Clinical Application of Botulinum Neurotoxin in Lower-Urinary-Tract Diseases and Dysfunctions: Where Are We Now and What More Can We Do?

Evaluation of efficacy and safety of Botulinum toxin-A injection at three deferent sites in treatment of premature ejaculation

BACKGROUND

Premature ejaculation (PE) is a common sexual problem, resulting in adverse effects on the quality of life, of both the patient and the partner. The idea of muscular contraction inhibition during the ejection phase of ejaculation by Botulinum toxin-A injection may delay ejaculation.

AIM OF STUDY

This study was performed to assess the efficacy and safety of Botulinum toxin-A injection in PE treatment.

MATERIAL AND METHODS

This study included 45 married male patients diagnosed with primary PE. All included patients were injected with 75 units of Dysport equal efficacy of 25 units of Botulinum toxin-A (Botox) into three sites: the root of the penis (Group 1), glans penis (Group 2), and each side of the ischiocavernosus muscle (Group 3). All patients were subjected to an assessment of intravaginal ejaculation latency time (IELT) using a stopwatch and answering the Premature Ejaculation Diagnostic Tool (PEDT) Questionnaire before and after treatment.

RESULTS

There was a statistically significant improvement in IELT after treatment in all groups. The most significant improvement was shown in Group 3 (average 108% increase), followed by Group 1 (74%) and Group 2 (40%), respectively. There was a positive correlation between age and the improvement in improved IELT. There was a statistically significant improvement in PEDTq scores in Group 1 and Group 3.

CONCLUSION

Botulinum toxin-A injection into the root of the penis and ischiocavernosus muscle could be recommended in the treatment of premature ejaculation.

Real-World Use of Intradetrusor Botulinum Toxin Injections: A Population-Based Study from France

In recent decades, intradetrusor injections of botulinum toxin A (BoNT-A) have been widely applied to treat incontinence in both idiopathic overactive bladder (iOAB) and neurogenic detrusor overactivity incontinence (NDOI). This analysis, based on the French National Hospital Discharge Database (PMSI), aims to describe real-world trends in intradetrusor BoNT-A use between 2014 and 2022. Among 32,864 patients who received at least one intradetrusor BoNT-A injection, 18,320 (55.7%) had conditions coded under iOAB, 13,376 (40.7%) under NDOI, and 1168 (3.6%) under other indications. The overall mean interval between two intradetrusor BoNT-A injections was 9.7 months, ranging from 8.7 months in patients with multiple sclerosis (MS) to 11.5 months in patients with cerebral pathologies. The median number of injections was two (quartile 1-quartile 3, 1-4) in patients with spina bifida, whereas it was five (2-10) in those with MS. Only 31% of patients with iOAB received more than two intradetrusor BoNT-A injections. Regardless of its indication, BoNT-A was well tolerated. Adverse events occurring during or requiring hospitalization included infections (3.8%), hematuria (0.53%), and bleeding episodes necessitating transfusions (0.11%), all recorded within the initial month following BoNT-A injection. Our analysis of the PMSI database highlights a broad spectrum of intradetrusor BoNT-A injection practices.

Non-cosmetic use of botulinum toxin in surgical conditions

Botulinum toxin (BTX) is a neurotoxin that has an ability to create a fully reversible relaxation of muscles through decreased release of acethylcholin. It also has an effect on the cholinergic autoimmune nervous system, and it can reduce pain sensitization. BTX is widely used in cosmetic treatments. In recent years, BTX has increasingly been used to treat several medical and surgical conditions. In many cases, this is despite weak evidence and without approval from the European Medicine Agency (EMA). This narrative review describes how BTX is used in the different surgical specialties and provides a brief overview of the use of BTX for non-cosmetic surgical conditions.

Promising Experimental Treatment in Animal Models and Human Studies of Interstitial Cystitis/Bladder Pain Syndrome

Interstitial cystitis/bladder pain Syndrome (IC/BPS) remains a mysterious and intricate urological disorder, presenting significant challenges to healthcare providers. Traditional guidelines for IC/BPS follow a hierarchical model based on symptom severity, advocating for conservative interventions as the initial step, followed by oral pharmacotherapy, intravesical treatments, and, in refractory cases, invasive surgical procedures. This approach embraces a multi-tiered strategy. However, the evolving understanding that IC/BPS represents a paroxysmal chronic pain syndrome, often involving extravesical manifestations and different subtypes, calls for a departure from this uniform approach. This review provides insights into recent advancements in experimental strategies in animal models and human studies. The identified therapeutic approaches fall into four categories: (i) anti-inflammation and anti-angiogenesis using monoclonal antibodies or immune modulation, (ii) regenerative medicine, including stem cell therapy, platelet-rich plasma, and low-intensity extracorporeal shock wave therapy, (iii) drug delivery systems leveraging nanotechnology, and (iv) drug delivery systems assisted by energy devices. Future investigations will require a broader range of animal models, studies on human bladder tissues, and well-designed clinical trials to establish the efficacy and safety of these therapeutic interventions.

