Choi et al. In eight type-5A cases, the accessory duct was combined it was less than 10 mm. with either type 1 (n=3), type 2 (n=3) or type 3A (n=2), and in eight type-5B cases, with either type 1 (n=6) or type 3A (n=2). DISCUSSION One of the three type-7 patterns, exhibiting complex Variations in the anatomy of the intrahepatic bile ducts variation, included a type 3A, with the accessory duct have long been recognized. Serious consideration of the pouring into the RPSD; in the second, the first-order surgical anatomy of the liver began, however, with the ad- branch of the left hepatic duct was absent, and the RPSD vent of minimally invasive therapeutic intervention for bile drained directly into the S3 branch of the LHD; in the third duct or hepatic resection, or partial liver transplantation. case there was trifurcation, with an accessory RPSD which Thus, accurate knowledge of the anatomy of IHDs is criti- poured into the caudate branch of the bile duct. cal. In donors with a type-1 pattern, the length of the first-or- Previous studies have reported that anatomic variants of der branch was 2.4 30 (mean, 12.8) mm; in 64 of the 188, IHDs were detected at ERCP or MRCP (2 4, 6, 7, 15); Fig. 5. Drainage of the RHD into the cystic duct (type 4). Operative cholangiogram shows the RHD (arrowheads), formed by fusion of the RASD (small arrows) and RPSD (large arrows), into the cystic duct. Asterisks=LHD Fig. 7. Segments II and III of the segmental duct drain individually into the RHD or CHD (type 6). Operative cholangiogram shows that segmental duct branches S2 (large arrows) and S3 (arrow- heads) drain into the CHD. There is no left main duct. A B Fig. 6. Accessory hepatic ducts (type 5). A. Drainage of an accessory hepatic duct into the CHD (type 5A). B. Drainage of an accessory hepatic duct into the RHD. Operative cholangiograms indicate that accessory hepatic ducts (arrowheads) drain into the CHD and RHD, respectively. Small arrows=RASD, large arrows=RPSD 88 Korean J Radiol 4(2), June 2003