Effectiveness of botulinum-A toxin for the treatment of refractory overactive bladder in children

Abstract & 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 symptomfree, 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.