IMPACT OF COLD ISCHEMIC TIME ON REJECTION AFTER LIVING DONOR LIVER TRANSPLANTATION: IS THERE A SAFE WINDOW?

초록

Background: Acute cellular rejection (ACR) is a critical complication following liver transplantation, and its prevention and management are essential for preserving graft function. Cold ischemic time (CIT) is known to be associated with various post-transplant complications, particularly in deceased donor liver transplantation, where prolonged CIT has been related to an increased risk of rejection. However, due to the relatedly short CIT in living donor liver transplantation (LDLT), studies investigating its impact remain limited. Purpose: This study aimed to evaluate the association between CIT and post-LT rejection in the setting of LDLT and to identify the safe window of CIT to minimize rejection risk in LDLT. Method: The data were obtained from three centers retrospectively. Among 161 patients who underwent LDLT between 2009 and 2022, cases of patients under 18 years old (n = 2) and ABO-incompatible LDLT (n = 43) were excluded. The remaining patients were divided into two groups based on a CIT threshold of 183 minutes: the short CIT group (≤183min, n = 79) and the prolonged CIT group (>183min, n = 37). Result(s): In baseline characteristics, most variables listed on the table were comparable between the two groups, except for alcoholic liver disease. In the operative variables, the amount of red blood cell transfusion and operation time differed significantly between the two groups, whereas warm ischemic time was comparable. In post-LT outcomes, the incidence of major complications such as vascular or biliary complications, did not differ significantly between the two groups. Notably, rejection occurred at a significantly different rate between the two groups. On univariate and multivariate Cox proportional hazards analyses of rejection free survival, cold ischemic time was identified as an independent risk factor among the variables examined in this study. The Kaplan-Meier curve for overall survival did not show a significant difference, whereas rejection-free survival differed significantly between the two groups. Conclusion(s): In conclusion, prolonged cold ischemia time above 183 minutes may significantly be associated with reduced rejection-free survival in LDLT.