Botulinum toxin type A improves benign prostatic hyperplasia symptoms in patients with small prostates

Using Neuromodulators to Improve Scar Formation, Keloids, Rosacea, and Antiaging

BACKGROUND

Botulinum toxin A (BoNT-A) treatment has many uses in dermatology. Its mechanism of action and long-term effects for scar formation, rosacea, and antiaging are still being investigated.

OBJECTIVE

To conduct a literature review on BoNT-A to further investigate its use in scar formation, rosacea, and antiaging.

METHODS

A literature review was conducted using PubMed on botulinum toxin treatment for scar formation, rosacea, and antiaging. Studies discussing the toxin mechanism of action and treatment algorithm were included. The authors also provided their personal experience in BoNT-A use for these 3 conditions.

RESULTS

The mechanism of action of Botulinum toxin A in improving scar formation, rosacea, and antiaging is now better understood. While it is effective in the short term, little is still known about how frequently treatment needs to be repeated and if there are any long-term effects.

CONCLUSION

While in vitro studies have supporting evidence on the mechanism of action of BoNT-A on scar formation, rosacea, and antiaging, further studies are needed to identify long-term treatment effects.

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

Botulinum toxin A (Botox) had been considered a promising drug that has an effect on functional disorders of the lower urinary tract. Because Botox exhibits anti-inflammatory and antispasmodic effects, Botox injection into the bladder can decrease detrusor contractility, reduce bladder hypersensitivity, and eliminate painful sensations. Injecting Botox into the bladder outlet can relax the hyperactivity of the bladder neck, and of the urethral smooth and striated muscles. Based on these therapeutic effects, Botox has been widely applied to treat lower-urinary-tract dysfunctions (LUTDs) such as overactive bladder and neurogenic detrusor overactivity. However, this treatment has not been licensed for use in other LUTDs such as interstitial cystitis, voiding dysfunction due to benign prostatic hyperplasia in men, and dysfunctional voiding in women. Botox has also not been approved for the treatment of children with overactive bladder and dysfunctional voiding; in patients with spinal cord injuries with detrusor sphincter dyssynergia and autonomic dysreflexia; or for poorly relaxed external sphincter in non-neurogenic patients. This article reviews the current knowledge regarding Botox treatment for LUTDs and discusses the potential clinical applications of Botox, as well as work that can be conducted in the future.

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 survivin-driven, tumor-activatable minicircle system for prostate cancer theranostics

Gene vectors regulated by tumor-specific promoters to express transgenes specifically in cancer cells are an emerging approach for cancer diagnosis and treatment. Minicircles are shortened plasmids stripped of prokaryotic sequences that have potency and safety characteristics beneficial for clinical translation. Previously, we developed minicircles driven by the tumor-specific survivin promoter, which exhibits elevated transcriptional activity in aggressive cancers, to express a secreted reporter for blood-based cancer detection. Here we present the first activatable, cancer theranostic minicircle system featuring a pair of diagnostic and therapeutic minicircles expressing Gaussia luciferase for urine-based cancer detection or cytosine deaminase:uracil phosphoribosyltransferase for gene-directed enzyme prodrug therapy. Diagnostic minicircles revealed urinary reporter output related to cellular survivin levels. Notably, mice with aggressive prostate tumors exhibited significantly higher urine reporter activity than mice with non-aggressive tumors and healthy mice after intratumoral minicircle administration. Therapeutic minicircles displayed specific cytotoxicity in survivin-rich cancer cells and significantly attenuated growth of aggressive orthotopic prostate tumors in mice. Use of these minicircles together creates a theranostic system that can first identify individuals carrying aggressive prostate cancer via a urinary test, followed by stringent control of tumor progression in stratified individuals who carry high-risk prostate lesions.

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.

A Comprehensive Review of the Diagnosis, Treatment, and Management of Urologic Chronic Pelvic Pain Syndrome

PURPOSE OF REVIEW

Urologic chronic pelvic pain syndrome (UCPPS) is a chronic, noncyclic pain condition which can lead to significant patient morbidity and disability. It is defined by pain in the pelvic region, lasting for greater than 3 to 6 months, with no readily identifiable disease process. The aim of this review is to provide a comprehensive update of diagnosis and treatment of UCPPS.

