This study aimed to classify the anatomical types of biliary strictures, including intrahepatic biliary stricture (IHBS), after living donor liver transplantations (LDLTs) using right liver grafts and evaluate their prognosis. Among 692 adult patients who underwent right liver LDLT, 198 recipients with biliary strictures (28.6%) were retrospectively reviewed. Based on data obtained during the first cholangiography, the patients' biliary strictures were classified into the following three types according to the levels and number of branches involved: Types 1 (anastomosis), 2 (second-order branch [a, one; b, two or more; c, extended to the third-order branch]), and 3 (whole graft [a, multifocal strictures; b, diffuse necrosis]). IHBS was defined as a nonanastomotic stricture. Among the 198 recipients with biliary strictures, the IHBS incidence rates were 38.4% (n = 76).The most common type of IHBS was 2c (n = 43, 56.6%), whereas Type 3 (n = 10, 13.2%) was uncommon. The intervention frequency per year significantly differed among the types (Type 1, 2.3; Type 2a, 2.3; Type 2b, 2.8; Type 2c, 4.3; and Type 3, 7.2; p < 0.001). The intervention-free period for more than 1 year, which was as follows, also differed among the types: Type 1, 84.4%; Type 2a, 87.5%; Type 2b, 86.7%; Type 2c, 72.1%; and Type 3, 50.0% (p = 0.048). The graft survival rates of Type 3 (80.0%) were significantly lower than those of the other types (p = 0.001). IHBSs are relatively common in right liver LDLTs. Although Type 3 IHBSs are rare, they require more intensive care and are associated with poorer graft survival rates than anastomosis strictures and Type 2 IHBS.

Background: Biliary complications account for unsolved common complications after living donor liver transplantation (LDLT). However, intrahepatic biliary stricture (IHBS) after LDLT is not common but requires intensive care. The purpose of this study is to classify IHBS and to evaluate the prognosis of IHBS after LDLT. Methods: From 2011 to 2018, 868 cases of the right liver LDLT were enrolled. According to cholangiographic appearance, types of biliary stricture were classified into four, based on level and number of involved branches: type 1 (anastomosis or the 1st order branch; single), type 2 (the 2nd order branch; a. single, b. double, c. extended to the 3rd order branch), type 3 (multifocal), type 4 (diffuse necrosis). IHBS was defined as type 2, 3 and 4. We evaluated biliary intervention free period more than 1 year after last intervention (IFY), intervention frequency per year and clinical relapse after IFY. Results: The overall incidence of biliary stricture including IHBS was 23% (n=198); IHBS was 9% (n=76). The most common type of stricture was type 1 (n=122, 62%) followed by type 2 (n=66, 33%), 3 (n=6, 3%) and 4 (n=4, 2%). Incidence of type 2 sub-classification consisted of 2a (n=8, 4%), 2b (n=15, 8%), 2c (n=43, 22%). IFY was more common in type 1 (85%) and 2 (a, 88%; b, 87%; c, 72%) than type 3 (67%) and 4 (25%) (P<0.05). Intervention frequency per year was higher in type 4 (12) than others (type 1, 3; type 2a, 2; type 2b, 4; type 2c, 5; type 3, 7) (P<0.05). Clinical relapse after IFY was more common in type 4 (50%) and 3 (67%) than type 2 (33%) and 1 (37%) but it was not significantly different (P>0.05). Conclusions: IHBS was not rare in right liver LDLT. Although multifocal stricture or diffuse necrosis of intrahepatic bile duct were uncommon, they required more interventions.