Secondary Perfusion to Model Viability of Livers Declined for Transplantation

Background/Objectives: The donor liver shortage has created an urgent need to utilize higher-risk grafts for transplantation. Normothermic machine perfusion enables ex vivo graft assessment prior to transplantation, offering a route to expand access safely. However, proposed performance metrics often fail to differentiate dysfunctional grafts from functional grafts. Organs showing borderline results require careful deliberation as clinicians seek to balance recipient safety with waiting list access. The crucial question remains: are we discarding organs appropriately? Methods: To address this question, we describe a novel “secondary perfusion” model. We suggest that organs declined for transplantation after normothermic perfusion be subjected to an additional trial of cold ischemia and warm reanimation, mimicking reperfusion. Results: We present a protocol description and proof-of-concept case study using a marginal donor liver, showing how secondary perfusion enabled confirmation of predicted dysfunction. Conclusions: We share a protocol for modeling the performance of discarded organs in a recipient. We aim for this proof of concept to enable further investigation of existing viability criteria and better inform clinical decision-making.