(PM P22) Pelvic Anastomosis without Protective Ileostomy is Safe in Patients Treated with Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy

Background. During cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC), surgeons are reluctant to perform unprotected pelvic anastomosis despite lack of supporting data. We analyzed pelvic anastomosis outcomes and factors that influence ostomy creation in CRS/HIPEC patients. Methods. A single-center, descriptive study of patients with rectal resection during CRS/HIPEC was conducted using a prospective database. Surgical variables were reviewed. Multinominal logistic regression of outcomes (end or protective ostomy) was performed with pre- and intraoperative factors as predictors. Results. Overall, 274 of 789 CRS/HIPEC patients underwent rectal resection, including 243 (89%) with pelvic anastomosis [232 (85%) without ostomy, 11 (4%) with protective ileostomy] and 31 (11%) with no anastomosis [16 (6%) with end colostomy, 15 (5%) with end ileostomy]. Median age was 57 and 29% (79) were male. Of 243 pelvic anastomosis patients, 3 (1.2%) had rectal anastomotic leaks, including 1 with a protective ileostomy. Other anastomotic leaks occurred in 3.6%. Overall, 13% had Clavien-Dindo complications ≥ IIIB and the readmission rate was 30%. Mortality at 30-days and 100-days was 0.4% and 2.2%, respectively. Male gender and primary rectal cancer were associated with protective ileostomy (odds ratio (OR)=7.01, 95%CI: 1.6-31.5, p=0.011, and OR=16.4, 95%CI: 3-88.4, p=0.001, respectively). Male gender and prior pelvic surgery were associated with end colostomy (OR=13.9, 95%CI: 3.7-53, p<0.0001, and OR=17.2, 95%CI: 3.8-78.6, p<0.0001). Conclusions. Pelvic bowel reconstruction without protective or end ostomy during CRS/HIPEC is safe. Protective ileostomy is associated with male gender and primary rectal cancer. End colostomy is associated with male gender and prior pelvic surgery.