A Predictive Model for Anastomotic Complications After Sphincter-Preserving Surgery for Rectal Cancer: Integrating Clinical and Anatomical Risk Factors.

Rectal cancer surgery presents a technical challenge due to the intricate anatomy of the pelvis, contributing to an increased risk of postoperative complications. The aim of this study was to assess the prognostic value of clinical and anatomical factors in predicting anastomotic complications after sphincter-preserving surgery for rectal cancer. Retrospective analysis. Taipei Medical University Hospital. A total of 527 patients with rectal cancer. Robotic or laparoscopic total mesorectal excision between 2012 and 2023. Preoperative clinical parameters and magnetic resonance imaging-derived anatomical measurements were subjected to multivariate analysis to develop a predictive model for postoperative anastomotic complications. Over a mean period of 66.2 (6-149) months, the incidence of anastomotic complications following sphincter-preserving surgery was 15.8%. Multivariate logistic regression identified six predictors of anastomotic complications: tumor-to-anal verge distance (p = 0.003), interspinous diameter (p = 0.030), clinical N stage (p = 0.047), angle α (p = 0.015), carcinoembryonic antigen level (p = 0.046), and American Society of Anesthesiologists classification (p = 0.015). These variables were incorporated into the final model, with an area under the receiver operating characteristic curve of 0.70 (95% confidence interval: 0.60-0.78). The top three predictors of anastomotic complications were tumor-to-anal verge distance, interspinous diameter, and clinical N stage. All data were obtained from a single institution, the study was retrospective, all pelvimetric measurements were obtained manually (introducing the possibility of interobserver variability and measurement error), and the parameters analyzed were limited to two-dimensional measurements. These findings highlight the role of clinical variables and pelvimetry in predicting anastomotic complications after minimally invasive rectal surgery. The developed regression model is a practical tool for refining preoperative planning and informed decision-making. See Video Abstract.