Clinical effect of alpha-1 antagonism by terazosin on external and internal urinary sphincter function

The urethra in continence and sensation: Neural aspects of urethral function

AIMS

Traditionally, the urethra has been considered a mere conduit to guide urine from the bladder to the external side of the body. Building evidence indicates that the urethra may directly influence bladder function via mechanisms restricted to the lower urinary tract (LUT).

METHODS

Here, we discuss the tissue arrangement of the urethra and addressed the contribution of new paraneuronal cells to LUT function. We also briefly reviewed two frequent LUT pathologies associated with urethral dysfunction.

RESULTS

Continence depends on an intact and functional urethral sphincter, composed of smooth, and striated muscle fibers and regulated by somatic and autonomic fibers. Recent studies suggest the existence of an urethro-vesical reflex that also contributes to normal LUT function. Indeed, the urethral lumen is lined by a specialized epithelium, the urothelium, in the proximal urethra. In this region, recent evidence demonstrates the presence of specific paraneuronal cells, expressing the neurotransmitters acetylcholine and serotonin. These cells are in close proximity of nerve fibers coursing in the lamina propria and are able to release neurotransmitters and rapidly induce detrusor contractions, supporting the existence of an urethro-vesical crosstalk.

CONCLUSION

The mechanism underlying the fast communication between the urethra and thebladder are beginning to be understood and should involve the interaction between specificepithelial cells and fibres innervating the urethral wall. It is likely that this reflex should bealtered in pathological conditions, becoming an attractive therapeutic target.

Managing Urological Disorders in Multiple Sclerosis Patients: A Review of Available and Emerging Therapies

Multiple sclerosis (MS) is a progressive neurological autoimmune disease with a diverse range of urological symptomatology, and most MS patients experience 1 or more moderate to severe urinary symptoms, as well as bladder and/or sexual disorders. Urologists play the director's role in evaluating and treating these patients. Therefore, identifying the proper evaluation tools and the most suitable therapeutic options for specific patients requires a thorough understanding of this disease process.

Rationales for a Urodynamic Study in Patients with Cervical Spondylotic Myelopathy

BACKGROUND

Detrusor sphincter dyssynergia, involuntary detrusor contractions (IDCs), and poor bladder compliance are common urodynamic findings in cervical spondylotic myelopathy (CSM). There is little information regarding the role of a urodynamic study after decompression surgery for CSM.

METHODS

Urodynamic study was performed before and 6 months after decompression of CSM. Japanese Orthopaedic Association score for cervical myelopathy and Neck Disability Index functional score were applied. International Prostate Symptom Score was applied in male patients, and 6-item Urogenital Distress Inventory was applied in female patients.

RESULTS

Mean patient age was 61.3 years. Final follow-up was obtained in 17 of 32 patients. Neurogenic bladder was confirmed in 11 (64.7%) patients, with 7 patients having poor bladder compliance, 3 patients having IDCs, and 6 patients having detrusor sphincter dyssynergia. Poor bladder compliance was normalized in 4 of 7 patients. IDCs disappeared in 2 (phasic IDCs) of 3 patients and improved in 1 (terminal IDC) patient. Detrusor sphincter dyssynergia markedly improved in 4 of 6 patients. Bladder compliance in 17 patients was 45.52 ± 23.71 before decompression surgery and 77.07 ± 39.85 after decompression surgery (P = 0.004). Both Japanese Orthopaedic Association and Neck Disability Index scores improved (P = 0.007 and P = 0.001, respectively). International Prostate Symptom Score and 6-item Urogenital Distress Inventory were not changed 6 months after surgery.

CONCLUSIONS

Neurogenic bladder could be partially controlled in patients with CSM after surgical decompression. The neurogenic component in the urodynamic study findings varied. Depending on the findings, further appropriate urologic treatments after neurologic decompression surgery should be considered.

Role of poor urethral sphincter relaxation in men with voiding dysfunction refractory to α-blocker therapy: Clinical characteristics and predictive factors

OBJECTIVES

This study evaluates the diagnostic value of poorly relaxed external sphincter (PRES) in men with voiding dysfunction. We analyzed clinical and video-urodynamic characteristics to identify predictive factors of PRES in patients with lower urinary tract symptoms (LUTS) refractory to α-1 adrenoceptor blocker (α-blocker) therapy.

METHODS

This retrospective study included 3379 men with LUTS in whom the initial 1-month α-blocker therapy failed. Clinical parameters and video-urodynamic results were analyzed. Patients with bladder outlet disorders including bladder neck obstruction (BNO), benign prostatic obstruction (BPO), urethral stricture (US), or PRES were categorized according to video-urodynamic findings. Predictive factors for PRES were analyzed.

