Anatomical location and number of injection sites of intravesical OnabotulinumtoxinA for females with refractory idiopathic overactive bladder: A scoping review

AIMS

The negative impact on quality of life and the economic-related burden to the patient and the health care system associated with idiopathic overactive bladder (iOAB) is well-documented. Intradetrusor OnabotulinumtoxinA (BTN/A) injections are a well-used treatment modality for the management of overactive detrusor refractory to medical management, with well-documented efficacy and safety profiles. There is currently no best practice guideline for the administration of BTN/A for this procedure and historically the trigone of the bladder has been excluded from the injection paradigm given the risk of vesicoureteral reflux (VUR).

METHODS

A scoping review methodology was employed to assess available literature to evaluate current techniques used. There is emerging literature that the inclusion of the trigone may increase the efficacy of the procedure, while maintaining a similar adverse effect profile. Similar results could also be obtained by decreasing the number of injection sites. A scoping review was completed with systematic methodology using the Preferred Systematic Reviews and Meta Analyses extension for Scoping Review checklist. The search strategy looked to evaluate BTN/A and number of injection sites and the inclusion of the trigone in female patients with iOAB. Studies with male or neurogenic bladder only were excluded. Mixed studies were included. A specialist research librarian was engaged, with supervision from a functional urologist using a combination of MeSH and natural language terms. Two investigators independently reviewed the titles and abstracts.

RESULTS

Twelve articles were included and were published between 2005 and 2021. There was no evidence of VUR in any of the results. All but one study reported similar if not improved efficacy of trigone-inclusion. Lower number of injection sites had similar efficacy profiles to higher numbers of intradetrusor injections.

CONCLUSIONS

Further high-quality randomized control trials of trigone inclusion and reduction of injection sites are required. It is hoped that with further exploration of intraoperative methods for BTN/A injections, the development of universally accepted guidelines may optimize management and experiences for patients with iOAB.

Pain Related to Intradetrusor BotulinumtoxinA: A Randomized Clinical Trial

IMPORTANCE

OnabotulinumtoxinA (BTX-A) is an effective treatment for overactive bladder (OAB), but few studies have been done to evaluate injection techniques.

OBJECTIVE

The primary objective was to evaluate procedural discomfort between 2 commonly used injection techniques for BTX-A.

STUDY DESIGN

This was a single-blinded, randomized clinical trial of women undergoing injection of 100 U BTX-A for idiopathic OAB. Patients were randomized to 5 mL/5 injection or 10 mL/10 injection groups. Bladder pain was assessed by a validated Numeric Pain Rating Scale. Overactive bladder symptoms were assessed with a standardized questionnaire (Overactive Bladder Questionnaire Short Form). Patient satisfaction, treatment efficacy, and adverse events were assessed at 30 days after procedure.

RESULTS

One hundred eight patients were randomized to 52 in the 5 mL/5 injection arm and 56 in the 10 mL/10 injection arm. Mean procedural pain scores were 3.2 (±2.3) in the 5 mL/5 injection group versus 3.6 (±2.1) in the 10 mL/10 injection group (P = 0.21). No difference was found when categorizing pain scores into ordinal outcomes of low (P = 0.55), medium (P = 0.70), and high (P = 1.0) or a binary outcome of low (P = 0.55) versus medium + high (P = 0.55). Multivariate analyses did not effect statistical significance between the 2 groups for the ordinal outcome (odds ratio = 1.86; 95% confidence interval = 0.77 = 4.52; P = 0.17) or the binary outcome (odds ratio = 1.81; 95% confidence interval = 0.68-4.77; P = 0.28). No difference was observed between overall patient satisfaction, global impression of improvement, Overactive Bladder Questionnaire Short Form scores, or adverse outcomes.

CONCLUSIONS

Procedural discomfort related to BTX-A injection for idiopathic OAB was not different between 2 injection protocols. Overall satisfaction was high for both groups, and there was no difference in symptom scores or adverse events.

