Optimization of an Evidence-based Organizational Model of Liver and Pancreas Transplant Using Cardiac Death Donors: a Pilot, Prospective, Randomized, Multicenter Study for the Comparison of Hypothermic Versus Normothermic Ex-vivo Preservation.

The persistent mismatch between patients waiting for a liver transplant (LT) and grafts availability promoted the use of donation after circulatory death (DCD). Italian law requires 20 minutes of continous flatline electrocardiogram to declared individual's circulatory death and such a long period of warm ischemia time forced the development of protocols using abdominal normothermic regional perfusion (NRP) followed by ex-vivo graft reperfusion by means of machine perfusion technology (MP) for its potential to minimize ischemia/reperfusion damage and promote organ repair and reconditioning prior to transplantation. An extensive evaluation of all DCD donors might increase donation rate by 30%, but, while kidney transplant from DCD donors is well implemented, no definitive data exist on the optimal use of NRP and MP in liver and pancreas transplantation and an organizational model is far to be implemented. Moreover, a randomized trial comparing hypothermic vs normothermic ex-vivo perfusion has never been performed. The proposed project will perform a pilot, open, randomized, prospective trials to evaluate the sequential use of NRP followed by ex-vivo MP (hypothermic (HMP) vs normothermic (NMP)) by measuring several indicators of organ damage and recovery with the target to set up the optimal organizational model for DCD donation:

1. Twenty LT from DCD donors after NRP (considered transplantable for the acceptance criteria in use) will be randomized 1:1 to ex-vivo HMP or NMP (multicenter study together with the center in Milan)
2. 40 liver grafts from ECD-DBD matching the inclusion criteria are randomized 1:1 to hypothermic machine perfusion (HMP) vs normothermic machine perfusion (NMP) and then transplanted To assess organ damage and repair capacity, the following investigations will be performed: -biomarkers of apoptosis, necrosis, innate-mediated inflammation and its resolution, angiogenesis and thrombosis during NRP -circulating biomarkers indicating damage, proliferation, angiogenetic and tissue remodelling factors; a targeted-metabolomic and lipidomic profiling during ex-vivo HMP or NMP in the perfusate and on blood samples in the peri and post-operative period; bile composition on graft subjected to NMP. Evaluation of necrosis, apoptosis and proliferation, immunohistochemical analysis, a targeted-metabolomic and lipidomic profiling, ATP measurement, and electronic microscopy investigations will be performed on liver tissue and bile duct biopsies after NRP, before and after ex-vivo reperfusion, and immediately after reperfusion in the recipient (only for transplantable grafts) Based on the collected data a new algorithm of organ evaluation, procurement, preservation and reconditioning will be formulated and disseminated.