Relief by botulinum toxin of voiding dysfunction due to benign prostatic hyperplasia: results of a randomized, placebo-controlled study

Patient Reported Outcomes Due to Bladder Neck Obstruction in Women Treated With Botulinum Toxin A Injection

INTRODUCTION

Primary bladder neck obstruction (BNO) occurs when the bladder neck fails to open during voiding, causing urinary symptoms despite no anatomic obstruction. The cause of BNO is unclear but may involve neurogenic dysregulation related to the sympathic nervous system such as upper motor neuron lesion or peripheral autonomic neuropathy (small fiber neuropathy (SFN)). Another etiology can incuded increased sympathetic tone secondary to anxiety or stress conditons. Botulinum toxin A (BoNT-A) to the bladder neck has been used in our practice to treat women with BNO who failed conventional therapies (alpha blockers, relaxation strategies). This is the first report of patient-reported outcomes after BoNT-A treatment in women with pelvic pain and BNO.

MATERIALS AND METHODS

We included female patients with pelvic pain and BNO who received BoNT-A to the bladder neck between January 2022 and March 2023, and mailed self-reported outcome questionnaires. The primary outcome was the Global Response Assessment (GRA); secondary outcomes included pain scores on the Visual Analogue Scale (VAS) and symptom checklists. BNO was diagnosed using Nitti Criteria (high bladder pressure, low flow in bladder neck on video urodynamics), supplemented by additional criteria (e.g., high voiding pressure, prolonged attempts, Valsalva effort, and cystoscopic evidence or symptoms related to BNO). Urodynamic studies followed International Continence Society standards. Additionally, due to BNO's association with SFN, patient history of biopsy-confirmed SFN was recorded.

RESULTS

Our inclusion criteria was satisfied among 18 patietns, with 17 completing the questionnaire. Out of those, 14 patients (77%) reported improvement on the GRA, with an average VAS of 8.3 ("Very Helpful"). The most commonly improved symptoms were feeling of incomplete emptying, difficulty starting stream, urethral burning, pain with urination, and pelvic pain. Postoperative symptom flares were reported in six patients for an average of 16 days. All six patients with biopsy-confirmed SFN showed significant improvement (VAS 8.7). Total of 14 patients (77%) indicated they would repeat the procedure.

CONCLUSIONS

BoNT-A to the bladder neck significantly improved pelvic pain and refractory hesitancy in women with bladder neck obstruction, especially in those with small fiber neuropathy. Symptom flares are common, but did not reduce interest in repeated treatments, and scheduling injections before symptom recurrence may mitigate these flares.

Lower urinary tract dysfunction in the central nervous system neurogenic bladder and the real-life treatment outcome of botulinum toxin A

Neurogenic lower urinary tract dysfunction (NLUTD) is common in patients with central nervous system (CNS) lesions. Cases of cerebrovascular accidents (CVA), Parkinson's disease, dementia, and other intracranial lesions develop poor bladder control with or without urinary difficulty due to loss of cortical perception of bladder filling sensation and poor coordination of urethral sphincter relaxation during reflex micturition. Patients with CNS lesions usually have overactive bladder (OAB) symptoms, including urgency, frequency, incontinence, voiding symptoms of dysuria, large postvoid residual volume, and retention. In elderly patients with severe CNS disease the OAB symptoms are usually difficult to adequately relieve by medical treatment, and thus, their quality of life is greatly. Botulinum toxin A (BoNT-A) is currently licensed and has been applied in patients with idiopathic and neurogenic OAB due to spinal cord injury or multiple sclerosis. However, the application of BoNT-A in the treatment of urinary incontinence due to NLUTD in chronic CNS lesions has not been well-documented. Although cohort studies and case series support BoNT-A treatment for neurogenic OAB, chronic urine retention after intravesical BoNT-A injection for OAB and exacerbated urinary incontinence after urethral BoNT-A injection for voiding dysfunction have greatly limited its application among patients with NLUTD due to CNS lesions. This article reviews the pathophysiology and clinical characteristics of NLUTD in patients with CNS lesions and the clinical effects and adverse events of BoNT-A injection for patients with NLUTD. A flowchart was created to outline the patient selection and treatment strategy for neurogenic OAB.

Early investigational agents for the treatment of benign prostatic hyperplasia'

INTRODUCTION

Benign prostatic hyperplasia (BPH), as a clinical entity that affects many people, has always been in the forefront of interest among researchers, pharmaceutical companies, and physicians. Patients with BPH exhibit a diverse range of symptoms, while current treatment options can occasionally cause adverse events. All the aforementioned have led to an increased demand for more effective treatment options.

AREAS COVERED

This review summarizes the outcomes of new medications used in a pre-clinical and clinical setting for the management of male lower urinary tract symptoms (LUTS)/BPH and provides information about ongoing trials and future directions in the management of this condition. More specifically, sheds light upon drug categories, such as reductase‑adrenoceptor antagonists, drugs interfering with the nitric oxide (NO)/cyclic guanosine monophosphate (GMP) signaling pathway, onabotulinumtoxinA, vitamin D3 (calcitriol) analogues, selective cannabinoid (CB) receptor agonists, talaporfin sodium, inhibitor of transforming growth factor beta 1 (TGF-β1), drugs targeting the hormonal control of the prostate, phytotherapy, and many more.

EXPERT OPINION

Clinical trials are being conducted on a number of new medications that may emerge as effective therapeutic alternatives in the coming years.

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.