Efficacy and safety of an alternative onabotulinumtoxinA injection paradigm for refractory overactive bladder

AIMS

In studies utilizing a 20-injection-site paradigm of onabotulinumtoxinA treatment for overactive bladder (OAB), some patients performed clean intermittent catheterization (CIC). An alternative injection paradigm of fewer injections targeting the lower bladder may reduce the need for CIC by maintaining upper bladder function. This study evaluated the efficacy and safety of an unapproved alternative 10-injection-site paradigm targeting the lower bladder.

METHODS

In this phase 4, double-blind, parallel-group study, patients with OAB and urinary incontinence (UI) for ≥6 months with ≥3 episodes of urinary urgency incontinence (no more than 1 UI-free day) and ≥8 micturitions per day over 3 days during screening were randomized 2:1 to onabotulinumtoxinA 100 U or placebo injected at 10 sites in the lower bladder.

RESULTS

Of 120 patients, 78 in the onabotulinumtoxinA group and 39 in the placebo group had efficacy assessments. In the double-blind phase, mean change from baseline at week 12 in daily frequency of UI episodes was greater with onabotulinumtoxinA (-2.9) versus placebo (-0.3) (least squares mean difference [LSMD]: -2.99, p < 0.0001). Achievement of 100% (odds ratio [OR]: 6.15 [95% confidence interval, CI: 0.75-50.37]), ≥75% (OR: 7.25 [2.00-26.29]), and ≥50% improvement (OR: 4.79 [1.87-12.28]) from baseline in UI episodes was greater with onabotulinumtoxinA versus placebo. Reductions from baseline in the daily average number of micturitions (LSMD: -2.24, p < 0.0001), nocturia (LSMD: -0.71, p = 0.0004), and urgency (LSMD: -2.56, p < 0.0001) were greater with onabotulinumtoxinA than with placebo. Treatment benefit was improved or greatly improved in the onabotulinumtoxinA group (74.0% of patients) versus placebo (17.6%) (OR: 13.03 [95% CI: 3.23-52.57]). Mean change from baseline in Incontinence Quality of Life score was greater with onabotulinumtoxinA versus placebo (LSMD: 24.2, p = 0.0012). Two of 78 (2.6%) patients in the onabotulinumtoxinA group used CIC during the double-blind period; no females used CIC during the double-blind period. Commonly reported adverse events (≥5%) were urinary tract infection (UTI), dysuria, and productive cough for both groups; rate of UTI was higher with onabotulinumtoxinA versus placebo.

CONCLUSION

In patients treated with onabotulinumtoxinA for OAB with UI, an unapproved alternative injection paradigm targeting the lower bladder demonstrated efficacy over placebo, with a low incidence of CIC.

Intravesical Injection of Botulinum Toxin Type A in Men without Bladder Outlet Obstruction and Post-Deobstructive Prostate Surgery

Purpose: A significant proportion of men without bladder outlet obstruction (BOO) have been reported to have overactive bladders (OAB). This article aimed to review the specific group of reports on the use of botulinum toxin type A (BTX-A) injections into the bladder wall. Materials and methods: Original articles reporting men with small prostates without BOO were identified through a literature search using the PubMed and EMBASE databases. Finally, we included 18 articles that reviewed the efficacy and adverse effects of BTX-A injections in men. Results: Of the 18 articles screened, 13 demonstrated the therapeutic efficacy and adverse effects of BTX-A injections in men. Three studies compared BTX-A injection response between patients without prior prostate surgery and those undergoing prior prostate surgery, including transurethral resection of the prostate and radical prostatectomy (RP). Patients with prior RP experienced better efficacy and had a low risk of side effects. Two studies focused on patients who had undergone prior surgery for stress urinary incontinence, including male sling and artificial urethral sphincter surgery. The BTX-A injection was a safe and effective procedure for this specific group. OAB in men was found to have a different pathophysiology mechanism from that in female patients, which may decrease the efficacy of BTX-A injection in men. However, patients with small prostates and low prostate-specific antigen levels demonstrated better efficacy and tolerability after BTX-A injection. Conclusions: Although intravesical injection of BTX-A was a good option for controlling refractory OAB in men, the evidence-based guidelines are still limited. Further research is necessary to better understand the role of BTX-A injections on various aspects and histories. Therefore, treating patients using strategies tailored to their individual conditions is important.

