Intraprostatic Botulinum Toxin Type A Injection in Patients Unfit for Surgery Presenting with Refractory Urinary Retention and Benign Prostatic Enlargement. Effect on Prostate Volume and Micturition Resumption

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.

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.

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.

Drug-Eluting Biopsy Needle as a Novel Strategy for Antimicrobial Prophylaxis in Transrectal Prostate Biopsy

Objectives:

To preclinically evaluate drug-eluting biopsy needles (patent pending WO2016118026) as a new potential way of antimicrobial prophylaxis for transrectal prostate biopsy.

Methods:

Twenty steel biopsy needles have been coated with polyvinyl alcohol, ciprofloxacin, and amikacin. Modified biopsy needles have been randomly divided into 3 groups (1:2:1 ratio). Needles from group I were immersed for 30 minutes in dedicated test tubes containing saline. Needles from group II were immersed (one by one) for 5 seconds in a set of 12 test tubes containing saline. Then, each solution was analyzed using high-performance liquid chromatography. The results were compared with the susceptibility break points for Escherichia coli. Group III was incubated with E coli strains on Mueller-Hinton plate and then the bacterial inhibition zones surrounding needles were measured.

Results:

The average concentration of antibiotics eluted from needles (group I) was 361.98 ± 15.36 µg/mL for amikacin and 63.87 ± 5.95 µg/mL for ciprofloxacin. The chromatographic analysis revealed the gradual release of both antibiotics from needles (group II). The concentration of amikacin released from needles exceeded the break-point value from first to ninth immersion. Ciprofloxacin concentration was higher than break-point value in all immersions. The average bacterial inhibition zone minor axis was 42 ± 5.7 mm (group III).

Conclusions:

The use of drug-eluting biopsy needle could be a new potential way of antimicrobial prophylaxis for transrectal prostate biopsy. This study confirmed its biological activity as well as the gradual release of antibiotics from its surface. Confirmation of its preventive role, in terms of infectious complications after transrectal prostate biopsy, has to be evaluated in a clinical trial.

[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.

Prostatic Artery Embolization as an Alternative to Indwelling Bladder Catheterization to Manage Benign Prostatic Hyperplasia in Poor Surgical Candidates

PURPOSE

To prospectively assess discontinuation of indwelling bladder catheterization (IBC) and relief of lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH) following prostate artery embolization (PAE) in poor surgical candidates.

METHODS

Patients ineligible for surgical intervention were offered PAE after at least 1 month of IBC for management of urinary retention secondary to BPH; exclusion criteria for PAE included eligibility for surgery, active bladder cancer or known prostate cancer. Embolization technical and clinical success were defined as bilateral prostate embolization and removal of IBC, respectively. Patients were followed for at least 6 months and evaluated for International Prostate Symptom Score, quality of life, prostate size and uroflowmetric parameters.

RESULTS

A total of 43 patients were enrolled; bilateral embolization was performed in 33 (76.7%), unilateral embolization was performed in 8 (18.6%), and two patients could not be embolized due to tortuous and atherosclerotic pelvic vasculature (4.7%). Among the patients who were embolized, mean prostate size decreased from 75.6 ± 33.2 to 63.0 ± 23.2 g (sign rank p = 0.0001, mean reduction of 19.6 ± 17.3%), and IBC removal was achieved in 33 patients (80.5%). Clavien II complications were reported in nine patients (21.9%) and included urinary tract infection (three patients, 7.3%) and recurrent acute urinary retention (six patients, 14.6%). Nine patients (22.0%) experienced post-embolization syndrome.

CONCLUSIONS

PAE is a safe and feasible for the relief of LUTS and IBC in highly comorbid patients without surgical treatment options.

[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.

