Indications and practice of diverting ileostomy after colorectal resection and anastomosis in ovarian cancer cytoreduction

Objective: To determine the factors related with diverting ileostomy performance after colorectal resection and anastomosis, in advanced ovarian cancer cytoreductive surgery. Methods: We have previously demonstrated the risk factors associated with anastomotic leak after colorectal anastomosis: Advanced age at surgery, low serum albumin level, additional bowel resections, manual anastomosis and distance of the anastomosis from the anal verge. However, use of diverting ileostomy is strongly variable and depends on individual surgeon preferences and training. Eight hospitals participated in this retrospective study. Data of 695 patients operated for ovarian cancer with primary colorectal anastomosis were included (January 2010–June 2018). Fourteen pre-/intraoperatively defined variables were identified and analysed as justification factors for use of diverting ileostomy. Results: The rate of diverting ileostomy in the entire cohort was 19.13% (133/695; range within individual centers 4.6–24.32%). Previous treatment with bevacizumab [OR 2.8 (1.3–6.1); p=0.01]; additional bowel resections [OR 3.0 (1.8–5.1); p<0.001]; extended operating time [OR 1.005 (1.003–1.006); p<0.001] and intra-operative red blood transfusion [OR 2.7 (1.4–5.3); p<0.001] were found to be independently associated with diverting ileostomy performance. Assuming a 7% AL rate cut-off, up to 51.8% of DI presented an AL risk below 7% and might have been spared. Conclusions: The risk factors that drive the gynecologic oncology surgeons to perform a diverting ileostomy, seem to differ from the actual risk factors that we have identified to be associated with postoperative anastomotic leak. Broader awareness of the risk factors that contribute to a higher perioperative risk profile, will facilitate a better risk stratification process and possibly avoid unnecessary stoma formation in ovarian cancer patients.