Cumulative incidence of ureteroenteric strictures after radical cystectomy in a population-based Swedish cohort

The incidence of benign ureteroenteric strictures following radical cystectomy (RC) for urinary bladder cancer (UBC) is investigated mainly in single-centre studies from high-volume centres. The aim of this study was to evaluate the cumulative incidence of strictures and risk factors in a population-based cohort. Data was collected from Bladder Cancer Data Base Sweden (BladderBaSe). The primary endpoint was stricture with intervention. Secondary endpoint included hydronephrosis both with/without intervention. In total, 5,816 patients were registered as having had RC due to UBC between 1997 and 2014. After a median follow-up of 23.5 months (IQR = 9.0-63.1 months; range = 0.0-214.0 months), we found that 515 (8.9%) patients underwent intervention for stricture. Seven hundred and sixty-one (13.1%) patients were diagnosed with hydronephrosis without intervention. The cumulative incidence of strictures with intervention was 19.7% (95% CI = 16.7-23.1%) during the 17 years of follow-up. In the first year, the cumulative incidence of strictures was 5.6% (95% CI = 5.0-6.2%), and in the first 2 years 8.4% (95% CI = 7.6-9.3%). For the secondary endpoint, the cumulative incidence was 30.4% (95% CI = 26.7-33.1%) after 17 years. Only the year of RC was associated with stricture incidence in Cox regression analysis, whereas hospital cystectomy volume, patient age and patient sex were not. Ureteroenteric strictures requiring intervention may be more common than previously reported, affecting nearly one fifth of patients who have undergone RC for UBC. The annual incidence was highest in the first 2 years after surgery but the cumulative incidence increased continuously during 17 years of follow-up.