RESULTS

A total of 3379 men were included in this study. Among the patients with voiding dysfunction, 905 (43.6%) had BPO, 624 (30.0%) had BNO, 487 (23.4%) had PRES, and 62 (3.0%) had US. Patients with PRES were younger and had a higher maximum flow rate, larger bladder capacity, smaller total prostate volume (TPV) and transition zone index, and a lower rate of LUTS of urgency or urge urinary incontinence (UUI) than other groups. On multivariate analysis, only small TPV and lower urgency/UUI rate were predictive factors of PRES. A scale composed of voided volume, TPV, and urgency/UUI predicted PRES with high specificity.

CONCLUSIONS

PRES was the etiology of voiding dysfunction in 23.4% of the men with LUTS refractory to α-blocker therapy. A simple scale composed of voiding volume, TPV, and urgency/UUI was useful in predicting the presence of PRES before video-urodynamic studies.

OnabotulinumtoxinA in overactive bladder: Evidence-based consensus recommendations

OBJECTIVE

To offer a set of useful recommendations for urologists who are starting to provide treatment of overactive bladders with onabotulinumtoxinA.

METHODS

A literature search to December 2013 was conducted, as well as a subsequent critical reading of the selected publications. The coordinators prepared a document that was submitted for review by the members of the Spanish Group for the use of Botulinum Toxin in Urology.

RESULTS

The expert group considered that onabotulinumtoxinA may be used for overactive bladder syndrome with urinary urge incontinence secondary to neurogenic or idiopathic detrusor overactivity for patients for whom conservative treatment and first-line medical treatment has failed, is not tolerated or is contraindicated. Treatment in most cases was performed with local intravesical anesthesia, although it can also be performed under epidural or general anesthesia. Patients must be informed of the possibility of requiring self-catheterization or temporary catheterization. Clinicians should ensure that the patients are capable of performing this catheterization before the treatment is conducted. Patients must also be informed of the need for antibiotic prophylaxis to reduce the risk of urinary tract infections. At least 2 follow-up visits are recommended: the first at days 7-14 after the injection and the second at 2-3 months. Reinjection is indicated when the effect of the treatment decreases.

CONCLUSION

These guidelines can help clinicians in their daily decisions and limit the potential risks associated with the incorrect use of the drug.

Detrusor sphincter dyssynergia: a review of physiology, diagnosis, and treatment strategies

Detrusor sphincter dyssynergia (DSD) is the urodynamic description of bladder outlet obstruction from detrusor muscle contraction with concomitant involuntary urethral sphincter activation. DSD is associated with neurologic conditions such as spinal cord injury, multiple sclerosis, and spina bifida and some of these neurogenic bladder patients with DSD may be at risk for autonomic dysreflexia, recurrent urinary tract infections, or upper tract compromise if the condition is not followed and treated appropriately. It is diagnosed most commonly during the voiding phase of urodynamic studies using EMG recordings and voiding cystourethrograms, although urethral pressure monitoring could also potentially be used. DSD can be sub-classified as either continuous or intermittent, although adoption of this terminology is not widespread. There are few validated oral pharmacologic treatment options for this condition but transurethral botulinum toxin injection have shown temporary efficacy in reducing bladder outlet obstruction. Urinary sphincterotomy has also demonstrated reproducible long term benefits in several studies, but the morbidity associated with this procedure can be high.

Treatment of detrusor external sphincter dyssynergia using ultrasound-guided trocar catheter transurethral botulinum toxin a injection in men with spinal cord injury

OBJECTIVE

To evaluate the effects of transrectal ultrasound-guided trocar catheter transurethral botulinum toxin A (BTX-A) injection into the external urethral sphincter (EUS) for treating detrusor external sphincter dyssynergia (DESD) in men with spinal cord injury (SCI).

DESIGN

Descriptive study.

SETTING

Hospital rehabilitation department.

PARTICIPANTS

Patients (N=15; mean age, 40.5y; range, 22-64y) with suprasacral SCI with confirmed DESD determined by urodynamic study.

INTERVENTIONS

A single dose of 100U BTX-A was injected into the EUS via transrectal ultrasound-guided trocar catheter transurethral injection.

MAIN OUTCOME MEASURES

Maximal detrusor pressure, detrusor leak point pressure, maximal pressure on static urethral pressure profilometry, postvoid residual volume, and maximal flow rate.