A state-of-art review on the preservation of sexual function among various minimally invasive surgical treatments for benign prostatic hyperplasia: Impact on erectile and ejaculatory domains

There is a strong association between benign prostatic hyperplasia (BPH)/lower urinary tract symptoms (LUTS) and sexual dysfunction. While transurethral resection of the prostate (TURP) is considered the standard BPH treatment, it is however associated with a high rate of erectile and ejaculatory dysfunctions. Over the past decade, new and novel minimally invasive BPH therapies have been shown to improve various parameters of voiding domains while minimizing adverse sexual effects. These minimally invasive BPH therapies can be largely be divided into those with cavitating technology (Rezum, Histotripsy, Aquablation), intra-prostatic injections (Botulinum neurotoxin Type A, Fexapotide Triflutate, prostate specific antigen-activated protoxin PRX-302), and mechanical devices which include intraprostatic stents (Urospinal 2™, Memotherm™, Memokath™, and Allium triangular prostatic stent™) and intraprostatic devices (iTIND™, Urolift™), as well as prostatic artery embolization. Published literature on these technologies showed reasonable preservation of erectile function with limited data reported on ejaculatory domain. Further validation of the performance of these novel minimally invasive treatment options for LUTS due to BPH in well-designed and multi-centre studies are desired, to evaluate their role (or lack of such a role) in clinical practice and whether these BPH therapies can provide equivalent standard or better than TURP.

Use of Botulinum Toxin in the Genitourinary System

Botulinum toxin injection has been widely accepted by the urology and urogynecology medical communities as a safe and effective treatment for refractory urinary incontinence. There are two approved genitourinary indications for botulinum toxin. OnabotulinumtoxinA (onaBoNTA) 200 U for the treatment of urinary incontinence due to detrusor overactivity associated with a neurologic condition (e.g., spinal cord injury, multiple sclerosis) in adults who have an inadequate response to or are intolerant of an anticholinergic medication. In addition, onaBoNTA 100 U is used for the treatment of overactive bladder with symptoms of urinary incontinence, urgency, and frequency, in adult patients who have an inadequate response to or are intolerant of an anticholinergic medication. We will discuss the application of botulinum toxin for genitourinary indications with a focus on bladder injection and on potential use of BoNT use in the prostate and pelvic floor.

Mechanism of Action of Botulinum Toxin A in Treatment of Functional Urological Disorders

Intravesical botulinum toxin (BoNT) injection is effective in reducing urgency and urinary incontinence. It temporarily inhibits the detrusor muscle contraction by blocking the release of acetylcholine (Ach) from the preganglionic and postganglionic nerves in the efferent nerves. BoNT-A also blocks ATP release from purinergic efferent nerves in the detrusor muscle. In afferent nerves, BoNT-A injection markedly reduces the urothelial ATP release and increases nitric oxide (NO) release from the urothelium. BoNT-A injection in the urethra or bladder has been developed in the past few decades as the treatment method for detrusor sphincter dyssyndergia, incontinence due to neurogenic or idiopathic detrusor overactivity, sensory disorders, including bladder hypersensitivity, overactive bladder, and interstitial cystitis/chronic pelvic pain syndrome. Although the FDA only approved BoNT-A injection treatment for neurogenic detrusor overactivity and for refractory overactive bladder, emerging clinical trials have demonstrated the benefits of BoNT-A treatment in functional urological disorders. Cautious selection of patients and urodynamic evaluation for confirmation of diagnosis are crucial to maximize the successful outcomes of BoNT-A treatment.

Can Botulinum Toxin A Still Have a Role in Treatment of Lower Urinary Tract Symptoms/Benign Prostatic Hyperplasia Through Inhibition of Chronic Prostatic Inflammation?

Patients with benign prostatic hyperplasia (BPH) can exhibit various lower urinary tract symptoms (LUTS) owing to bladder outlet obstruction (BOO), prostatic inflammation, and bladder response to BOO. The pathogenesis of BPH involves an imbalance of internal hormones and chronic prostatic inflammation, possibly triggered by prostatic infection, autoimmune responses, neurogenic inflammation, oxidative stress, and autonomic dysfunction. Botulinum toxin A (BoNT-A) is well recognized for its ability to block acetylcholine release at the neuromuscular junction by cleaving synaptosomal-associated proteins. Although current large clinical trials have shown no clinical benefits of BoNT-A for the management of LUTS due to BPH, BoNT-A has demonstrated beneficial effects in certain subsets of BPH patients with LUTS, especially in males with concomitant chronic prostatitis/chronic pelvic pain syndrome and smaller prostate. We conducted a review of published literature in Pubmed, using Botulinum toxin, BPH, BOO, inflammation, LUTS, and prostatitis as the key words. This article reviewed the mechanisms of BPH pathogenesis and anti-inflammatory effects of BoNT-A. The results suggested that to achieve effectiveness, the treatment of BPH with BoNT-A should be tailored according to more detailed clinical information and reliable biomarkers.

Outcome of Botulinum Toxin-A intraprostatic injection for benign prostatic hyperplasia induced lower urinary tract symptoms: A prospective multicenter study

INTRODUCTION

Our aim was to determine the factors predicting the outcome of intraprostatic injection of Botulinum Toxin-A (BTX-A) in the treatment of benign prostatic hyperplasia (BPH)-induced lower urinary tract symptoms (LUTS) and to evaluate its efficacy and safety.

METHODS

Between September 2016 and May 2018, 45 Egyptian patients, with BPH-induced LUTS were included; the indication was a failure of medical treatment, unfit, or refusing surgical intervention. Measurements of prostate size by TRUS, total PSA level before and 12 weeks after injection. IPSS, uroflow, and postvoiding residual urine (PVR) were measured before injection, 2, 4, 8 and 12 weeks postinjection. 100 U BTX-A vial was diluted with 10 mL of saline then injected into the transition zone at base and midzone of the prostate by TRUS.

RESULTS

The mean patients' age was 64.4 ± 6.6 years. Mean baseline IPSS 24.06 decreased to 18.75 at 2 weeks and progressively decreased to 16.37 at 12 weeks (P < 0.001), Q _max of 9.08 mL/s. increased to 10.44 at 2 weeks and 11.44 at 12 weeks (P < 0.001), mean prostate volume was 67.44cc; decreased to 66.06cc (P < 0.001) at 12 weeks and mean residual urine was 82.62 mL and decreased to 57.66 mL at 12 weeks.

DISCUSSION

Intraprostatic injection of BTX-A as modality treatment of LUTS/BPH significantly improve IPSS, Q _max , PVR, and decrease prostate volume. We can suspect better results with this line of treatment in patients with IPSS ≤ 22 and Q _max  ≤ 10 mL/min and prostate volume ≤ 56.5cc.

