Role of resection for Bismuth type IV hilar cholangiocarcinoma and analysis of determining factors for curative resection

PURPOSE Extended liver resection may provide long-term survival in selected patients with Bismuth type IV hilar cholangiocarcinoma (HCCA). The purpose of this study was to identify anatomical factors that predict curative-intended resection. METHODS Thirty-three of 159 patients with Bismuth type IV HCCA underwent major hepato-biliary resection with curative intent (CIR) between 2000 and 2010. Disease extent and anatomical variations were analyzed as factors enabling CIR. RESULTS CIR ratio with hilar trifurcation bile duct variation (13/16) was significantly higher than that with other bile duct variation types (18/25). Hilum to left second bile duct confluence and tumor infiltration over left second bile duct confluence lengths in right-sided CIR were significantly shorter than those lengths in left-sided CIR (10.8 ± 4.9 and 2.7 ± 0.8 mm vs. 16.5 ± 8.4 and 7.0 ± 5.3 mm, respectively). Left-sided CIR patients had a marginally higher proportion of tumors invading ≤5 mm over the right second confluence than that in right-sided CIR patients (13/17 vs. 6/16; P = 0.061). The 3-year survival rate after CIR (28%) was significantly higher than after non-CIR (6.1%). CONCLUSION We recommend the criteria of CIR as bile duct variation type, length of hilum to contralateral second bile duct confluence, and extent of tumor infiltration over the second confluence for Bismuth type IV HCCA.