Parastomal hernia development after cystectomy and ileal conduit for bladder cancer: results from the Dartmouth ileal conduit enhancement (DICE) project

Introduction: Limited information exists regarding parastomal hernia development in bladder cancer patients. The purpose of this investigation was to describe the natural history of parastomal hernias and identify risk factors for hernia development in patients who undergo cystectomy with ileal conduit urinary diversion. Materials and methods: A retrospective cohort study was performed of bladder cancer patients who underwent cystectomy with ileal conduit urinary diversion between January 1st 2009 and July 31st 2018 at Dartmouth-Hitchcock Medical Center. The primary outcome of interest was the presence of a parastomal hernia as evident on postoperative cross-sectional imaging obtained for disease surveillance. Results: A total of 107 patients were included with a mean age of 70.9 years and 29.9% being female. Parastomal hernias were identified in 68.2% of bladder cancer patients who underwent cystectomy with ileal conduit urinary diversion. Forty percent of patients with a parastomal hernia reported symptoms related to their hernia, while 12.5% underwent operative repair. After multivariate adjustment, patients with a postop body mass index (BMI) > 30 kg/m(2) (odds ratio LORI: 21.8, 95% CI: 1.6-305.2) or stage III or IV bladder cancer (OR: 18, 95% CI: 2.1-157.5), had significantly greater odds of parastomal hernia development. Fifty percent of parastomal hernias were identified 1.3 years from surgery, while 75% were identified by 2 years after cystectomy. Conclusion: Parastomal hernias developed in over two-thirds of bladder cancer patients and occurred rapidly following cystectomy and ileal conduit urinary diversion. Greater postoperative BMI and bladder cancer stage were identified as significant risk factors for parastomal hernia development. Significant opportunity exists to reduce morbidity associated with parastomal hernias in this population.