Long-term efficacy and durability of botulinum-A toxin for refractory dysfunctional voiding in children

We evaluated our long-term experience with intrasphincteric botulinum toxin A injection in children with dysfunctional voiding.

From January 2006 through July 2012 we saw 2,172 neurologically normal children due to dysfunctional voiding. Of patients who presented to these visits we retrospectively identified the charts of 12 with dysfunctional voiding (8 females) in whom urotherapy and medical management failed and who underwent botulinum toxin A injection to the external urinary sphincter. Mean patient age at surgery was 10.5 years (range 4 to 19). Average followup was 45 months (range 20 to 71). Preoperatively and postoperatively all children were evaluated with history and physical examination, voiding diary, renal and pelvic ultrasound with post-void residual volume measurement and uroflowmetry.

Eight of the 12 children (67%) experienced significant improvement in voiding parameters. Before vs after treatment mean ± SD post-void residual urine volume was 115 ± 83 vs 57 ± 61 ml (p = 0.016) and the mean maximum flow rate was 11.8 ± 8.1 vs 20.4 ± 7.9 ml per second. Half of the cohort required a second injection an average of 15 months later. Three of the 4 patients who failed to show improvement had neuropsychiatric problems and 1 had evidence of bladder underactivity.

Our results demonstrate reasonable efficacy and durability of intrasphincteric botulinum toxin A injection in children with refractory dysfunctional voiding. Neuropsychiatric issues appear to negatively influence the success rate. Long-term followup is vital to identify patients in whom repeat injection may be necessary.