RECENT FINDINGS

UCPPS encompasses chronic pelvic pain syndrome or chronic prostatitis (CP/CPPS) in men and interstitial cystitis or painful bladder syndrome (IC/PBS) in women. Underlying inflammatory, immunologic, and neuropathic components have been implicated in the pathogenesis of UCPPS. For optimal patient management, an individualized and multimodal approach is recommended. Medical management and physical therapy are the mainstays of treatment. Injection therapy may offer additional relief in medically refractory patients. Further minimally invasive management may include spinal cord and peripheral nerve stimulation, though evidence supporting efficacy is limited.

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.

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.

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.

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.

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.

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.

Botulinum Toxin A Injection in the Bladder Neck: A Promising Treatment for Urinary Retention

Secondary to failure of optimal medical therapy and the high morbidity that accompanies surgical techniques in high risk patients, the use of de novo treatments including botulinum toxin A is emerging in the treatment of benign prostatic hyperplasia (BPH). However, the treatment of urinary retention secondary to BPH via injecting botulinum toxin into the bladder neck is not well established in the literature. This case report describes the case of a 75-year-old male patient with a chronic history of obstructive lower urinary tract symptoms (LUTS) and multiple comorbidities who was admitted to the hospital for management of recurrent urinary retention. The patient was not a surgical candidate for transurethral incision of the prostate (TUIP) or transurethral resection of the prostate (TURP). Botulinum toxin injection into the bladder neck was performed with very satisfying results. Botulinum toxin injection in the bladder neck presents a promising minimally invasive, tolerated, and cost-effective approach for the treatment of urinary retention in patients with benign prostatic obstruction who are not candidates for surgery or in whom medical treatment has failed. More research is needed to identify the efficacy of this novel approach.

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.

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.

The effect of botulinum neurotoxin type A on capsule formation around silicone implants: the in vivo and in vitro study

This study confirms that botulinum neurotoxin type A (BoNT-A) decreases capsular contracture and elucidates a possible mechanism. Silicone blocks were implanted subcutaneously in 20 mice. The experimental groups received BoNT-A (1, 2·5 or 5 U) instilled into the subcutaneous pocket. After 30 days, periprosthetic capsules were harvested and evaluated. The effect of BoNT-A on the differentiation of human dermal fibroblasts to myofibroblasts in culture was examined by Western blot analysis. Changes in transforming growth factor-beta1 (TGF-β1) expression in cultured fibroblasts were determined by enzyme-linked immunosorbent assay (ELISA). In in vivo study, the thickness of capsules (P < 0·05) and the number of alpha-smooth muscle actin (α-SMA)(+) cells in capsules (P < 0·05) were significantly decreased in the experimental groups. TGF-β1 was significantly underexpressed in the experimental groups (P < 0·05). In in vitro study, BoNT-A did not significantly affect fibroblast viability. Western blot analysis showed that α-SMA protein levels were significantly decreased in the experimental groups (P < 0·05). Based on ELISA, the amount of TGF-β1 was significantly decreased in the experimental groups (P < 0·05), especially cells treated with a high dose of BoNT-A (P < 0·001). This study confirms that BoNT-A prevents capsular formation around silicone implants, possibly by blocking TGF-β1 signalling and interrupting the differentiation of fibroblasts to myofibroblasts.

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.

[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.

New emerging technologies in benign prostatic hyperplasia

PURPOSE OF REVIEW

Transurethral resection of the prostate has long been held as the gold standard for treatment of benign prostatic hyperplasia (BPH); however, there have been significant innovations in other less invasive alternative treatments for BPH in recent years. Our purpose is to present emerging surgical treatment modalities which have been presented in the last 12 months.

RECENT FINDINGS

We report recent results in different treatment options for BPH. The concept of stenting the urethra has already been introduced nearly 20 years ago in urology and like intraprostatic injection of botulinum toxin it has found application in urological treatment of bladder outlet obstruction. The prostatic urethral lift procedure is a novel surgical minimal invasive approach needing long-term results. Intraprostatic injections with NX-1207 and histotripsy fractionation of prostate tissue are treatment modalities, which are currently under evaluation for a clinical application in humans.

