Figure 2.

Currently available preservation technology for in-situ and ex-situ machine liver perfusion. Multiple new technologies for liver graft treatment and assessment are currently used and tested. Two main concepts include first the replacement of cold storage by perfusion or and endischemic approach, where livers are perfused after cold storage. Different temperatures and perfusate compositions are in use and one main interest is the definition of clinically relevant viability criteria, to decide if an injured or suboptimal liver can be utilized for transplantation or not. Importantly, multiple reasons apply for the decline of a certain graft at different categories and timepoints between the first donor allocation, liver procurement and implantation at the recipient centre. Clinical trials and case series, which are designed to assess the impact of machine perfusion technology should report such reasons and also the risk factors for livers of the declined cohort.