Objectives: To assess the impact of ischemia reperfusion injury (IRI) on DCD outcomes in liver transplantation.
Methods: Between 2002-2017, 455 DCD transplant were performed at our institution, of which 248 had post reperfusion biopsy that were graded for IRI into four categories (0-no necrotic hepatocytes, 1-scattered foci of single cell necrosis/ drop-out, 2-perivenular zonal necrosis, 3-broader necrosis).
Results: Grade 0, 1, 2 and 3 were 20.7%, 44.5%, 23.4% and 11.3% respectively.  In univariate analysis, grade 3 was significantly associated with donor functional warm ischemia>30 minutes (p= 0.036) and donor bilirubin>30 mmol/l (p= 0.014). IRI grade was also associated with MELD>20 (p=0.024), recipient coagulopathy (INR>2, PLT<70, p=0.011) and portal vein reperfusion, rather than artery (p=0.012).
Patient and graft survival were significantly associated with the grade of IRI (p=0.05). Patient survival at 1, 5, 10 years was: grade 0= 97.5, 94.7, 72.2 %; grade 1= 96.0, 78.6, 69.1%, grade 2= 91.2,79.8,67.1 %, and grade 3= 82.8, 77.6, 57.7 %.  Similarly graft survival at 1, 5, 10 years were in group 0 97.8, 94.3, 80.9%, group 1 94.9, 84.3, 72.4 %, group 2 91.2, 83.0, 73.4 %, and group 3 83.1, 73.3,68.6 %, respectively.
The incidence of PNF, HAT and re-transplantation was not associated with the grade of IRI. Patient with IRI had higher rates of re-laparotomies for bleeding (p=0.016) and higher peak AST in the first seven postoperative days (p=0.013). However, no association was observed between IRI and early allograft dysfunction, biliary complications, grade of rejection, viral and malignant recurrence post-transplant.
Conclusion: IRI is an independent risk factor for graft and patient survival. The exact reasons for this are unclear. This grading system might be of use to predict outcome post-liver transplantation. Efforts to minimize IRI are important at a time of organ shortage and increasing use of marginal grafts.