SUMMARY

Anaesthesia-free outpatient capability, lack of sexual side-effects and avoidance of actual surgery are attractive to patient and clinician alike. Some of the presented treatments may establish in clinical practice as a suitable treatment alternative to transurethral resection of the prostate and medical therapy.

Treatment of lower urinary tract symptoms: agents for intraprostatic injection

When the currently available pharmacotherapeutic principles used for treatment of male lower urinary tract symptoms (LUTS) fail, transurethral resection of the prostate still remains the widely applied gold-standard therapy, since the majority of minimally invasive therapies have not achieved the same efficacy and/or lack an evidence base to support their routine use. Intraprostatic injection therapy, which probably is the oldest minimally invasive surgical treatment, has not been widely used, but recent reports of successful treatments with several new agents have renewed interest in this approach. Anhydrous ethanol still seems to be one of the most extensively studied injectables to date, but intraprostatic injection of botulinum toxin has received much recent attention, with regard to both its mechanism of action and efficacy. In addition, other agents such as NX-1207 and PRX302 have been reported to have promising effects. Injection therapy, using the transperineal, transrectal and transurethral routes for delivery of the active compounds, seems to be an effective minimally invasive surgical therapy for LUTS associated with benign prostatic hyperplasia (BPH). However, further studies on mechanisms of action of the novel agents used, and controlled clinical trials documenting their efficacy and side-effects (which are largely lacking), are needed before their place in the treatment of BPH/LUTS can be properly assessed.

Botulinum neurotoxin type A for the treatment of benign prostatic hyperplasia: randomized study comparing two doses

PURPOSE

To assess the efficacy and safety of intraprostatic injection of two botulinum neurotoxin type A (BoNT-A) doses for the treatment of benign prostatic hyperplasia (BPH).

MATERIALS AND METHODS

Men with symptomatic BPH who failed medical treatment were randomized to receive 100 U or 200 U of BoNT-A into the prostate. The International Prostatic Symptom Score (IPSS), maximum flow rate (Q(max)), post-void residual volume (PVR), PSA levels and prostate volume before injection and after 3 and 6 months were evaluated. Adverse events were compared between the groups.

RESULTS

Thirty four patients were evaluated, including 17 in the BoNT-A 100 U group and 17 in the BoNT-A 200 U group. Baseline characteristics were similar in both groups. Both doses produced significant improvements in IPSS, Q(max) and PVR after 3 and 6 months and both doses promoted comparable effects. Prostate volume was affected by 200 U BoNT-A injection only after 6 months of treatment. PSA levels were significantly affected in the 100 U group only after 6 months of treatment. In the 200 U group, PSA levels were significantly decreased after 3 and 6 months. The complication rate was similar in both groups.

CONCLUSIONS

Efficacy and safety of both BoNT-A doses are similar for BPH treatment in the short term followup.

Urodynamic effects of transrectal intraprostatic Ona botulinum toxin A injections for symptomatic benign prostatic hyperplasia

OBJECTIVE

To investigate urodynamic, symptomatic, and histologic effects of intraprostatic injection with Ona botulinum toxin A for benign prostatic hyperplasia.

METHODS

Patients >55 years with symptomatic benign prostatic hyperplasia failing medical therapy were treated. Inclusion criteria were International Prostate Symptom Score >7, prostate volume 30-50 cm(3), and urodynamic bladder outlet obstruction >Schäfer grade 2. A transrectal intraprostatic injection of 200 IU Ona botulinum toxin A was given. Filling cystometry and pressure flow studies were performed at 3, 6, and 12 months post injection. International Prostate Symptom Score, International Prostate Symptom Score quality of life, prostate-specific antigen, and prostate volume were measured up until 12 months; prostate biopsies before and after Ona botulinum toxin A injection were done for histology and cell proliferation.

RESULTS

Fifteen men (mean age 64.9 years) were included. Ona botulinum toxin A injection was well tolerated with few complications. Postvoid residual improved (170 to 80 mL), but maximum flow rate and bladder outlet resistance parameters did not change during follow-up. International Prostate Symptom Score and International Prostate Symptom Score quality of life improved (22 to 13 and 5 to 2, respectively), whereas prostate-specific antigen and prostate volume remained unaltered. Cell proliferation did not decrease and in 37% and 64% of pre- and posttreatment biopsies, respectively, some degree of prostatitis was found. Ten of 15 patients eventually underwent transurethral prostate resection because of persisting symptoms.

