OBJECTIVE: This study aimed to identify factors influencing the decision to perform diverting ileostomy during cytoreductive surgery with colon resection for advanced ovarian cancer and investigate the associated complications and survival outcomes. METHODS: This was a retrospective cohort study of patients with advanced ovarian cancer who underwent cytoreductive surgery with colon resection and re-anastomosis between January 2010 and July 2020. Multivariate analysis was performed on the factors contributing to diverting ileostomy identified in the univariate analysis. RESULTS: Of the 134 patients, 60 (44.8%) underwent diverting ileostomies. The median follow-up was 35.75 months (range
0.03-145.05) and the median age was 57 (range
26-86). The anastomotic leakage rate was 3.7% (n = 5). On the univariate analysis, longer operative time (10 vs 6.4 hours), multiple bowel resections (>
1 vs 1 hour), total colon resection length, pre-operative paracentesis, intraoperative ascites, and transfusion were associated with diverting ileostomy. In the multivariate analysis, longer operative time (OR 1.61, p <
.0001) and total colon resection length (OR 1.06, p = .027) remained significant. Diverting ileostomy was associated with higher rates of intensive care unit admission (14.3% vs 2.8%, p = .001), dehydration (40% vs 9.5%, p <
.0001), and acute kidney injury (16.4% vs 1.4%, p = .002). The median progression-free survival was similar (23.87 vs 21.24 months in non-diverted vs diverted ileostomy, p = .82). CONCLUSIONS: Longer operative time and total length of colon resection influenced the selection of diverting ileostomy. The patients selected for diversion underwent multiple bowel resections more frequently, received more transfusions, and developed intraoperative ascites. These findings suggest that surgeons favor diversion for more extensive procedures. Patients who underwent diverted ileostomy experienced more short-term complications, likely reflecting the surgical complexity. Progression-free survival remained similar between the 2 groups, with diverse patients experiencing stoma-related morbidity over time, mainly dehydration and acute kidney injury. A prospective model to predict anastomotic leak risk may reduce diverting ileostomy rates.