Prognostic impact of low versus high inferior mesenteric artery ligation in rectosigmoid cancer: individual patient data meta-analysis of randomized trials.

The optimal level of inferior mesenteric artery ligation in rectosigmoid cancer surgery remains a matter of debate. This study evaluated the prognostic impact of low ligation (LL) versus high ligation (HL) after rectal or sigmoid cancer resection. A reconstructed individual patient data meta-analysis of randomized clinical trials (RCTs) was performed using restricted mean survival time difference (RMSTD) estimation. PubMed, MEDLINE, Scopus, Web of Science, ClinicalTrials.gov, Cochrane Central Library, and Google Scholar were searched. Primary outcomes were 5-year overall (OS) and disease-free survival (DFS). The RMSTD, risk ratio (RR), standardized mean difference (SMD), and 95% confidence interval (c.i.) were used as pooled effect size measures. The certainty of evidence was categorized with the GRADE framework. Overall, 1152 patients from five RCTs were included; 34% underwent LL. Baseline demographics and pathological tumour stage were balanced among the LL and HL groups. At the 60-month follow-up, the OS and DFS estimates for LL versus HL were 1.40 months (95% c.i. -0.18 to 2.98; moderate level of certainty) and 0.71 months (95% c.i. -1.55 to 3.03; moderate level of certainty). Anastomotic leak (RR 0.71), overall complications (RR 0.79), total number of lymph nodes retrieved (SMD 0.01), and operating time (SMD 0.08) were comparable. This meta-analysis did not detect a statistically significant difference in 5-year OS and DFS between LL and HL in patients with rectosigmoid cancer.