Comparison of short-term outcomes among hand-sewn, stapled, and two-stage Turnbull–Cutait pull-through anastomoses in TaTME for low rectal cancer

BACKGROUND: Although transanal total mesorectal excision (TaTME) has been recognized as an important surgical method for low rectal cancer, optimal anastomotic techniques remain debated. This study compared short-term outcomes of hand-sewn coloanal anastomosis (CAA), single-stapled anastomosis (SSA), and two-stage Turnbull-Cutait pull-through coloanal anastomosis (TCA). METHODS: A retrospective analysis of 147 patients who underwent TaTME for low rectal cancer (tumor distal margin ≤ 5 cm from anal verge) was conducted between July 2020 and July 2023. The patients were categorized into CAA, SSA, and TCA groups based on the anastomosis. The primary endpoint was anastomosis-related complications that included anastomotic leakage, anastomotic bleeding, and anastomotic stricture. The secondary endpoints included neorectal prolapse, pathological outcomes, perioperative outcomes, stoma-related outcomes, and functional outcomes assessed through the low anterior resection syndrome (LARS) scoring system. RESULTS: Among 147 patients with low rectal cancer, 42 patients underwent CAA, 69 patients underwent SSA, and 36 patients underwent TCA. Operative time was shortest in the SSA group and longest in the TCA group (p = 0.023). TCA demonstrated a lower protective stoma rate (p = 0.005), higher splenic flexure mobilization (SFM) rate (p = 0.014), and extended postoperative hospital stay (p < 0.001) compared to CAA and SSA. Pathologically, TCA resulted in longer length of resected bowel (p < 0.001), with similar distal resection margins and lymph node yield. The complication rates were similar among the three groups, although the TCA group had a higher incidence of neorectal prolapse (p < 0.001). LARS scores improved gradually in all groups postoperatively, with SSA potentially reducing its incidence. CONCLUSION: In TaTME, SSA may reduce the incidence of LARS, whereas TCA avoids the need for a stoma at the expense of longer bowel resection and an increased risk of neorectal prolapse. Patient-specific selection of the anastomotic technique remains recommended.