RESULTS

After BTX-A transurethral injection, 4 (28.5%) patients showed an excellent result and 7 (46.7%) patients showed an improved result, whereas 4 (28.5%) patients experienced treatment failure. The overall success rate was 75.2%. We observed a significant decrease in static urethral pressure (P<.05) and detrusor leak point pressure after treatment (P<.05), but not in detrusor pressure. The postvoid residual volume were significantly decreased in the fourth week after treatment (P<.05).

CONCLUSIONS

Transrectal ultrasound-guided trocar catheter transurethral BTX-A injection into the EUS effectively suppresses or ameliorates DESD. A potential advantage of the method is that ultrasound guidance may not be necessary in the next injection.

[Drug therapy of urethral diseases]

AIM

To describe drugs targeting urethra and prostate to treat dysfunctions such LUTS related to BPH, primary bladder neck obstruction (PBNO), detrusor sphincter dyssynergia (DSD) or sphincter deficiency (SD).

METHOD

Pubmed search for efficacy, mode of action and side effects for each molecule. Additional data were searched from the French regulatory agencies web sites (HAS and ANSM).

RESULTS

To treat LUTS related to BPH alpha-blockers (AB) and 5-alpha reductase inhibitors (5ARIs) have a clearer efficacy than plant extract. Daily Phosphodiesterase 5 inhibitors (PDE5Is) alone or in association with AB also demonstrate efficacy in this indication. AB are an option in PBNO and DSD related to multiple sclerosis. Although Botulinum toxin A derived molecules decrease urethral pressure in patient with DSD related to spinal cord injury or multiple sclerosis, efficiency remains to be demonstrated. Duloxetine a serotonin reuptake inhibitor increases urethral sphincter pressure and reduce stress urinary incontinence in women and men. Nevertheless, moderate efficacy combine with frequent side effects lead French regulation agency to reject its agreement.

CONCLUSION

Armamenterium to treat urethral dysfunctions has recently increases. Two new therapeutic classes emerge: PDE5Is to treat LUTS related to BPH and an SRIs (Duloxetine) to treat stress urinary incontinence. Efficacy and safety evaluation of all the possible associations between drugs targeting urethra and/or bladder is needed to a subtler and more efficient pharmacologic modulation of lower urinary tract dysfunction.

The neurogenic bladder: an update with management strategies for primary care physicians

Patients with lesions of the central nervous system often have neurogenic bladder dysfunction. Lifelong bladder monitoring and management in these patients is necessary to prevent severe complications, including renal damage. The urodynamic test, performed by neurourologists or other specially trained providers, is the definitive test for diagnosis and management of neurogenic bladder dysfunction. This article describes the indications and technique of urodynamic testing and the interpretation of the results of such testing. The management of patients with neurogenic bladder dysfunction is also discussed.

Outcome after treatment of detrusor–sphincter dyssynergia by temporary stent

OBJECTIVES

To evaluate follow-up treatments used after treatment of detrusor-sphincter dyssynergia (DSD) by a temporary urethral sphincter stent.

MATERIALS AND METHODS

Between February 1994 and June 2003, 147 men with a mean age of 41.3+/-14.4 years were treated by temporary urethral stent inserted across the external sphincter for DSD. The underlying neurologic disease was quadriplegia in 85 cases, multiple sclerosis in 24 cases and paraplegia in 21 cases. A Nissenkorn (Bard) stent was used in 130 cases and a Diabolo (Porgès) stent was used in 17 cases. All patients were either unable to or they refused to perform intermittent self-catheterization. DSD was demonstrated by urodynamic studies in every case.

RESULTS

The mean duration of temporary stenting was 10.15+/-16.07 months. After temporary stenting, 92 patients were treated by permanent stent (Ultraflex, Boston Scientifics), 7 started intermittent self-catheterization, 12 had repeated changes of the temporary stent, 4 had an indwelling catheter, 3 underwent cystectomy with non-continent diversion, 2 were treated by endoscopic sphincterotomy, 1 was treated by bladder neck incision, 1 was treated by neuromodulation and 1 was treated by cystostomy. Fifteen patients were lost to follow-up. Two patients died during follow-up (not related to DSD).

CONCLUSION

After treatment of DSD by a temporary urethral sphincter stent, 70.7% of patients subsequently require a permanent urethral sphincter stent. This period allows selection of patients unlikely to benefit from permanent urethral sphincter stent.

