Botox-induced prostatic involution

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.

Therapeutic effects of add-on botulinum toxin A on patients with large benign prostatic hyperplasia and unsatisfactory response to combined medical therapy

OBJECTIVE

Botulinum toxin A (BoNT-A) injections into the prostate have been reported to be effective and durable in the treatment of small benign prostatic hyperplasia (BPH). This study evaluated the effectiveness of BoNT-A in patients with large BPH with an unsatisfactory response to combined alpha-blocker and 5-alpha-reductase inhibitor therapy.

MATERIAL AND METHODS

Sixty patients with BPH and total prostate volume (TPV) of > 60 ml with unsatisfactory response to combination medical therapy were randomly assigned to receive add-on intraprostatic BoNT-A injection (n=30) or continued medical therapy (control group). Patients in the treatment group received 200-600 U of Botox injected into the prostate. Outcome parameters including International Prostate Symptom Score (IPSS), quality of life index (QoL-I), TPV, maximum flow rate (Q(max)) and postvoid residual (PVR) were compared between treatment and control groups at baseline, 6 months and 12 months.

RESULTS

Significant decreases in IPSS, QoL-I and TPV, and increase in Q(max) were observed at 6 months and remained stable at 12 months in the treatment group. Improvements in IPSS and QoL-I were also observed at 6 months and a decrease in TPV at 12 months was noted in the control group. However, no significant changes in any parameters except for QoL-I at 6 and 12 months were noted between the treatment and control groups. Acute urinary retention developed in three patients receiving BoNT-A treatment. Three BoNT-A and two medical treatment patients converted to transurethral surgery at the end of study.

CONCLUSIONS

This study shows that add-on prostatic BoNT-A medical treatment can reduce prostate volume and improve lower urinary tract symptom score and QoL-I within 6 months in the treatment of large BPH. However, the therapeutic effect at 12 months was similar to combination medical treatment.

Cancer-related axonogenesis and neurogenesis in prostate cancer

PURPOSE

Perineural invasion is the only interaction between cancer cells and nerves studied to date. It is a symbiotic relationship between cancer and nerves that results in growth advantage for both. In this article, we present data on a novel biological phenomenon, cancer-related axonogenesis and neurogenesis.

EXPERIMENTAL DESIGN

We identify spatial and temporal associations between increased nerve density and preneoplastic and neoplastic lesions of the human prostate.

RESULTS

Nerve density was increased in cancer areas as well as in preneoplastic lesions compared with controls. Two- and three-dimensional reconstructions of entire prostates confirmed axonogenesis in human tumors. Furthermore, patients with prostate cancer had increased numbers of neurons in their prostatic ganglia compared with controls, corroborating neurogenesis. Finally, two in vitro models confirmed that cancer cells, particularly when interacting with nerves in perineural invasion, induce neurite outgrowth in prostate cancer. Neurogenesis is correlated with features of aggressive prostate cancer and with recurrence in prostate cancer. We also present a putative regulatory mechanism based on semaphorin 4F (S4F). S4F is overexpressed in cancers cells in the perineural in vitro model. Overexpression of S4F in prostate cancer cells induces neurogenesis in the N1E-115 neurogenesis assay and S4F inhibition by small interfering RNA blocks this effect.

CONCLUSIONS

This is the first description of cancer-related neurogenesis and its putative regulatory mechanism.

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.

Inhibition of prostate efferent neurotransmission by amikacin

BACKGROUND

It has been suggested that manipulation of the autonomic nerve supply to the prostate leads to loss of functional and structural integrity of the gland, and that these changes may be useful in treating prostatic diseases. This study investigates the effect of amikacin on prostate efferent neurotransmission in vitro, in both rat and human prostate samples.

METHODS

Prostate samples, obtained from male Wistar rats and 8 patients undergoing endoscopic surgery for benign prostatic hyperplasia, were studied by measurement of isometric contraction induced by electrical field stimulation (EFS), noradrenalin, carbachol, serotonin and ATP, in the presence or absence of amikacin 10(-3) M in a low-Ca medium.

RESULTS

Amikacin significantly reduced EFS-induced contraction of isolated rat and human prostate samples by 45 +/- 6.5% (P < 0.01) and 47 +/- 6% (P < 0.01), respectively. Contraction was restored after addition of calcium chloride 2 x 10(-3) M. Amikacin-induced relaxation in rat prostate samples was greater than the effect of magnesium and weaker than those of prazosin and verapamil, but comparable in extent with the latter. No significant effect was observed on rat prostate contractile response to noradrenaline as to ATP in the presence of amikacin. Rat prostate contraction to carbachol and serotonin was inhibited by 35 +/- 11% (P < 0.05) and 59 +/- 11.7% (P < 0.01), respectively, after addition of amikacin 10(-3) M.

CONCLUSIONS

Amikacin reduces in vitro both rat and human prostate contraction elicited by pre-junctional stimulation, but does not affect prostate contraction evoked by post-junctional stimulation. Our results indicate that amikacin affects prostatic efferent neurotransmission.

