Effectiveness of Botulinum-A Toxin for the Treatment of Refractory Overactive Bladder in Children

Aims: We describe our experience with botulinum-A toxin (BTX-A) in children presenting idiopathic overactive bladder (OAB) refractory to anticholinergic drugs. Material and Methods: 21 patients, aged 8-12 years, were treated over a 3-year period. BTX-A was administered at a dosage of 12.5 UI /kg body weight, without exceeding 200 UI, at 20 detrusor sites. To ensure a stable solution, each 100 UI of botulinum toxin was diluted with 5 cc saline solution just prior to performing the cystoscopy. Results: No patient presented with severe systemic complications or urinary retention after injection therapy; 6 patients presented with slight hematuria for 2-3 days. The clinical results were as follows. At 6 months, 8/21 patients (38%) showed full response, 12/21 (57%) had a partial response after a 2(nd) injection, and 1/21 (4.7%) showed no response after a 2(nd) injection. At 12 months, 16 patients (76%) had a full response, 4 (19%) showed a partial response after a 3(rd) injection, and 1 patient (4.7%) still had no response. At 18 months, 18 patients (85%) showed a full response, 2 patients (9.5%) had a partial response, 1 patient (4.7%) had no response. At the end of this study, 8/21 patients (38%) were symptom-free, after only one botulinum detrusor injection, 13/21 patients (61.9%) received a second botulinum injection because of recurrence of urinary incontinence 6-7 months after the initial treatment, and 4/21 patients (19%) received a third injection 12-14 months after the initial treatment, of whom 2 had a full response and 2 had a partial response. Patient no. 20 refused any further botulinum treatment after the 2(nd) unsuccessful injection series. Conclusion: Intravesical BTX-A injection appears to be safe and useful in children presenting with idiopathic overactive drug-resistant bladder.