The role of ex‐situ hypothermic oxygenated machine perfusion and cold preservation time in extended criteria DCD and DBD

Hypothermic-oxygenated machine perfusion (HOPE) has the potential to counterbalance the detrimental consequences of cold and warm ischemia time in both brain death donors (DBD) and donors after circulatory death (DCD). Herein, we investigated the protective effects of HOPE in extended criteria (ECD) DBD and over-extended warm ischemia time (WIT) DCD grafts. The present retrospective case-series study included 50 livers subjected to end-ischemic HOPE or dual (D)HOPE in two liver transplant (LT) Centers from January 2018 to December 2019. All DCD donors were subjected to normothermic regional perfusion before organ procurement. Results are expressed as median (IQR). In the study period, 21 grafts derived from over-extended WIT DCD donors (total WIT 54 (40-60) min and 75% classified as futile), while 29 from ECD DBD. Three biliary complications and one case of ischemia-type biliary lesions were diagnosed. The rate of early allograft dysfunction (EAD) was 20% and those patients had higher comprehensive-complication index. Through a changing point analysis, cold preservation time (CPT) >9h was associated with prolonged hospital stay (p=0.02), higher rate of EAD (p=0.009) and worst post-LT complications (p=0.02). Logistic regression analyses indicated a significant relationship between CPT and early allograft dysfunction. No differences were showed in terms of early post-LT results between LT performed with DCD and BDB. Overall, our data are fully comparable with benchmark criteria in LT. In conclusion, the application of (D)HOPE allowed to obtain satisfactory and promising results using ECD-DBD and over-extended DCD grafts. Our findings indicate the need to reduce CPT also in the setting of DHOPE, particularly for grafts showing poor quality.