Onabotulinum toxin A in children with refractory idiopathic overactive bladder: medium-term outcomes

Response to Treatment with Botulinum Neurotoxin A (BoNT-A) in Children and Adolescents with Neurogenic Lower Urinary Tract Dysfunction and Idiopathic Overactive Bladder: A Systematic Review and Meta-Analysis

INTRODUCTION

Botulinum neurotoxin A (BoNT-A) is a treatment option for neurogenic lower urinary tract dysfunctions (NLUTD) and idiopathic overactive bladder (OAB) in adults. Recently, its use has gained popularity in paediatric urology. Transitional urology deals with adolescents affected by congenital urological issues, who mature into adulthood. The aim of this systematic review was to update the current knowledge on the use of BoNT-A in children and adolescents.

METHODS

A comprehensive search in PubMed, Scopus, and Web of Science databases was performed from articles published up to September 2024. Both prospective and retrospective single-cohort or comparative studies evaluating outcomes of interest were included. These consisted of the amelioration of urinary incontinence (UI), continence rates, improvement of urodynamic parameters (maximum detrusor pressure during voiding, maximum bladder capacity, and bladder compliance), and type and prevalence of adverse/side effects. Qualitative and quantitative data syntheses were provided. Moderators and meta-regression analyses were carried out as well.

RESULTS

Forty-one full-text manuscripts were selected of which 26 focused on children with NLUTD, 13 on idiopathic OAB, and two on both conditions. Overall, 1521 patients were included of whom 715 were male, 646 female, and 160 of unknown sex. Mean age varied between 5.6 and 15.6 years. No studies specifically focused on transitional urology, despite patients up to at least 17 years of age being included. Several differences existed in design, type, dose, way of administration, outcomes measured and follow-up time; however, all studies independently showed an improvement of UI and urodynamic parameters with no major side/adverse events. Pooled analysis showed a mean rate of improvement in UI scores/episodes of 75.87% within a period of 3-6 months following BoNT-A treatment. Meta-regression analyses demonstrated a significant correlation between dryness rate and both patients' age (negative) and bladder compliance (positive).

CONCLUSIONS

Several uncontrolled or comparative studies provided significative evidence of the clinical benefit and safety of BoNT-A administration in children in terms of UI relief and improvement of urodynamic parameters, with neurogenic aetiologies being the most investigated conditions. A reduced bladder compliance was identified as one of the potential predictors of poor response to BoNT-A. Moreover, the earlier the treatment was started the higher the success rate that was reached in terms of dryness/urinary continence achievement.

Prevalence and allergy-related risk factors of overactive bladder in children in Northeast China

Objective

The objective of this study was to investigate the prevalence of overactive bladder (OAB) and its risk factors related to allergies among children in Northeastern China.

Methods

A community survey on OAB was conducted in Northeast China from 1 April 2022 to 30 April 2022. The survey targeted children aged 5-14 years and utilized questionnaires. A total of 1,394 children were enrolled, and their parents were requested to fill out a questionnaire to provide basic information about the children. This encompassed details regarding the presence or absence of urgent urination unrelated to urinary tract infection, urinary tract infection, allergic rhinitis, asthma or cough variant asthma, atopic dermatitis, anaphylactic conjunctivitis, urticaria, constipation, and attention deficit hyperactivity disorder (ADHD). The prevalence of OAB was calculated. The chi-squared test was used to analyze OAB-related factors, which were subsequently included in the logistic regression model for multi-factor analysis.

Results

The overall OAB prevalence was 10.7% (120 of 1,121), including 47 mild cases (39.2%), 71 moderate cases (59.1%), and 2 severe cases (1.7%). OAB prevalence decreased with age (p < 0.05). The risk factors associated with OAB were allergic asthma (OR = 1.87, 95%CI: 1.12-3.13), atopic dermatitis (OR = 2.45, 95%CI: 1.61-3.73), anaphylactic conjunctivitis (OR = 1.61, 95%CI: 1.07-2.42), and urticaria (OR = 1.93, 95%CI: 1.40-2.66).

Conclusion

OAB prevalence among children in Northeastern China was found to be 10.7%, with its risk factors being allergic asthma, anaphylactic conjunctivitis, urticaria, and atopic dermatitis. The identification of allergy-related risk factors may provide new ideas for the prevention and treatment of OAB.

