Botulinum Neurotoxin Type A in paediatric non-neurogenic therapy resistant overactive bladder: a cohort study

INTRODUCTION AND OBJECTIVE: Intradetrusor Botulinum Neurotoxin Type A (BoNT-A) is an increasingly applied treatment modality for overactive bladder (OAB) in children with refractory urinary incontinence. Despite that, evidence is sparse, and the potential not fully understood. The aim of this study was to evaluate the effectiveness and safety of intradetrusor injection in children with refractory functional OAB and urinary incontinence. Furthermore, we aimed to identify predictors of efficacy and side effects to BoNT-A treatment. MATERIALS AND METHODS: We conducted a cohort study of children with OAB and urinary incontinence who received intradetrusor injection of BoNT-A in the period 01.01.2016 to 31.12.2020 at our centre. All patients were refractory to standard urotherapy, anticholinergics, mirabegron and the combination of these treatments. Patients with neurogenic bladder were excluded. Primary endpoint was the reduction on the frequency of urinary incontinence episodes from baseline. Secondary endpoints included urodynamic parameters and uroflowmetry characteristics as well as side effects. RESULTS: Forty-three children (mean age at first treatment 10.7 ± 1.8, 30 males) were included. After first treatment, a reduction of ≥ 50% in incontinence episodes was seen in 58% of patients with daytime urinary incontinence (DUI) and 47% of patients with nocturnal enuresis (NE). Adverse events, mainly urinary tract infections (UTI), were reported by 16% of patients after first treatment. Our analysis identified normal cystometric compliance as a significant predictor of treatment effect We estimated the mean duration of effect to be approximately 7 months. CONCLUSIONS: Intradetrusor BoNT-A injection appears to be a safe and effective option in treating refractory urinary incontinent children with overactive bladder. We identified cystometric compliance as a predictor of response. Most children necessitate repeated treatments. Further prospective and controlled studies are necessary in order to fully identify predictors and potential of treatment.