Establishing a Reference Framework for Outcomes After Machine-Preserved Liver Transplantation in Europe

Machine perfusion (MP) has become routine clinical practice in liver transplantation. However, as the field has matured, direct randomized comparisons between distinct MP modalities have become increasingly impractical, given that donor and graft characteristics often predetermine the optimal preservation strategy. Consequently, many studies continue to reference historical benchmark cohorts from the pre-perfusion era, or use risk scores developed before routine utilization of MP. These cohorts, while once valuable, fail to account for the paradigm shift that MP has introduced. Likewise, commonly used donor- and recipient-based risk scores were developed prior to the adoption of MP. While these scores aim to assess survival or morbidity after transplantation, none of them guide decisions about MP use or the most suitable perfusion protocol. As MP technologies continue to evolve there is a critical need for an updated reference framework that accurately reflects current clinical practice and captures the best achievable outcomes across all MP modalities.

Inclusion Criteria: * All postmortal livers accepted (transplanted and not-transplanted after machine perfusion) upon organ offer for patients \>18 years at the time of liver transplantation. * All donor types (DBD, DCD) * Preservation either with static cold storage alone or combined with machine perfusion (MP). * Donor livers underwent MP as part of routine clinical practice and the choice of perfusion protocol was made according to institutional standard practice. * Eligible MP protocols are: 1. end-ischemic single- or dual hypothermic oxygenated MP \[e(D)HOPE\], 2. end-ischemic (back-to-base) normothermic MP \[eNMP\], 3. continuous (device-to-donor) normothermic MP \[cNMP\], 4. e(D)HOPE followed by controlled oxygenated rewarming and normothermic MP \[e(D)HOPE-COR-NMP)\], 5. e(D)HOPE followed by normothermic MP \[e(D)HOPE-NMP\], or 6. Normothermic regional perfusion followed by SCS or an ex situ MP protocol. * A minimum follow-up of 12 months after liver transplantation is required. Exclusion Criteria: * Livers that were allocated to a MP protocol as part of a prospective randomized or interventional clinical trial comparing different preservation techniques or any other invention. * Living donor liver transplantation