Lack of anti-inflammatory effect of botulinum toxin type A in experimental models of inflammation

Botulinum toxin type A (BTX-A) has a long-lasting antinociceptive activity and less clear effect on inflammation. It was proposed that these two effects share the same mechanism--the inhibition of neurotransmitter exocytosis from peripheral nerve endings. However, till now possible anti-inflammatory action of BTX-A did not evoke much attention. In the present paper, we investigate possible anti-inflammatory action of the toxin in carrageenan and capsaicin models of inflammation in rats. BTX-A (5 and 10 U/kg) was injected into the plantar surface of the rat right hind-paw pad 5 days before the injection of the carrageenan (1%) or capsaicin (0.1%) at the same site. Carrageenan-induced paw oedema and capsaicin-induced protein extravasation were measured. Control, inflamed and BTX-A pretreated inflamed paws were photographed and histopathological analysis (haematoxylin & eosin) was performed. Pretreatment with BTX-A had no effect on the size of carrageenan-induced paw oedema, measured as paw volume and weight or capsaicin-induced plasma extravasations, measured by Evans blue as a marker of protein leakage. Neither macroscopic nor microscopic analysis showed a significant difference between BTX-A pretreated and control inflamed tissue. Results show dissociation between the effect of BTX-A on pain and inflammation thus questioning the validity of the suggested assumption about the common peripheral mechanism of action.

Botulinum neurotoxin: evolution from poison, to research tool--onto medicinal therapeutic and future pharmaceutical panacea

Botulinum neurotoxin (BoNT), for more than a hundred years, has been a recognized poisonous principle in spoiled food. As its chemical structure became unraveled, and as more knowledge was gained over its mechanism of toxicity, it became clear that BoNT had the potential to act therapeutically as a targeted toxin that could inactivate specific nerve populations, and thus achieve a therapeutic goal. BoNT has evolved over the past 25 years into a viable therapeutic, now being a first line treatment for dystonia, overtly altering the course of progression of this disorder. BoNT is used for hyperhidrosis and gustatory sweating syndrome, alleviation of pain, as a treatment for overactive bladder, achalasia and anal fissure; and it has gained popularity as a cosmetic aid. Many other possible uses are being explored. The greatest potential for BoNT may lie in its being a molecular Trojan Horse - able to carry a specific enzyme or specific drug to the inside of a cancer or other type of cell while bypassing other cells and thereby having little or no ill effect. BoNT's pharmaceutical potential is boundless.

The use of botulinum neurotoxin type A (BoNTA) in urology

The use of Botulinum neurotoxin type A (BoNT/A) in the lower urinary tract was pioneered as early as 20 years ago with injections into the urethral sphincter reducing bladder voiding pressures, urethral pressures, and post-void residual urine. Over the past 9 years, the use of BoNT/A has revolutionised the treatment of intractable symptoms associated with the neurogenic or idiopathic overactive bladder, both in adults and children. The duration of clinical improvement is 6-11 months, is accompanied by significant amelioration of patients' quality of life and repeat bladder treatments appear to have sustained effects. Despite evidence for an effect on the afferent pathways, its mode of action in the human bladder remains largely unknown. The use of BoNT/A has also expanded into the painful bladder syndrome and in benign prostatic diseases, with promising preliminary results. This review aims to provide an insight of the use of BoNT/A in the lower urinary tract, addressing issues such as treatment outcomes and safety, mechanisms of action and potential for future research.

Prostate growth and prevalence of prostate diseases in early onset spinal cord injuries

BACKGROUND

Controversial data on modifications of prostate size, function and disease of spinal cord injury (SCI) patients has been previously reported.

OBJECTIVE

An analytical observational cohort study on male SCI patients was planned in order to evaluate prostate gland growth, including benign prostatic hyperplasia in relation to the age of the patient at SCI onset. Additional evaluations considered hormonal and biochemical parameters and prostate cancer.

DESIGN, SETTING AND PARTICIPANTS

113 SCI patients (mean age 61.3) and 109 age-matched able bodied subjects (mean age 65.4) were enrolled and stratified according to the patient age at SCI onset (< or = 30, 31-49, and > or = 50 years).

INTERVENTION

A complete medical history was then collected from all SCI patients and able bodied subjects.

MEASUREMENTS

Total prostate antigen (PSA) and testosterone (T) serum levels and urine culture were collected. Digital rectal examination and transrectal ultrasonography were performed.

RESULTS AND LIMITATIONS

Patients with SCI showed PSA value and prostate size significantly lower than those observed in able bodied subjects, and an inverse relationship was observed in SCI patients between these two parameters and patient age at the time of lesion onset. T serum levels were lower in SCI patients when compared to able bodied subjects. No SCI patient presented prostate cancer, while 9.7% of control subjects were affected by prostate cancer.

CONCLUSIONS

Prostate volume and PSA levels are lower in SCI patients and are inversely related to the patient age at lesion onset. Whether this effect is mediated directly or indirectly by a impaired nerve supply to the prostate remains to be determined. Despite the present observation of reduced prostate disease, as during the last twenty years life expectancy in SCI patients has improved significantly, the need to screen these patients for the occurrence of prostate disease should not be disregarded.

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

OBJECTIVES

To evaluate the effect of intraprostatic injection of botulinum toxin A (BoNTA) on prostate volume and refractory urinary retention in patients with benign prostatic enlargement.

METHODS

Twenty-one men with benign prostatic enlargement on chronic indwelling catheter for at least 3 mo who were not candidates for surgery because of poor general condition received 200 U BoNTA in the transition zone by transrectal approach under ultrasound guidance. Patients were reevaluated at 1 and 3 mo posttreatment.

