Right-side versus left-side hemihepatectomy for the treatment of Bismuth type IV perihilar cholangiocarcinoma: a comparative study.

Objective: Radical surgical resection is the only potentially curative treatment for perihilar cholangiocarcinoma (PHC) patients. However, data on left-sided hemihepatectomy (LH) and right-sided hemihepatectomy (RH) outcomes for Bismuth-Corlette type IV PHC are scarce and controversial. This study aimed to explore surgical and long-term outcomes of LH and RH in these patients. Methods: Medical records of Bismuth type IV PHC patients who had liver resection from 2009 to 2018 were retrospectively analyzed. Surgical results and long-term survival were the primary outcomes, compared via one-to-one propensity score matching (PSM). Results: 218 Bismuth type IV PHC patients (146 LH, 72 RH) were analyzed. The RH group had a higher proportion of preoperative biliary drainage (p = 0.02) and more frequent portal vein embolization (p < 0.0001). R0 resection rate was 90.37% (197/218) with no significant LH-RH difference. Post-operative severe complication (grades 3-5) and 90-day mortality rates were comparable. Overall survival was similar (overall cohort: p=0.21; matched cohort: p=0.54). But in the overall cohort, R0-resected RH patients had marginally better survival (p = 0.064). Prognostic factors included carbohydrate antigen 19-9 (CA19-9), age, tumor vascular invasion, and severe post-operative complications. Conclusions: The postoperative morbidity and mortality rate was comparable between LH and RH for Bismuth type IV PHC. Although RH showed a favorable survival from the Kaplan-Meier survival curve, no significant difference was observed in overall survival after LH versus RH for the overall cohort and the matched cohort after PSM.