Do Trisectionectomies Improve Outcomes for Localized Bismuth-Corlette Type II and III Perihilar Cholangiocarcinoma?Insights from a Nationwide French Cohort Study

Objective: To determine whether extending resections to trisectionectomies (TS) improves long-term outcomes in Bismuth-Corlette (BC) type II-III perihilar cholangiocarcinomas (PHC). Summary Background Data: Hemihepatectomy extended to segment 1 (EH) is the standard surgical approach for BC type II-III PHC. Methods: This nationwide French retrospective study compared patients undergoing right-/left-sided TS and EH for BC II-III PHC between 2010 and 2020. The primary endpoint was overall survival (OS) with secondary endpoints including disease-free survival (DFS), R0-resection rate and postoperative outcomes. Propensity score (PS) and inverse probability treatment weighting (IPTW) were applied to balance confounders. Kaplan-Meier curves and log-rank tests were used for survival analysis, with adjusted hazard ratios (aHR) derived from mixed-effects multivariable Cox models clustered within hospitals. Results: Among 443 patients (median age 66, 57.1% men), 286 (64.6%) underwent TS and 157 (35.4%) EH. TS achieved more frequently R0 resection (83.9% vs. 75.8%, P =0.037), had more frequent Grade B-C liver failure (23.4% vs. 11.3%, P =0.002) but similar 90-day severe morbidity (Clavien-Dindo≥3) and mortality rates with EH (51.6% vs. 50.7%, P =0.85 and 12.9% vs. 14.0%, P =0.55). TS significantly improved OS and DFS (52.4 months [42.5-104.5] vs. 31 months [24.3-42.3], P <0.001 and 39.9 months [26.2-66.2] vs. 24.3 months [20.7-36.3], P =0.01) and was independently associated with improved OS in the original cohort (aHR: 0.63 [0.46-0.88], P =0.007), IPTW pseudo-population (aHR: 0.63 [0.41-0.95], P =0.029) and across different BC subtypes and side of resection. Conclusions: TS improves oncological outcomes compared to EH in BC II-III PHC resection and should be strongly considered when feasible