Risk factors and risk prediction modelling for pelvic sepsis and anastomotic leak following robotic total mesorectal excision with primary anastomosis for rectal cancer

Background Reporting of pelvic sepsis rates following robotic total mesorectal excision (R‐TME) for rectal cancer is inconsistent. This IDEAL stage 2b international multicentre study analysed the prevalence of pelvic sepsis rates and associated risk factors following R‐TME and generated a risk prediction model for anastomotic leak (AL). Methods Patients were identified through the EUREKA ( E xpert D U tch, F RE nch and U K robotic rectal c A ncer centres) collaborative. Adult patients undergoing R‐TME with primary anastomosis for biopsy‐proven rectal cancer were considered for inclusion. The primary outcome was to report the prevalence and risk factors associated with pelvic sepsis and anastomotic leak and subsequently to generate a risk prediction model for AL (categorized by ISREC criteria). Receiver operating characteristic (ROC) analysis was performed to confirm the prediction model for significant risk factors for AL (AUC > 0.5). Calibration and discrimination to assess model predictive accuracy were also performed. Results A total of 912 patients were analysed. 14% of patients developed pelvic sepsis and 7% an AL. Pelvic sepsis was associated with the following risk factors: male gender [OR 1.650 (95% CI 1.092–2.539, p = 0.020)], administration of NACRT (with the highest prevalence observed following SCRT) [OR 0.650 (95% CI 0.421–0.994, p = 0.049)], increasing duration of surgery [OR 0.997 (95% CI 0.994–0.999, p = 0.040)]. A moderate strength [AUC: 0.613 (95% CI 0.557–0.612)] risk of pelvic sepsis prediction model for robotic TME for rectal cancer was generated. On internal validation, moderate prediction was further maintained [training group AUC 0.610 (95% CI 0.544–0.611), verification group AUC 0.623 (95% CI 0.524–0.622)]. Conclusion Fourteen per cent of patients will develop pelvic sepsis following robotic TME with primary anastomosis for rectal cancer, and 7% will develop an anastomotic leak. Risk factors associated with pelvic sepsis include male gender, neoadjuvant therapy (SCRT) and longer duration of surgery.