RESULTS

Patients had a mean age of 80+/-2 yr. Injections were done without anaesthetic support as an outpatient procedure. No significant local effects occurred. Baseline prostate volume of 70+/-10 ml decreased to 57+/-10 ml (p<0.0006) at 1 mo and to 47+/-7 ml (p=0.03 against 1 mo) at 3 mo. At 1 mo, 16 patients (76%) could resume voiding with a mean Qmax of 9.0+/-1.2 ml/s. At 3 mo, 17 patients (81%) voided with a mean Qmax of 10.3+/-1.4 ml/s. Residual urine was 80+/-19 ml and 92+/-24 ml at the two time points, respectively. Mean serum total PSA decreased from 6.0+/-1.1 ng/ml at baseline to 5.0+/-0.9 ng/ml at 3 mo (p=0.04).

CONCLUSIONS

BoNTA injection into the prostate swiftly reduces prostate volume and may be a promising treatment for refractory urinary retention in patients with benign prostatic enlargement who are unfit for surgery. Future studies will determine the duration of BoNTA effect.

Botulinum toxin injection therapy in the management of lower urinary tract dysfunction

We have great pleasure in introducing this supplement containing a collection of articles reviewing the contemporary clinical management of functional disorders of the lower urinary tract (LUT) with particular emphasis on the potential role of botulinum toxin injection therapy. Detrusor sphincter dyssynergia (DSD), detrusor overactivity (DO), painful bladder syndrome (PBS) and LUT symptoms consequent on bladder outflow obstruction (LUTS/BPH) have all been treated by the injection of botulinum toxin. This treatment can be administered as a minimally invasive, outpatient procedure which on the initial trials for DO (particularly of neurogenic aetiology) shows a remarkable efficacy with effects lasting up to a year after a single treatment with few significant side effects. Success has been reported with the management of detrusor sphincter dyssynergia and preliminary series report positive outcomes in the management of PBS and LUTS/BPH. However, most of the studies to date include small numbers and have a recruitment bias with few randomised controlled trials having been reported. The answers to some of the key questions are addressed with reference to our contemporary knowledge. It is clear that considerable work both clinical and basic science still needs to be performed to answer the many remaining questions with regard to this treatment modality but undoubtedly it will be a major future treatment option in those with intractable symptoms or those unable to tolerate medications. Currently, all botulinum toxin use for urological conditions is off-label and unlicensed, therefore caution should be exercised until future large randomised studies are reported.

Amikacin: A Novel Modulator of Vesical and Prostate Efferences. An in vitro Experimental Study

The autonomic efferent neurotransmission to the bladder and prostate smooth muscle is a potential target for drug therapy of specific low urinary tract disfunction (LUTD). Since amikacin and other amynoglicosides were reported to affect neurotransmission by a pre-junctional mechanism, we investigated the effect of amikacin on isolated rat and human detrusor smooth muscle contraction and on isolated rat and human prostate contraction, to further evaluate its potential relaxant properties.

Materials and Methods

Samples of detrusor smooth muscle and prostate tissue, obtained from 97 rats and 16 patients undergoing surgery, were studied through the measurement of isometric contraction induced by electrical field stimulation (EFS) and other pharmacological stimuli in the presence or absence of 1mM amikacin in a low-Ca medium.

Results

Amikacin 1 mM significantly reduced contraction of isolated rat and human detrusor muscle and prostate, achieved with pre-junctional stimulation, while no significant effect was observed on contraction induced by pharmacological post-junctional stimulators. EFS contraction inhibited by amikacin was restored after addition of calcium chloride. The amikacin effect was comparable to the effect of magnesium ions, which are known to exert a pre-junctional inhibition of neurotransmitter release.

Conclusions

Amikacin significantly inhibited rat and human detrusor and prostate contraction evoked by pre-junctional stimulation in vitro, suggesting a depressant effect on autonomic efferent neurotransmission. Further pharmacokinetics studies and researches on related compounds may hold potential for future development in the treatment of specific low urinary tract disfunction (LUTD).

Hitting below the belt (Bladder): Botulinum treatment of urethral and prostate disorders

Botulinum toxin type A (BTX-A) has been used to treat urethral and prostatic diseases (off-label uses). Injection of BTX-A into the external sphincter of patients with detrusor external sphincter dyssynergia has been shown to successfully lower postvoid residual volumes and detrusor pressures. Average efficacy is 3 to 4 months, but long-term effects on detrusor leak point pressures or renal function are unknown. Injection of BTX-A into the prostate has shown promising short-term results (< or = 12 months) in improving the symptoms, postvoid residual volumes, maximal urinary flow rates, and prostate sizes in patients with benign prostatic hyperplasia. The mechanisms of action and long-term durability of this treatment modality are unknown. Evidence supporting the use of BTX-A in treating detrusor hypocontractility, pelvic floor dysfunction, postpubovaginal sling retention, urethral stricture, prostatitis, and chronic pelvic pain syndrome in men is preliminary and deserves further evaluation.

Effects of Botulinum Toxin A on the Contractile Function of Dog Prostate

OBJECTIVES

To study effects of botulinum toxin A (BoNT/A) on prostate contractile function in dogs.

METHODS

One hundred units (N=6) or 200 units (N=5) BoNT/A was injected into dog prostate. Sham control group (N=7) received normal saline injections. Before and 1 mo after injection, prostate urethral pressure response to electrostimulation and intravenous (IV) norepinephrine was measured. Contractile responses of prostate strips were tested in tissue bath. Structural changes were evaluated with conventional histology and smoothelin immunohistochemistry.

