Extended Lymphadenectomy Versus Regional Lymphadenectomy in Resectable Hilar Cholangiocarcinoma.

Aim: The aim of this study is to compare the effects of extended lymphadenectomy (E-LD) and regional lymphadenectomy (R-LD) on outcome after radical resection of hilar cholangiocarcinoma (HCCA).

Methods: Data of 290 patients who underwent radical resection of HCCA were retrospectively analyzed. Demographic characteristics, surgical variables, and tumor and LN characteristics were evaluated for association with survival.

Results: A total of 63 patients underwent E-LD. Patients who underwent E-LD were more likely to have portal vein embolization (14.3% vs. 5.7%), radical hepatectomy (36.2% vs. 26.0%), higher proportion of M1 patients (22.2% vs. 5.3%), more lymph nodes (LNs) retrieved (17 vs. 7), and positive common hepatic artery lymph nodes (21.4% vs. 12.6%) when compared with R-LD (all P < 0.05). The Kaplan-Meier curve of overall survival for patients who underwent E-LD indicated improvement over patients who underwent R-LD in M0 (33.39 vs. 21.31 months; P = 0.032) and R0 resection (32.97 vs. 21.02 months; P = 0.044) disease, but not observed in M1 disease (P > 0.05). After propensity score matching, E-LD was not associated with a significant improvement in overall survival (OS) even in all subgroup analysis (all P > 0.05). On multivariable analysis, E-LD was associated with improved overall survival, but not after propensity score matching.

Conclusion: E-LD is more likely to be performed in higher stage tumors. E-LD significantly increases LN retrieval, thereby preventing under-staging and improving survival prediction. E-LD should not be adopted for HCCA patients with intraoperatively confirmed distant LN metastases. Future studies are required to further assess whether E-LD should be performed in negative celiac, superior mesenteric, and para-aortic lymph node in HCCA patients.