EP1073 - Robotic Intracorporeal Versus Laparoscopic Extracorporeal Anastomosis in Left-Sided Colorectal Cancer: A Propensity Score-Weighted Comparative Study of Short-Term Outcomes

Purpose/Background: Minimally invasive surgery has become the standard for colorectal cancer, with both laparoscopic and robotic approaches demonstrating superior recovery and comparable oncologic outcomes to open surgery. However, the optimal anastomotic strategy for left-sided resections remains controversial. The robotic intracorporeal single-stapling anastomosis (RiSSA) technique may offer technical advantages in confined pelvic spaces, but comparative data against conventional laparoscopic double-stapling anastomosis (LapDSA) remain limited. This study aimed to compare short-term clinical outcomes between RiSSA and LapDSA using a propensity score-based overlap weighting approach to minimize selection bias.

Methods/Interventions: This single-center, retrospective cohort study included patients who underwent curative minimally invasive resection for left-sided colorectal cancer between May 2023 and May 2025. Patients were categorized into RiSSA (n = 45) and LapDSA (n = 211) groups. Overlap weighting based on propensity scores was applied to balance baseline characteristics between cohorts. Short-term postoperative outcomes, including overall complications, anastomotic leakage, reoperation, readmission, and recovery parameters, were compared using doubly robust adjusted models.

Results/Outcomes: After weighting, excellent covariate balance was achieved (standardized mean differences < 0.25). The overall 30-day complication rate was comparable between RiSSA and LapDSA (26.7% vs 25.1%; adjusted OR 0.94, 95% CI 0.42-2.13, p = 0.89). Anastomotic leakage occurred in 8.9% and 3.8% of patients, respectively (adjusted OR 1.83, 95% CI 0.41-8.24, p = 0.43). No RiSSA cases required ICU admission or conversion to open surgery. Operative time was significantly longer for RiSSA (mean difference +60.3 min, p = 0.003), while blood loss, length of stay, and bowel function recovery were comparable.

Conclusion/Discussion: Robotic intracorporeal single-stapling anastomosis demonstrated comparable short-term safety and efficacy to laparoscopic double-stapling anastomosis for left-sided colorectal cancer, with the only significant difference being longer operative time. These findings suggest that the robotic intracorporeal approach can be safely integrated into colorectal practice as a feasible strategy-level alternative during the transition from laparoscopic to robotic surgery.