Objective To evaluate the clinical value of preserving left colonic artery in preventing the anastomotic stenosis after operation of middle and low rectal cancer.

Methods Sixty patients with mid and low rectal cancer and underwent laparoscopic resection (Dixon) in Xinhua Hospital Affiliated to Dalian University from January 2017 to December 2018 were selected. The patients were divided into the preserved left colonic artery group (preserved group) and excised left colonic artery group (excised group), with 30 patients in each group. CT angiography (CTA) was used to examined the types of inferior mesenteric artery (IMA). And the influences of IMA types and Riolan artery arcade absence on the postoperative anastomotic stenosis were analyzed.

Results Among the sixty patients, the proportion of IMA-Ⅰ, -Ⅱ, and -Ⅲ types were 51.7% (31/60), 10.0% (6/60), and 38.3% (23/60), respectively, and no one with IMA-Ⅳ. The proportion of Riolan artery arcade absence was 68.3% (41/60). The postoperative anastomotic stenosis rate in the preserved group (10.0%) was lower than that in the excised group (33.3%, P=0.028). In the two groups, no patient with IMA-Ⅰ, -Ⅱ had the postoperative anastomotic stenosis regardless of the presence of Riolan artery arcade absence. In the excised group, the postoperative anastomotic stenosis occurred in majority of patients with Riolan artery arcade absence and IMA-Ⅲ type (9/10).

Conclusions The preservation of left colonic artery is crucial to prevent the postoperative anastomotic stenosis of middle and low rectal cancer, especially in patients with Riolan artery arcade absence and IMA-Ⅲ type.