[Use of botulinum toxin A in pelvic floor dysfunctions in the elderly: A review]

INTRODUCTION

The present article is the final report of a multi-disciplinary meeting supported by the GRAPPPA (group for research applied to pelvic floor dysfunctions in the elderly). The objective was to conduct a comprehensive review on the role of botulinum toxin A (BonTA) in the treatment of pelvic floor dysfunctions in the elderly.

METHODS

The present article, written as a comprehensive review of the literature, combines data issued from the scientific literature with expert's opinions. Review of the literature was performed using the online bibliographic database MedLine (National Library of Medicine). Regarding intra-detrusor BonTA injections, only articles focusing on elderly patients (>65 yo) were included. Regarding other localizations, given the limited number of data, all articles reporting outcomes of BonTA were included, regardless of studies population age. In case of missing or insufficient data, expert's opinions were formulated.

RESULTS

Although, available data are lacking in this specific population, it appears that BonTA could be used in the non-fraily elderly patients to treat overactive bladder or even neurogenic detrusor overactivity, with a success rate comparable to younger population at 3 months (88.9% vs. 91.2%), 6 months (49.4% vs. 52.1%) and 12 months (23.1% vs. 22.3%), as well as a significant decrease in number of voids per day (11.4 vs. 5.29 P<0.001) and in the number of pads per day (4.0 vs. 1.3, P<0.01). Furthermore, BonTA is likely to be offered in the future as a treatment of fecal incontinence and obstructed defecation syndrome symptoms. Concerning bladder outlet obstruction/voiding dysfunction symptoms, intra-urethral sphincter BonTA should not be recommended.

CONCLUSION

BonTA injections are of interest in the management of various pelvic floor dysfunctions in the elderly, and its various applications should be better evaluated in this specific population in order to further determine its safety and efficacy.

Intraprostatic injections for lower urinary tract symptoms/benign prostatic enlargement treatment

INTRODUCTION

Endoscopic surgical treatment represents the gold standard in patients with lower urinary tract symptoms (LUTS) when medical treatment fails. In the past years there has been a growing interest in intraprostatic injections which represent a minimally invasive alternative for those patients not suitable for surgery. Aim of our study is to systematically review all the available data on intraprostatic injections for the treatment of LUTS patients with benign prostatic enlargement (BPE).

EVIDENCE ACQUISITION

A systematic review of the literature using the Medline, Scopus and Web of Science databases for relevant articles published until June 2018 was performed using both the Medical Subjects Heading and free test protocols. The MeSH search was conducted by combining the following terms: "Intraprostatic Injections," "Botulinum Toxin A," "Onabotulinum," "Ethanol," "Lower Urinary tract Symptoms," "Benign prostatic enlargement," "Benign Prostatic Hyperplasia," "NX1207," "PRX302." Each article's title and abstract were reviewed for their appropriateness and their relevance with regards to the relationship to intraprostatic injections.

EVIDENCE SYNTHESIS

Intraprostatic injections for the treatment of LUTS/BPE patients may be performed using different products as: ethanol, onabotulinum toxin A, NX1207 and PRX 302. Ethanol, the first agent for intraprostatic use, showed promising results in prospective trials, however, the rare but serious adverse events associated with extraprostatic diffusion of ethanol stopped its use. Many studies on onabotulinum toxin A (BotoxR) have been performed, however, two large randomized clinical trials showed no differences in terms of symptoms improvements and flow improvements when compared to placebo. Two new promising drugs NX 1207 and PRX 302 have been developped in the past years. NX 1207 showed lack of efficacy in the two large European phase III RCT. PRX 302 showed promising results in phase I and II studies, however, definitive results from a large phase III randomized controlled trial (RCT) are awaited before drawing any definitive conclusions.

CONCLUSIONS

Intraprostatic injections are still to be considered investigational for the minimally invasive management of LUTS/BPE patients. Emerging data suggest a possible role of new agents in the near future when definitive data of ongoing RCTs will be available.

Novel Applications of OnabotulinumtoxinA in Lower Urinary Tract Dysfunction

OnabotulinumtoxinA (BoNT-A) was first used to treat neurogenic lower urinary tract dysfunction (LUTD) 30 years ago. Recently, application of BoNT-A in LUTD have become more common since the approval of intravesical BoNT-A injection for patients with both overactive bladders (OAB) and neurogenic detrusor overactivity (NDO) by regulatory agencies in many countries. Although unlicensed, BoNT-A has been recommended to treat patients with interstitial cystitis/bladder pain syndrome (IC/BPS) under different guidelines. BoNT-A delivery with liposome-encapsulation and gelation hydrogel intravesical instillation provided a potentially less invasive and more convenient form of application for patients with OAB or IC/BPS. BoNT-A injections into the urethral sphincter for spinal cord injury patients with detrusor-sphincter dyssynergia have been used for a long time. New evidence revealed that it could also be applied to patients with non-neurogenic dysfunctional voiding. Previous studies and meta-analyses suggest that BoNT-A injections for patients with benign prostate hyperplasia do not have a better therapeutic effect than placebo. However, new randomized and placebo-controlled trials revealed intraprostatic BoNT-A injection is superior to placebo in specific patients. A recent trial also showed intraprostatic BoNT-A injection could significantly reduce pain in patients with chronic prostatitis. Both careful selection of patients and prudent use of urodynamic evaluation results to confirm diagnoses are essential for successful outcomes of BoNT-A treatment for LUTD.

Investigational procedures in benign prostatic hypertrophy

PURPOSE OF REVIEW

As benign prostatic hypertrophy (BPH) becomes a more common disease, there has been a dramatic rise in the number of investigational procedures being developed to manage it. We seek to present an overview of the most recently developed treatments and present clinical data related to application wherever available.