RESULTS

Injection of normal saline and 100 units BoNT/A did not significantly change prostate urethral pressure response to IV norepinephrine and electrostimulation. However, injection of 200 units BoNT/A significantly reduced prostate urethral pressure response to IV norepinephrine and electrostimulation. Contractile responses of prostate strips to potassium chloride, electrostimulation, and phenylephrine did not differ between sham control and 100U groups. In the 200U group, however, all responses were less than those of sham controls. Control and BoNT/A groups exhibited nitric oxide-related relaxation in prostate strips precontracted by phenylephrine. Injection of 100 units BoNT/A induced mild atrophy of prostate gland; injection of 200 units BoNT/A induced more pronounced atrophic changes in prostate gland and vacuoles formation in smooth muscle cells of stromal tissue.

CONCLUSIONS

Injecting BoNT/A into dog prostate reduces contractile function while maintaining relaxation response of the prostate. These effects make BoNT/A a viable option in managing prostate-related symptoms. However, large, randomized clinical studies to determine long-term effects and safety of BoNT/A application in human prostates are required.

Premiers résultats de la toxine botulique dans le traitement de l’hyperplasie bénigne de la prostate

Botulinum toxin was first used in urology in the field of neuro-urology as treatment for detrusor-sphincter dyssynergia and incontinence due to neurogenic overactive bladder. Its action has now been clearly demonstrated and it is now widely used for the treatment of neurogenic overactive bladder. Can botulinum toxin also constitute an effective treatment for benign prostatic hyperplasia (BPH)? Intraprostatic botulinum toxin injections have been shown to have a significant clinical and urodynamic efficacy by acting on both the static and dynamic components of BPH. The advantages of botulinum toxin are its ease of use, the absence of any reported adverse effects and its prolonged duration of action. Well conducted, prospective, controlled studies on larger sample sizes must now be performed to confirm these preliminary results. This review of the literature presents the preliminary results of intraprostatic botulinum toxin injection supporting its use in the treatment of symptomatic benign prostatic hyperplasia.

Intérêts des antidiurétiques, des anticholinergiques, des anti-inflammatoires et de la toxine botulinique pour le traitement des troubles mictionnels liés à I’HBP (Forum CTMH-AFU 2005)

New therapeutic approaches have recently been investigated in order to improve the voiding disorders of patient with lower urinary tract symptoms related to benign prostatic hyperplasia. The purpose of this article is to provide a review of these treatments: anti-inflammatory, antidiuretic, anticholinergic and botulinum toxin. Anticholinergic drugs associated with a risk of urinary retention, appear to be effective for irritative disorders in combination with an alpha-blocker. Antidiuretics can be proposed in patients younger than 65 with disabling polyuria confirmed by a voiding diary, related to BPH and refractory to conventional treatment of BPH. The interaction between inflammation and BPH has not yet been clarified, but anti-inflammatory drugs appear to improve symptoms and may have a place in short-term treatment of BPH, as their long-term use is not recommended and COX-2 inhibitors have been withdrawn from the market. Finally, botulinum toxin could have a place in the treatment of disorders related to BPH if clinical studies confirm the recently published promising results. These new approaches will probably be integrated into guidelines and flow-charts for the treatment of voiding disorders related to BPH.

Botulinum toxin, Quo Vadis?

Botulinum toxin (BTX), derived from the exotoxin of Clostridium botulinum, cleaves Soluble N-ethylmaleimide-sensitive factor-Attachment protein REceptor (SNARE) proteins, causing chemodenervation of cholinergic neurons. BTX also inhibits exocytosis of vesicles containing norepinephrine, glutamate, substance P and calcitonin gene-related peptide (CGRP) and inhibits expression of the vanilloid receptor. Clinical applications of BTX, which include the treatment of overactive skeletal and smooth muscles, hypersecretory and painful disorders, have increased exponentially since it was first used clinically to treat strabismus more than two decades ago. In this editorial, we discuss reports of new therapeutic indications of BTX, and propose new areas for research.

Prostate-specific antigen and prostate volume in Korean men with spinal cord injury: a case–control study

STUDY DESIGN

Prospective, cross-sectional, case-control study.

SETTING

Outpatient department in Seoul, Korea.

OBJECTIVES

To assess prostate volume and serum prostate-specific antigen (PSA) levels in Korean men with spinal cord injury (SCI).

METHODS

A total of 31 SCI patients with ages ranging between 45 and 81 years old (median age, 58 years) were studied. Thirty-one age-matched individuals without SCI were enrolled in the study as controls. We tested PSA levels and performed transrectal ultrasonographies on all enrolled patients. Of the patients with SCI, 20 were evaluated for testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) levels.

RESULTS

Serum PSA levels and prostate volume parameters in the two groups had similar values: the median (5th-95th percentiles) serum PSA level was 1.56 ng/ml (0.12-9.77) for SCI patients and 1.04 ng/ml (0.50-2.98) for controls (P=0.481), whereas the median (5th-95th percentiles) prostate volume was 18.33 ml (10.16-76.78) for SCI patients and 20.80 ml (14.23-41.22) for controls (P=0.072). No significant differences were found when serum PSA levels and prostate volumes were compared according to SCI patient injury characteristics. Testosterone levels were lower than the normal range in 7 SCI patients (35%), LH was higher than the normal range in 10 SCI patients (20%), and FSH was higher than the normal range in eight SCI patients (40%). We observed an age-related increase in FSH levels (r=0.634, P=0.004), although hormone levels did not correlate with serum PSA levels and prostate volume parameters.

CONCLUSIONS

According to our results, serum PSA levels and prostate volume in Korean SCI patients are not different from those in uninjured men and are not affected by injury characteristics.

