Long-term survival outcome of portal vein embolization in patients with perihilar cholangiocarcinoma: a retrospective cohort study

Perihilar cholangiocarcinoma (CCA) often requires extended hepatectomy for curative treatment, especially in Bismuth type III–IV. However, the risk of post-hepatectomy liver failure (PHLF) cannot be ignored. Portal vein embolization (PVE) is a preoperative optimization method that reduces risk of PHLF, and improves surgical safety. This study investigated the impact of PVE on surgical outcomes and long-term survival in patients with Bismuth type III-IV perihilar CCA. We retrospectively reviewed the data of 137 patients diagnosed with Bismuth type III–IV perihilar CCA between April 2011 and August 2021. Among 137 patients, 88 were included in the analyses and divided into three groups: resection without PVE (group A); resection after PVE (group B); and no resection after PVE (group C). The main outcomes of this study were surgical outcomes and long-term survival outcomes of each group. Survival analyses were performed using inverse probability treatment weighting (IPTW) and Cox regression analysis stratified by surgical resection. Among 88 patients, 18 underwent resection without PVE (group A), 55 underwent resection after PVE (group B), and 15 did not proceed to surgery after PVE (group C). There was no significant difference in median recurrence-free survival (RFS) and overall survival (OS) between groups A and B (mRFS 11.9 vs. 18.1 months, P = 0.099; mOS 18.9 vs. 24.8 months; P = 0.454) after IPTW. However, a significant difference was found in median OS between groups B and C (25.9 vs. 10.2 months; P = 0.002). In the stratified Cox regression analysis in groups B and C, age (adjusted hazard ratio [aHR] 1.979ㅡ13.208), and percentage of future liver remnant after PVE (post-PVE FLR; aHR 0.160ㅡ0.744) were associated with OS regardless of surgical resection. PVE reduces the risk of post-hepatectomy liver failure and enables extended hepatectomy without comparing oncologic outcomes. Furthermore, in groups that underwent PVE, post-PVE measured FLR was an independent prognostic factor of OS, regardless of surgical resection.