Intravesical Injection of Botulinum Toxin Type A in Patients with Refractory Overactive Bladder-Results between Young and Elderly Populations, and Factors Associated with Unfavorable Outcomes

Intravesical botulinum toxin type A (BoNT-A) injection has been recognized as the standard treatment for refractory overactive bladder (OAB). However, its therapeutic efficacy and safety have not been thoroughly reviewed in elderly patients. This study aims to provide treatment outcomes for patients aged ≥75 years, and to identify factors associated with unfavorable outcomes. Patients receiving intradetrusor injections of 100 U onabotulinumtoxinA for refractory OAB between 2011 and 2021 were retrospectively reviewed. Urodynamic parameters, underlying comorbidities, subjective success, and unfavorable outcomes were assessed. A total of 192 patients were included, and 65 of them were classified into the elderly group. For the elderly group, 60.0% experienced subjective dryness, and 84.6% remained subjective success at 6 months after the injections. The prevalence rates of common unfavorable outcomes, including urinary tract infections, large post-void residual urine volume, and urinary retention, were 9.2%, 27.7%, and 12.3%, respectively. Multivariate analysis revealed that female, baseline urodynamic parameters, and diabetes mellitus were associated with unfavorable outcomes in the elderly group. Intravesical BoNT-A injections provide comparable therapeutic efficacy and safety concerns in elderly patients with refractory OAB. A thorough consultation for treatment benefits and possible adverse events is mandatory before the procedure.

Reduced versus standard intradetrusor OnabotulinumtoxinA injections for treatment of overactive bladder

BACKGROUND

Intradetrusor onabotulinumtoxinA injection is an effective advanced treatment for overactive bladder. While the effective dosages have been well studied, very little data exist on treatment efficacy using differing injection techniques. The objective of this study was to determine whether the efficacy of a reduced injection technique of 5 injection sites was noninferior to the standard technique of 20 injection sites of intradetrusor onabotulinumtoxinA for treatment of overactive bladder.

METHODS

In this randomized noninferiority trial, men and women seeking treatment of overactive bladder with intradetrusor onabotulinumtoxinA injections were randomized to receive 100 units administered via either a reduced injection technique of 5 injection sites or a standard injection technique of 20 injection sites. Subjects completed a series of standardized questionnaires at baseline and at 4-12 weeks postprocedure to determine symptom severity and treatment efficacy. The primary outcome was treatment efficacy as determined by Overactive Bladder Questionnaire-Short Form with a noninferiority margin of 15 points. Secondary outcomes were incidence of urinary tract infection and urinary retention requiring catheterization.

RESULTS

Data from 77 subjects were available for analysis with 39 in the control arm (20 injections) and 38 in the study arm (5 injections). There was a significant improvement in both arms from baseline to follow-up in Overactive Bladder Questionnaire-Short Form and International Consultation on Incontinence Questionnaire scores (p < 0.001). Overall treatment success was 68% with no statistically significant difference between arms. A significant difference between arms was found on the Overactive Bladder Questionnaire-Short Form quality of life survey favoring the control arm (confidence interval [CI]: 0.36-20.5, p = 0.04). However, there were no significant differences between arms in the remaining validated questionnaires. The study arm did not demonstrate noninferiority to the control arm. Subjects in the study arm were significantly more likely to express a willingness to undergo the procedure again (odds ratio = 3.8, 95% CI: 1.42-10.67, p = 0.004). Adverse events did not differ between arms.