Safety and Tolerability of Sedation-Free Flexible Cystoscopy for Intradetrusor Botulinum Toxin-A Injection

PURPOSE

Intradetrusor botulinum toxin-A injection is a promising emerging therapy for neurogenic and idiopathic overactive bladder that is refractory to current antimuscarinic agents. We evaluated a sedation-free procedure using flexible endoscopy to perform intradetrusor botulinum toxin-A injection using a validated pain score to assess the tolerability of this technique.

MATERIALS AND METHODS

Five men and 22 women with idiopathic overactive bladder refractory to antimuscarinics were prospectively evaluated and randomized to 100 U (14) or 150 U botulinum toxin-A (13). Subjects underwent BTA injection with intravesical lidocaine using a 14Fr Olympus flexible cystoscope, which accommodates a 27 gauge flexible Olympus injection needle. Patients were evaluated with the visual analog scale to evaluate discomfort during and 15 minutes after the procedure. Procedure time was recorded.

RESULTS

In 22 female patients the mean pain score was 3.1 (range 0 to 10) during the procedure and 0.7 (range 0 to 7) 15 minutes after the procedure. In 5 male patients the mean pain score was 1.6 (range 0 to 3.5) during the procedure and 0.0 with all reporting no pain 15 minutes after the procedure. Mean procedure time was 4.5 minutes (range 4 to 6). Only 1 of the 27 patients requested sedation before any subsequent injections.

CONCLUSIONS

Sedation-free intradetrusor botulinum toxin-A injection using intravesical lidocaine and flexible endoscopy is a well tolerated and safe procedure to perform in an office setting.

Botulinum toxin for the treatment of lower urinary tract symptoms due to benign prostatic hyperplasia

Botulinum toxin (BTX) is the most potent biological toxin used for the treatment of urologic conditions. During the last 3 years, the use of BTX has been extended to the treatment of symptomatic benign prostatic hyperplasia, however, the actual mechanism through which BTX can reduce prostate volume and infravesical resistance is not well understood. This article reviews the main effects of BTX in prostate tissues. A critical analysis of the outcomes of patients who were studied in clinical series that used this toxin to treat lower urinary tract symptoms related to benign prostatic hyperplasia is also presented.

Histopathological and radiological investigations of the influence of botulinum toxin on the submandibular gland of the rat

The aim of the study was to correlate the sonographic features of Botox A injection in rat submandibular gland with the histopathological changes. Fifteen Wistar albino rats were randomly assigned to 2 groups. Group 1 (control group) consisted of 5 animals not given any substance. Group 2 was divided as "a" and "b" each consisting of 5 animals. A median cervical incision has been performed to the rats in group 2 and 2.5 U Botulinum toxin A reconstituted 0.1 ml physiologic saline was injected into the right gland. Sonograms were obtained before the application, at the first day of the Botox A application, in addition to group 2a on the 14th day, and on 28th day to group 2b. Gland size was lower in group 2a and 2b comparing to control group. The gland size of group 2b was lower than group 2a. There was no change in vascularization. There was no other histopathological change except lymphocytic infiltration in group 2. It was observed that Botox A injection does not have a direct effect on the cells in submandibular gland but it causes a homogenic shrinking in gland size without atrophy.

LUTS treatment: Future treatment options

Lower urinary tract symptoms (LUTS) are commonly divided into storage, voiding, and postmicturition symptoms, and may occur in both men and women. Male LUTS have historically been linked to benign prostatic hyperplasia (BPH), but are not necessarily prostate related. The focus of treatment for LUTS has thus shifted from the prostate to the bladder and other extraprostatic sites. LUTS include symptoms of the overactive bladder (OAB), which are often associated with detrusor overactivity. Treatment for LUTS suggestive of BPH has traditionally involved the use of alpha(1)-adrenoceptor (AR) antagonists; 5alpha-reductase inhibitors; and phytotherapy-however, several new therapeutic principles have shown promise. Selective beta(3)-adrenoceptor agonists and antimuscarinics are potentially useful agents for treating LUTS, particularly for storage symptoms secondary to outflow obstruction. Other agents of potential or actual importance are antagonists of P2X(3) receptors, botulinum toxin type A, endothelin (ET)-converting enzyme inhibitors, and drugs acting at vanilloid, angiotensin, and vitamin D(3) receptor sites. Drugs interfering with the nitric oxide/cGMP-cAMP pathway, Rho-kinase and COX inhibitors, as well as drugs targeting receptors and mechanisms within the CNS, are also of interest and deserving of further study for the treatment of LUTS.

The application of botulinum toxin in the prostate

PURPOSE

Botulinum neurotoxin is the most potent naturally occurring toxin known to inhibit various neurotransmitters. Injection of botulinum neurotoxin into the bladder and urethral sphincter has been used to treat bladder hyperactivity and sphincter dyssynergia. Recently botulinum neurotoxin application was extended to prostate disorders. Why would a urologist want to target the prostate?

MATERIALS AND METHODS

We reviewed the literature on the mechanisms of action and clinical efficacy of botulinum neurotoxin treatment of the prostate. In addition to our personal clinical experience and basic research, information was gathered from MEDLINE and published abstracts from international meetings. We also present basic research and discuss the potential mechanism of action of botulinum neurotoxin on the prostate.

RESULTS

There are 8 current peer reviewed publications on the injection of botulinum neurotoxin in the prostate. Cystoscopic transurethral or transperineal/transrectal ultrasound guided techniques have been used. Outcome improvement reported includes decreases in prostate size, prostate specific antigen and residual urine volume, and improvement in the flow rate and symptom score lasting 6 months or longer.