RECENT FINDINGS

As a greater number of treatments become available for BPH, improved diagnostic testing could prove beneficial in helping guide patient selection. Efforts are underway to identify serum biomarkers associated with BPH as well as new classifications strategies, specifically with MRI, to determine both the anatomy of BPH as well as its histologic distribution. Outpatient-based procedures for BPH currently being developed include the temporary implantable nitinol device as well as intraprostatic injections such as Botox and PRX302. Aquablation is a novel technique that uses robotically guided high-pressured saline to ablate prostate tissue. Early data suggests noninferiority compared with TURP. Finally, efforts are underway to apply robotics to BPH with the advent of a robotic transurethral platform being designed for prostate enucleation.

SUMMARY

Many new techniques are poised to be introduced to the BPH market over the coming years. The unique risk/benefit profiles as well as associated clinical outcomes of each will need to be studied in detail in order to help identify proper roles in the management of patients with symptomatic disease.

Botulinum toxin and benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is a clinical condition where lower urinary tract symptoms are caused by both a physically obstructing prostate as well as tight smooth muscles around the bladder outlet. Treatment of this condition with botulinum toxin has been used since 2003, but this interest has somewhat died down after two large randomized controlled trials (RCTs) showing equivalence of results between their treatment and placebo arms. However, with review of animal studies and unexplained exaggerated effect of the placebo arms of the two RCTs, together with recent data of sustained benefits after 18 months of treatment, the place of botulinum toxin in the BPH field is probably still present.

Botulinum toxin in the treatment of overactive bladder

Clinical effectiveness of botulinum toxin (BTX) in the treatment of both neurogenic and idiopathic detrusor overactivity has been demonstrated in several studies. However, different protocols and techniques have been used by authors.

Methods.

Literature review on intradetrusor injection of BTX for detrusor overactivity.

Results.

The greatest clinical experience reports the use of 200 and 300 U Botox®. Available data suggest that clinical efficacy, duration, and the side effect profile is similar at these doses. Very few data, on the other hand, are available regarding the clinical outcomes using the Dysport® preparation; isolated reports support that efficacy is similar when using a dosing range of 500 to 1000 SU with increased risk of systemic side effects using 1000 SU. A variety of injection volumes was used, demonstrating similar efficacy and tolerability profile. Clinical effect duration extends six to ten months in the majority of studies. Data suggest that a repeated injection scheme proves successful in the vast majority of initial responders.

Conclusions.

Safety, effectiveness, specificity and reversibility make BTX a new attractive treatment modality for overactive bladder syndrome. However, more experience is needed to standardize the injection protocol with respect to therapeutic outcomes and adverse effects.

Minimally invasive surgical therapies for benign prostatic hypertrophy: The rise in minimally invasive surgical therapies

The prevalence of benign prostatic hypertrophy (BPH) causing bothersome lower urinary tract symptoms increases with our ageing population. Treatment of BPH traditionally begins with medical therapy and surgical intervention is then considered for those whose symptoms progress despite treatment. Minimally invasive surgical therapies have been developed as an intermediary in the treatment of BPH with the aim of decreasing the invasiveness of interventions. These therapies also aim to reduce morbidity and dysfunction related to invasive surgical procedures. Multiple treatment options exist in this group including mechanical and thermo-ablative strategies. Emerging therapies utilizing differing technologies range from the established to the experimental. We review the current literature related to these minimally invasive therapies and the evidence of their effectiveness in treating BPH. The role of minimally invasive surgical therapies in the treatment of BPH is still yet to be strongly defined. Given the experimental nature of many of the modalities, further study is required prior to their recommendation as alternatives to invasive surgical therapy. More mature evidence is required for the analysis of durability of effect of these therapies to make robust conclusions of their effectiveness.

A Relevant Midterm (12 Months) Placebo Effect on Lower Urinary Tract Symptoms and Maximum Flow Rate in Male Lower Urinary Tract Symptom and Benign Prostatic Hyperplasia-A Meta-analysis

OBJECTIVE

To assess the mid- to long-term placebo effect of the medical and instrumental management of male lower urinary tract symptoms. This is generally a long-term treatment strategy. Therefore, knowledge on the mid- to long-term placebo effect is of considerable interest. The paucity of data on this topic prompted us to investigate this issue in a meta-analysis.

METHODS

All randomized controlled trials (RCTs) with the indication of benign prostatic hyperplasia and lower urinary tract symptoms containing a placebo- or sham treatment arm and with a follow-up of 12 months were eligible. The 12-month effect of placebo or sham treatment on the International Prostate Symptom Score (the quality-of-life question was not analyzed herein) and the American Urological Association Symptom Score and on the maximum flow rate was quantified.

RESULTS

A total of 25 RCTs with 10.587 patients were eligible. Twenty-three studies were placebo controlled (plant extracts: n = 4, 5α-reductase inhibitors [5ARIs]: n = 9, α-blocker: n = 5, combination therapy of 5ARI and α-blocker: n = 3, and intraprostatic botulinum toxin A injection: n = 2), and 2 RCTs with transurethral microwave thermotherapy (TUMT) had a sham treatment arm. At 12 months, the mean International Prostate Symptom Score improved by a mean of 4.4 points under placebo or sham treatment with a range of 0.7-6.8 points: plant extracts, -3.6; 5ARI, -3.4; α-blocker, -4.3; combination therapy, -4.3; botulinum toxin A, -3.9; and TUMT, -6.8. The mean maximum flow rate improvement at 12 months under placebo or sham was not relevant (+0.8 mL/s), yet there were remarkable differences between trials: plant extracts, -0.3 mL/s; 5ARI, +0.8 mL/s; α-blocker, +1.1 mL/s; combination therapy, +1.4 mL/s; and TUMT, +1.0 mL/s.

CONCLUSION

This meta-analysis demonstrates the mid-term placebo effect on lower urinary tract function, particularly concerning subjective improvement. The degree of the placebo effect varies considerable between studies even at 12 months.

