Objective To investigate the clinical efficacy of intraoperative regional lymphadenectomy and extended lymphadenectomy in resectable hilar cholangiocarcinoma.

Methods The propensity score matching and retrospective cohort study was conducted. The clinicopathological data of 187 patients of hilar cholangiocarcinoma who were admitted to Henan University People′s Hospital from January 2014 to January 2018 were collected. There were 105 males and 82 females, aged (57±9)years. Of the 187 patients, 62 patients undergoing hilar cholangiocarcinoma resection with extended lymphadenectomy were divided into the extended group, and 125 patients undergoing hilar cholangiocarcinoma resection with regional lymphadenectomy were divided into the regional group. Observation indicators: (1) propensity score matching status and comparison of clinical data of patients between the two groups after matching; (2) intraoperative and postoperative conditions; (3) follow-up. Comparison of measurement data with normal distribu-tion between groups was conducted using the independent sample t test. Comparison of measurement data with skewed distribution between groups was conducted using the Mann-Whitney U test. Comparison of count data between groups was conducted using the chi-square test. Comparison of ordinal data was conducted using the rank sum test. The Kaplan-Meier method was used to plot calculate survival rate and survival curve. The Log-rank test was used for survival analysis. Propen-sity score matching was performed using the 1∶1 nearest neighbor matching method, with the caliper value of 0.1.

Results (1) Propen-sity score matching status and comparison of clinical data of patients between the two groups after matching. Of the 187 patients, 104 patients were success-fully matched, with 52 cases in each of the extended group and the regional group. After propensity score matching, the elimination of tumor diameter, neural invasion, Bismuth classification, and TNM staging confounding bias ensured comparability. (2) Intraoperative and postoperative conditions. After pro-pensity score matching, the operation time of the extended group was (341±83)minutes, the number of lymph node dissected was 12.3±4.5, the number of positive lymph node dissected was 2.2±0.7, cases of postoperative new lymphadenectasis was 17. The above indicators of the regional group were (311±73)minutes, 9.2±3.4, 1.5±0.5, 44, respectively. There were significant differences in the above indicators between patients of the two groups (t=-1.99, -3.92, -5.57, χ²=31.18, P < 0.05). (3) Follow-up. After propensity score matching, all 104 patients were followed up after surgery, with the follow-up time of 29(range, 3-49)months. The postoperative 3-year overall survival rate was 44.2% of the extended group, versus 30.8% of the regional group, showing a significant difference between the two groups (χ²=4.41, P < 0.05).

Conclusions The perioperative safety of regional lymphadenectomy and extended lymphadenectomy in the radical resection of hilar cholangiocarcinoma are comparable. Extended lymphadenectomy can increase the number of positive lymph node detected and improve the postoperative survival rate of patients.