Management of detrusor-external sphincter dyssynergia

Detrusor-external sphincter dyssynergia (DSD) is a debilitating problem in patients with spinal cord injury. DSD carries a high risk of complications, and even life expectancy can be affected. The mainstay of treatment is the use of antimuscarinic medication and catheterization, but in those for whom this is not possible external sphincterotomy has been the traditional management route. External sphincterotomy, however, is associated with significant risks, including hemorrhage, erectile dysfunction and the need for repeat procedures, and over the last decade alternatives have been investigated, such as urethral stents and botulinum toxin injection. We present a review of DSD, including the current management strategies and prospects for future treatment.

Oral nitric oxide donors: a new pharmacological approach to detrusor-sphincter dyssynergia in spinal cord injured patients?

PURPOSE

Detrusor-sphincter dyssynergia is a common cause of bladder outlet obstruction in spinal cord injured patients and leads to poor bladder emptying and high bladder pressures, which if left untreated might cause renal failure. In this study, we tested the recently published hypothesis that oral administration of a nitric oxide donor could be a new pharmacological approach to treat detrusor-sphincter dyssynergia in humans with spinal cord injury.

METHODS

12 male spinal cord injured patients presenting with neurogenic detrusor overactivity and detrusor-sphincter dyssynergia were studied. 6 performed clean intermittent catheterisation and 6 used suprapubic tapping for bladder emptying. During cystometry the bladder was filled until the first overactive bladder contraction accompanied by detrusor-sphincter dyssynergia occurred while bladder and external urethral sphincter pressures were continuously recorded. Then the bladder was emptied and the patients received 10 mg of isosorbide dinitrate sublingually. Resting pressures were recorded and cystometry was repeated starting 15 min after drug administration. Maximal and mean values for bladder and external urethral sphincter pressures were calculated in both fillings and statistically compared by analysis of variance for repeated measurements (level of significance p < 0.05).

RESULTS

Nitric oxide significantly reduced external urethral sphincter pressures at rest (p < 0.05) and during dyssynergic contraction (p < 0.05) while bladder pressures at rest and during contraction as well as the reflex volume remained unchanged. In the patients who used suprapubic tapping for bladder emptying the mean post triggering residual volume was significantly reduced (p < 0.05).

CONCLUSIONS

Oral administration of nitric oxide donors significantly reduced bladder outlet obstruction due to detrusor-sphincter dyssynergia suggesting a role for nitric oxide in inhibitory neurotransmission to the urethral sphincter. This new approach could offer a potential pharmacological option to treat detrusor-sphincter dyssynergia in spinal cord injured patients.

The effect of nitric oxide on the resting tone and the contractile behaviour of the external urethral sphincter: a functional urodynamic study in healthy humans

AIMS

This functional urodynamic study assessed the effect of the nitric oxide donor isosorbide dinitrate on the external urethral sphincter and hypothesised first that nitric oxide could lower the resting sphincter pressure, second that nitric oxide could influence the sphincter contractility during magnetic stimulation, and third that nitric oxide could induce a faster external urethral sphincter fatigue during continuous magnetic stimulation.

METHODS

Eight healthy males gave their written informed consent and were included. A 2-channel microtip pressure transducer catheter was inserted into the urethra measuring the bladder and the external urethral sphincter pressure. Magnetic stimulation of the sacral roots was performed to evoke reproducible contractions of the external urethral sphincter. The baseline protocol included six single pulse stimulations and three stimulations 10sec in duration each for two frequencies 5Hz and 50Hz with intensities at the motor threshold of the pelvic floor. Then the subjects received 10 mg of isosorbide nitrate sublingually and the protocol was repeated 5min, 20min, 40min and 60min after drug administration.

RESULTS

The sublingual administration of isosorbide dinitrate could significantly reduce the resting pressure of the external urethral sphincter for at least one hour. The maximal contractile strength measured as the maximal urethral pressure during single pulse and continuous magnetic stimulation of the sacral roots also decreased significantly. Nitric oxide did not induce a significantly faster fatigue of the external urethral sphincter during continuous magnetic stimulation of the sacral roots.

CONCLUSIONS

This study shows a functionally relevant effect of nitric oxide on the resting tone and the contractile behaviour of the human external urethral sphincter in vivo while the fatigue properties did not changed significantly. Nitric oxide donors could offer a new pharmacological approach to treat urinary retention due to overactive or non-relaxing external urethral sphincter.

