Urodynamic assessment of children treated with botulinum toxin A injections for urge incontinence: a pilot study

This study aimed to investigate changes in urodynamic findings and symptoms after detrusor injections of botulinum toxin A (BTX-A) in children with idiopathic detrusor overactivity (IDO) and urge incontinence.

Eight girls and five boys, aged 7-19 years, who had urge incontinence refractory to scheduled voiding and anticholinergics, were included this prospective study. Urodynamic studies showed postoperative IDO in 12 patients. A dose of 50-100 IU (1.3 -- 4.8 IU/kg) BTX-A was primarily administered at 15-20 detrusor sites. A control urodynamic study was performed within 3 months after the injections. Seven patients had a repeated procedure 16 (range 6-24) months on the average after the first one.

Eleven of the 13 patients had daily incontinence and two had incontinence a couple of times a week in association with urge symptoms. Postoperatively, no patient had urinary retention, but one girl had a urinary tract infection 4 months after the therapy. Five patients had a full response, seven partial responses and one no response 1-3 months after the first treatment. After 1 year, three of nine patients still have full response. Maximum cystometric capacity increased after the first treatment from a median of 227 ml to 379 ml (p = 0.005) and the number of patients with uninhibited detrusor contractions more than 30 cmH₂O during the filling phase decreased from eight to two out of 13 (p = 0.041).

Intradetrusor BTX-A injections effectively reduce day-time wetting, significantly increase bladder volume and decrease detrusor overactivity in children with urge incontinence refractory to scheduled voidings and anticholinergics.