Use of botulinum toxin for voiding dysfunction

The use of botulinum toxin A (BoNT-A) has expanded across a range of lower urinary tract conditions. This review provides an overview of the current indications for BoNT-A in the lower urinary tract and critically evaluates the published evidence within each area. The classic application of BoNT-A has been in the management of refractory neurogenic detrusor overactivity (NDO) and overactive bladder (OAB). There is a large volume of high-quality evidence, including numerous randomized placebo-controlled trials, which demonstrate the efficacy of BoNT-A over a long follow-up period. The culmination of this robust evidence-base has led to onabotulinumtoxin A (onaBoNT-A) receiving regulatory approval as a second-line treatment for NDO at a dose of 200 U and OAB at dose of 100 U. Other applications for BoNT-A are used on an off-license basis and include interstitial cystitis/bladder pain syndrome (IC/BPS), benign prostatic hyperplasia (BPH), and detrusor sphincter dyssynergia (DSD). These applications are associated with a less mature evidence-base although the literature is rapidly evolving. At present, the results for painful bladder syndrome (PBS) are promising and BoNT-A injections are recommended as a fourth line option in recent international guidelines, although larger randomized study with longer follow-up are required to confirm the initial findings. As a treatment for DSD, BoNT-A injections have shown potential but only in a small number of trials of limited quality. No definite recommendation can be made based on the current evidence. Finally, the results for the treatment of BPH have been variable and recent high quality randomized controlled trials (RCTs) have suggested no benefit over placebo so at present it cannot be recommended for routine clinical practice. Future advances of BoNT-A include liposome encapsulated formulations which are being developed as an alternative to intravesical injections.

[What role does botulinum toxin play in the treatment of benign prostatic hyperplasia?]

La toxine botulique (TB) a fait son apparition en urologie dans le champ de la neuro-urologie comme traitement de la dyssynergie vésico-sphinctérienne et de l'incontinence par hyperactivité détrusorienne neurogène. Son action est maintenant clairement démontrée et constitue désormais un traitement largement utilisé dans l'hyperactivité vésicale neurogène. La toxine botulique peut-elle constituer un traitement efficace de l'hyperplasie bénigne de prostate (HBP)? L’injection intraprostatique de TB a récemment été étudiée dans le traitement de l’HBP. Elle semble permettre une amélioration importante des symptômes urinaires sans effets secondaires significatifs et pourrait donc représenter une alternative mini-invasive intéressante aux traitements classiques de l’HBP. Les avantages de son utilisation sont la simplicité de sa mise en oeuvre, l'absence d'effets secondaires rapportés et sa durée d'action prolongée. Des études soigneusement menées, prospectives, contrôlées portant sur des effectifs plus grands sont désormais nécessaires pour confirmer ces premiers résultats. Nous proposons a à travers ce travail une exposition des connaissances actuelles des mécanismes d’action de la TB au niveau prostatique et les résultats des principales études cliniques dans l’HBP.

[Minimally invasive treatment of benign prostatic hyperplasia]

Novel minimally invasive treatment options for the management of male lower urinary tract symptoms (LUTS) due to bladder outlet obstruction (BOO) aim to provide equal efficacy compared to standard techniques with a more favourable safety profile. The preservation of all aspects of male sexual function including antegrade ejaculation is increasingly important to patients. It should be ideally performed in an outpatient setting under local anesthesia to assure a short recovery time. Novel injectables for intraprostatic application (botulinum neurotoxin A, NX-1207, PRX302) have emerged and first phase III results could not confirm the promising initial data. For mechanical devices like Urolift® the early and mid-term benefits demonstrate a rapid and durable symptom relief without compromising sexual function. Novel innovative procedures like aquablation (AquaBeam®) are entering the scene, but their feasibility, efficacy and safety still need to be addressed in randomized controlled trials.

Effect of Onabotulinum Toxin A on Substance P and Receptor Neurokinin 1 in the Rat Ventral Prostate

INTRODUCTION

The objective of this work is to examine if sensory innervation impacts lower urinary tract symptoms (LUTS). Onabotulinum toxin A (BoNTA) has been used for the treatment of overactive and neurogenic bladder and as a treatment for LUTS secondary to benign prostatic hyperplasia (BPH). The mechanism of how BoNTA impacts LUTS/BPH is unclear. In rats, BoNTA injection causes prostate denervation, apoptosis and atrophy. In clinical trials reduced prostate size and LUTS are observed inconsistently, suggesting a neurologic component. We will examine if BoNTA treatment inhibits substance P production in sensory nerve fibers in the rat prostate.

METHODS

Twenty Sprague Dawley rats were divided into four groups including 1X PBS (control, n=6), 2.5 units Onabotulinum toxin A (BoNTA, n=6), 5 units BoNTA (n=6) injected into both lobes of the ventral prostate (VP) and sham surgery (n=2). Rats were Euthanized after one week. Substance P and its receptor neurokinin 1 localization and quantification were performed by counting the number of stained neurons and nerve bundles, by semi-quantitative immunohistochemical analysis and by western analysis.

RESULTS

Substance P was localized in neuronal axons and bundles in the stroma of the VP but not in the epithelium. Receptor neurokinin 1 was identified in neuronal bundles of the stroma and in columnar epithelium of the VP ducts. Substance P decreased ~90% after BoNTA treatment (p=0.0001) while receptor neurokinin 1 did not change by IHC (p=0.213) or Western (p=0.3675).

CONCLUSIONS

BoNTA treatment decreases substance P in the rat VP.

Intraprostatic Botulinum Neurotoxin Type A Injection for Benign Prostatic Hyperplasia-A Spotlight in Reality

Botulinum toxin is a neurotoxin produced by the bacterium Clostridium botulinum. It inhibits the release of acetylcholine and other neurotransmitters from the nerve terminal. Botulinum toxin, specifically toxin type A (BoNT-A) has been used since the 1970s to reduce the muscular hypercontraction disorders. The application of BoNT-A in urology field started from intra-bladder injection for overactive bladder, which has been recognized as third line therapy in many countries. Since prostate gland as well as bladder is under the influence of autonomic innervation, theorectically, injection of BoNT-A into the prostate induces chemo-denervation and modulation of prostate function, and reduces lower urinary tract symptoms (LUTS). This article reviews the application of BoNT-A in patients with LUTS/ benign prostatic hyperplasia (BPH) from mechanisms of action to clinical results. BoNT-A has been shown to induce prostate apoptosis, downregulation of alpha 1A receptors, and reduce contractile function of prostate in animal studies. Open studies of intraprostate BoNT-A injection have demonstrated promising results of reducing LUTS and improvement of voiding function in human LUTS/BPH, however, intraprostatic BoNT-A injection did not perform better than the placebo group in recent publications of placebo controlled studies. We suggested that BoNT-A prostate injection might benefit selected population of BPH/LUTS, but it is unlikely to be an effective therapy for general population of male LUTS/BPH.

