Intradetrusor Injections of Botulinum Toxin A in Adults with Spinal Dysraphism

The aim of the current study was to determine the outcomes of botulinum toxin A intradetrusor injections in adult patients with spina bifida.

All patients with spinal dysraphism who underwent intradetrusor injections of botulinum toxin A from 2002 to 2016 at a total of 14 centers were retrospectively included in analysis. The primary end point was the global success of injections, defined subjectively as the combination of urgency, urinary incontinence and detrusor overactivity/low bladder compliance resolution. Univariate and multivariate analysis was performed to seek predictors of global success.

A total of 125 patients were included in study. The global success rate of the first injection was 62.3% with resolution of urinary incontinence in 73.5% of patients. All urodynamic parameters had improved significantly by 6 to 8 weeks compared to baseline, including maximum detrusor pressure (-12 cm H₂O, p <0.001), maximum cystometric capacity (86.6 ml, p <0.001) and compliance (8.9 ml/cm H₂O, p = 0.002). A total of 20 complications (3.6%) were recorded for the 561 intradetrusor botulinum toxin A injections, including 3 muscular weakness complications. The global success rate of the first injection was significantly lower in patients with poor compliance (34.4% vs 86.9%, OR 0.08, p <0.001). On multivariate analysis poor compliance was associated with a lower global success rate (OR 0.13, p <0.001). Female gender (OR 3.53, p = 0.01) and patient age (OR 39.9, p <0.001) were predictors of global success.

Intradetrusor botulinum toxin A injections were effective in adult patients with spina bifida who had detrusor overactivity. In contrast, effectiveness was much lower in adult patients with spina bifida who had poor bladder compliance. The other predictors of global success were female gender and older age.