New criteria for preoperative liver function assessment with safety margins to avoid postoperative mortality during liver resection for hilar cholangiocarcinoma

Background: Despite recent medical advancements, surgery for hilar cholangiocarcinoma is associated with high complication and mortality rates. This may be partly attributed to the absence of established preoperative liver evaluation criteria for safe surgery. This study aimed to propose a reliable indicator for safe and well-planned management of major hepatectomy with extrahepatic bile duct resection. Methods: We included 150 patients who underwent major hepatectomy with extrahepatic bile duct resection between 2013 and 2021 in Japan. The risk factors for post-hepatectomy liver failure (PHLF) were retrospectively analyzed. Results: PHLF was observed in 24 (16.0 %) patients who underwent major hepatectomy with extrahepatic bile duct resection. In the multivariate analysis, the identified risk factors for PHLF were the ratio of future remnant liver volume to total liver volume (FRLV/TLV) ≤ 42 % and indocyanine green clearance fraction of the future remnant liver (ICGK-F) ≤ 0.07. Patients with these two factors were significantly associated with PHLF compared with those with either one or none of the risk factors (60.0 % vs 15.1 % and 8.1 %, respectively). Conclusion: The combinational use of ICGK-F and FRLV/TLV is useful for preoperative liver function assessment with a safety margin to avoid PHLF and postoperative mortality in hepatectomy for hilar cholangiocarcinoma.