Background: Left-sided hepatectomy for perihilar cholangiocarcinoma includes conventional left hepatectomy (C-LH; H1234-B), extended left hepatectomy (E-LH; H12345'8'-B-MHV), and left trisectionectomy (LT; H123458-B). The anatomical characteristics of the resected length of the right hepatic duct (RHD) in E-LH remain unclear. This study aimed to characterize the length of the RHD across procedures.
Methods: Patients who underwent left-sided hepatectomy for perihilar tumors between 2015 and 2023 were retrospectively reviewed. The shortest distance between the proximal bile duct stump and left hepatic duct orifice was measured on the resected specimens. The lengths and clinicopathological features of the procedures were compared.
Results: In total, 205 patients were included: C-LH (n = 80), E-LH (n = 53), and LT (n = 72). The length of the right anterior hepatic duct was longer in E-LH than that in C-LH (15.2 vs. 13.0 mm, p = 0.006). Similarly, the length of the right posterior hepatic duct increased stepwise from C-LH to E-LH and LT (13.3, 16.6, and 20.0 mm, respectively).
Conclusions: E-LH is an intermediate procedure between C-LH and LT with respect to the resected length of the RHD. The additional bile duct length achieved by E-LH is minimal, and this procedure should be selected primarily to secure the parenchymal margin rather than ductal clearance.
Keywords: Perihilar cholangiocarcinoma; extended left hepatectomy; left trisectionectomy; left‐sided hepatectomy; right hepatic duct length.
© 2026 The Author(s). Journal of Hepato‐Biliary‐Pancreatic Sciences published by John Wiley & Sons Australia, Ltd on behalf of Japanese Society of Hepato‐Biliary‐Pancreatic Surgery.