The significance of ureterocele diameter for management and outcome.

Introduction: Ureteroceles are rare congenital malformations of the urinary tract and challenging in management. Other than localisation (ectopic or orthotopic) and features of the upper tract, there are no well-tested predictive variables. We aimed at evaluating the initial sonographically measured ureterocele diameter (UD) as a predictor for underlying anatomy, success of primary management and long-term complications.

Patients and methods: All patients (n = 131, 41m/90f) referred to a single tertiary department with the diagnosis of an ureterocele between 07/1995 and 07/2019 were included. The UD was measured sonographically at the time of initial diagnosis. Most patients (n = 108, 82.4 %) underwent scintigraphy (either MAG3 or DMSA-scan) and voiding cystourethrography. After initial wait-and-see or primary endoscopic intervention, complications and symptomatic or high-grade VUR were indications for further surgical treatment, following an individualised protocol. Beneath data from sonographic exams, occurrence of urinary tract infections and voiding problems, all surgical and endoscopic data was recorded. Variables were examined using univariate and stepwise multivariate statistical methods.

Results: With a median age at first presentation of 2 months (IQR 8) the mean follow-up accounted to 6.5 years ± 4.8 years (range 0-20 years, median 5.4 years, IQR 7.3). Information on the initial diameter was available in 123 patients (94 %) with a median of 14 mm (IQR 14, range: 4-40). In a stepwise multivariate analysis, the UD significantly correlated with the localisation (ectopic/orthotopic, p = 0.001, AUC 0.7), successful primary endoscopic intervention (p = 0.02, AUC 0.71) and successful wait-and-see (p = 0.003, AUC 0.82). Female sex showed a significant impact on the probability of successful primary endoscopic intervention (p = 0.002, AUC 0.71) and was besides age the only variable correlating with UTIs prior to treatment (p = 0.01, AUC 0.8) whereas UD was not. Figure. The anatomic localisation (ectopic or orthotopic) showed less significance than UD in all the analyses performed. In a prediction model based on the multivariate analysis a diameter of <10 mm and >26 mm showed a ≥90 % probability of either orthotopic or ectopic localisation.

Conclusion: In this retrospective cohort sonographically measured ureterocele diameter was an easy and non-invasively detectable feature predicting localisation and proved a stronger predictive variable for the success of primary management strategies, superior to endoscopically verified ureterocele localisation, in a stepwise multivariant analysis. Furthermore, UD was predictive of long-term complications with an AUC of 0.7. Conversely, neither UD nor localisation predicted the frequency of UTIs prior to treatment, underlining the importance of CAP, especially in female patients.