[Botulinum toxin in male lower urinary tract symptoms (LUTS): What can we expect?]

During the last two decades botulinum toxin has also conquered urology. Botulinum toxin reduces the contractility and sensitivity of the detrusor muscle and relieves pain. It is therefore a promising drug whose use in men also appears promising. The following article highlights the practical relevance of botulinum toxin for male lower urinary tract symptoms (LUTS). But first of all, a distinction must be made between use in male LUTS due to benign prostate syndrome (BPS) and use in cases of overactive bladder (OAB) alone. A differentiated diagnosis and treatment of male LUTS is therefore essential.

Ultrasound-assisted intravesical botulinum toxin A delivery attenuates acetic acid-induced bladder hyperactivity in rats

Background: Intradetrusor injection of botulinum toxin A (BTX-A) is an effective treatment for overactive bladder (OAB). However, the occurrence of adverse events associated with BTX-A injection therapy hinders its acceptance among patients and its clinical promotion. Intravesical instillation of BTX-A offers a promising alternative to injection therapy for treating OAB. Nevertheless, due to the presence of the bladder permeability barrier (BPB) and the high molecular weight of BTX-A, direct instillation is unable to penetrate the bladder urothelium. Purpose: This study aims to investigate the safety and feasibility of ultrasound-assisted intravesical delivery of BTX-A and its potential benefits in a rat model of bladder hyperactivity induced by acetic acid instillation. Methods: Hengli BTX-A and microbubbles (MB) were mixed and prepared as a novel complex. The size distribution and zeta potentials of the complex were measured. On day 1, rats' bladders were instilled with 1 mL of saline, BTX-A (20 U in 1 mL), MB, or MB-BTX-A (20 U in 1 mL) complex with or without ultrasound (US) exposure (1 MHz, 1.5 W/cm2, 50% duty cycle, sonication for 10 s with a 10-s pause for a total of 10 min). The instillations were maintained for 30 min. After 7 days, cystometry was performed by filling the bladder with saline and 0.3% acetic acid (AA). Bladders were collected, weighed, and processed for immunoblotting, enzyme-linked immunosorbent assay (ELISA), histologic, and immunofluorescence analyses. Expression and distribution of SNAP-25 and SNAP-23 were assessed using Western blot and immunofluorescence. Calcitonin gene-related peptide (CGRP) in the bladder was detected using ELISA. Results: Intercontraction intervals (ICI) decreased by 72.99%, 76.16%, and 73.96% in rats pretreated with saline, BTX-A, and US + MB, respectively. However, rats treated with US + MB + BTX-A showed a significantly reduced response to AA instillation (57.31% decrease in ICI) without affecting amplitude, baseline pressure, or threshold pressure. Rats treated with US + MB + BTX-A exhibited increased cleavage of SNAP-25 and CGRP expression compared to the control group. Conclusion: Ultrasound-assisted intravesical delivery of BTX-A, with the assistance of MB cavitation, led to cleavage of SNAP-25, inhibition of calcitonin gene-related peptide release from afferent nerve terminals, and amelioration of acetic acid-induced bladder hyperactivity. These results support ultrasound-assisted intravesical delivery as an efficient non-injection method for administering BTX-A.

Efficacy of Intravesical Botulinum Toxin A Injection in the Treatment of Refractory Overactive Bladder in Children

This study aimed to evaluate the efficacy of intravesical botulinum toxin A (BoNT-A) injections for the treatment of pediatric overactive bladder (OAB) by exploring the differential treatment outcomes in children with different OAB etiologies and those who received additional intrasphincteric BoNT-A injections. We performed a retrospective review of all pediatric patients who received intravesical BoNT-A injections between January 2002 and December 2021. All patients underwent a urodynamic study at baseline and three months after BoNT-A administration. A Global Response Assessment (GRA) score of ≥2 at three months after BoNT-A injection was defined as successful treatment. Fifteen pediatric patients (median age, 11 years), including six boys and nine girls, were enrolled in the study. A statistically significant decrease in detrusor pressure from baseline to three months postoperatively was observed. Thirteen (86.7%) patients reported successful results (GRA ≥ 2). The cause of OAB and additional intrasphincteric BoNT-A injections did not affect the improvement in urodynamic parameters and treatment success. The study demonstrated that intravesical BoNT-A injection is effective and safe for the treatment of neurogenic and non-neurogenic OAB in children refractory to conventional therapies. Additionally, intrasphincteric BoNT-A injections do not provide additional benefits in the treatment of pediatric OAB.