CONCLUSIONS

Botulinum toxin has demonstrated exciting and promising preliminary results for male lower urinary tract symptoms. Translational research suggests novel mechanism of action of botulinum toxin in the prostate for benign prostatic hyperplasia and chronic nonbacterial prostatitis. It may even be considered as adjuvant treatment for prostate cancer. The use of botulinum neurotoxin in the prostate is currently Food and Drug Administration off label and in support of evidence based medicine practices caution should be applied until larger, randomized clinical studies are completed. More basic research is needed to identify the mechanisms by which botulinum toxin affects the prostate.

Botulinum-A toxin: an exciting new treatment option for prostatic disease

Recently, botulinum neurotoxin type A (BoNT-A) application in the lower urinary tract has been extended to prostate disorders and we would like to review the literature on the mechanisms of action and clinical efficacy of BoNT-A treatment in the prostate. The information was gathered from MEDLINE, abstracts from recent urological meetings and from personal experience. BoNT has demonstrated promising preliminary results for male prostatic disease and translational research suggests a novel mechanism of action of BoNT in the prostate. It is important to remember that the application of BoNT in the prostate is not approved by the regulatory agencies and caution should be applied until larger randomised clinical studies are completed.

Evaluation of short term clinical effects and presumptive mechanism of botulinum toxin type A as a treatment modality of benign prostatic hyperplasia

The purpose of this study was to evaluate the effect and investigate the putative mechanism of botulinum toxin type A (BTA) applied to the treatment of benign prostatic hyperplasia (BPH). A total of 52 patients with symptomatic BPH were evaluated. Transperineal intraprostatic injection under transrectal ultrasonography was carried out. BTA dissolved in 4 to 9 mL of saline was used from 100 U to 300 U, according to prostate volume. Twenty-six patients received only BTA (BT group), and 26 received both BTA and one month of an alpha-adrenergic antagonist (BTalpha group). The therapeutic outcomes were evaluated by comparing parameters such as international prostate symptom score (IPSS), quality of life, prostate specific antigen, prostate volume, post-void residual urine, and peak urinary flow rate. At the one month follow- up, 18 patients in the BT group and 21 in the BTalpha group had subjective symptomatic relief (p = 0.337). Only IPSS5 (weak stream) was significantly different between the BT group and BTalpha groups (p = 0.034). At the three month follow-up, 39 patients had subjective symptomatic relief. The storage symptoms were improved more than the voiding symptoms. Additionally, about 50 percent of the patients whose voiding symptom improved expressed improved erectile function. BTA injection seems to be an alternative treatment for BPH. The differences after the one month evaluation between the BT and the BTalpha groups might suggest that the adrenergic influence could be relatively reinforced by the anticholinergic effect of BTA. Nitric oxide would thus be involved in a BTA action mechanism in BPH.

Sustained beneficial effects of intraprostatic botulinum toxin type A on lower urinary tract symptoms and quality of life in men with benign prostatic hyperplasia

OBJECTIVE

To present a comprehensive experience with intraprostatic botulinum toxin-type A (BoNT-A) injection in men with symptomatic benign prostatic hyperplasia (BPH) and to assess the efficacy on lower urinary tract symptoms (LUTS) and quality of life (QoL).

PATIENTS AND METHODS

In all, 41 men (mean age 69.1 years, sd 7.1 ) with an International Prostate Symptom Score of > or = 8, peak flow rate of < 12 mL/s, and who were refractory to medical treatment were injected with BoNT-A (Botox, Allergan, Inc., CA, USA) at 100 U (21 men, for prostate volume < 30 mL) or 200 U (20, for prostate volume > 30 mL) into the prostate transperineally under transrectal ultrasonography guidance. Study exclusion criteria were confirmed or suspected malignancy, previous pelvic surgery or trauma and previous invasive treatment for BPH. The clinical effects were evaluated at baseline and at 1, 3 and 6 months after treatment.

RESULTS

There were no significant local or systemic side-effects in any men. LUTS and QoL indices improved by > 30% in 31 of the 41 men (76%), and four of five men with urinary retention for > 1 month could void spontaneously at 1 week to 1 month after the BoNT-A injection. In 12 of 41 men (29%) there was no change in prostate volume, yet seven of these men still had a > 30% improvement in maximum flow rate, LUTS and QoL. The efficacy was sustained at 12 months.

CONCLUSION

BoNT-A injected into the prostate is safe and effective for men with symptomatic BPH. The mechanisms of relief of symptoms might not depend totally on the volume shrinkage; the inhibitory effect on the smooth muscle tone and aberrant sensory function might also be important.

The potential and promise of using botulinum toxin in the prostate gland

Botulinum neurotoxin (BoNT) has been called the 'most poisonous poison' and a potential bioterrorist weapon. However, it is possible to use the elegant and specific activity of this toxin to treat various medical conditions. Recently, the application of BoNT was extended to prostate disorders, and we review published reports on the mechanisms of action and clinical efficacy of BoNT in the prostate. The information was gathered from Medline, abstracts from recent urological meetings, and from personal experience. BoNT has shown promising preliminary results for male lower urinary tract symptoms, and translational research suggests a novel mechanism of action of BoNT in the prostate. Importantly, the application of BoNT in the prostate is not approved by the regulatory agencies and caution should be used until larger randomized clinical studies are completed.

