Sacral neuromodulation for women with Fowler's syndrome

Evaluation of the efficacy of sacral neuromodulation in the treatment of voiding dysfunction after endometriosis surgery

Pelvic surgery for endometriosis is associated with a risk of bladder and digestive sequelae. Sacral neuromodulation (SNM) has been shown to be effective in the treatment of overactive bladder (OAB) and voiding dysfunction (VD). This study aimed to evaluate the efficacy of sacral neuromodulation (SNM) in treating voiding dysfunction (VD) following endometriosis surgery. A retrospective analysis was conducted on data from women who underwent SNM testing for persistent VD after endometriosis surgery. The study included 21 patients from a French tertiary referral center. Patient characteristics, lower urinary tract symptoms, urodynamic findings, SNM procedures, and outcomes were assessed. The primary outcome was the success of SNM treatment for VD. After a median follow-up of 55 months, 60% of patients achieved successful outcomes, with significant improvements of VD and quality of life. Moreover, more than half of patients who required clean intermittent self-catheterization (CISC) before SNM were able to wean off CISC. Complications such as infections and paraesthesia were observed, but overall, SNM was found to be effective and well tolerated. Age and the interval between endometriosis surgery and SNM testing were associated with treatment success. This study adds to the limited existing literature on SNM for VD after endometriosis surgery and suggests that SNM can be a valuable therapeutic option for these patients. Further research is needed to identify predictive factors and mechanisms underlying the effectiveness of SNM in this context. MRI-compatible and rechargeable devices, has improved the feasibility of SNM for these patients. In conclusion, SNM offers promise as a treatment option for persistent VD after endometriosis surgery, warranting further investigation. LEVEL OF EVIDENCE: 4.

Role of opioid and β-adrenergic receptors in bladder underactivity induced by prolonged pudendal nerve stimulation in cats

AIMS

To determine the role of opioid and β-adrenergic receptors in bladder underactivity induced by prolonged pudendal nerve stimulation (PNS).

METHODS

In α-chloralose anesthetized cats, 30-min PNS was applied repeatedly for 3-9 times to induce poststimulation or persistent bladder underactivity. Then, naloxone (opioid receptor antagonist, 1 mg/kg, IV) or propranolol (β-adrenergic receptor antagonist, 3 mg/kg, IV) was given to reverse the bladder underactivity. After the drug treatment, an additional 30-min PNS was applied to counteract the drug effect. Repeated cystometrograms were performed by slowly (1-2 mL/min) infusing the bladder with saline via a urethral catheter to determine the bladder underactivity and the treatment effects.

RESULTS

Prolonged (2-4.5 h) PNS induced bladder underactivity evident as a large bladder capacity (169 ± 49% of control) and a reduced amplitude of bladder contraction (59 ± 17% of control). Naloxone fully reversed the bladder underactivity by reducing bladder capacity to 113 ± 58% and increasing the amplitude of bladder contraction to 104 ± 34%. After administration of naloxone an additional 30-min PNS temporarily increased the bladder capacity to the underactive bladder level (193 ± 74%) without changing the amplitude of the bladder contraction. Propranolol had no effect on bladder underactivity.

CONCLUSIONS

A tonic enkephalinergic inhibitory mechanism in the CNS plays a critical role in the bladder underactivity induced by prolonged PNS, while the peripheral β-adrenergic receptor mechanism in the detrusor is not involved. This study provides basic science evidence consistent with the clinical observation that comorbid opioid usage may contribute to voiding dysfunction in patients with Fowler's syndrome.

European Association of Urology Guidelines on the Management of Female Non-neurogenic Lower Urinary Tract Symptoms. Part 2: Underactive Bladder, Bladder Outlet Obstruction, and Nocturia

CONTEXT

Female lower urinary tract symptoms (LUTS) are a common presentation in urological practice. Thus far, only a limited number of female LUTS conditions have been included in the European Association of Urology (EAU) guidelines compendium. The new non-neurogenic female LUTS guidelines expand the remit to include these symptoms and conditions.

OBJECTIVE

To summarise the management of underactive bladder (UAB), bladder outlet obstruction (BOO), and nocturia in females.

