Research Coordinator to Loma Linda University Department of Urology Loma Linda University
Introduction: Children with vesicoureteral reflux (VUR) are known to be at increased risk of urinary tract infection (UTI). With a trend towards observational management of children with VUR, untreated VUR and subsequent UTI can lead to significant morbidity. The purpose of this study was to identify risk factors for development of UTI in a modern cohort of children with primary VUR. Methods: We performed a review of a prospectively maintained clinical database of children with primary VUR at a single children’s hospital from July 2013 to June 2022. Children were included if they were diagnosed with primary VUR by voiding cystourethrography between the ages of 1 day to 18 years. Patients with secondary VUR were excluded. Demographic and clinical data were collected. The primary endpoint was development of a UTI defined by pyuria (> 6 WBC/hpf or positive leukocyte esterase) on urinalysis and single-organism urine culture greater than 50,000 CFU/mL. Low-grade (LG) VUR was defined as International VUR grades 1-3 and high-grade (HG) VUR was defined as International VUR grades 4 and 5. Dilated ureter was defined as any ureteral dilation greater than 2 mm. Data were analyzed by performing univariate and multivariate Cox proportional hazards regressions as well as Chi Square tests. Results: A total of 242 children had primary VUR, 116 (47.9%) male and 126 (52.1%) female. UTI occurred in 42 (17.3%) children with primary VUR, with an average follow-up time of 20.1 months [IQR of 6.2 - 45.0]. Female sex (HR: 2.39, 95% CI 1.22 - 4.67, p = 0.011) and younger age at presentation of VUR (HR-1: 1.01, 95% CI 1.00 - 1.02, p = 0.015) were found to be independent risk factors on multivariate analysis. Univariate analysis showed increased UTI rates in dilated ureter (14.6% non-dilated vs 30.5% dilated, p = 0.024), HG VUR grade (13.2% in LG vs 23.7% in HG, p = 0.038), and renal pelvis anterior-posterior diameter (APD) (16.9% = 15 mm, 31.9% >15 mm p = 0.032). Circumcision, degree of phimosis, constipation, voiding dysfunction, SFU grade of hydronephrosis, and prior febrile UTI were not found to be independent risk factors. Conclusions: Risk factors for UTI in children with primary VUR include female sex, age younger than 50 days old, dilated ureter, HG VUR, and hydronephrosis with APD greater than 15 mm. Treatment may be individualized to treat these higher risk patients. Further multi-institutional study of patients with primary VUR may help to further elucidate risk factors for UTI and improve the management of these patients. SOURCE OF Funding: none