Other therapies for BPH patients: desmopressin, anti-cholinergic, anti-inflammatory drugs, and botulinum toxin

The usual treatments of benign prostate hyperplasia (BPH) including the alpha-blockers, the inhibitors of the 5-alpha reductase and the phytotherapy drugs allow significant improvements of the lower urinary tracts symptoms (LUTS). However, some patients are not responders or have side effects due to the treatments. Other therapeutic approaches described in the literature are possible in order to alleviate the LUTS. The anti-cholinergic drugs seem to be efficient against the irritating symptoms even if they are supposed to be contra-indicated when there is BPH. Anti-diuretic hormone could be useful to treat nocturia due to diuresis reversal. Inflammation is a part of the underlying mechanisms of BPH and as such the role of the anti-inflammatory drugs has to be revised. Eventually, botulinum toxin is more and more used for patients with neurological bladder and could also have a role in LUTS. If the coming clinical studies on those different treatments confirm the preliminary results, the learning societies in charge of the guidelines would have to update the decision trees by adding these new therapeutic approaches.

Intraprostatic injection of botulinum toxin type-A relieves bladder outlet obstruction in human and induces prostate apoptosis in dogs

BACKGROUND

With the increasing interest with botulinum toxin--A (BTX-A) application in the lower urinary tract, we investigated the BTX-A effects on the canine prostate and also in men with bladder outlet obstruction (BOO) due to benign prostatic hyperplasia (BPH).

METHODS

Transperineal injection into the prostate using transrectal ultrasound (TRUS) was performed throughout the study. Saline with or without 100 U of BTX-A was injected into mongrel dogs prostate. One or 3 months later, the prostate was harvested for morphologic and apoptotic study. In addition, eight BPH patients refractory to alpha-blockers were treated with ultrasound guided intraprostatic injection of 200 U of BTX-A.

RESULTS

In the BTX-A treated dogs, atrophy and diffuse apoptosis was observed with H&E stain and TUNEL stain at 1 and 3 months. Clinically, the mean prostate volume, symptom score, and quality of life index were significantly reduced by 18.8%, 73.1%, and 61.5% respectively. Maximal flow rate significantly increased by 72.0%.

CONCLUSION

Intraprostatic BTX-A injection induces prostate apotosis in dogs and relieves BOO in humans. It is therefore a promising alternative treatment for refractory BOO due to BPH.

Management of bladder, prostatic and pelvic floor disorders

Since its introduction in the late 1970s for the treatment of strabismus and blepharospasm, botulinum toxin (BoNT) has been increasingly used in the interventional treatment of several other disorders characterized by excessive or inappropriate muscle contractions. Over the years, the number of primary clinical publications has grown exponentially, and still continues to increase. It has been shown that BoNT blocks cholinergic nerve endings in the autonomic nervous system but does not block non-adrenergic non-cholinergic responses mediated by nitric oxide (NO). The present paper reviews a number of recent clinical indications for urological and pelvic floor dysfunctions, such as overactive and neurogenic bladder, non-bacterial prostatitis, benign prostatic hyperplasia, chronic anal fissure, or conditions associated to hyperactivity of the puborectalis muscle during straining. These indications provide a new promising palette of indications for future usage of BoNT in clinical practice.

Prostate activity and prostate cancer in spinal cord injury

In addition to androgen, autonomic nerves may be involved in prostatic function. As patients with spinal cord injury (SCI) have impaired innervation of the prostate, the prostate volume and prostate-specific antigen (PSA) level in patients with SCI may be different from those of healthy men. Experiments in rats with SCI indicate that neurogenic factors play an important role in prostate growth and function but the same phenomena may not occur in men with SCI because the current animal models differ from clinical results in humans in several respects. Although many of studies indicate the importance of intact peripheral innervation on the secretory function of the prostate, the effect of more central denervation such as occurs in complete SCI at the cervical, thoracic, or lumbar levels on prostatic function is unclear. In addition, the impact of central nervous system injury on prostatic secretory activity, and consequently on serum PSA levels, is also not clear. Furthermore, the impact of hormonal changes on prostate cancer development and prognosis observed in patients with SCI may also be affected by the level of injury and patient age at the time of injury, which have not been studied. In this article, we review prostate activity and prostate cancer in SCI and discuss how they may relate to neurogenic factors.

Novel action of botulinum toxin on the stromal and epithelial components of the prostate gland

PURPOSE

Intraprostatic injection of BTX-A has demonstrated clinical improvement in men with bladder outlet obstruction. We investigated the mechanisms of action of BTX-A on the prostate.

MATERIALS AND METHODS

Adult male Sprague-Dawley rats were injected with varying doses of BTX-A into the prostate and the prostates were harvested after 1 or 2 weeks. The effects of BTX-A on prostate histology, and the proliferative and apoptotic indexes were determined using hematoxylin and eosin staining, proliferative cell nuclear antigen staining and TUNEL staining, respectively. Changes in alpha(1A) adrenergic receptor and androgen receptor were evaluated by Western blotting.

RESULTS

One week after BTX-A injection generalized prostate atrophy was observed. There was a significant increase in apoptotic cells (12, 16 and 22-fold), and decrease in proliferative cells (38%, 77% and 80%) and alpha(1A) adrenergic receptor (13%, 80% and 81%) for 5, 10 and 20 U, respectively. There was no significant change in androgen receptors. The effects were decreased 2 weeks after BTX-A treatment.

