Urodynamic Abnormalities in Children with Primary Bilateral Vesicoureteral Reflux

Bilateral vesicoureteral reflux (VUR) has been associated with poor long-term prognosis, and research focusing exclusively on its effect on urinary bladder function is lacking. This study aims to assess the urodynamic characteristics of children with bilateral VUR and identify factors influencing renal function.

A retrospective analysis was performed on children diagnosed with bilateral VUR who underwent urodynamic examination in the outpatient department of our institution from January 2019 to January 2023. All patients underwent comprehensive assessments, including voiding cystourethrography, urinary system ultrasound and urodynamic examination, to analyse the urodynamic features associated with different clinical characteristics.

The study included 148 children with bilateral VUR, amongst whom 92 (62.2%) exhibited urodynamic abnormalities, including idiopathic detrusor overactivity (DO) in 30 cases (20.3%) and dysfunctional voiding (DV) in 58 cases (39.2%). DV was prevalent in children under 5 years of age, whereas idiopathic DO was predominantly observed in children older than 2 years of age. Children older than 5 years of age exhibited a trend towards reduced bladder volume, whereas those younger than 2 years of age often had increased bladder volume and residual urine. Multivariate analysis identified bilateral severe VUR as an independent risk factor for abnormal estimated glomerular filtration rate.

DV tends to be more common in younger children with larger bladder volumes and increased residual urine than in older children. By contrast, older children are more susceptible to idiopathic DO associated with smaller bladder volumes than younger children. Bilateral severe reflux increases the likelihood of renal functional abnormalities, which appear to be a consequence of congenital scarring rather than abnormalities in bladder function.