CONCLUSIONS

A reduced injection technique for administration of intradetrusor onabotulinumtoxinA demonstrates similar efficacy to the standard injection technique but did not demonstrate noninferiority. Subjects preferred the reduced injection technique over the standard technique. A reduced injection technique is a safe and effective alternative to the standard technique.

Postprocedural Pain Associated With 5 Versus 20 Intradetrusor Injections of onabotulinumtoxinA for Treatment of Overactive Bladder: A Multicenter Randomized Clinical Trial

IMPORTANCE

Intradetrusor injection of onabotulinumtoxinA is performed via varying injection paradigms but no studies have studied the various effects of these paradigms on patient experience with the procedure.

OBJECTIVES

This randomized clinical trial aims to compare pain and procedure time between patients receiving a 100-unit dose of onabotulinumtoxinA in 5 injections compared to 20 injections for the treatment of idiopathic overactive bladder or urgency urinary incontinence.

STUDY DESIGN

Patients presenting with refractory overactive bladder or urgency urinary incontinence at 2 clinical sites were identified and randomized to undergo onabotulinumtoxinA treatment with 5 injections versus 20 injections. Patients rated their pain level on a 10-point visual analog scale at procedure completion. The procedure duration was recorded with a stopwatch. Patients were followed up 6 weeks postprocedure, at which time they completed a Global Response Assessment to determine subjective efficacy of treatment. Participants were additionally monitored for incidence of adverse events in the follow-up period.

RESULTS

The average pain score was not statistically significant between groups (2; interquartile range, 1-4 for the 5 injection group vs 3; interquartile range, 2-4 for the 20 injection group; P = 0.27). Patients who received 5 injections experienced significantly shorter mean procedure time as compared with patients who received 20 injections (76 seconds vs 176 seconds; P < 0.001). There were no differences in subjective efficacy or adverse events between groups.

CONCLUSIONS

Perceived pain, efficacy, and postprocedure complications did not significantly differ between patients receiving 5 injections and 20 injections, but procedure time was significantly shorter.

Bladder Dysfunction in Older Adults: The Botulinum Toxin Option

Bladder dysfunction, which involves inadequacies of urine storage or emptying, increases with age. Conventional medications may have insufficient efficacy for patients with refractory lower urinary tract symptoms, and their concomitant adverse events (AEs) may be intolerable for the older adult population. For decades, the botulinum toxin type A (BoNT-A) injection has been an option for managing urine frequency, urge incontinence, and voiding dysfunction in the general population refractory to conventional management. This review focuses on studies of BoNT-A application in the management of bladder dysfunction in older adult patients aged ≥ 65 years. In this target population, intravesical BoNT-A injections provide similar efficacy in idiopathic overactive bladder to that in younger adults. Good clinical response has also been demonstrated in older adult patients presenting with storage dysfunction and with various concomitant underlying neurological diseases. However, caution must be taken for the AEs that occur after intravesical BoNT-A injection, including increased post-void residual urine, acute urine retention, and urinary tract infection. Most evidence shows that age is not a major determinant of AEs after adjusting for other factors. In contrast to its application in storage dysfunction, evidence for voiding dysfunction in older adults is scarce. In general, BoNT-A may be a reasonable option for older adult patients with refractory storage dysfunction because of its promising clinical response without significant systemic AEs. Overall, clinicians should be aware of the balance between the therapeutic efficacy of BoNT-A and local AEs in vulnerable members of this population.

Associations between the Patient Perception of Bladder Condition score and overactive bladder syndrome symptoms at baseline and upon treatment

BACKGROUND

Patient-reported outcomes such as the Patient Perception of Bladder Condition (PPBC) score are frequently used to characterize overactive bladder syndrome (OAB) patients and their treatment outcomes. However, little information is available on the relationship of such scores to OAB symptoms at the individual patient level.

