Usefulness of the one-step technique in functional end-to-end anastomosis for colonic surgery: results of a prospective multicentre cohort study from the Japanese KYCC group.

Background: Although functional end-to-end anastomosis (FEEA) using a stapler in the colorectal field has been recognised worldwide, the technique varies by surgeon, and the safety of anastomosis using different techniques is unknown.

Methods: This multicentre prospective observational cohort study was conducted by the KYCC Study Group in Yokohama, Japan, and included patients who underwent colonic resection at seven centres between April 2020 and March 2022. This study compared the incidence of surgery-related abdominal complications (SAC: anastomotic leakage [AL], anastomotic bleeding, intra-abdominal abscess, enteritis, ileus, surgical site infection, and other abdominal complications) between two different methods of FEEA (one-step [OS] method: simultaneous anastomosis and bowel resection; two-step [TS] method: anastomosis after bowel resection). Complications of Clavien-Dindo classification grade 2 or higher were assessed.

Results: Among 293 eligible cases, the OS and TS methods were used in 194 (66.2%) and 99 (33.8%) patients, respectively. The baseline characteristics were similar between the groups. The OS method used fewer staplers (three vs. four staplers, p < 0.00001). There were no significant differences in SAC rate between the OS (19.1%) and the TS (16.2%) groups (p = 0.44). The OS group had four cases (2.1%) of AL (two patients; grade 3, two patients; grade 2) while the TS group had one case (1.0%) of grade 2 AL (p = 0.67). Multivariate logistic regression analysis showed that male sex (odds ratio [OR] 3.95; p < 0.00001), an open surgical approach (OR 2.36; p = 0.03), and longer operative duration (OR,2.79; p = 0.002) were independent predictors of complications, whereas the OS method was not an independent predictor (OR 1.17; p = 0.66).

Conclusions: The OS and the TS technique for stapled colonic anastomosis in a FEEA had a similar postoperative complication rate.

Trial Registration Number: UMIN000039902 (registration date 23 March 2020).