Many reports have dealt with the outcome of botulinum-a toxin (BTX-A) detrusor injections in patients with neurogenic or nonneurogenic detrusor overactivity. BTX-A detrusor injections have been described in adult patients with neurogenic detrusor overactivity due to spinal cord injury.
Researchers from Germany were able to carry out the same experiments successfully in children with a neurogenic bladder. After many reports of this "wonder drug," several questions have arisen, including what this injection treatment means for neurourologic patients in the longer term; whether bladder function changes after repeated BTX-A injections, and whether this procedure has a proper place in the treatment algorithm of young patients with neurogenic bladder. In an extension of their previous studies, the authors, set out o assess the long-term success of treatment with repeated botulinum-A toxin (BTX-A; Botox) injections into the detrusor muscle for neurogenic detrusor overactivity in children.
In their study published in the October issue of Urology, the researchers reviewed the charts of 10 children (average age at first injection 11.2 years) with neurogenic detrusor overactivity who had received at least three BTX-A detrusor injections; four had received five or more injections. The total dose of BTX-A was 85 to 300 U. They measured the urodynamic outcomes 6 months after each injection and compared the results after the first injection with the results after the third and fifth injections (in the children who had five or more injections).
The relative changes - each in comparison with the value before injection therapy - after the first versus the fifth injection were as follows: the reflex volume increased by 81% versus 88%, maximal detrusor pressure decreased by 7% versus 39%, maximal cystometric bladder capacity increased by 88% versus 72%, and bladder compliance showed no change at the 6-month follow-up visit after the first injection and an increase of 109% after the fifth injection. The results after the third injection were generally similar to those after the fifth injection. No major side effects occurred.
Patients with difficult bladder conditions refractory to anticholinergic drugs have traditionally undergone immediate surgical procedures, such as bladder augmentation. However, according to this new study, BTX-A detrusor injection offers a reliable alternative and protects some of those difficult-to-treat patients for years.