METHODS

We have performed a post hoc analysis of two large noninterventional studies (n = 1345 and 745) in which patients received propiverine extended release (30 or 45 mg/day) for 12 weeks to determine the strength of nonparametric correlations between PPBC and OAB symptoms at baseline, after treatment and with treatment-associated changes thereof.

RESULTS

PPBC was not correlated with age but with episode frequencies of urgency, incontinence, micturitions, and nocturia, but the strength of correlations was only moderate (Spearman rank correlation coefficient 0.2045-0.3553). Similarly moderate correlations were observed after treatment and when changes in PPBC were compared to those of OAB symptoms, although these correlations were somewhat stronger.

CONCLUSIONS

PPBC is only moderately correlated to OAB symptoms indicating that it characterizes patients beyond what is captured by their symptoms.

Modifications to Botulinum toxin A delivery in the management of detrusor overactivity recalcitrant to initial injections: a review

PURPOSE

One quarter of patients will not respond to initial intra-detrusor Botulinum toxin A (BTX) injections for detrusor overactivity. Alternative treatment options include long-term catheterization, sacral neuromodulation, urinary diversion or bladder augmentation. Some of these procedures are invasive. This review explores modifications to BTX delivery that can improve outcome.

METHODS

A search of Medline, Embase and Cochrane Library to December 2017 was performed according to Preferred Reporting Items for Systematic Review and Metaanalysis (PRISMA) guidelines. Search criteria included, dose escalation, increasing injection site number, trigone injection, switching preparation and alternative methods of BTX delivery.

RESULTS

Several modifications to BTX delivery may improve response. There is moderate evidence that increasing the dose from 100 U to 200 U results in statistically better symptom control. Trigone-including injections were associated with significantly improved patient-reported symptom scores, as well as superior results in urodynamic outcomes without risking urinary retention and vesico-ureteric reflux. Switching from onabotulinum (OTA) or abobotulinum (ATA) or vice versa may also improve response in over 50% of patients as shown in limited studies. Increasing the number of injection sites is not beneficial. Indeed, decreasing the number of injections to as low as three sites does not result in decreased clinical outcomes. Injection-free delivery is associated with lower efficacy compared to conventional intradetrusor injections.

CONCLUSION

Before contemplating alternative treatments, practitioners can try to improve on BTX delivery. Firstly, the dose can be increased to 200 U; the trigone included in the injection sites and switching brands may also be helpful.

Recent research on the role of urodynamic study in the diagnosis and treatment of male lower urinary tract symptoms and urinary incontinence

Although evidence shows that urodynamic study may not improve outcomes, it can be used to evaluate men with lower urinary tract symptoms (LUTSs) which have not been adequately delineated and treated. In young men with LUTS not responding to treatment based on clinical examination, or elderly men with LUTS and incontinence, a complete urodynamic evaluation is mandatory to understand the pathophysiology underlying LUTS, such as bladder outlet obstruction (BOO), detrusor overactivity, and detrusor underactivity. Preoperative urodynamic study-proven BOO is a predictor of a successful surgical outcome. An urodynamic study should be performed when patients with LUTS are planning to undergo surgical treatment for benign prostatic obstruction.

The role of botulinum toxin A in treating neurogenic bladder

Neurogenic detrusor overactivity (NDO) can result in lower and upper urinary tract complications and eventually even in end-stage kidney failure. Since the driving force of this clinical cascade is high bladder pressure, controlling intravesical pressure in NDO patients improves both quality of life and life-expectancy in these patients. Botulinum toxin A (BTX-A) has proven its efficacy in reducing intravesical pressure and in reducing incontinence episodes. BTX-A also improves quality of life in patients with NDO. Both onabotulinumtoxinA (Botox^®, Allergan, Irvine, USA) and abobotulinumtoxinA (Dysport^®, Ipsen, Paris, France) have a level A recommendation for NDO-treatment. The recommended dose for intradetrusor injections in NDO patients is 200 U of onabotulinumtoxinA or 500 U of abobotulinumtoxinA. The drug is generally administered extratrigonal in the detrusor muscle, via cystoscopic guided injection at 20 sites in 1 mL injections. Intradetrusor BTX-A injections are safe, with mostly local complications such as urinary tract infection and high post-void residual or retention. The effect of the toxin lasts for approximately 9 months. Repeat injections can be performed without loss of efficacy. Different injection techniques, novel ways of BTX-A administration, eliminating the need for injection or new BTX-A types with better/longer response rates could change the field in the future.