CONCLUSIONS

BTX-A injection into the prostate alters cellular dynamics by inducing apoptosis, inhibiting proliferation and down-regulating alpha(1A) adrenergic receptors. BTX-A may potentially be the drug that has dual actions on the static and dynamic components of benign prostatic hyperplasia.

Botulinum Toxin Type A Injections to Salivary Glands: Combination With Single Event Multilevel Chemoneurolysis in 2 Children With Severe Spastic Quadriplegic Cerebral Palsy

We describe 2 children with severe spastic quadriplegic cerebral palsy (CP) who have significant drooling and frequent aspiration pneumonia. They underwent simultaneous botulinum toxin type A (BTX-A) injections to salivary glands for drooling and prevention of aspiration pneumonia along with single-event multilevel chemoneurolysis (SEMLC) with BTX-A and 5% phenol for severe diffuse spasticity. There was significant improvement in drooling, frequency of aspiration pneumonia, and spasticity without adverse effect. BTX-A injections into the salivary glands, in addition to SEMLC, for these 2 children with medically complicated severe spastic quadriplegic CP, were safe and highly successful procedures, which improved their health-related quality of life.

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

OBJECTIVES

To expand the clinical use of botulinum toxin A (BTX-A) in treating patients with small prostates and symptomatic benign prostatic hyperplasia (BPH). BTX-A injection into the prostate in patients with voiding dysfunction and large prostates has been reported.

METHODS

Sixteen men with symptomatic BPH, a prostate volume less than 30 cm3, peak flow rate less than 12 mL/s, and with refractory disease after at least 1 month of alpha-blocker treatment received BTX-A 100 U injection into the prostate transperineally under transrectal ultrasound guidance. The clinical effects were evaluated at baseline and after treatment.

RESULTS

No significant local or systemic side effects were observed in any of the patients. All patients reported subjective improvement starting at approximately 1 week and achieved a maximal effect after 1 month that was maintained at 3 and 6 months. At 6 to 12 months (mean 10) of follow-up, no patient had symptom recurrence. The mean prostate volume, symptom score, and quality-of-life index were significantly reduced by 13.3% (from 19.6 +/- 1.2 to 17.0 +/- 1.1 cm3), 52.6% (from 18.8 +/- 1.6 to 8.9 +/- 1.9), and 44.7% (from 3.8 +/- 0.3 to 2.1 +/- 0.3), respectively. The maximal flow rate increased significantly by 39.8% (from 7.3 +/- 0.7 to 11.8 +/- 0.8 mL/s). In 2 patients who underwent biopsy 1 month after BTX-A injection, terminal deoxynucleotidyl-mediated deoxyuridine triphosphate nick end labeling staining demonstrated an increase in apoptotic activity, not only in the glandular component, but also in the stromal component of the prostatic tissue.

CONCLUSIONS

BTX-A injected into the prostate is a promising treatment for patients with small prostates and symptomatic BPH.

Urologic applications of botulinum toxin therapy for voiding dysfunction

Botulinum toxin is primarily a presynaptic neuromuscular blocking agent inducing selective and reversible muscle weakness up to several months when injected intramuscularly in small quantities. The clinical use of botulinum toxin type-A has gained widespread acceptance and application for numerous adult and pediatric spasticity syndromes. This has led to the urologic adoption of this minimally invasive therapy for the treatment of idiopathic and neurogenic detrusor overactivity, interstitial cystitis, detrusor-sphincter dyssynergia, urinary retention, and prostatic conditions. Outlined below is an overview of the clinical adoption of this therapy for the treatment of various dysfunctions of the lower urinary tract.

Injectable neuromodulatory agents: botulinum toxin therapy

Botulinum toxin therapy is a diverse treatment option for various dysfunctions of the lower urinary tract. The limited but growing clinical experience reveals that temporary chemodenervation with reduction or loss of neuronal activity at the target organ may be achieved with minimal risk. This highly favorable risk-benefit ratio in urology is derived from the clinical ability to treat an end-organ condition effectively with controllable site-specific delivery (eg, subcutaneous, intramuscular, or instillation) combined with high affinity for toxin uptake by the peripheral cholinergic nerves. Although many questions remain regarding the optimal use of this minimally invasive option for urologic applications, the opportunity for expanding indications will provide urologists with more options for addressing difficult challenges in voiding dysfunction.

Botulinum toxin in the management of lower urinary tract dysfunction: contemporary update

PURPOSE OF REVIEW

To review the most recent experience concerning the application of botulinum toxin in the human lower urinary tract.

RECENT FINDINGS

Botulinum toxin was initially applied in the bladder of patients with spinal neurogenic detrusor overactivity and urinary incontinence, or in the urethra in cases of detrusor external sphincter dyssynergia. A large multicentric European study fully confirmed the initial expectancy in the former condition. In addition, the application of botulinum toxin was extended to the treatment of other urological disorders including non-neurogenic detrusor overactivity, non-relaxing urethral sphincter and detrusor underactivity. Interesting reports on the injection of botulinum toxin into the prostate of patients with benign prostatic hyperplasia are also reviewed.

SUMMARY

Bladder injection of botulinum toxin is not yet an approved treatment for lower urinary tract dysfunction. Nevertheless, available data suggest that in the near future the toxin will become a standard therapeutic option in incontinent patients with neurogenic and non-neurogenic forms of overactive bladder, who do not respond to or do not tolerate anticholinergic medication. In addition, it might be expected that urethral botulinum toxin injections improve bladder emptying in patients with dysfunctional voiding problems besides detrusor external sphincter dyssynergia.