Placebo Medication and Sham Surgery Responses in Benign Prostatic Hyperplasia Treatments: Implications for Clinical Trials

Placebo medications and sham surgeries have long been thought to be inert treatments. These groups served as a threshold to which an active treatment should be compared in a randomized trial to determine the true efficacy of the active treatment. However, surprising changes in subjective symptom scores and objective measures of voiding have been demonstrated in numerous placebo medication or sham surgery arms of trials. The exact mechanisms by which these inactive treatments augment patient outcomes are not clearly defined and multiple theories have been proposed to explain the often pronounced response. It appears that urologic outcomes are particularly prone to these effects and the astute physician should keep these responses in mind when interpreting any trial on a new therapy.

Use of Botulinum Toxin A in the Treatment of Lower Urinary Tract Disorders: A Review of the Literature

Botulinum neurotoxin (BoNT) is used to treat a variety of ailments, and its therapeutic application in lower urinary tract disorders (LUTDs) is well studied. Robust evidence supporting the efficacy and tolerability of BoNT in the treatment of neurogenic detrusor overactivity (NDO) and non-neurogenic overactive bladder (OAB) has led to regulatory approval for these conditions. Use of BoNT in the treatment of interstitial cystitis/bladder pain syndrome, chronic pelvic pain, and detrusor sphincter dyssynergia has demonstrated some promise, but is still evolving and off-label for these indications. Trials to date do not support the use of BoNT for benign prostatic hyperplasia. This comprehensive review outlines the mechanisms of BoNT in the treatment of LUTDs in adults and presents background and updated data examining the efficacy and adverse events associated with the use of BoNT in common urologic applications.

Use of Botulinum Toxin in Urologic Diseases

OnabotulinumtoxinA (onaBoNTA) is approved by the US Food and Drug Administration for the treatment of urinary incontinence due to neurogenic detrusor overactivity and for the treatment of refractory overactive bladder. As a treatment for benign prostatic hyperplasia, onaBoNTA showed no difference over placebo in recently published studies. In contrast, treating interstitial cystitis/bladder pain syndrome with onaBoNTA has shown efficacy, and the current American Urological Association guideline for the diagnosis and treatment of interstitial cystitis/bladder pain syndrome lists onaBoNTA as fourth-line treatment. This comprehensive review will present all studied applications of onaBoNTA within the lower urinary tract.

Efficacy and safety of botulinum toxin injection for benign prostatic hyperplasia: a systematic review and meta-analysis

PURPOSE

The aim of this study was to overcome the limitation of overlooking the placebo effect in previous studies and to demonstrate the overall treatment efficacy and safety of botulinum toxin type A (BTX-A) compared with placebo.

METHODS

We conducted a systematic review and meta-analysis of the published literature in PubMed, Cochrane Library, and Embase reporting on BTX use in lower urinary tract symptoms (LUTS)/benign prostate hyperplasia (BPH). Single-group analysis for the placebo effect and meta-regression analysis for the moderator effect were performed with high-quality RCTs compared with placebo.

RESULTS

A total of three studies were included, with a total sample size of 522 subjects (260 subjects in the experimental group and 262 subjects in the control group). Study duration ranged from 8 to 24 weeks. The pooled overall SMD in the mean change in IPSS for the BTX-A group versus the placebo group was -1.02 (95 % CI -1.97, -0.07). The other outcomes (Q max, prostate volume, and post-voided residual volume) were not statistically different between the two groups. The placebo effect in single-group analysis ranged from 0 to 27.9 % for IPSS, and from -1.1 to 28.7 % for Q max (lowest to highest, respectively).

CONCLUSIONS

This evidence-based systematic review and meta-analysis of the BTX-A injection for LUTS/BPH showed no differences in efficacy compared with placebo and also showed no difference in procedure-related adverse events occurred. Thus, the results of this study do not provide evidence of clinical benefits of using the BTX-A injection for LUTS/BPH in real clinical practice.

Botulinum neurotoxin: Progress in negating its neurotoxicity; and in extending its therapeutic utility via molecular engineering. MiniReview

While the poisonous effects of botulinum neurotoxin (BoNT) have been recognized since antiquity, the overall actions and mechanisms of effects of BoNT have been elucidated primarily over the past several decades. The general utility of BoNT is described in the paper, but the focus is mainly on the approaches towards negating the toxic effects of BoNT, and on the projection of an engineered BoNT molecule serving as a Trojan Horse to deliver a therapeutic load for treatment of a host of medical disorders. The BoNT molecule is configured with a binding domain, a zinc-dependent protease with specificity primarily for vesicular proteins, and a translocation domain for delivery of the metalloprotease into the cytoplasm. The anti-toxin approaches for BoNT include the use of vaccines, antibodies, block of BoNT binding or translocation, inhibition of metalloprotease activity, impeded translocation of the protease/catalytic domain, and inhibition of the downstream Src signaling pathway. Projections of BoNT as a therapeutic include its targeting to non-cholinergic nerves, also targeting to non-neuronal cells for treatment of hypersecretory disorders (e.g., cystic fibrosis), and treatment of hormonal disorders (e.g., acromegaly). Still in the exploratory phase, there is the expectation of major advances in BoNT neuroprotective strategies and burgeoning utility of engineered BoNTs as therapeutics.

