New Biomarkers for Organ Viability Assessment During Hypothermic Machine Perfusion in Liver Transplantation: the Role of Extemporaneous Histological Examination.

Liver transplantation is a life-saving treatment for patients with severe liver disease. Because of the shortage of donor organs, transplant centers increasingly use donor livers that may be more vulnerable to injury and dysfunction. To improve the quality of these organs before transplantation, many centers use hypothermic oxygenated machine perfusion (HOPE or D-HOPE), a technique that preserves the liver under cold, oxygenated conditions. However, there are currently no widely accepted methods to determine whether a liver is functioning well enough during this preservation process. The purpose of this study is to investigate whether changes observed in liver tissue during hypothermic machine perfusion can help predict how well the transplanted liver will function after surgery. The study will compare liver biopsy samples collected before and after one hour of perfusion and will analyze biological markers released into the perfusion fluid, including markers of mitochondrial injury and inflammation. The main question this study aims to answer is whether histological changes occurring during hypothermic perfusion, alone or in combination with biochemical biomarkers, can accurately predict liver graft viability and post-transplant outcomes. Researchers will also evaluate whether these data can be used to develop an artificial intelligence-based model to support clinical decision-making during organ preservation. A total of 150 adult liver transplant recipients receiving donor livers treated with HOPE or D-HOPE will be enrolled at three Italian liver transplant centers. Participants will be followed for 90 days after transplantation to assess liver graft function, graft survival, patient survival, and post-transplant complications. The results of this study may improve the assessment of donor liver quality before transplantation and help clinicians make more informed decisions about organ use, ultimately increasing the safety and effectiveness of liver transplantation.

Inclusion Criteria: 1. Adult liver transplant recipients (≥18 years of age). 2. Donor liver grafts from either Donation after Brain Death (DBD) or Donation after Circulatory Death (DCD). 3. Grafts undergoing hypothermic oxygenated perfusion (HOPE) (HOPE or D-HOPE) for a minimum duration of 1 hour prior to transplantation. 4. Availability of two wedge liver biopsy samples: one pre perfusion and one post-perfusion. 5. Grafts preserved using standard cold storage protocols and transported in ice-cold Servator C™ solution. 6. Informed consent obtained from the recipient (or legal representative, where applicable) for the use of clinical and histological data for research purposes. Exclusion Criteria: 1. Inadequate or fragmented biopsy samples, preventing proper histological evaluation. 2. Biopsy samples showing histological features of pre-existing chronic liver disease (e.g., cirrhosis, autoimmune hepatitis, chronic viral hepatitis). 3. Liver grafts subjected to normothermic perfusion or other non hypothermic perfusion techniques. 4. Organs undergoing experimental or non-standard perfusion protocols. 5. Grafts from donors \