Single-stapled anastomosis is associated with a lower anastomotic leak rate than double-stapled technique after minimally invasive total mesorectal excision for MRI-defined low rectal cancer

Background: After total mesorectal excision, distal rectal transection and anastomosis are critical for short-term, oncological, and functional outcomes, including anastomotic leak. A double-pursestring, single-stapled anastomosis avoids cross-stapling, overcoming the potential drawbacks of transabdominal rectal transection and double-stapled anastomosis. This study aims to compare the anastomotic leak rate in double-stapled and single-stapled anastomoses after minimally invasive total mesorectal excision for magnetic resonance imaging-defined low rectal cancer. Methods: Adult patients (>18 years old) undergoing minimally invasive total mesorectal excision for magnetic resonance imaging-defined low rectal cancer with a stapled low anastomosis (below 5 centimeters from the anal verge) between January 2010 and January 2022 at a single institution were allocated to 2 groups according to the anastomosis: double-stapled (abdominal stapled transection and double-stapled anastomosis) or single-stapled (transanal rectal transection and double-pursestring single-stapled anastomosis). The exclusion criteria were nonrestorative procedures or any type of manual anastomosis. The primary endpoint was the rate of 90-day clinical and radiologic anastomotic leak. Results: In total, 185 single-stapled and 458 double-stapled were included. Clinical and tumor characteristics were comparable between the groups. The 90-day anastomotic leak rate was significantly lower in the single-stapled group (6.48% vs 15.28%; P = .002), with similar rates of grade and timing. Thirty- and 90-day complication rates were higher in the double-stapled group (P = .0001; P = .02), with comparable Clavien-Dindo grades. At multivariable analysis, double-stapled anastomosis (P = .01), active smoking (P = .03), and the presence of comorbidities (P = .01) resulted as independent risk factors for an anastomotic leak. Conclusion: Transanal transection and double-pursestring, single-stapled anastomosis were associated with a lower anastomotic leak rate after minimally invasive total mesorectal excision for magnetic resonance imaging-defined low rectal cancer.