Current and potential urological applications of botulinum toxin A

Botulinum toxin subtype A (BoNT-A) is a potent neurotoxin that can selectively modulate neurotransmitter release from nerve endings, resulting in muscular paralysis. BoNT-A might also act on sensory nerves, and have an anti-inflammatory effect. In the first urological use of BoNT-A, injection into the urethral sphincters of patients with detrusor-sphincter dyssynergia resulted in a reduction of urethral resistance and improved voiding efficiency. Subsequently, intravesical BoNT-A injections have received regulatory approval for treatment of neurogenic detrusor overactivity owing to spinal cord lesions or multiple sclerosis, and idiopathic overactive bladder in adults. BoNT-A has also been widely used to treat patients with the off-label indications of neurogenic or non-neurogenic voiding dysfunction and male lower urinary tract symptoms owing to BPH and bladder-neck dysfunction. Other indications for which urologists have applied BoNT-A injections include interstitial cystitis/bladder pain syndrome, bladder oversensitivity and chronic pelvic pain syndrome. BoNT-A is currently delivered as an intravesical injection; however, use of liposome encapsulated formulations is also beginning to show some therapeutic potential.

Use of botulinum toxin for genitourinary conditions: What is the evidence?

Botulinum toxin A is licensed for the treatment of urinary incontinence due to neurogenic detrusor overactivity (NDO) and overactive bladder (OAB). Only onabotulinumtoxinA has at this moment such approval, in NDO at a dose of 200 U and in OAB at a dose of 100 U. Regulatory phase 3 trials have been carried out in both conditions. In NDO it was shown to decrease urinary incontinence, to improve urodynamic parameters and to increase quality of life in multiple sclerosis and spinal cord injured patients. Adverse events included urinary tract infections and necessity of de novo clean intermittent catheterization, which occurred mainly in patients with multiple sclerosis. In OAB patients with urge incontinence, onabotulinumtoxinA decreased urinary incontinence and micturition frequency while improving quality of life. Again, main adverse events were urinary tract infections and transient urinary retentions. Long-term studies in both NDO and OAB demonstrate the efficacy and safety of the treatment. Available phase 3 trials of onabotulinumtoxinA in benign prostatic hyperplasia did not show any relevant efficacy in improving lower urinary tract symptoms.

Intraprostatic injections for lower urinary tract symptoms treatment

PURPOSE OF REVIEW

The purpose of this study is to review and discuss recently published (2013-2014) experimental and clinical studies of intraprostatic injection therapy as an alternative treatment of lower urinary tract symptoms (LUTS).

RECENT FINDINGS

Recent focus has been on intraprostatic injection of botulinum toxin both with regard to mechanism of action and efficacy. In contrast to the promising findings in several previous studies, a recent large, randomized, placebo-controlled trial found no differences between onabotulinumtoxin A treatment and placebo. There is little new information on the use of anhydrous ethanol and agents such as NX-1207 and PRX302, which previously have been reported to have promising effects.

SUMMARY

Intraprostatic injection of different agents as a minimally invasive surgical therapy for LUTS associated with benign prostatic hyperplasia seems attractive and may have a potential as a treatment alternative, but so far, available results are not convincing. Further studies on the mechanisms of action of novel agents, and controlled clinical trials documenting their efficacy and side-effects when injected into the prostate are needed before their place in the treatment of benign prostatic hyperplasia/LUTS can be properly assessed.

New intraprostatic injectables and prostatic urethral lift for male LUTS

Treatment modalities for male lower urinary tract symptoms (LUTS) comprise a broad spectrum of medical and surgical options. Interest is growing in minimally invasive treatment options, which should ideally be performed in an outpatient setting and have a short recovery time, durable efficacy and a good safety profile. The preservation of all aspects of sexual function, including antegrade ejaculation, seems to be increasingly important for patients. Initial experimental data on new minimally invasive procedures-such as the intraprostatic injection of novel agents including botulinum neurotoxin A (BoNT-A), NX-1207 and PRX302-were promising, but clinical trials have not confirmed the findings. Trials of the mechanical prostatic urethral lift device-Urolift(®) (Neotract, Inc., USA)-have been positive, but further long-term results are needed to confirm its beneficial effects.

Clinically and Statistically Significant Changes Seen in Sham Surgery Arms of Randomized, Controlled Benign Prostatic Hyperplasia Surgery Trials

PURPOSE

Medication trials frequently involve a placebo arm to more fairly assess the efficacy of the study drug. However, benign prostatic hyperplasia surgery trials rarely include a sham surgery group due to the inherent risks associated with simulating treatment in these patients. As a result the placebo response to sham surgery for benign prostatic hyperplasia is largely unknown.

MATERIALS AND METHODS

We systematically reviewed the available literature to look for randomized, controlled trials involving endoscopic or intraprostatic injection benign prostatic hyperplasia treatments that included a sham surgical arm from January 1990 to February 2015. Studies that included an objective symptom questionnaire and maximum urinary flow at 3 months were included. Results were analyzed together with weighting based on study sample size.

RESULTS

The initial search yielded a total of 1,998 potential studies. After reviewing abstracts and full text articles 14 randomized, controlled trials were included in some part. An average decrease from 22.3 to 16.7 (-27%) was seen in studies of the AUASS (American Urological Association symptom score) 3 months after a sham endoscopic procedure (p=0.0003) with an increase in maximum urinary flow of 1.3 ml per second (14%, p=0.001) at 3 months. Prostate injection based studies at 3 months were similar with a decrease from 21.3 to 15.7 (-26%, p<0.001). Maximum urinary flow increased by 2.0 ml per second (23%, p=0.043).

CONCLUSIONS

Sham controlled endoscopic and injection benign prostatic hyperplasia interventions demonstrate a considerable and statistically significant change in symptom scores and maximum urinary flow, which is comparable to the response seen in medication trials. Future uncontrolled benign prostatic hyperplasia surgical trials should consider these findings when interpreting outcomes.

A synopsis of drugs currently in preclinical and early clinical development for the treatment of benign prostatic hyperplasia

INTRODUCTION

Benign prostatic hyperplasia (BPH) is a common disease among men and significantly impacts quality of life by causing lower urinary tract symptoms (LUTS). Current medical therapies are not always adequate in controlling LUTS or slowing disease progression, and there is unmet need for new effective therapeutic options.

AREAS COVERED

The authors review the standard current medical therapies for BPH which include the use of α-1 blockers, 5-α reductase inhibitors, combination therapy and PDE inhibitors. Following this, the authors then discuss new therapies that are currently undergoing preclinical and clinical investigation.

