Intradetrusor onabotulinum-a toxin injections in children with therapy-resistant idiopathic detrusor overactivity. A retrospective study

Abstract

Introduction and objective: The use of intravesical onabotulinum-A toxin (BoNT-A) injections in the treatment of idiopathic detrusor overactivity has been widely studied in adults [2-5]. However, in pediatric populations, study groups are small, and results are not yet sufficient to support this treatment as a standard practice. The aim of this study is to determine the effectiveness and safety of this treatment in children with non-neurogenic detrusor overactivity, resistant to conservative therapy.

Material and methods: We retrospectively evaluated the effect and safety of the intradetrusor injection of 100 Units (U) of BoNT-A in 257 children with therapy-resistant non-neurogenic detrusor overactivity between May 2003 and August 2017. Outcome parameters were the number of daytime incontinence and enuresis episodes per week and bladder capacity (BC). Treatment outcomes were classified into complete response, partial response, or no response.

Results: The database includes 257 children, of which are 102 girls and 155 boys. Median age of first BoNT-A injection was 8 years (range 4-18 years). Of the patients with enuresis, daytime incontinence or both, a complete response was seen in 50%, 45.7%, and 17%, respectively. BC was significantly higher after the first, second, and third injection of 100 U BoNT-A. We estimated that the mean duration of the effect of an injection with a dose of 100 U is around 12 months. After the first injection, one girl (0.4%) developed urinary retention, which required temporary clean intermittent catheterization (CIC). Seventeen patients (6.6%) developed a urinary tract infection. In three patients (1.2%), postoperative vesicoureteral reflux was seen.

Discussion: A distinction between the effect on daytime incontinence and enuresis was made. A poorer effect on enuresis in children who suffered from both conditions was observed. Drawbacks of this study are its retrospective design and the lack of anticholinergic treatment standardization before and after BoNT-A injection.

Conclusion: BoNT-A injection is a potentially effective adjuvant therapy in the treatment of children with therapy-resistant overactive bladder (OAB). Bladder capacity increases significantly after the first, second, and third injections. A better effect on daytime incontinence than on enuresis was seen. Prospective randomized trials with standardization of conservative treatment and symptoms questionnaires are necessary to confirm the beneficial effect of BoNT-A injections on BC and incontinence.

Keywords: Botulinum toxin; Detrusor overactivity in children; Intravesical injections; Non-neurogenic detrusor overactivity.