Role of Urological Botulinum Toxin-A Injection for Overactive Bladder and Voiding Dysfunction in Patients with Parkinson's Disease or Post-Stroke

Botulinum toxin A (BoNT-A) paralyzes muscle by blocking acetylcholine release at the synaptic junction. BoNT-A has shown its therapeutic effects in neurological disorders such as Parkinson's disease (PD) and post-stroke spasticity. A high proportion of patients with PD and post-stroke develop neurogenic detrusor overactivity (nDO) and then develop urinary incontinence and overactive bladder (OAB) symptoms. This study aimed to disclose the safety and efficacy of BoNT-A injection in treating bladder and voiding dysfunction in PD and post-stroke patients by reviewing the current evidence. At present, intradetrusor injection of BoNT-A is a Food and Drug Administration (FDA)-approved third-line therapy for nDO and idiopathic OAB. Although intradetrusor injection of onaBoNT-A 200 U is already approved for nDO treatment, most researchers would like to manage PD and post-stroke patients by using onaBoNT-A 100 U intradetrusor injection to achieve long-term efficacy and reduce adverse effects. However, in contrast to its inclusion in the International Continence Society guidelines for PD treatment, the clinical use of BoNT-A for post-stroke patients is limited to experimental use due to the development of urinary retention in about one-fifth of patients. For treating urethral pseudodyssynergia, half of patients may respond to onaBoNT-A 100 U urethral injection. However, refinement is needed to reduce unwanted urinary incontinence.

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.

Liposome-Encapsulated Botulinum Toxin A in Treatment of Functional Bladder Disorders

Botulinum toxin A (BoNT-A) intravesical injections have been used to treat patients with refractory functional bladder disorders such as overactive bladder (OAB) and interstitial cystitis/bladder pain syndrome (IC/BPS), but the risk of adverse events and the need for repeated injections continue to prevent widespread application of this treatment. Liposomes are vesicles that comprise concentric phospholipid layers and an aqueous core; their flexible compositions enable them to adsorb and fuse with cell membranes and to deliver drugs or proteins into cells. Therefore, liposomes have been considered as promising vehicles for the less invasive delivery of BoNT-A. In previous placebo-controlled trials including patients with OAB refractory to medical treatment, it was shown that liposomal BoNT-A could significantly decrease the frequency and urgency of urination. In patients with IC/BPS, it was shown that liposomal BoNT-A could also improve bladder pain, but the therapeutic efficacy was not superior to that of the placebo. As the therapeutic mechanisms of BoNT-A include the decreased expression of nerve growth factors, P2X3 receptors, and vanilloid receptors on C-fibers, liposomal BoNT-A might play a more promising role in the treatment of bladder oversensitivity. This article features the contemporary literature regarding BoNT-A, liposomes, and liposomal BoNT-A treatment for functional bladder disorders and potential clinical applications in the future.

Urogenital dysfunction following neurotrauma

PURPOSE OF REVIEW

Trauma affecting the nervous system can have widespread consequences, depending on the location and severity of injury. The sensorimotor and cognitive deficits due to neurotrauma have been studied extensively. Although the overall mortality due to neurotrauma has reduced, the disability and morbidity due to neurotrauma has not significantly reduced and focus on urogenital disturbances in these patients has been limited. This article reviews the limited evidence and scientific literature on this topic.

RECENT FINDINGS

Lower urinary tract symptoms are commonly reported in patients with neurotrauma, both acutely and over the long term. Multiple medical and surgical approaches are available for managing bladder dysfunction in these patients. Sexual dysfunction and changes in sexual behaviour are reported by patients with neurotrauma and are usually multifactorial. Treatment options for sexual dysfunction are available and their management requires a holistic approach.

SUMMARY

Urogenital dysfunction contributes significantly to the overall functional outcome and impaired quality of life in patients with neurotrauma. A better understanding of the mechanisms behind the urogenital abnormalities is needed for efficient management and treatment.