Objective To investigate the anatomic classification and reconstruction of right intrahepatic bile duct in the donor liver of split liver transplantation (SLT).

Methods The retrospective and descriptive study was constructed. The clinical data of 85 patients who underwent SLT in the Third Affiliated Hospital of Sun Yat‑sen University from July 2014 to January 2022 were collected. There were 65 males and 20 females, aged 45(range, 1-82)years. Observation indicators: (1) surgical conditions; (2) anatomy of right intrahepatic bile duct; (3) bile duct reconstruction; (4) postoperative biliary complications; (5) follow‑up. Measurement data with normal distribution were represented as Mean±SD, and measurement data with skewed distribution were represented as M(range) or M(Q₁,Q₃).Count data were described as absolute numbers or percentages, and comparison between groups was conducted using the chi‑square test or Fisher exact probability.

Results (1) Surgical conditions. Of the 85 donor livers, 11 donor livers were split between the left and right hemilivers, and 74 donor livers were split between the classic right trilobe and left lateral lobe. The cold ischemia time of 85 donor livers was 291(273, 354)minutes, and the operation time, anhepatic phase time and volume of intraoperative blood transfusion of 85 recipients were (497±97)minutes, 51(40, 80)minutes and 8(7, 12)U. (2) Anatomy of right intrahepatic bile duct. Of the 85 donor livers, there were 47 donor livers with classic bile duct anatomical model (type 1), of the ratio as 55.3%(47/85), and 38 donor livers with anatomical variants, of the ratio as 44.7%(38/85). Of the 38 donor livers with anatomical variants, 7 donor livers were type 2, 16 donor livers were type 3a, 2 donor livers were type 3b, 2 donor livers were type 3c, 1 donor liver was type 4, 3 donor livers were type 5a, 4 donor livers were type 5b, 3 donor livers were type 6. For bile duct splitting patterns of the 85 donor livers, 84 donor livers were split with the main trunk of common hepatic duct preserving in the right hemiliver or right trilobe, and 1 donor liver were treated with complete left and right hemiliver splitting to preserve the main trunk of the common hepatic duct in the left hemiliver and the right hemiliver in the right hepatic duct (type 1 bile duct anatomical model). There were 84 donor livers with only one bile duct opening, and 1 donor liver with two bile duct openings (type 3c bile duct anatomical model). (3) Bile duct reconstruction. Of the 85 recipients, there were 69 recipients with common bile duct end‑to‑end anastomosis to common bile duct of donor liver (38 donor livers with type 1 bile duct anatomical model, 5 donor livers with type 2 bile duct anatomical model, 14 donor livers with type 3a bile duct anatomical model, 2 donor livers with type 3b bile duct anatomical model, 1 donor liver with type 4 bile duct anatomical model, 3 donor livers with type 5a bile duct anatomical model, 4 donor livers with type 5b bile duct anatomical model, 2 donor livers with type 6 bile duct anatomical model), 11 recipients with jejunum anastomosis to common bile duct of donor liver (7 donor livers with type 1 bile duct anatomical model, 2 donor livers with type 2 bile duct anatomical model, 1 donor liver with type 3c bile duct anatomical model, 1 donor liver with type 6 bile duct anatomical model), 3 recipients with jejunum anastomosis to common hepatic duct of donor liver (1 donor liver with type 1 bile duct anatomical model, 2 donor livers with type 3a bile duct anatomical model), 1 recipient with jejunum anastomosis to right hepatic duct of donor liver (type 1 bile duct anatomical model), 1 recipient with common hepatic duct end‑to‑end anastomosis to right posterior branch of donor liver combined with jejunum of the recipient Roux‑en‑y anastomosis to common hepatic duct of donor liver (type 3c bile duct anatomical model). (4) Postoperative biliary complications. Of the 85 recipients, 6 cases had postoperative biliary complications, with an incidence of 7.1% (6/85). Of the 6 recipients with postoperative biliary complications, there were 5 recipients with donor liver with type 1 bile duct anatomical model, including 3 cases undergoing postoperative biliary stricture with biliary leakage and 2 cases undergoing postoperative biliary anastomotic stricture, 1 recipient with donor liver with type 3b bile duct anatomical model and undergoing postoperative biliary anastomotic stricture and bile leakage in the liver section. Cases with biliary complications were 5 in the 47 recipients with donor liver with classic bile duct anatomical model and 1 in the 38 recipients with donor liver with anato-mical variants, showing no significant difference between them (P>0.05). (5) Follow‑up. There were 83 recipients receiving followed up for 52(12,96)months. During the follow‑up period, 2 recipients died due to non‑biliary complication factors (1 donor liver with type 1 bile duct anatomical model and 1 donor liver with 3a bile duct anatomical model).

Conclusion The anatomical classification of right intrahepatic bile duct of donor liver in SLT is mainly classical bile duct anatomical model, and the bile duct reconstruction scheme is mainly common bile duct of donor liver end‑to‑end anasto-mosis to common bile duct of recipient.