Korean clinical practice guideline for benign prostatic hyperplasia

In 2014, the Korean Urological Association organized the Benign Prostatic Hyperplasia Guideline Developing Committee composed of experts in the field of benign prostatic hyperplasia (BPH) with the participation of the Korean Academy of Family Medicine and the Korean Continence Society to develop a Korean clinical practice guideline for BPH. The purpose of this clinical practice guideline is to provide current and comprehensive recommendations for the evaluation and treatment of BPH. The committee developed the guideline mainly by adapting existing guidelines and partially by using the de novo method. A comprehensive literature review was carried out primarily from 2009 to 2013 by using medical search engines including data from Korea. Based on the published evidence, recommendations were synthesized, and the level of evidence of the recommendations was determined by using methods adapted from the 2011 Oxford Centre for Evidence-Based Medicine. Meta-analysis was done for one key question and four recommendations. A draft guideline was reviewed by expert peer reviewers and discussed at an expert consensus meeting until final agreement was achieved. This evidence-based guideline for BPH provides recommendations to primary practitioners and urologists for the diagnosis and treatment of BPH in men older than 40 years.

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.

Photoselective Vaporization of the Prostate in Men With Refractory Urinary Retention

OBJECTIVE

To assess the efficacy of photoselective vaporization of the prostate (PVP) and the predictive factors of treatment failure in patients with refractory urinary retention.

MATERIALS AND METHODS

From January 2006 to December 2013, we prospectively included all patients treated by PVP preoperatively catheterized for urinary retention. The primary end point was the number of patients free of indwelling catheters 3 months after the procedure. Univariate and multivariate analyses were performed to identify the predictive factors of treatment failure.

RESULTS

One hundred fifty-two patients were included in the final analysis. The percentage of patients free of indwelling catheters was 91.5% 3 months after PVP. Two factors were identified as predictive of treatment failure at 3 months in multivariate analysis: a smaller preoperative ultrasonographic prostate volume (UPV; odds ratio [OR] = 0.91; P = .008) and a higher volume of primary urinary retention (OR = 1.03; P = .003). Forty-two patients (27.6%) required early recatheterization within 7 days after surgery. Smaller UPV was the only predictive factor of treatment failure in the early postoperative in multivariate analysis (OR = 0.97; P = .01).

CONCLUSION

Nearly one-third of patients treated for refractory urinary retention fail the first trial without catheter after PVP, but 91.5% are free of indwelling catheter 3 months after surgery. A smaller preoperative UPV and a higher retention volume were predictive of PVP failure in patients with preoperative indwelling catheters.

Purinergic signalling in the urinary tract in health and disease

Purinergic signalling is involved in a number of physiological and pathophysiological activities in the lower urinary tract. In the bladder of laboratory animals there is parasympathetic excitatory cotransmission with the purinergic and cholinergic components being approximately equal, acting via P2X1 and muscarinic receptors, respectively. Purinergic mechanosensory transduction occurs where ATP, released from urothelial cells during distension of bladder and ureter, acts on P2X3 and P2X2/3 receptors on suburothelial sensory nerves to initiate the voiding reflex, via low threshold fibres, and nociception, via high threshold fibres. In human bladder the purinergic component of parasympathetic cotransmission is less than 3 %, but in pathological conditions, such as interstitial cystitis, obstructed and neuropathic bladder, the purinergic component is increased to 40 %. Other pathological conditions of the bladder have been shown to involve purinoceptor-mediated activities, including multiple sclerosis, ischaemia, diabetes, cancer and bacterial infections. In the ureter, P2X7 receptors have been implicated in inflammation and fibrosis. Purinergic therapeutic strategies are being explored that hopefully will be developed and bring benefit and relief to many patients with urinary tract disorders.

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.

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.

Botulinum toxin injection for lower urinary tract dysfunction

Botulinum toxin has been recently accepted as a novel treatment for lower urinary tract dysfunctions refractory to conventional treatment. Review of the clinical trials in recent years, botulinum toxin type A has been widely used in the urethra or urinary bladder to treat voiding dysfunction due to detrusor sphincter dyssynergia, incontinence due to neurogenic or idiopathic detrusor overactivity, sensory disorders such as bladder hypersensitivity, overactive bladder, and interstitial cystitis/painful bladder syndrome. Intravesical botulinum toxin type A injection is effective in treatment of urinary incontinence due to detrusor overactivity in men and women, as well as in children. Currently botulinum toxin type A has also been applied to treat lower urinary tract symptoms due to benign prostatic hyperplasia in patients not suitable for surgery. This article reviewed the recent advances of botulinum toxin type A on lower urinary tract dysfunction.