Practical Aspects of Botulinum Toxin-A Treatment in Patients With Overactive Bladder Syndrome

Intravesical onabotulinumtoxinA (BoNT-A) injection is an effective treatment for overactive bladder syndrome (OAB) that is refractory to antimuscarinics. An injectable dose of 100 U has been suggested to achieve the optimal balance of benefit and safety in patients with OAB. BoNT-A (total volume of 10 mL) was administered as evenly distributed intradetrusor injections (5 U) across 20 sites approximately 1 cm apart (0.5 mL per site) using a flexible or rigid cystoscope. Treatment with BoNT-A was generally well tolerated by most patients, and most treatment-related adverse events were localized to the urinary tract. The prevalence of OAB increases with age, and elderly patients are more vulnerable to complications. The short-term efficacy of intravesical BoNT-A injection for refractory OAB with no treatment-related complications in the elderly population has been documented. Frail elderly patients can experience the same treatment results, such as significantly improved urgent urinary incontinence and quality of life, as young and nonfrail elderly patients with 100-U BoNT-A injections. However, increased risk of larger postvoid residual (PVR) urine and lower long-term success rates were noted in frail elderly patients; around 11% had acute urinary retention, while 60% had PVR urine volume >150 mL after treatment. In addition, intravesical injection of BoNT-A effectively decreased urgency symptoms in elderly patients with OAB and central nervous system lesions. The adverse effects were acceptable, while the long-term effects were comparable to those in patients with OAB without central nervous system lesions. Nonetheless, the possibility of longstanding urinary retention and chronic catheterization in this vulnerable population requires careful evaluation before treatment with intravesical BoNT-A. In conclusion, the current findings indicate that intravesical BoNT-A is an effective and safe treatment for OAB in elderly patients.

Does Reduction of Number of Intradetrusor Injection Sites of aboBoNTA (Dysport®) Impact Efficacy and Safety in a Rat Model of Neurogenic Detrusor Overactivity?

Intradetrusor injections of Botulinum toxin A—currently onabotulinumtoxinA—is registered as a second-line treatment to treat neurogenic detrusor overactivity (NDO). The common clinical practice is 30 × 1 mL injections in the detrusor; however, protocols remain variable and standardization is warranted. The effect of reducing the number of injection sites of Dysport^® abobotulinumtoxinA (aboBoNTA) was assessed in the spinal cord-injured rat (SCI). Nineteen days post-spinalization, female rats received intradetrusor injections of saline or aboBoNTA 22.5 U distributed among four or eight sites. Two days after injection, continuous cystometry was performed in conscious rats. Efficacy of aboBoNTA 22.5 U was assessed versus aggregated saline groups on clinically-relevant parameters: maximal pressure, bladder capacity, compliance, voiding efficiency, as well as amplitude, frequency, and volume threshold for nonvoiding contractions (NVC). AboBoNTA 22.5 U significantly decreased maximal pressure, without affecting voiding efficiency. Injected in four sites, aboBoNTA significantly increased bladder capacity and compliance while only the latter when in eight sites. AboBoNTA significantly reduced NVC frequency and amplitude. This preclinical investigation showed similar inhibiting effects of aboBoNTA despite the number of sites reduction. Further studies are warranted to optimize dosing schemes to improve the risk-benefit ratio of BoNTA-based treatment modalities for NDO and further idiopathic overactive bladder.