Natural History and Predictors of Parastomal Hernia after Robot-Assisted Radical Cystectomy and Ileal Conduit Urinary Diversion

PURPOSE: We investigated the prevalence of and variables associated with parastomal hernia and its outcomes after robot-assisted radical cystectomy and ileal conduit creation for bladder cancer. MATERIALS AND METHODS: We retrospectively reviewed the records of patients who underwent robot-assisted radical cystectomy at our institution. Parastomal hernia was defined as the protrusion of abdominal contents through the stomal defect in the abdominal wall on cross-sectional imaging. Parastomal hernia was further described in terms of patient and hernia characteristics, symptoms, management and outcomes. The Kaplan-Meier method was used to determine time to parastomal hernia and time to surgery. Multivariate stepwise logistic regression was done to evaluate variables associated with parastomal hernia. On multivariate analysis operative time (OR 1.25, 95% CI 1.21-3.90, p <0.001), a fascial defect 30 mm or greater (OR 5.23, 95% CI 2.32-11.8, p <0.001) and a lower postoperative estimated glomerular filtration rate (OR 2.17, 95% CI 1.21-3.90, p = 0.01) were significantly associated with parastomal hernia. CONCLUSIONS: Symptoms develop in approximately a third of patients with parastomal hernia and 15% will require surgery. The risk of parastomal hernia plateaued after postoperative year 3. Longer operative time, a larger fascial defect and lower postoperative kidney function were associated with parastomal hernia.