Botulinum Neurotoxin Type A in paediatric non-neurogenic therapy resistant overactive bladder: a cohort study

INTRODUCTION AND OBJECTIVE

Intradetrusor Botulinum Neurotoxin Type A (BoNT-A) is an increasingly applied treatment modality for overactive bladder (OAB) in children with refractory urinary incontinence. Despite that, evidence is sparse, and the potential not fully understood. The aim of this study was to evaluate the effectiveness and safety of intradetrusor injection in children with refractory functional OAB and urinary incontinence. Furthermore, we aimed to identify predictors of efficacy and side effects to BoNT-A treatment.

MATERIALS AND METHODS

We conducted a cohort study of children with OAB and urinary incontinence who received intradetrusor injection of BoNT-A in the period 01.01.2016 to 31.12.2020 at our centre. All patients were refractory to standard urotherapy, anticholinergics, mirabegron and the combination of these treatments. Patients with neurogenic bladder were excluded. Primary endpoint was the reduction on the frequency of urinary incontinence episodes from baseline. Secondary endpoints included urodynamic parameters and uroflowmetry characteristics as well as side effects.

RESULTS

Forty-three children (mean age at first treatment 10.7 ± 1.8, 30 males) were included. After first treatment, a reduction of ≥ 50% in incontinence episodes was seen in 58% of patients with daytime urinary incontinence (DUI) and 47% of patients with nocturnal enuresis (NE). Adverse events, mainly urinary tract infections (UTI), were reported by 16% of patients after first treatment. Our analysis identified normal cystometric compliance as a significant predictor of treatment effect We estimated the mean duration of effect to be approximately 7 months.

CONCLUSIONS

Intradetrusor BoNT-A injection appears to be a safe and effective option in treating refractory urinary incontinent children with overactive bladder. We identified cystometric compliance as a predictor of response. Most children necessitate repeated treatments. Further prospective and controlled studies are necessary in order to fully identify predictors and potential of treatment.

Long-Term Adherence to Onabotulinum Toxin-A Intradetrusor Injections for Neurogenic Dysfunction in Children-A Retrospective Single-Center Evaluation

Onabotulinum Toxin-A (BTX-A) is a second-line treatment for neurogenic bladder (NB). It requires repeated injections over time, which is a possible limit for long-term adherence, especially in children, as general anesthesia is required. Almost 50% of adults discontinue therapy; few data on pediatric patients are present. The aim of this study is to share our long-term experience of BTX-A adherence in children. This study is a retrospective review of 230 refractory NB patients treated with BTX-A. The inclusion criteria were ≥3 treatments and the first injection performed ≥10 years before the study endpoint. Fifty-four patients were included. Mean follow-up was 10.2 years; mean treatment number was 6.4 for each patient. During follow-up, 7% did not need BTX-A anymore; 76% discontinued therapy, with a prevalence of acquired NB (64% acquired vs. 34% congenital; p = 0.03); sex-based and urodynamic findings did not influence the discontinuation rate (p = 0.6, p = 0.2, respectively). Considering those who withdrew from the therapy, 43% were lost to follow-up/died after a mean of 7.5 years (although 33% still experienced clinical efficacy); 33% changed therapy after a mean of 5.8 years (with reduced efficacy in 22%, persistent efficacy in 11%). BTX-A is a safe and effective therapy for pediatric patients. The treatment abandonment rate is higher for children than for adults; no specific reasons were highlighted. It is necessary to evaluate any age-specific factors to explain these data.

Onabotulinum Toxin A Intradetrusor Injections in Children with Neurogenic Lower Urinary Tract Dysfunction: Long-Term Histological Effects on the Bladder Wall

BACKGROUND

In the last twenty-five years, Onabotulinum Toxin A (BTX-A) has gained increasing popularity for neurogenic lower urinary tract dysfunction (NLUTD) treatment. To maintain its efficacy, repeated BTX-A intradetrusor injections are required over time, with unknown effects on the bladder wall in children. The aim of this paper is to report long-term effects on the bladder wall in children treated with BTX-A.

METHODS

Children with NLUTD not responsive to anticholinergics were treated with BTX-A, according to our protocol, with bladder wall control using endoscopic cold-cup biopsy. Specimens were evaluated considering edema, chronic inflammation, and fibrosis.

