NORMOTHERMIC machine perfusion (NMP) has become an essential tool for assessing liver grafts from different donor types. Liver transplantation remains the primary life-saving treatment for end-stage liver disease, but organ shortages have driven wider use of extended criteria donors, including donors after circulatory death (DCD). This meta-analysis highlights how NMP may allow for safe transplantation of DCD and donation after brain death (DBD) livers, despite differences in donor risk factors.
Understanding Donor Risk Differences
DCD liver grafts face prolonged warm ischaemia time during the agonal phase, which can impair cellular function. Historically, this has led to higher rates of non-anastomotic biliary strictures and slightly lower three-year graft and patient survival compared to DBD livers. In the Netherlands, DCD donation now makes up roughly 50% of all organ donations, and with liver utilisation from these donors doubling over the last decade, highlighting the need for reliable assessment methods.
Assessing Viability with NMP
The meta-analysis of 16 studies included 568 livers: 297 DBD and 271 DCD grafts, all assessed using NMP for viability. Only clinical livers were included; duplicate or animal studies were excluded. NMP enables real-time evaluation of liver function, including perfusion, enzyme release, and bile production, providing clinicians with information to determine whether a high-risk graft is suitable for transplantation.
Key Outcomes and Limitations
Despite DBD grafts being older and heavier with longer cold ischaemia times, post-transplant outcomes were excellent across donor types. Primary non-function occurred in just one DCD case, early allograft dysfunction rates were low, and retransplant rates were similar between groups. Subgroup analyses suggested that stricter viability criteria modestly reduced DCD utilisation but did not compromise outcomes. Limitations include a small proportion of livers undergoing normothermic regional perfusion before NMP (11% of DCD grafts) and potential surgeon selection bias in graft assignment.
Implications for Clinical Practice
These findings indicate that normothermic machine perfusion can support the use of high-risk livers from both donors after circulatory death and donors after brain death that might otherwise be excluded from transplantation. Clinicians may increasingly rely on viability assessment rather than donor type alone, optimising transplant decisions and reducing organ discard. Future research should focus on standardising viability criteria for NMP to predict graft success and guide the safe use of high-risk donors.
Reference
den Dekker AMP et al. Liver transplant outcomes of deceased donor types following normothermic machine perfusion: A meta-analysis. Ann Hepatol. 2026;DOI:10.1016/j.aohep.2026.102187.
Featured image: Gorodenkoff on Adobe stock
