Effects of mesenteric artery ligation level on patients with locally advanced rectal cancer after neoadjuvant chemoradiotherapy: a retrospective cohort study

There is currently limited research on the optimal level of inferior mesenteric artery (IMA) ligation during surgery for patients with locally advanced rectal cancer (LARC) undergoing neoadjuvant chemoradiotherapy (nCRT). We carried out a retrospective cohort study to analyze the impact of IMA ligation level on surgical outcomes and long-term patient prognosis. The data originated from a multicenter randomized controlled trial conducted across six tertiary referral hospitals in Beijing, involving patients with LARC undergoing nCRT followed by radical surgery. Patients were divided into high ligation (HL) and low ligation (LL) groups on the basis of the ligation level of IMA. Evaluation parameters included surgical outcomes, complications, long-term survival, and quality of life questionnaires. From August 2017 to April 2022, a total of 337 patients were included in the analysis. The number of lymph nodes retrieved was higher in the LL group compared with the HL group. Patients in both groups experienced a significant decrease in quality-of-life scores, but no difference in the extent of this decline was observed between the two groups. There were no significant differences between the two groups in terms of operation time, intraoperative blood loss, and other factors. There was also no significant difference in DFS (p = 0.818) and OS (p = 0.945) between the two groups. For patients with LARC undergoing nCRT, the level of IMA ligation during radical surgery does not significantly impact complications or long-term prognosis. The selection of ligation pattern should be on the basis of a comprehensive assessment of factors including metastatic risk, vascular anatomy, comorbidity (such as atherosclerosis), and surgical skills of the surgeons.