RESULTS

Of the 230 patients treated from 1997 to 2022, we considered only specimens obtained in patients who had received ≥5 treatments (36 children), considered as the threshold to evaluate clinical effectiveness on long-term treatment with BTX-A. Most of them had congenital NLUTD (25 patients) and detrusor overactivity (27 patients). In all, increased edema and chronic inflammation with reduced fibrosis over time was reported; these data were not statistically significant. No difference was observed between patients with congenital and acquired diseases.

CONCLUSIONS

Repeated intradetrusor BTX-A injections are not related to significant histological alterations in children, similarly with adults, and repeated injections could be considered safe.

Intravesical botulinum-A toxin in children with refractory non-neurogenic overactive bladder

INTRODUCTION

Overactive bladder (OAB) with urinary incontinence poses a potentially significant impact on daily activities and quality of life. OAB can be unresponsive to specific urotherapy and antispasmodic medication. Due to its successful outcomes in the treatment of neurogenic bladder, intravesical botulinum-A toxin (BTX-A) became a possible solution for children refractory to treatment.

OBJECTIVE

To analyse the outcomes of intravesical BTX-A injections on bladder volume and incontinence in children with refractory OAB.

STUDY DESIGN

The charts of children diagnosed with refractory non-neurogenic OAB who underwent BTX-A treatment in our centre since 2011 were retrospectively analysed. The functional bladder volume (FBV) is expressed as a percentage of the expected bladder capacity (EBC) for age. Dependent variables were compared using the Wilcoxon Signed Rank test. A multivariate logistic regression was used to identify predictors of the response on urinary incontinence.

RESULTS

Fifty children (41 boys) with a median age of 9.9 years were included. In the short term, there was a significant increase in FBV after initial BTX-A treatment from a median of 52.9%-70% (p = 0.000). In the short (<6 months) and long term (6-12 months) 72% and 46% showed improvement of continence, respectively. Male gender and small baseline FBV predict a positive outcome on continence in the long term. The most prevalent complications were urinary tract infections occurring in five cases (10%).

DISCUSSION

Although BTX-A injections serve as an effective therapy to increase bladder volume in non-neurogenic OAB children, the outcomes on urinary incontinence are highly variable. This may be a consequence of the multifactorial aspects of this condition. BTX-A will enable children to inhibit their bladder urgency. The effectiveness of post-BTX-A urotherapy training will therefore most probably be higher. We believe that BTX-A injections should be reserved for children refractory to both specific urotherapy and medication. An appropriate population seems to be children with severe OAB symptoms, confirmed detrusor overactivity in urodynamic study and reduced bladder volume.

CONCLUSION

In refractory OAB children, BTX-A injections are safe and effective in enlarging bladder volume and reducing OAB symptoms, particularly in the first six months after injection.

Transcutaneous sacral electrical stimulation versus oxibutynin for the treatment of overactive bladder in children

BACKGROUND

Nowadays there is still no ideal treatment for paediatric overactive bladder. Initial management measures (urotherapy and constipation control), resolve 40% of cases. The second line of treatment in overactive bladder is anticholinergic drugs, above all oxybutynin. Although most patients improve with these therapies, the complete resolution rate is around 30-40%. Sacral transcutaneous electrical nerve stimulation has recently emerged as a new alternative in the management of patients with refractory paediatric overactive bladder. However, only a few studies have been done to compare the effectiveness of this therapy versus conventional drugs.

OBJETIVE

The objective of the present study is to compare, in children with overactive bladder, the efficacy of the sacral transcutaneous electrical nerve stimulation versus oxybutynin therapy.

MATERIALS AND METHODS

We performed a prospective and randomized study of patients with diagnosis of overactive bladder treated with sacral transcutaneous electrical nerve stimulation versus oxybutynin, during the period July 2018-July 2020. Patients refractory to standard urotherapy and constipation management randomly received one of the therapeutic alternatives. Treatment was maintained for 6 months.

RESULTS

86 patients were included in the study: 40 patients received electrotherapy (group 1) and 46 patients received oxybutynin (group 2). Before starting the treatment assigned both groups were comparable related to the voiding symptomatology as well as the severity of the overactive bladder. Sacral transcutaneous electrical nerve stimulation was significantly more effective than oxybutynin, with a higher percentage of complete resolution of symptoms in the management of paediatric overactive bladder.

