The aim of this study was to evaluate the impact of intradetrusor botulinum toxin injections on bladder capacity and urinary incontinence in patients with neurogenic bladder and to compare outcomes between patients treated with onabotulinumtoxinA and abobotulinumtoxinA. A secondary objective was to evaluate the duration of continence following treatment.

A retrospective observational study was conducted including patients with neurogenic detrusor overactivity who underwent intradetrusor botulinum toxin injections (200 IU onabotulinumtoxinA and 600–800 IU abobotulinumtoxinA) under local anesthesia at a tertiary urology center. Clinical and urodynamic data were collected from standardized case report forms. Baseline assessment included cystometric bladder capacity, detrusor pressure during filling, post-void residual volume, and number of daily urinary incontinence episodes. Follow-up evaluation was performed at 1 month and 6 months after treatment. Paired statistical analyses were used to compare baseline parameters with follow-up values, and independent comparisons were performed between treatment groups. Duration of treatment effect was evaluated using Kaplan–Meier analysis based on time to recurrence of urinary incontinence requiring reinjection. Multivariable regression analysis was performed to explore predictors of improvement in bladder capacity.

A total of 49 patients were included in the study. Nineteen patients received onabotulinumtoxinA and thirty received abobotulinumtoxinA. Mean bladder capacity increased significantly following treatment, from approximately 282 ml at baseline to 637 ml at first follow-up. Urinary incontinence episodes decreased from 5.44 to 1.17 per 24 hours. Improvements in both bladder capacity and continence were maintained at the second follow-up visit. Comparison between treatment groups demonstrated similar improvements in bladder capacity and reduction of incontinence episodes with both preparations, with no statistically significant differences observed. Kaplan–Meier analysis showed a median duration of continence of approximately 7–8 months, with most patients requiring reinjection between 6 and 9 months. Multivariable regression analysis suggested that increasing patient age was associated with greater improvement in bladder capacity, whereas toxin dose was not significantly associated with treatment response.
A subgroup analysis was performed in patients who received both treatments at different time points. Sixteen patients were included in a within-patient paired analysis. Mean bladder capacity after onabotulinumtoxinA injection was 552.7 ml compared to 621.6 ml after abobotulinumtoxinA injection (p = 0.515). Mean incontinence episodes per 24 hours were 1.63 and 1.25 respectively (p = 0.625). Duration of continence was similar between treatments at approximately 7.4 months. No statistically significant differences were identified between the two preparations.

The findings of this study confirm that intradetrusor botulinum toxin injection provides significant clinical and urodynamic benefits in patients with neurogenic detrusor overactivity in a real-world clinical setting. The substantial increase in bladder capacity and marked reduction in daily urinary incontinence episodes observed after treatment are consistent with previously reported. Importantly, this study demonstrated comparable effectiveness between onabotulinumtoxinA and abobotulinumtoxinA across multiple outcome measures, including bladder capacity, incontinence reduction, and duration of treatment effect. The within-patient subgroup analysis further strengthens this finding, as it reduces inter-patient variability and allows direct comparison between the two preparations in the same individuals. The finding that increasing age was associated with greater improvement in bladder capacity may reflect differences in bladder compliance or disease characteristics in older patients, although further research is required to clarify this relationship. Overall, these results suggest that both botulinum toxin preparations offer similar therapeutic benefit and durability in patients with neurogenic detrusor overactivity.

Intradetrusor botulinum toxin injection is an effective treatment for neurogenic detrusor overactivity, resulting in significant improvement in bladder capacity and urinary continence. Both onabotulinumtoxinA and abobotulinumtoxinA demonstrated similar clinical effectiveness and durability, supporting the use of either preparation in patients with refractory neurogenic bladder dysfunction.

Karsenty G, Denys P, Amarenco G, De Seze M, Gamé X, Haab F, Kerdraon J, Perrouin-Verbe B, Ruffion A, Saussine C, Soler JM, Schurch B, Chartier-Kastler E. Botulinum toxin A (Botox) intradetrusor injections in adults with neurogenic detrusor overactivity/neurogenic overactive bladder: a systematic literature review. Eur Urol. 2008 Feb;53(2):275-87. doi: 10.1016/j.eururo.2007.10.013. Epub 2007 Oct 16. PMID: 17988791.
Ravindra P, Jackson BL, Parkinson RJ. Botulinum toxin type A for the treatment of non-neurogenic overactive bladder: does using onabotulinumtoxinA (Botox(®) ) or abobotulinumtoxinA (Dysport(®) ) make a difference? BJU Int. 2013 Jul;112(1):94-9. doi: 10.1111/bju.12028. Epub 2013 Mar 12. PMID: 23490404.
Ginsberg DA, Boone TB, Cameron AP, Gousse A, Kaufman MR, Keays E, Kennelly MJ, Lemack GE, Rovner ES, Souter LH, Yang CC, Kraus SR. The AUA/SUFU Guideline on Adult Neurogenic Lower Urinary Tract Dysfunction: Treatment and Follow-up. J Urol. 2021 Nov;206(5):1106-1113. doi: 10.1097/JU.0000000000002239. Epub 2021 Sep 8. PMID: 34495688.