Efficacy and safety of intradetrusor onabotulinumtoxinA injection for managing paediatric non-neurogenic overactive bladder: A prospective case-series study

Objectives: To evaluate the outcome of intradetrusor onabotulinumtoxinA (Botox®; Allergan Inc., Dublin, Ireland) (IDB) injection in children and adolescents with non-neurogenic overactive bladder (OAB) refractory or resistant to treatment. Patients and Methods: In all, 91 patients underwent evaluation using subjective scores and urodynamic studies (UDS), including determination of maximum bladder capacity (MBC) and evaluating the capacity deficit vs the expected bladder capacity (EBC), and uroflowmetry determination of voided volume, maximum urinary flow rate (Q(max)) and post-void residual urine volume (PVR). All patients received oxybutynin (0.3–0.5 mg/kg/day) for 3 months and re-evaluated patients who developed drug intolerability, persistence or recurrence of OAB received 100 U IDB injection using 20 injection sites, with trigone and sphincter sparing. All patients were re-evaluated 3-monthly for subjective scoring and at the end of the 12-month follow-up with UDS. Results: In all, 43 patients underwent IDB injection and at the end of the 12-month follow-up the success rate for IDB injection was 90.7%. All patients showed progressively decreasing scores compared to baseline scores. At the 12-month follow-up, MBC, voided volume, and Q(max) were significantly higher, whilst capacity deficit and PVR were significantly lower than baseline measures. The frequency of patients satisfied with the outcome of IDB was high. Conclusion: For children with OAB refractory or resistant to biofeedback therapy, anti-cholinergic drugs must be tried first with IDB reserved for cases who fail to respond, are intolerant or recur after medical treatment. IDB using 100 U Botox, at 20 injection sites with trigone and sphincter sparing, is successful with a high satisfaction rate and free of postoperative problems. Abbreviations: EBC: expected bladder capacity; IDB: intradetrusor onabotulinumtoxinA; MBC: maximum bladder capacity; OAB: overactive bladder; OABSS: Overactive Bladder Symptom Score; PPBC: Patient Perception of Bladder Condition; PVR: post-void residual urine volume; TENS: transcutaneous electrical nerve stimulation; Q(max): maximum urinary flow rate; UDS: urodynamic studies; UI: urinary incontinence