Level of inferior mesenteric artery ligation does not affect rectal cancer treatment outcomes despite better cancer-specific survival after low ligation-randomized trial results

Abstract

Aim: In rectal cancer surgery, the problem about which of the mesenteric artery ligation variants (high or low) is more beneficial to the patient remains unsolved. Recent meta-analyses suggest that the risk of surgical complications is similar for both ligation variants. The main objective was to compare the survival time in both groups with a minimum 48 months' follow-up. Secondary objectives were comparison of the number of harvested lymph nodes, the complication rate and other selected data related to the surgery.

Method: This was a randomized, single-centre, unblinded clinical trial of adult patients (n = 130) with cT1-3M0/ycT0-3M0 rectal and rectosigmoid junction adenocarcinoma undergoing radical open surgery. The intervention level was inferior mesenteric artery ligation.

Results: The mean and median survival in the whole group was 45 months, while in the survivor group it was 83 and 82 months. The survival for 1-5 years, overall survival and disease-free survival were similar in both groups. The cancer-specific survival time was longer in the low inferior mesenteric artery ligation group (P = 0.005 for all and P = 0.02 for pTNM Stage III patients) There were no differences in the incidence of anastomotic leakage and overall morbidity. The median number of lymph nodes located at the root of the inferior mesenteric artery was 1; the mean was 1.7. They were not metastatic in any case. The median total number of harvested nodes was similar in both groups.

Conclusions: In radically treated adenocarcinoma of the rectum and the rectosigmoid junction, the level of inferior mesenteric artery ligation below the left colic artery branch provides similar treatment results to inferior mesenteric artery ligation just below its branching from the aorta in relation to overall and disease-free survival, and the risk of complications. Low inferior mesenteric artery ligation results in better cancer-specific survival. The risk of metastases at the mesenteric nodes is negligible.

Keywords: artery ligation level; inferior mesenteric artery; rectal cancer.