VOIDING DIARY

All the parameters obtained with the voiding calendar significantly improved in both groups at the end of the treatment. The increase in MaVV was significantly higher in group-1.

DVISS (DYSFUNCTIONAL VOIDING AND INCONTINENCE SCORING SYSTEM)

We observed a progressive decrease in the mean score obtained in the DVISS questionnaire over time in both groups. This decrease was significantly higher in group-1 compared to group-2 (p < 0.005). The mean value obtained in the DVISS questionnaire in group-1 was 6 (interquartile range: 3-9) at the end of the treatment (lower than the diagnostic cut-off point for daytime condition in the DVISS, 8.5). In group-2, the mean value obtained in the DVISS questionnaire was 10 (interquartile range: 8.75-13.25), higher than the cut-off point.

COMPLICATIONS

A greater number of adverse effects was obtained in group-2 (26.1% versus 15%, p < 0.05). Constipation (n: 6, 10.9%), and abdominal pain (n: 2,4.3%) were the most frequent adverse effects in this group. The adverse events reported in group-1 were contact dermatitis (n: 1.2%) and fecal losses [2] or urgency [5].

CONCLUSION

Oxybutynin and sacral transcutaneous electrical nerve stimulation are both effective therapies in the management of paediatric overactive bladder. However, electrotherapy has been shown to be a more effective therapy with a complete clinical resolution rate in a larger number of patients. Furthermore, the rate of adverse effects secondary to electrotherapy is significantly lower than those treated with oxybutynin.

Beyond botulinum neurotoxin A for chemodenervation of the bladder

PURPOSE OF REVIEW

Botulinum neurotoxin A (BoNT/A), or Botox, is a popular option for overactive bladder (OAB) and neurogenic bladder (NGB) with or without incontinence. This review aims to discuss the clinical outcomes of BoNT in adult and pediatric bladder conditions, and introduces the potential benefit of novel, engineered neurotoxins beyond BoNT/A.

RECENT FINDINGS

A large volume of evidence supports the use of Botox for OAB (to reduce urgency, frequency and incontinence episodes), and for NGB (to decrease incontinence and improve bladder capacity and detrusor pressures). Botox is now also Food & Drug Administration (FDA)-approved for pediatric neurogenic detrusor overactivity. However, urinary retention, diminished response over time and treatment failures are prevalent issues with Botox. Modifying natural BoNTs or forming chimeric toxins are alternatives to BoNT/A that may have higher efficacy and lower side-effect profile. One example is BoNT/BMY-WW. This novel engineered toxin binds to a more commonly expressed synaptotagmin receptor, with potentially more potent paralytic effect and less capacity for systemic diffusion.

SUMMARY

Novel engineered neurotoxins may be the next frontier in OAB and NGB therapy.

Mirabegron in Overactive Bladder and Its Role in Exit Strategy After Botulinum Toxin Treatment in Children

PURPOSE

Mirabegron is a recent addition to the management options of overactive bladder (OAB) in children. The purpose of this study was to ascertain the role of Mirabegron in the treatment algorithm of therapy-resistant OAB especially after botulinum toxin.

METHODS

Case notes of all children receiving Mirabegron between July 2017 and February 2020 were reviewed.

RESULTS

Forty one children (21 females, 20 males), mean age 12.6 [8-17] years old, commenced Mirabegron: 35 idiopathic OAB, 6 neuropathic OAB. The mean duration of treatment was 20.7 [3-45] months. In total 24 (59%) had Mirabegron after partial/no response to anticholinergics, and 17 (41%) patients had Mirabegron subsequent to botulinum toxin A (BtA) as an exit strategy. In total 35 (85%) patients had combination therapy (Mirabegron and anticholinergics), and 6 (15%) patients had Mirabegron only. Fourteen (34%) had complete response, 17 (41%) had partial response, and 10 (24%) had no response. Side effects were reported in 7 (17%) patients with discontinuation necessitated in 3.

CONCLUSION

Mirabegron when used alone or in combination with anticholinergics resulted in complete/partial response in 76% of anticholinergic therapy-resistant OAB. In addition to being an important step in treatment escalation after no/partial response to anticholinergics, it has a crucial role in the exit strategy for recurring symptoms after BtA wears off.

