Primary graft dysfunction after living donor liver transplantation is characterized by delayed functional hyperbilirubinemia.

The purpose of this study is to propose a new concept of primary graft dysfunction (PGD) after living donor liver transplantation (LDLT), characterized by delayed functional hyperbilirubinemia (DFH) and a high early graft mortality rate. A total of 210 adult-to-adult LDLT grafts without anatomical, immunological or hepatitis-related issues were included. All of the grafts with early mortality (n = 13) caused by PGD in LDLT had maximum total bilirubin levels >20 mg/dL after postoperative day 7 (p < 0.001). No other factors, including prothrombin time, ammonia level or ascites output after surgery were associated with early mortality. Thus, DFH of >20 mg/dL for >seven consecutive days occurring after postoperative day 7 (DFH-20) was used to characterize PGD. DFH-20 showed high sensitivity (100%) and specificity (95.4%) for PGD with early mortality. Among the grafts with DFH-20 (n = 22), those with early mortality (n = 13) showed coagulopathy (PT-INR > 2), compared with those without mortality (p = 0.002). Pathological findings in the grafts with DFH-20 included hepatocyte ballooning and cholestasis, which were particularly prominent in the centrilobular zone. PGD after LDLT is associated with DFH-20 caused by graft, recipient and surgical factors, and increases the risk of early graft mortality.