Objectives: To 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.
Methods: We 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. We 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).
Results: 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.
Conclusions: Although we surveyed only a few patients, the efficacy seems clear in all the urodynamic measures after repeated BTX-A detrusor injections in children with neurogenic bladder. Also, we found no evidence of drug tolerance. Thus, BTX-A detrusor injection has gained additional importance in the treatment of these difficult-to-treat patients.