Risk factors and natural history of parastomal hernia after radical cystectomy and ileal conduit.

Objective: To investigate the incidence, risk factors and natural history of parastomal hernia (PSH).

Materials And Methods: We reviewed the records of patients who underwent radical cystectomy (RC) and ileal conduit (IC) procedure between 2007 and 2020. Patients who had available follow-up computed tomography (CT) imaging were included in this study. All CT scans were re-reviewed for detection of PSH according to Moreno-Matias classification. Patients who developed hernia were followed up and classified into stable or progressive (defined as radiological upgrading and/or need for surgical intervention) groups. Multivariable Cox regression was performed to identify independent predictors of hernia development and progression.

Results: A total of 361 patients were included in this study. The incidence of radiological PSH was 30%, graded as I (56.5%), II (12%) and III (31.5%). The median (interquartile range [IQR]) time to radiological hernia was 8 (5-15) months. During the median (IQR) follow-up of 27 (13-47) months in 108 patients with a hernia, 26% patients progressed. The median (IQR) time to progression was 12 (6-21) months. On multivariable analysis, female gender (hazard ratio [HR] 1.86), diabetes (HR 1.81), chronic obstructive pulmonary disease (COPD; HR 1.78) and higher body mass index (BMI; HR 1.07 for each unit) were independent predictors for radiological PSH development. No significant factor was found to be associated with hernia progression.

Conclusion: Radiological PSH after RC and IC occurred in 30% of patients, a quarter of whom progressed in a median time of 12 months. Female gender, diabetes, COPD and high BMI were independent predictors for radiological hernia development.