Botulinum A Toxin Urethral Sphincter Injection in Children With Nonneurogenic Neurogenic Bladder

Abstract

Purpose: We evaluated botulinum-A toxin (Botox®) injection into the urethral urinary sphincter in children with nonneurogenic neurogenic bladder to decrease urethral resistance and improve voiding. In these patients α-blocker medications had failed and injection was an alternative to unavailable biofeedback. Materials and Methods: Prospective treatment was performed in 10 children 6 to 17 years old (mean age 8) with nonneurogenic neurogenic bladder using botulinum-A toxin (Botox®). Preoperatively all children were evaluated by ultrasound, voiding cystourethrography, excretory urography, magnetic resonance imaging and urodynamic studies, including pressure flow, electromyography and uroflowmetry. One patient had unilateral G3 reflux and 4 had bilateral G1 to G3 hydronephrosis. Using a rigid pediatric endoscope and a 4Fr injection needle 50 to 100 IU botulinum-A toxin were injected into the external sphincter at the 3, 6 and 9 o’clock positions. Followup was 6 to 15 months. Repeat injections every month were given according to the response with a maximum of 3 injections. Results: Immediately after botulinum-A toxin injection all except 1 patient were able to void without catheterization. No acute complications occurred. Four patients with bilateral hydronephrosis and the patient with the refluxing unit showed regression. Postoperatively post-void residual urine decreased by 89%, detrusor leak point pressure decreased significantly by a mean ± SD of 66 ± 18 vs 37 ± 4 cm H₂O and uroflowmetry showed a marked increase in maximum urine flow of 2 ± 2 vs 17.8 ± 8 ml per second. Three injections were needed in 1 patient to attain the desired response. Conclusions: Urethral sphincter botulinum-A toxin injection could be considered a reliable treatment modality in children with nonneurogenic neurogenic bladder after the failure of conservative therapy.