Botulinum-a toxin detrusor injection as a novel approach in the treatment of bladder spasticity in children with neurogenic bladder

Abstract

Objectives: Children with neurogenic hyper-reflexive bladder in whom classical therapy with anticholinergic drugs and intermittent catheterization fails are threatened by high intravesical pressure, vesicoureteral reflux, and impairment of kidney function. Surgery, such as bladder augmentation, is often necessary in such cases. To obviate surgery in these high-risk children, we investigated the use of detrusor injection of botulinum-A toxin (Botox).

Methods: Our subjects were 20 children with hyper-reflexive detrusor muscle and high bladder pressure, over 40 cmH(2)O despite anticholinergic therapy. After baseline urodynamic measurements, we injected botulinum-A toxin into the detrusor muscle at 30-50 sites at 12 U/kg of body weight up to a maximum of 300 U. Follow-up cystometric measurements were taken two to four weeks and three and six months after injection.

Results: From basic measurements to follow-up cystometry, mean reflex volume changed from 97.1 ml before injection to 178.6 ml after four weeks (p<0.01) and to 162.8 ml after three months (p<0.01). After six months mean reflex volume returned to 119.3 ml (n.s.). Maximal bladder capacity changed from 163.1 ml to 219.9 ml (p<0.01), to 200.6 ml (p<0.01) and to 222.4 ml (p<0.01), respectively, and maximal detrusor pressure changed from 59.6 cmH(2)O to 34.9 cmH(2)O (p<0.01), to 46.7 cmH(2)O (n.s.) and to 61.8 cmH(2)O (n.s.), respectively.

Conclusion: Botulinum-A toxin (Botox) is effective when injected into the hyper-reflexive detrusor muscle. It is a valuable treatment option in the management of neurogenic bladder. The effect lasts about six months, and then reinjection is necessary.