Improving outcomes of in situ split liver transplantation in Italy over the last 25 years

background & aims: split liver transplant(ation) (SLT) is still considered a challenging procedure that is by no means widely accepted. we aimed to present data on 25-year trends in SLT in italy, and to investigate if, and to what extent, outcomes have improved nationwide during this time. methods: the study included all consecutive SLTs performed from may 1993 to december 2019, divided into three consecutive periods: 1993-2005, 2006-2014, and 2015-2019, which match changes in national allocation policies. primary outcomes were patient and graft survival, and the relative impact of each study period. results: SLT accounted for 8.9% of all liver transplants performed in Italy. a total of 1,715 in situ split liver grafts were included in the analysis: 868 left lateral segments (LLSs) and 847 extended right grafts (ERGs). a significant improvement in patient and graft survival (p <0.001) was observed with ERGs over the three periods. predictors of graft survival were cold ischaemia time (CIT) <6 h (p = 0.009), UNOS status 2b (p <0.001), UNOS status 3 (p = 0.009), and transplant centre volumes: 25-50 cases vs. <25 cases (p = 0.003). patient survival was significantly higher with LLS grafts in period 2 vs. period 1 (p = 0.008). no significant improvement in graft survival was seen over the three periods, where predictors of graft survival were CIT <6 h (p = 0.007), CIT <6 h vs. >-10 h (p = 0.019), UNOS status 2b (p = 0.038), and UNOS status 3 (p = 0.009). retransplantation was a risk factor in split liver graft recipients, with significantly worse graft and patient survival for both types of graft (p <0.001). conclusions: our analysis showed Italian SLT outcomes to have improved over the last 25 years. these results could help to dispel reservations regarding the use of this procedure.