To evaluate the effect of the number of dissected lymph nodes on the safety and prognosis of pancreaticoduodenectomy for distal cholangiocarcinoma.

Clinical data of 104 patients with distal cholangiocarcinoma who underwent pancreatoduodenectomy in Beijing Chaoyang Hospital Affiliated to Capital Medical University from January 2015 to December 2021 were retrospectively analyzed. The informed consents of all patients were obtained and the local ethical committee approval was received. Among them, 60 patients were male and 44 female, aged from 29 to 84 years, with a median age of 66 years. The effect of the number of dissected lymph nodes on perioperative complications and survival was evaluated. The threshold value of lymph node number was determined by X-tile software. All patients were divided into two groups according to the threshold value. The number of lymph nodes between two groups was compared by t test, and the incidence of complications was compared by Chi-square test. Survival analysis was performed by Kaplan-Meier method and Log-rank test.

The number of dissected lymph nodes was 3-45. According to the threshold value of 24 lymph nodes, all patients were divided into the <24 (n=80) and ≥24 groups (n=24). The number of dissected lymph nodes in the <24 group and ≥24 group was 15±5 and 31±6, and the difference was statistically significant (t=-13.101, P<0.05). The incidence of postoperative complications and perioperative mortality rate in two groups were 21%(5/24), 4%(1/24) and 21%(26/80), 5%(4/80), and the differences were not statistically significant (χ²=1.201, 0.142; P>0.05). The postoperative 1-, 3- and 5-year overall survival rates of patients in two groups were 72.6%, 33.2%, 25.9% and 87.1%, 63.7%, 63.7%, respectively, and the differences were statistically significant (χ²=6.170, P<0.05).

For patients with distal cholangiocarcinoma undergoing pancreatoduodenectomy, the number of dissected lymph nodes ≥24 can significantly improve clinical prognosis without sacrificing perioperative safety.