Removal of the "dog-ear" during laparoscopic anterior resection with double stapling technique reduces the anastomotic leakage: a prospective cohort study.

Background: In laparoscopic preresection, the use of double anastomosis techniques creates a potential anastomotic angle (called a "dog-ear"), which represents an area with a high incidence of anastomotic leakage.

Methods: This prospective study, conducted from July 2022 to July 2023, ultimately included 471 patients undergoing laparoscopic colorectal cancer surgery using dual anastomosis techniques. Among them, 179 patients had one or two stapled corners removed during the surgery using a modified double stapling technique (MDST), while 292 patients did not have stapled corners removed during surgery using the traditional double stapler technique (DST). The incidence of anastomotic fistula and the probability of anastomotic bleeding within 30 days after operation were analyzed.

Results: In the surgery, 179 patients had one or two dog-ears removed, constituting the MDST group (n = 179). The remaining 292 patients did not have a dog-ear removed, constituting the no dog-ear removal group (DST group, n = 292). Statistical analysis revealed a significant difference between the two groups in terms of anastomotic leakage (6 [3.4%] vs 23 [7.9%]; relative risk 0.426; 95% CI 0.177-1.025; p = 0.047). Additionally, a significant difference was observed in preventing anastomotic bleeding by removing one or both dog-ears (7 [3.9%] vs 30 [10.3%], relative risk 0.381; 95% CI 0.171-0.848; p = 0.013).

Conclusions: This prospective study indicates that removing one or both dog-ears during surgery is beneficial in preventing anastomotic leakage and anastomotic bleeding.