High versus low ligation of the inferior mesenteric artery during transanal total mesorectal excision for low rectal cancer: impact on postoperative anastomotic leakage.

Introduction: Whether preserving the left colic artery (LCA) during transanal total mesorectal excision is beneficial remains unclear. This study evaluated the effects of LCA-preserving low ligation versus high ligation of the inferior mesenteric artery without LCA preservation on anastomotic leakage. Methods: We retrospectively reviewed patients with low rectal cancer at the First Affiliated Hospital of Chongqing Medical University (January 2014-January 2024). After propensity score matching, 182 patients were assigned to LCA preservation (n = 91, low ligation) or non-preservation (n = 91, high ligation) groups according to whether the LCA was preserved. Perioperative characteristics, pathological findings, and incidence of anastomotic leakage were compared, and subgroup analyses were performed. Results: The incidence of postoperative leakage in the LCA preservation group was lower than in the non-preservation group (4.3% vs. 13.2%, p = 0.036). Among patients who received neoadjuvant therapy, LCA preservation was associated with a lower incidence of anastomotic leakage rates (7.0% vs. 24.0%, p = 0.049). Discussion: LCA preservation may have clinical value in selected patients with low rectal cancer, particularly those receiving neoadjuvant therapy.