Efficacy of side-to-end anastomosis to prevent anastomotic leakage after anterior resection for rectal cancer

The present study aimed to investigate whether side-to-end anastomosis could provide an improved surgical outcome, such as lower anastomotic leakage rate, compared with end-to-end anastomosis, following anterior resection for rectal and rectosigmoid cancer. This retrospective study included 162 patients with rectal cancer who underwent elective anterior resection between January 2012 and October 2019 at a single institution. Patients with double cancers or colonic J-pouch were excluded. Anastomotic leakage was defined clinically and radiologically. Side-to-end anastomosis was introduced in the International University of Health and Welfare Mita Hospital in January 2017. Side-to-end anastomosis was performed in 63 patients, while end-to-end anastomosis was performed in 99 patients. Tumors tended to be located lower in the rectum in the side-to-end anastomosis group than in the end-to-end anastomosis group. No significant differences were observed in other patient characteristics. The incidence of anastomotic leakage was significantly lower in the side-to-end anastomosis group than in the end-to-end anastomosis group (3/63, 4.8% vs. 18/99, 18.2%, respectively, P=0.02). No significant differences were observed in the incidence rates of other complications. Univariate and multivariate analyses revealed that a smoking habit (P=0.04) and side-to-end anastomosis (P=0.02) were significantly associated with anastomotic leakage. In conclusion, side-to-end anastomosis using a double-stapling technique following anterior resection for rectal cancer may prevent anastomotic leakage.