EXPERT OPINION

Existing preclinical and clinical trials have highlighted many promising therapies to treat BPH. Further investigation with larger clinical trials is needed to establish these drugs as standard therapies. As the number of drugs in the arsenal against BPH continues to grow, providers and patients will have to engage in a discussion that weighs the risks and benefits of each therapy.

Lower urinary tract symptoms in men

Benign prostatic hyperplasia (BPH) is a highly prevalent and costly condition that affects older men worldwide. Many affected men develop lower urinary tract symptoms, which can have a negative impact on their quality of life. In the past, transurethral resection of the prostate (TURP) was the mainstay of treatment. However, several efficacious drug treatments have been developed, which have transformed BPH from an acute surgical entity to a chronic medical condition. Specifically, multiple clinical trials have shown that α adrenoceptor antagonists can significantly ameliorate lower urinary tract symptoms. Moreover, 5α reductase inhibitors, alone or combined with an α adrenoceptor antagonist, can reverse the natural course of BPH, reducing the risk of urinary retention and the need for surgical intervention. Newer medical regimens including the use of antimuscarinic agents or phosphodiesterase type 5 inhibitors, have shown promise in men with predominantly storage symptoms and concomitant erectile dysfunction, respectively. For men who do not adequately respond to conservative measures or pharmacotherapy, minimally invasive surgical techniques (such as transurethral needle ablation, microwave thermotherapy, and prostatic urethral lift) may be of benefit, although they lack the durability of TURP. A variety of laser procedures have also been introduced, whose improved hemostatic properties abrogate many of the complications associated with traditional surgery.

The Minimally Invasive Treatments for Benign Prostrate Hyperplasia

The prevalence of benign prostatic hyperplasia (BPH) increases with age, affecting more than 50% of men above the age of 50 to varying degrees. As it enlarges, it compresses onto the urethra causing bladder outlet obstruction. This can cause a spectrum of problems ranging from irritative and obstructive lower urinary tract symptoms (LUTS) to retention of urine with obstructive uropathy. Transurethral resection of prostate (TURP) is the standard for surgical intervention, however with the advent of an ageing population, there is an increasing number of patients who have ischaemic heart disease who require long-term anticoagulation and have multiple co-morbidities that put them at an increased risk of general anaesthesia. This review aims to critically appraise the effectiveness and evidence for use of these minimally invasive techniques.

Both PubMed and Ovid were used to search for randomised control trials (RCT) comparing the various minimally invasive techniques against TURP. In cases where there were no RCTs, the results of the respective trial were compiled. This was later compiled in a summary table.

An effective minimally invasive treatment modality will play a complimentary role to TURP which remains the standard of surgical treatment for BPH. Technologies progressing towards rapid re-creation of prostatic channel, minimal blood loss and non-urethral instrumentation will bridge the divide between pharmacotherapy and surgery.

An updated systematic review and statistical comparison of standardised mean outcomes for the use of botulinum toxin in the management of lower urinary tract disorders

CONTEXT

Botulinum toxin A (BoNTA) has received regulatory approval for use in neurogenic detrusor overactivity (NDO) and overactive bladder (OAB), but it remains unlicensed in other lower urinary tract symptoms (LUTS) indications such as nonneurogenic LUTS in men with benign prostatic enlargement (LUTS/BPE), bladder pain syndrome (BPS), and detrusor sphincter dyssynergia (DSD).

OBJECTIVE

To compare statistically the outcomes of high level of evidence (LE) studies with placebo using BoNTA for LUTS indications; NDO, OAB, LUTS/BPE, BPS and DSD.

EVIDENCE ACQUISITION

We conducted a systematic review of the published literature on PubMed, Scopus, and Embase reporting on BoNTA use in LUTS dysfunction. Statistical comparison was made between high LE studies with placebo and low LE studies.

EVIDENCE SYNTHESIS

In adult NDO, there are significantly greater improvements with BoNTA in daily incontinence and catheterisation episodes (-63% and -18%, respectively; p<0.01), and the urodynamic parameters of maximum cystometric capacity (MCC), reflex volume, and maximum detrusor pressure (MDP) (68%, 61%, and -42%, respectively; all p<0.01). In OAB, BoNTA leads to significant improvements in bladder diary parameters such as daily frequency (-29%), daily urgency (-38%), and daily incontinence (-59%) (all p<0.02). The urodynamic parameters of MCC and MDP improved by 58% (p=0.04) and -29% (p=0.002), respectively. The risk of urinary tract infection was significantly increased from placebo at 21% versus 7% (p<0.001), respectively; the risk of intermittent self-catherisation increased from 0% to 12% (p<0.001). Men with LUTS/BPE showed no significant improvements in International Prostate Symptom Score, maximum flow rate, or prostate volume. There were insufficient data for statistical analysis in DSD, BPS, and paediatric studies. Low LE studies were found to overestimate the effects of BoNTA in all indications, but differences from high LE studies were significant in only a few parameters.

CONCLUSIONS

BoNTA significantly improves all symptoms and urodynamic parameters in NDO and OAB. The effect of BoNTA in treating LUTS dysfunction appears to be overestimated in lower as opposed to higher LE studies.

[New treatment strategies for male lower urinary tract symptoms]

For patients with lower urinary tract symptoms (LUTS), α1-adrenoreceptor inhibitors and 5-alpha reductase inhibitors as well as their combination are considered the gold standard. In addition, anticholinergic agents are being introduced as monotherapy or in combination with α1-adrenocepetor inhibitors for patients with predominant storage disorders. Phosphodiesterase 5 (PDE5) inhibitors are often the best option for patients with LUTS who also suffer from erectile dysfunction. Recently, novel treatment options have been presented and intraprostatic injection of various agents, such as botulinum toxin A, NX-1207 and PRX302 has shown promising initial results. In addition, innovative minimally invasive treatment options, such as UroLift® appear to be efficacious and safe in this patient cohort. Particular emphasis should be laid on patients with LUTS and concomitant sexual disorders.