Background: We evaluated the efficacy of botulinum-A toxin (BTX-A) injection into detrusor muscle in patients with incontinence resistant to anticholinergic drugs due to detrusor overactivity.

Methods: Our prospective study included 12 male patients with detrusor overactivity and incontinence due to spinal cord injury, which had been unsuccessfully treated with anticholinergic medication. Under visual control through the cystoscope 300 units of BTX-A were injected into detrusor muscle at 30 sites, sparing the trigone. After the treatment patients continued to perform clean intermittent self-catheterization (CIC) and clinical follow-up was planned for 6 weeks, 6 months and 9 months after treatment and urodynamic study was repeated after 6 weeks.

Results: At the 6-week follow-up complete continence was restored in  9 of the 12 patients and after 6 months of 9 continent patients 1 patient lost his follow-up  from the study and 7 were still continent. After 9 months 3 patients remained continent. Mean cystometric bladder capacity (p<0.001), compliance (p<0.001), and mean post-void residual urine volume significantly increased (p<0.001), whereas maximal detrusor contraction pressure significantly decreased (p<0.001).

Conclusions: BTX-A injections appears to be an effective and safe therapeutic option for overactive bladder in adult patients with spinal cord injury failing anticholinergic therapy even if these patients present with very low bladder compliance. Patients may require repeated injections after 6 months to remain continent.