The Effect of Intravesical OnabotulinumtoxinA (Botox) Injections on Urinary Bladder Functions in Children

Abstract

Background: Children with overactive bladder and urinary incontinence are probably the most difficult to manage because of the serious effects on kidney functions and social life. Botulinum toxin has shown its effectiveness in lowering the bladder pressure and obtain adequate continence with nearly no complications. Objective: To evaluate clinical and urodynamic efficiency of intravesical OnabotulinumtoxinA (Botox) injections in children with lower urinary tract symptoms and overactive bladder. These pediatric patients were resistant to the urotherapy and the anticholinergic treatment. Patients and Methods: Eleven patients aged from 5 to 13 years old (median age 8.5 years old), 6 males and 5 females with daytime and or nighttime urinary incontinence with lower urinary tract symptoms and detrusor overactivity detected by urodynamic study. five cases have idiopathic detrusor overactivity , four cases with neurogenic overactive bladder and two cases have detrusor sphincter dyssynergia (DSD), were treated with onabotulinumtoxinA ( Botox) injections after failure of the urotherapy and anticholinergic treatment and followed up in urology clinic 3 , 6 , 9 , 12 months post injection . Assessment the patients were obtained clinically through the bladder diary and the dysfunctional voiding scoring system and by urodynamic study before and after Botox injections. We used onabotA (Botox) in 10 units / kg with maximal dose 300 units via cystoscopy into 21 different sites. Results: We noted improvement of the urgency in all patients (totally disappeared) and frequency, in the patients with voluntary voiding who didn’t require intermittent catheterization. Absence leakage during the daytime between CIC in (6 patients) and in the patient with voluntary voiding (5 patients) after Botox injections. All patients were having a daily episodes of nocturnal enuresis before Botox injections and totally disappeared in 2 patients (40%), three patients (60%) were having two episodes of nocturnal enuresis / week. after Botox injections. Remaining 6 patients, the urinary catheter was inserted during sleep. Dysfunctional voiding system score (DVSS) has been significantly decreased (marked improvement) after Botox injections, the mean was 16.73 before Botox and decreased to 6.18 after Botox (p -value < 0.001). The maximal detrusor pressure was significantly decreased in 9 patients after Botox injections, the mean was 88.67 cmH2O before Botox and decreased to 50 cmH2O after Botox (p-value= 0.022). The micturating cystometric capacity (MCC) was increased after Botox injections also in those 9 patients. The mean was 136.11 before Botox and was increased to 162.78 ml after Botox (p-value=0.137). The post voiding residual volume was decreased after Botox injections in 5 patients who were having voluntary voiding, the mean was 64 ml before Botox and decreased after improving the emptying function of the bladder to 24 ml after Botox injections i.e.59.6% the mean decrease in PVR after Botox injections (p-value=0.014). The detrusor leakage pressure was decreased after Botox injections in 4 patients. The mean was 80.5 cmH2O before Botox injections and decreased to 46.5 cmH2O after Botox injections. (P-value =0.281) Conclusion: onabotulinumtoxinA (Botox) is an adequate alternative to more invasive surgical interventions in children with lower urinary tract symptoms and incontinence who failed medical treatment.