CONCLUSION

Intraprostatic Ona botulinum toxin A for symptomatic benign prostatic hyperplasia did not affect urodynamic outcomes, except for postvoid residual. Although symptom scores improved, we were not able to show change in prostate volume, prostate-specific antigen, or histologic outcomes. A placebo effect of intraprostatic Ona botulinum toxin A could not be ruled out.

Intra-prostatic injection of botulinum toxin type A in treatment of dogs with spontaneous benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is a common, naturally developing, age-related condition in dogs. The pathogenesis of BPH is not completely known; however, DHT is a hormone involved in enlargement of the prostate. Recently, the effect of botulinum toxin A (BT-A) was investigated in the rat and human prostate and has shown to induce atrophy of the gland on the canine prostate. This study investigated the effect of BT-A in the canine prostate and on the semen. Eight sexually intact male dogs with BPH (detected radiographically and ultrasonographically), and with clinical signs of BPH (e.g. hematuria or tenesmus) were used. Each lobe of the prostate received an injection of 125 U of BT-A with one-needle pass under transabdominal ultrasound guidance. The clinical results were evaluated at baseline and after treatment. No local complications or systemic adverse effects were reported. At 4 weeks, the mean prostate volume (PV) was not significantly changed after BT-A (from 17.70 ± 6.34 to 16.48 ± 5.98 cm(3)). At 8 weeks the PV had further decreased to 16.04 ± 5.80 cm(3), reaching its maximum effect, but that change was not significant. The results were maintained at 16 weeks. All dogs had normal libido, erection, and ejaculation during semen collection. No significant difference was observed in all seminal parameters. Results suggest that the administration of 250 U of BT-A do not contribute to PV reduction and do not adversely affect the semen quality of dogs with BPH.

Expression of apoptosis-regulating genes in the rat prostate following botulinum toxin type A injection

Background

Onabotulinumtoxin A (OnabotA) injection has been investigated as a novel treatment for benign prostatic enlargement caused by benign prostatic hyperplasia. An OnabotA - induced volume reduction caused by sympathetic fibers impairment has been proposed as a potential mechanism of action. Our aim was to investigate the expression of apoptosis-regulating proteins in the rat prostate following OnabotA intraprostatic injection.

Methods

Adult Wistar rats were injected in the ventral lobes of the prostate with 10 U of OnabotA or saline. A set of OnabotA-injected animals was further treated with 0.5 mg/kg of phenylephrine (PHE) subcutaneously daily. All animals were sacrificed after 1 week and had their prostates harvested. Immunohistochemical staining was performed for Bax, Bcl-xL and caspase-3 proteins and visualized by the avidin-biotin method. The optical density of the glandular cells was also determined, with measurement of differences between average optical densities for each group.

Results

Saline-treated animals showed intense epithelial staining for Bcl-xL and a faint labelling for both Bax and Caspase-3. OnabotA-treated rats showed a reduced epithelial staining of Bcl-xL and a consistently increased Bax and Caspase-3 staining when compared with saline-treated animals. PHE-treated animals showed a stronger Bcl-xL staining and reduced staining of both Bax and Caspase-3 when compared to the OnabotA group. Mean signal intensity measurements for each immunoreaction confirmed a significant decrease of the signal intensity for Bcl-xL and a significant increase of the signal intensity for Bax and Caspase 3 in OnabotA-injected animals when compared with the control group. In OnabotA+PHE treated animals mean signal intensity for Bcl-xL, Bax and Caspase 3 immunoreactions was identical to that of the control animals.

Conclusions

These results support the hypothesis that OnabotA activates apoptotic pathways in the rat prostate through a mechanism that involves sympathetic outflow impairment.

Effects of 100 and 300 units of onabotulinum toxin A on lower urinary tract symptoms of benign prostatic hyperplasia: a phase II randomized clinical trial

PURPOSE

We conducted a 2-stage, multicenter, double-blind, randomized phase II clinical trial of 100 and 300 unit doses of onabotulinum toxin A to treat the lower urinary tract symptoms of benign prostatic hyperplasia.