Intradetrusor onabotulinum-a toxin injections in children with therapy-resistant idiopathic detrusor overactivity. A retrospective study

INTRODUCTION AND OBJECTIVE

The use of intravesical onabotulinum-A toxin (BoNT-A) injections in the treatment of idiopathic detrusor overactivity has been widely studied in adults [2-5]. However, in pediatric populations, study groups are small, and results are not yet sufficient to support this treatment as a standard practice. The aim of this study is to determine the effectiveness and safety of this treatment in children with non-neurogenic detrusor overactivity, resistant to conservative therapy.

MATERIAL AND METHODS

We retrospectively evaluated the effect and safety of the intradetrusor injection of 100 Units (U) of BoNT-A in 257 children with therapy-resistant non-neurogenic detrusor overactivity between May 2003 and August 2017. Outcome parameters were the number of daytime incontinence and enuresis episodes per week and bladder capacity (BC). Treatment outcomes were classified into complete response, partial response, or no response.

RESULTS

The database includes 257 children, of which are 102 girls and 155 boys. Median age of first BoNT-A injection was 8 years (range 4-18 years). Of the patients with enuresis, daytime incontinence or both, a complete response was seen in 50%, 45.7%, and 17%, respectively. BC was significantly higher after the first, second, and third injection of 100 U BoNT-A. We estimated that the mean duration of the effect of an injection with a dose of 100 U is around 12 months. After the first injection, one girl (0.4%) developed urinary retention, which required temporary clean intermittent catheterization (CIC). Seventeen patients (6.6%) developed a urinary tract infection. In three patients (1.2%), postoperative vesicoureteral reflux was seen.

DISCUSSION

A distinction between the effect on daytime incontinence and enuresis was made. A poorer effect on enuresis in children who suffered from both conditions was observed. Drawbacks of this study are its retrospective design and the lack of anticholinergic treatment standardization before and after BoNT-A injection.

CONCLUSION

BoNT-A injection is a potentially effective adjuvant therapy in the treatment of children with therapy-resistant overactive bladder (OAB). Bladder capacity increases significantly after the first, second, and third injections. A better effect on daytime incontinence than on enuresis was seen. Prospective randomized trials with standardization of conservative treatment and symptoms questionnaires are necessary to confirm the beneficial effect of BoNT-A injections on BC and incontinence.

Assessment of Needs in Children Suffering From Refractory Non-neurogenic Urinary and Fecal Incontinence and Their Caregivers' Needs and Attitudes Toward Alternative Therapies (SNM, TENS)

Background: Non-neurogenic urinary and fecal incontinence (UI, FI) affects approximately 6% of North American children with 1% of cases becoming refractory (nonresponsive to standard therapies). Incontinence has major potential long-term physiological and psychological implications for patients and their families. While Sacral Neuromodulation (SNM) and Transcutaneous Nerve Stimulation (TENS) are alternative therapies available for the treatment of refractory UI/FI, these are not approved for use in children in Canada. The present study assessed participants' perception of current treatments, incontinence burden, and attitudes toward novel therapies in a single pediatric institution. Methods: Multiple validated questionnaires including Dysfunctional Voiding Scoring System (DVSS), Bristol Stool Chart (BSC), Pediatric Incontinence measurement (PinQ), and Time-Driven Activity Based Costing were used to perform a needs assessment for patients with non-neurogenic refractory incontinence, and to determine patients' and caregivers' attitudes toward alternative therapies. Results: 75% of patients and 89% of caregivers reported a moderate to severe impact of incontinence on QoL with diminished social interactions among the primary concerns. Caregivers were frustrated with current treatments and were open to trying alternative therapies (SNM and TENS), which, at least in the case of SNM, seems to be less expensive, possibly less burdensome and more effective than current surgical options. Conclusion: Pediatric refractory UI/FI has a large impact on patients' and caregivers' QoL and alternative therapies with the potential to improve QoL of patients and caregivers should be further investigated as a substitute for surgery.

Medical Management of Neurogenic Bladder for Children and Adults: A Review

Neurogenic bladder is a chronic condition affecting patients of all ages with significant medical and quality of life implications. Goals of treatment consist of protection of the upper urinary tract and promotion of reliable urinary continence. Successful management involves medications and most often bladder drainage via clean intermittent catheterization. This article reviews current literature on medical management to achieve goals of treatment.