vs 49.6 mm, P = 0.044), and G values (5.8 vs 4.9k dynes/cm2, P = 0.043) than SCS organs. Hyperfibrinolysis after implantation was also mitigated by NMP, with fewer patients requiring aggressive factor correction during surgery (LY30 = 0, NMP vs SCS: 83% vs 60%, P = 0.004). Consequently, NMP organs required significantly fewer platelet units to be transfused during the transplant procedure (median: 0 vs 5, P = 0.001). Conclusions. In this study, we have shown that NMP liver grafts return better coagulation profiles intraoperatively, which could be attributed to the preservation of liver grafts under physiological conditions.

Transplanting Marginal Organs in the Era of Modern Machine Perfusion and Advanced Organ Monitoring

“…An electron shift toward succinate and subsequent reverse electron transfer upon reperfusion is discussed as a mechanism of damage and target of therapy in liver HMP (82). NMP is suggested to mitigate post-reperfusion hyperfibrinolysis (83) and inflammation (84). While these may be indirect effects of NMP, the actual immediate therapeutic mechanisms (if any) may be glycogen repletion and ATP regeneration (85).…”

Machine Perfusions in Liver Transplantation: The Evidence‐Based Position Paper of the Italian Society of Organ and Tissue Transplantation

“…To date, only 2 prospective RCTs (29,38) and 3 prospective studies (26,30,39) comparing NMP and SCS have been published, whereas other available articles were small case series or case reports. (27,28,(31)(32)(33)(34)(35)(36)(37)(40)(41)(42)(43)(44)(45)(46)(47)(48)(49)(50)(51)(52) Also, no national or international registries exist (Table 3).…”

Assessment and Transplantation of Orphan Donor Livers: A Back‐to‐Base Approach to Normothermic Machine Perfusion

“…In addition, post hoc analysis showed reduced ischemia/ reperfusion injury and increased synthetic capacity of NMP-perfused livers as evidenced by improved thromboelastography and reduced platelet transfusion requirements. (19,20) These findings indicate that NMP may be better able to preserve organ function, especially for the extended periods of time described in this manuscript.…”