Botulinum toxin as a new therapy option for voiding disorders: current state of the art

Botulinum toxin is a presynaptic neuromuscular blocking agent inducing selective and reversible muscle weakness up to several months when injected intramuscularly in minute quantities. Different medical disciplines have discovered the toxin to treat mainly muscular hypercontraction. In urology, indications for botulinum-A toxin have been neurogenic detrusor overactivity, detrusor-sphincter dyssynergia, motor and sensory urge and, more recently, chronic prostatic pain. The available literature was reviewed using Medline Services. The keywords "botulinum-A toxin", "detrusor-sphincter dyssynergia", "neurogenic bladder", "spinal cord injury", "denervation", "chronic prostatic pain", "chronic urinary retention" were used to obtain references. A toxin injection is effective to treat detrusor-sphincter dyssynergia when injected either transurethrally or transperineally. After treatment, external urethral sphincter pressure, voiding pressure and post-void residual volume decreased. The effect lasts between 2 to 9 months depending on the number of injections. Best indications seem to be multiple sclerosis and incomplete spinal cord injury patients suffering from neurogenic detrusor overactivity and detrusor-sphincter dyssynergia. According to the previous results, the use of botulinum-A toxin injections into the external urethral sphincter has been extended to a variety of bladder obstructions and to decrease outlet resistance in patients with acontractile detrusor. In cases of successful treatment, spontaneous voiding re-occurs and catheterization can be resumed. Injections of the toxin into the external urethral sphincter also seem to have a beneficial effect on chronic prostatic pain, presumably by reducing hypertonicity and hyperactivity of the external urethral sphincter. Injections of botulinum-A toxin into the detrusor muscle has first been tested to treat neurogenic detrusor activity in spinal cord injured patients and in myelomeningocele children. Long lasting (mean 9 months) detrusor relaxation occurs after injection of usually 300 units of Botox). Continence is restored in about 95% of the patients and anticholinergic drugs can be markedly reduced or even stopped. Excellent results of botulinum-A toxin injections into the detrusor in neurogenic detrusor overactivity have lead to an expansion of this treatment to incontinence due to idiopathic detrusor overactivity. Although preliminary results are promising, adequate dosage of the toxin required for this indication is not yet known. In conclusion, it appears that botulinum toxin injection into either the external urethral sphincter or the detrusor offers new promising treatment options for many different urological dysfunctions. However, large controlled trials are absolutely required to establish the role of botulinum-A toxin injections in the fields of urology and neurourology on evidence based medicine.

Sphincterotomy and the treatment of detrusor-sphincter dyssynergia: current status, future prospects

STUDY DESIGN

Literature review of current treatment options for detrusor-sphincter dyssynergia (DSD) in spinal cord injury.

OBJECTIVES

To review the outcomes and complications associated with external sphincterotomy and to summarise the results and complications of alternative treatment options for detrusor-sphincter dyssynergia in spinal cord injury. In addition, we propose a potential alternative future drug treatment for external sphincter dyssynergia based upon recent research on the neuropharmacology of the external urethral sphincter.

SETTING

The National Spinal Injuries Centre, Stoke Mandeville Hospital, Aylesbury, UK.

METHODS

Medline search from 1966 to 2002 using the words 'external sphincterotomy', 'detrusor-sphincter dyssynergia' and 'neurogenic bladder combined with surgery'.

RESULTS

While external sphincterotomy is an effective treatment for DSD, a significant number of men following this procedure continue to have high intrarenal pressures, recurrent urinary infection or troublesome autonomic dysreflexia and a worryingly high proportion demonstrate persistently raised leak point pressures, putting them at subsequent risk of renal damage. Alternative treatments for external sphincter dyssynergia include urethral stents and balloon dilatation, both of which are effective. However, over the long term stents can undergo encrustation and there remains a definite risk of stent migration necessitating stent removal or replacement. Balloon dilatation of the external sphincter is associated with a risk of subsequent stricture formation. Intraurethral Botulinum A toxin seems to be effective though there have been no large randomised studies comparing it against placebo. However, it is not a durable treatment option and it has not found a common place in the treatment of DSD. There is now a considerable amount of experimental data from both animal and human studies to suggest that nitric oxide (NO) is an important physiological inhibitory neurotransmitter in the urethral sphincter, mediating relaxation of the external urethral sphincter. The potential role of sphincter NO augmentation for treatment of DSD is discussed.

CONCLUSION

External sphincterotomy remains the mainstay of treatment for urodynamically significant detrusor-sphincter dyssynergia, but in recent years a number of effective, alternative treatment options have become available. While at present there is no effective systemic drug treatment, recent research into external sphincter neuropharmacology suggests that systemic or topical augmentation of external sphincter NO may provide an effective method for lowering sphincter pressure.