MATERIALS AND METHODS

Men 50 years old or older with clinically diagnosed benign prostatic hyperplasia, American Urological Association symptom index 8 or greater, maximum urinary flow rate less than 15 ml per second, voided volume 125 ml or greater, and post-void residual 350 ml or less were randomized to prostatic transrectal injection of 100 or 300 units of onabotulinum toxin A. The primary outcome was at least 30% improvement from baseline to 3 months in American Urological Association symptom index and/or maximum urinary flow rate and safety. The men were followed for 12 months.

RESULTS

A total of 134 men were randomized and treated (68 with 100 units, 66 with 300 units), with 131 assessed at 3 months and 108 assessed at 12 months. Each dose met the 3-month primary outcome criteria. In the 100 unit arm the mean baseline American Urological Association symptom index of 18.8 decreased by 7.1 and 6.9 at 3 and 12 months, respectively. In the 300 unit arm the baseline of 19.5 decreased by 8.9 and 7.1, respectively. In the 100 unit arm the mean baseline maximum urinary flow rate of 10.0 ml per second increased by 2.5 and 2.2, respectively, and in the 300 unit arm the baseline of 9.6 increased by 2.6 and 2.3, respectively.

CONCLUSIONS

The intraprostatic injection of 100 or 300 units of onabotulinum toxin A passed predetermined criteria for treatment efficacy and safety, and a randomized trial with either dose is warranted. The 100 unit dose may be preferable due to similar efficacy with reduced costs and adverse effects.

Injection therapy for prostatic disease: A renaissance concept

Purpose:

Initially conceived as an intervention for prostatic infection, injection therapy has been used to alleviate urinary retention, and is now primarily investigated for the treatment of lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH). For over a century, intraprostatic injection has been used as a minimally invasive surgical therapy (MIST), and is on the verge of a rebirth. This review will familiarize the reader with the origins and history of intraprostatic injection, and its evolution using transperineal, transrectal and transurethral routes with multiple injectants.

Materials and Methods:

A MEDLINE review of the literature on intraprostatic injections published between 1966 and 2007 was performed, augmented with articles and documents dating back to 1832.

Results:

Transperineal and transurethral injections have the most systematic evaluation in patients. There are advantages and disadvantages associated with each route. Most injectants consistently produce localized coagulative necrosis and gland volume reduction with varying degrees of LUTS relief. Anhydrous ethanol (AE) is the most extensively studied injected agent to date.

Conclusions:

Injection therapy is a promising minimally invasive treatment option for various prostatic conditions and has been examined for over 100 years. Further experience in systematic laboratory research and completion of currently ongoing clinical trials is necessary before widespread clinical application.

Modulation of urinary bladder innervation: TRPV1 and botulinum toxin A

The persisting interest around neurotoxins such as vanilloids and botulinum toxin (BoNT) derives from their marked effect on detrusor overactivity refractory to conventional antimuscarinic treatments. In addition, both are administered by intravesical route. This offers three potential advantages. First, intravesical therapy is an easy way to provide high concentrations of pharmacological agents in the bladder tissue without causing unsuitable levels in other organs. Second, drugs effective on the bladder, but inappropriate for systemic administration, can be safely used as it is the case of vanilloids and BoNT. Third, the effects of one single treatment might be extremely longlasting, contributing to render these therapies highly attractive to patients despite the fact that the reasons to the prolonged effect are still incompletely understood. Attractive as it may be, intravesical pharmacological therapy should still be considered as a second-line treatment in patients refractory to conventional oral antimuscarinic therapy or who do not tolerate its systemic side effects. However, the increasing off-label use of these neurotoxins justifies a reappraisal of their pharmacological properties.

A review of botulinum toxin use for chronic pelvic pain syndrome

The inability of urologists to consistently and effectively treat men with chronic pelvic pain syndrome (CPPS), also known as chronic abacterial prostatitis, is a source of great frustration. Botulinum toxin (BTX), a potent neurotoxin, can act on most of the peripheral nerves of the pelvis through a variety of mechanisms. BTX injection therapy for CPPS treatment has shown modest improvements. BTX is ideal for integration into a multimodal treatment plan, which may help achieve pain relief in men with chronic pelvic pain.