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.

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.

Botulinum neurotoxin A for benign prostatic hyperplasia

PURPOSE OF REVIEW

The injection of botulinum neurotoxin A (BoNT-A) into the prostate represents an alternative, minimal invasive treatment for lower urinary tract symptoms suggestive of benign prostatic hyperplasia (BPH), which gained the interest of urologists during the last years, although it is not yet licensed. The purpose of this review is to summarize the mechanisms through which BoNT-A could inhibit the progression of BPH and eliminate the lower urinary tract symptoms according to the findings of animal studies. Furthermore, we review clinical studies to report the efficacy and safety of intraprostatic BoNT-A injection according to various injection protocols.

RECENT FINDINGS

The experimental studies report induced relaxation of the prostate, atrophy, and reduction in its size through inhibition of the trophic effect of the autonomic system on the prostate gland. Also, a possible mechanism of reduction in lower urinary tract symptoms might take place through inhibition of sensory afferents from the prostate to the spinal cord. Clinical studies report symptomatic relief and improvement in the measured parameters during the follow-up period, whereas local or systematic side-effects are rare.

SUMMARY

We should recognize that, at present, this therapy is still experimental. Although the results of the clinical studies are encouraging, the level of evidence is low. Clearly, we need large-scale, clinical, placebo-controlled, randomized studies, including long-term surveillance to document the evidence of this therapy and, eventually, to register BoNT-A for this indication.

Intravesical botulinum toxin for lower urinary tract dysfunction

Botulinum neurotoxin has achieved substantial clinical benefits in neurogenic detrusor overactivity. More contentious has been its extension to management of refractory idiopathic detrusor overactivity, in which risk of impaired voiding function and consequent need for intermittent catheterisation may counteract the quality-of-life benefits of improved storage function. Several issues remain uncertain for this unlicensed treatment, and clear insights into long-term consequences are needed before it can be regarded as an established mainstream treatment.

Intraprostatic Botulinum Toxin Type A injection in patients with benign prostatic enlargement: duration of the effect of a single treatment

Background

Botulinum Toxin Type-A (BoNT/A) intraprostatic injection can induce prostatic involution and improve LUTS and urinary flow in patients with Benign Prostatic Enlargement (BPE). However, the duration of these effects is unknown. The objective of this work was to determine the duration of prostate volume reduction after one single intraprostatic injection of 200U of Botulinum Toxin Type-A.

Methods

This is an extension of a 6 month study in which 21 frail elderly patients with refractory urinary retention and unfit for surgery were submitted to intraprostatic injection of BoNT/A-200U, by ultrasound guided transrectal approach. In spite of frail conditions, eleven patients could be followed during 18 months. Prostate volume, total serum PSA, maximal flow rate (Qmax), residual volume (PVR) and IPSS-QoL scores were determined at 1, 3, 6, 12 and 18 months post-treatment.

Results

Mean prostate volume at baseline, 82 ± 16 ml progressively decreased from month one coming to 49 ± 9,5 ml (p = 0,003) at month six. From this moment on, prostate volume slowly recovered, becoming identical to baseline at 18 months (73 ± 16 ml, p = 0.03). Albeit non significant, serum PSA showed a 25% decrease from baseline to month 6. The 11 patients resumed spontaneous voiding at month one. Mean Qmax was 11,3 ± 1,7 ml/sec and remained unchanged during the follow-up period. PVR ranged from 55 ± 17 to 82 ± 20 ml and IPSS score from10 to 12 points.

Conclusion

Intraprostatic BoNT/A injection is safe and can reduce prostate volume for a period of 18 months. During this time a marked symptomatic improvement can be maintained.

Botulinum toxin type A inhibits the growth of LNCaP human prostate cancer cells in vitro and in vivo

INTRODUCTION AND OBJECTIVE

Botulinum toxin type A (BTA) intraprostatic injection induces an improvement of urinary symptoms related to benign prostatic hypertrophy (BPH). Infra-clinical prostate cancer (PCa) foci and pre-neoplasic lesions occur concomitantly with BPH in a significant number of patients. The objective of this study was to address whether BTA influences the growth of prostate tumors.

