Liver transplantation with uncontrolled versus controlled DCD donors using normothermic regional perfusion and ex-situ machine perfusion

Ethical issues in organ procurement: donation after normothermic regional perfusion in liver transplantation

PURPOSE OF REVIEW

With ongoing organ shortages, new perfusion technologies are being embraced to help fill the unmet requirement. Improvement in utilization of donation after cardiac death (DCD) donors has the potential to greatly expand the pool of usable liver allografts. Normothermic regional perfusion (NRP) has been shown to increase usage of DCD donors and improve recipient outcomes. Yet, there remains heterogeneity in its usage worldwide.

RECENT FINDINGS

Results from the first US multicenter study show improved biliary outcomes with NRP, consistent with prior data from Europe. Internationally, there are wide variations in DCD and NRP usage, highlighting the opportunities for improvement and increased utilization. The ethics of this technique continue to be considered.

SUMMARY

NRP is a sound technique that can improve utilization for DCD donors, thereby increasing organ supply. Its usage is increasing worldwide. New data continue to show the benefit of this procurement strategy. NRP agrees with the principles of ethics.

Air-ventilated normothermic mechanical perfusion improves susceptibility to donation after circulatory death and cold preservation-induced cholestatic liver injury through PPAR-γ/UGT1A1 axis

End-ischemic normothermic mechanical perfusion (NMP) could provide a curative treatment to reduce cholestatic liver injury from donation after circulatory death (DCD) in donors. However, the underlying mechanism remains elusive. Our previous study demonstrated that air-ventilated NMP could improve functional recovery of DCD in a preclinical NMP rat model. Here, metabolomics analysis revealed that air-ventilated NMP alleviated DCD- and cold preservation-induced cholestatic liver injury, as shown by the elevated release of alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, and γ-glutamyl transferase (GGT) in the perfusate (p < .05) and the reduction in the levels of bile acid metabolites, including ω-muricholic acid, glycohyodeoxycholic acid, glycocholic acid, and glycochenodeoxycholate (GCDC) in the perfused livers (p < .05). In addition, the expression of the key bile acid metabolism enzyme UDP-glucuronosyltransferase 1A1 (UGT1A1), which is predominantly expressed in hepatocytes, was substantially elevated in the DCD rat liver, followed by air-ventilated NMP (p < .05), and in vitro, this increase was induced by decreased GCDC and hypoxia-reoxygenation in the hepatic cells HepG2 and L02 (p < .05). Knockdown of UGT1A1 in hepatic cells by siRNA aggravated hepatic injury caused by GCDC and hypoxia-reoxygenation, as indicated by the ALT and AST levels in the supernatant. Mechanistically, UGT1A1 is transcriptionally regulated by peroxisome proliferator-activator receptor-γ (PPAR-γ) under hypoxia-physoxia. Taken together, our data revealed that air-ventilated NMP could alleviate DCD- and cold preservation-induced cholestatic liver injury through PPAR-γ/UGT1A1 axis. Based on the results from this study, air-ventilated NMP confers a promising approach for predicting and alleviating cholestatic liver injury through PPAR-γ/UGT1A1 axis.