Introduction The mainstay treatment for intrahepatic cholangiocarcinoma is surgical resection, the impact of lymph node dissection and the scope of lymph node dissection for intrahepatic cholangiocarcinoma surgery is controversial. However, research on the comparative of regional lymphadenectomy and extended lymphadenectomy is still limited. This study will explore the effect of regional lymphadenectomy and extended lymphadenectomy in intrahepatic cholangiocarcinoma surgery patients to provide reliable evidence for further standardize the scope of lymph node dissection for intrahepatic cholangiocarcinoma surgery. Methods and analysis This is a prospective, multicentre, randomised controlled trial in intrahepatic cholangiocarcinoma surgery patients. A total of 174 patients will be enrolled at the first clinic visit in sites from China. Participants will be allocated randomly to the regional lymphadenectomy group and extended lymphadenectomy group (1:1 ratio). Patients in different groups undergo the corresponding surgery. Primary study outcome is disease-free survival (DFS). Secondary study outcomes include incidence of severe Clavien-Dindo complications (＞II), safety of operation, overall survival (OS), three-year survival rate, five-year survival rate and median mortality. Participants will be followed up at baseline, post-operation, every 3 months for the first 2 years and 6 months for the next 3 years to evaluate the impact of different surgery types. The analysis will be done according to protocol cohorts, adjusted by variables associated with intrahepatic cholangiocarcinoma. Ethics and dissemination This study was approved by the ethical review committee of the second affiliated hospital Zhejiang University school of medicine (2019-261) and will provide reference for standardize the scope of lymph node dissection for intrahepatic cholangiocarcinoma surgery. Trial registration: ClinicalTrials.gov, NCT04078230. Registered on September 6, 2019. The study is expected to last for more than five years, and the first patient was enrolled on August 22, 2020, and a total of 17 patients have been enrolled so far.

The authors have declared no competing interest.

NCT 04078230

This study was supported by grants from The Second Affiliated Hospital of Zhejiang University Medical College (RCT-2019-018B).

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