METHODS

Proliferation of PC-3 and LNCaP cell lines exposed or not to BTA (Botox) was assessed and compared. Presence of synaptic vesicle 2 (SV2) protein, the membrane receptor of BTA, was studied in both cell lines. After nude mice bearing LNCaP xenografts received intra-tumoral BTA or saline injection, tumor volume, serum PSA, histopathology and detection of apoptosis were comparatively assessed.

RESULTS

BTA significantly reduced LNCaP cell proliferation and increased apoptosis in a dose-dependent manner but did not affect PC-3. The SV2 receptor was present in both cell lines at a ratio of 4:1 (LNCaP/PC-3). One unit of BTA resulted in a significantly lower growth rate and slower PSA progression over 28 days compare to controls. The tumors were morphologically similar. There were significantly more apoptotic cells compared to controls.

CONCLUSION

BTA inhibits the growth of LNCaP human PCa cells in vitro and in vivo. These findings indicate that intra-prostatic BTA injections to treat BPH are unlikely to promote the growth of co-existing infra-clinical PCa foci in men. A potential inhibitory effect of BTA on the growth of human PCa should be further studied.

Botulinum toxin in the treatment of OAB, BPH, and IC

Botulinum neurotoxins (BoNTs) are well known for their ability to potently and selectively disrupt and modulate neurotransmission. BoNT is currently undergoing regulatory evaluation for urological disorders in the United States and the European Union and is not FDA approved for urologic use. Overactive bladder (OAB) and benign prostatic hyperplasia (BPH) are common urologic conditions characterized by urinary frequency, urgency, nocturia, urge incontinence and, in the case of BPH, decreased urine flow that are currently being evaluated in clinical trials with BoNT-A. Interstitial cystitis (IC) is a chronic condition in which patients describe urinary frequency, urgency and associated bladder/pelvic pain. In the two former conditions, BoNT-A is currently being evaluated in Phase II or Phase III clinical trials as a therapeutic agent. Evidence for BoNT in the treatment of IC is limited to small case series. The purpose of this article is to provide up to date clinical evidence regarding the use of BoNT to treat these three urologic problems. For the sake of clarity, BoNT-A describes the use of Botox unless otherwise specified. In addition, when describing OAB, two sub-populations exist: those with OAB of neurogenic origin (NDO) and those with OAB of unknown (idiopathic) origin (IDO).

Relief by botulinum toxin of lower urinary tract symptoms owing to benign prostatic hyperplasia: early and long-term results

OBJECTIVES

To present a comprehensive experience with intraprostatic botulinum toxin (BT) injection in men with symptomatic benign prostatic hyperplasia (BPH).

METHODS

In this open-label study using an outpatient setting, 77 men with BPH received 200 intraprostatic BT A units (Botox) using an ultrasound-guided transperineal approach. We evaluated the American Urological Association (AUA) score, serum prostate-specific antigen (PSA), prostatic volume, residual volume, and peak urinary flow rates. The primary endpoint was symptomatic improvement after treatment, as measured by means of AUA score and peak urinary flow rates. The secondary endpoint was the evaluation of prostatic volume, serum PSA, and residual urinary volume.

RESULTS

No significant local effects occurred. At their 1-month evaluation, 41 patients had subjective symptomatic relief. Compared with baseline values, AUA score was reduced from 24.1 +/- 4.6 to 12.6 +/- 2.9 (P = .00001), and serum PSA from 6.2 +/- 1.7 to 4.8 +/- 1.0 ng/mL (P = .03). At the same time, prostatic volume and residual urine volume were reduced by 12.7% and 12.8%, respectively, and mean peak urinary flow rate increased (P = .01). At 2 months' evaluation, 55 patients had subjective symptomatic relief. AUA score was reduced by 63.9% (P = .00001) compared with baseline values. In the same patients, serum PSA, prostatic volume, and residual urine volume were reduced by 51.6% (P = .00001), 42.8% (P = .00001), and 55.9% (P = .002), respectively, and mean peak urinary flow rate increased significantly.

CONCLUSIONS

Intraprostatic BT seems to be a promising approach to the treatment of BPH. It is safe, effective, well-tolerated, and not related to the patient's willingness to complete treatment.