Comparison of Bismuth IIIa and IIIb Types of Hilar Cholangiocarcinoma: a Multi-center Case Series Analysis of China

The differences between Bismuth IIIa and IIIb types of hilar cholangiocarcinoma are unclear. Thus, this study aimed to compare the clinical characteristics of the Bismuth IIIa and IIIb types of hilar cholangiocarcinoma. A case series analysis was designed to explore the clinical and pathological findings and survival of 144 patients with hilar cholangiocarcinoma who underwent curative hepatectomy between 2007 and 2018. The patients in the IIIa group received portal vein embolization and transfusion more frequently than those in the IIIb group (18.3% vs. 0.0%, P < 0.05 and 36.6% vs. 25.0%, P < 0.05). The incidence of posthepatectomy liver failure and serious surgical complications (≥ grade B) was significantly higher in the IIIa group than in the IIIb group (12.2% vs. 4.5%, P < 0.01 and 32.9% vs. 9.1%, P < 0.01). Tumors of the patients in the IIIa group had more advanced T and N stages than those of the patients in the IIIb group (P < 0.01). The patients in the IIIa group had poorer disease-free and overall survival rates than those in the IIIb group (P = 0.014 and P = 0.048). N stage and lymphovascular invasion were independently correlated with disease-free survival, whereas T and N stages were independently correlated with overall survival in the IIIb group. Meanwhile, T stage, N stage, and lymphovascular invasion were independently correlated with disease-free survival, whereas posthepatectomy liver failure, complication, and T stage were independently correlated with overall survival in the IIIa group. Hepatic and portal vessel metastasis occurred more frequently in the IIIa group than in the IIIb group (7.3% vs. 0.0%, P < 0.05). In our centers, patients with Bismuth IIIb hilar cholangiocarcinoma exhibited better disease-free and overall survival rates with more favorable clinicopathological characteristics than those with IIIa hilar cholangiocarcinoma.