Left-side vs. right-side hepatectomy for Hilar Cholangiocarcinoma: A meta-analysis

Goals: We aim to draw a conclusion which type of hepatectomy could be the priority for hilar cholangiocarcinoma patients. Background: Surgery is established as only potentially curative treatment for hilar cholangiocarcinoma. However, whether hepatectomy should be preferred to the left-side hepatectomy, which includes left hemihepatectomy, extended left hemihepatectomy and left trisectionectomy, or right-side hepatectomy, which represents right hemihepatectomy, extended right hemihepatectomy and right trisectionectomy, is debated. In this meta-analysis, we evaluated and compared the efficacy and safety of left-side hepatectomy and right-side hepatectomy in patients with hilar cholangiocarcinoma. Study: We systematically retrieved the MEDLINE, PubMed and Cochrane library and related bibliography up to February 2020. The primary outcome is overall survival, and secondary outcomes include 1-, 3-, and 5-Year survival rates, morbidity, mortality, R0 resection rate and operation time. Based on heterogeneity, fixed-effects model or random-effects models were established through meta-analysis. Results: : Eleven studies (11 cohort studies, totally 1031 patients) were involved in this study. The overall survival of patients underwent left-side hepatectomy was comparable to that of patients underwent right-side hepatectomy (hazard ratio, 1.27 [95% confidence interval, 0.98-1.63]). And there was no significant difference observed in 1-year (relative risk, 1.01 [95% CI, 0.89-1.15]), 3-year (relative risk, 0.94 [95% confidence interval, 0.80-1.11]), and 5-year survival (relative risk, 0.82 [95% confidence interval, 0.67-1.01]) rates between left-side hepatectomy group and the right-side hepatectomy group. Comparing with right-side hepatectomy cluster, the hilar cholangiocarcinoma patients in left-side hepatectomy cluster presented better overall postoperative morbidity (relative risk, 0.82 [95% confidence interval, 0.71-0.96]) and major postoperative morbidity (relative risk, 0.73 [95% confidence interval, 0.56-0.95]). The post-hepatectomy liver failure rate (relative risk, 0.22 [95% confidence interval, 0.09-0.56]) and procedure-related mortality (relative risk, 0.41 [95% confidence interval, 0.23-0.70]) in left-side hepatectomy group was better than that of right-side hepatectomy group. Besides, the R0 resection rate was similar between left-side hepatectomy group and right-side hepatectomy group (relative risk, 0.95 [95% confidence interval, 0.87-1.03]). And the operation time for left-side hepatectomy were significantly longer than those for right-side hepatectomy (mean difference, 38.68 [95% confidence interval, 7.41-69.95]). Conclusion: Through meta-analysis, we explored the comparable long-term outcomes and better short-term outcomes in left-side hepatectomy group as is compared to right-side hepatectomy group of hilar cholangiocarcinoma patients. In this study, the evidence obtained might indicate that the choice of left-side hepatectomy or right-side hepatectomy had better depend on the site of hilar cholangiocarcinoma in every patient.