Efficacy and prognosis evaluation of left colic artery preservation in laparoscopic NOSES for rectal cancer: retrospective survival analysis.

This retrospective cohort study aimed to clarify the impact of preserving the left colic artery (LCA) during laparoscopic Natural Orifice Specimen Extraction Surgery (lapNOSES) for rectal cancer (RC) on perioperative outcomes and 3-year survival, and to examine treatment-by-covariate interactions on recurrence-free survival (RFS) and overall survival (OS). No significant interactions were identified for RFS, whereas significant interactions for OS were observed among patients with larger maximum tumor diameter and elevated CEA levels. RC patients who underwent lapNOSES between January 2018 and January 2022 were grouped according to LCA preservation status. Baseline clinicopathological features, perioperative indicators, and three-year follow-up data were collected. Kaplan-Meier and log-rank tests were employed for survival analysis, and prognostic factors were evaluated using Cox proportional hazard modeling. The baseline characteristics of the two groups were generally balanced. Perioperatively, surgical duration, splenic flexure mobilization, ileostomy creation, anastomotic leak (AL), urinary retention, and bowel perfusion status showed marked differences between groups (P<0.05), while intraoperative hemorrhage volume and surgical site infection did not differ significantly (P>0.05). Reduced 3-year recurrence/metastasis rates were observed in the LCA-preservation group (RFS: P=0.005), although 3-year overall mortality showed no notable difference (OS: P=0.463). In the multivariable Cox model, failure to preserve LCA independently predicted inferior RFS (HR=4.091, P=0.022), along with advanced age, elevated preoperative CEA/CA19-9, advanced TNM staging, and poor differentiation; postoperative adjuvant chemotherapy was protective (P=0.045). For OS (but not RFS), significant interactions were observed between the treatment plan and maximum tumor diameter as well as CEA elevation (P<0.001 and P=0.007, respectively). In conclusion, preserving the LCA in lapNOSES for RC is associated with lower 3-year recurrence/metastasis risks without compromising long-term survival, and individualized strategies should be considered based on tumor burden and CEA levels.