Ureterocele with duplex collecting systems and febrile urinary tract infection risk

Purpose Ureterocele has been hypothesized to be the risk factor for febrile urinary tract infections (F-UTIs) in patients with duplex collecting systems, but this has not been proved, and our goal was to assess the relation between ureterocele with duplex collecting systems and F-UTIs. Methods We included individual-participant data from patients seen for complicated duplex collecting systems from 2010 to 2020 retrospectively followed. Those with using continuous low-dose antibiotic prophylaxis and incompletely duplicated systems were removed from the study. The participants were divided into two cohorts according to patients with or without ureterocele. The primary endpoint of this study was recurrent F-UTIs. Results We analyzed medical reports of 300 patients, of which 75% were female. Among the 300 patients, F-UTIs developed in 111/159 (69.8%) patients in the ureterocele group and in 69/141 (48.9%) patients in the no-ureterocele group. Univariate analysis found no discernible difference except in grade of hydronephrosis between ureterocele group and no-ureterocele group. Moreover, Cox proportional regression analysis revealed that patients of duplex system ureterocele might be intrinsically more prone to develop F-UTIs (adjusted hazard ratio 1.894; 95% CI 1.412–2.542; p