To observe the surgical anatomy of the left colic artery (LCA) during laparoscopic natural orifice specimen extraction surgery (NOSES) for colorectal cancer and to explore the preservation techniques during surgery and its clinical efficacy on patients.

The clinical data of 85 patients with colorectal cancer who underwent laparoscopic LCA-preserving NOSES operation in Sichuan Cancer Hospital from January 2017 to December 2021 were retrospectively analyzed. Among them, LCA anatomy of 54 patients was observed and recorded, combined with the operation video, the anatomical course and surgical classification of LCA were analyzed, and the operation skills and clinical effect of preserving LCA were discussed.

From all cases, we observed that the LCA emanated from the left side of the inferior mesenteric artery (IMA), and the average distance was about (3.5±1.1) cm from the root of the IMA to the emanation of LCA; Among them, 75.9% (41/54) cases, the LCA intersected in front of the IMV when it traveled outward, and 24.1% (13/54) cases crossed from the rear; twenty-three cases had the LCA branching from the IMA alone (type Ⅰ, 42.6%); nine cases had the LCA co-truncating with the sigmoid artery (SA) (type Ⅱ, 16.7%), nineteen cases had the LCA co-truncating with the superior rectal artery (SRA) and SA (type Ⅲ, 35.2%), and 3 cases had the LCA co-truncating with SRA and two or more SA (type Ⅳ, 5.6%). No absence of LCA was found in this group. All operations performed on 85 patients were successfully completed. Two patients (2.4%) developed anastomotic leakage after surgery, one was cured by conservative treatment, and the other underwent ileostomy. No mortality occurred. The average hospital stay after surgery was (10.4±3.4) days.

The surgical route of LCA is diverse, and its anatomical variation is complex. Preservation of LCA during laparoscopic surgery requires high surgical skills. However, the combination of LCA-preserving operation and NOSES technology during laparoscopic colorectal cancer surgery is expected to maximize the surgical concepts of damage control, function protection, and minimally invasion.