Short- and Long-term Outcomes of Three-Row Versus Two-Row Circular Staplers for Low Colorectal Anastomosis After Total Mesorectal Excision: A Single-Center, Randomized, Single-Blind, Phase III Trial (THREESTAPLER Study).

Abstract

Anastomotic leakage remains a critical complication in colorectal surgery. This study compared the efficacy of three-row versus two-row circular staplers in reducing anastomotic leakage rates. Prospective, randomized, single-center, non-inferiority trial. Clinic of Colorectal and Minimally Invasive Surgery, University Hospital Nº 2, Sechenov University. The trial included patients who underwent low anterior resection with total mesorectal excision. Patients were randomized 1:1 to 2-row or 3-row stapler group using centralized, computer-generated randomization. Outcome adjudicators, data collectors, and data analysts were blinded. Anastomotic leakage incidence; intra- and postoperative anastomotic bleeding; 30-day complications; low anterior resection syndrome; anastomotic stenosis; adverse events; time to and permanence of stoma; and 5-year overall survival. Among 154 patients included in the study, the anastomotic leakage rate was 16.9% (13/77) in the 3-row group compared to 15.6% (12/77) in the 2-row group (p = 0.8). The observed difference between groups was 1.3%, with a one-sided 95% confidence interval bounded below by -8.47%. The rates of anastomotic stricture were 1.4% (n = 2) in the two-row group and 0.7% (n = 1) in the 3-row group (p = 1). No patients experienced anastomotic hemorrhage. Stoma closure was successfully performed in 147 patients (95.5%). The 5-year overall survival was 80.2% (95% confidence interval, 69.4-92.8) in the 3-row group versus 83.8% (95% confidence interval, 75.6-92.3) in the 2-row group (p = 0.80). Routine postoperative proctography was not performed, clinically silent (Grade A) leaks may have been missed; the study was underpowered because the assumed 12% anastomotic leakage difference for sample-size estimation was optimistic; neoadjuvant regimen heterogeneity may have influenced outcomes; and the single-center design may limit generalizability. The three-row stapler was not non-inferior to the 2-row stapler in preventing anastomotic leakage. See Video Abstract.Clinical trial registration number: NCT03910699.