EVIDENCE ACQUISITION

The literature search was updated in September 2021 and evidence synthesis was conducted using modified GRADE approach as outlined for all EAU guidelines. A new systematic review on BOO was carried out by the panel for purposes of this guideline.

EVIDENCE SYNTHESIS

The important considerations for informing guideline recommendations are presented, along with a summary of all the guideline recommendations.

CONCLUSIONS

Non-neurogenic female LUTS are an important presentation of urological dysfunction. Initial evaluation, diagnosis, and management should be carried out in a structured and logical fashion on the basis of the best available evidence. This guideline serves to present this evidence to practising urologists and other health care providers in an easily accessible and digestible format.

PATIENT SUMMARY

This report summarises the main recommendations from the European Association of Urology guideline on symptoms and diseases of the female lower urinary tract (bladder and urethra) not associated with neurological disease. We cover recommendations related to the treatment of underactive bladder, obstruction of the bladder outlet, and nighttime urination.

Superficial peroneal neuromodulation of nonobstructive urinary retention induced by prolonged pudendal afferent activity in cats

The purpose of this study is to determine whether superficial peroneal nerve stimulation (SPNS) can improve nonobstructive urinary retention (NOUR) induced by prolonged pudendal nerve stimulation (PNS). In this exploratory acute study using eight cats under anesthesia, PNS and SPNS were applied by nerve cuff electrodes. Skin surface electrodes were also used for SPNS. A double lumen catheter was inserted via the bladder dome for bladder infusion and pressure measurement and to allow voiding without a physical urethral outlet obstruction. The voided and postvoid residual (PVR) volumes were also recorded. NOUR induced by repetitive (4-13 times) application of 30-min PNS significantly (P < 0.05) reduced voiding efficiency by 49.5 ± 16.8% of control (78.3 ± 7.9%), with a large PVR volume at 208.2 ± 82.6% of control bladder capacity. SPNS (1 Hz, 0.2 ms) at 1.5-2 times threshold intensity (T) for inducing posterior thigh muscle contractions was applied either continuously (SPNSc) or intermittently (SPNSi) during cystometrograms to improve the PNS-induced NOUR. SPNSc and SPNSi applied by nerve cuff electrodes significantly (P < 0.05) increased voiding efficiency to 74.5 ± 18.9% and 67.0 ± 15.3%, respectively, and reduced PVR volume to 54.5 ± 39.0% and 88.3 ± 56.0%, respectively. SPNSc and SPNSi applied noninvasively by skin surface electrodes also improved NOUR similar to the stimulation applied by a cuff electrode. This study indicates that abnormal pudendal afferent activity could be a pathophysiological cause for the NOUR occurring in Fowler's syndrome and a noninvasive superficial peroneal neuromodulation therapy might be developed to treat NOUR in patients with Fowler's syndrome.

Superficial peroneal neuromodulation of persistent bladder underactivity induced by prolonged pudendal afferent nerve stimulation in cats

The purpose of this study is to determine whether superficial peroneal nerve stimulation (SPNS) can reverse persistent bladder underactivity induced by prolonged pudendal nerve stimulation (PNS). In 16 α-chloralose-anesthetized cats, PNS and SPNS were applied by nerve cuff electrodes. Skin surface electrodes were also used for SPNS. Bladder underactivity consisting of a significant increase in bladder capacity to 157.8 ± 10.9% of control and a significant reduction in bladder contraction amplitude to 56.0 ± 5.0% of control was induced by repetitive (4-16 times) application of 30-min PNS. SPNS (1 Hz, 0.2 ms) at 1.5-2 times threshold intensity (T) for inducing posterior thigh muscle contractions was applied either continuously (SPNSc) or intermittently (SPNSi) during a cystometrogram (CMG) to determine whether the stimulation can reverse the PNS-induced bladder underactivity. SPNSc or SPNSi applied by nerve cuff electrodes during the prolonged PNS inhibition significantly reduced bladder capacity to 124.4 ± 10.7% and 132.4 ± 14.2% of control, respectively, and increased contraction amplitude to 85.3 ± 6.2% and 75.8 ± 4.7%, respectively. Transcutaneous SPNSc and SPNSi also significantly reduced bladder capacity and increased contraction amplitude. Additional PNS applied during the bladder underactivity further increased bladder capacity, whereas SPNSc applied simultaneously with the PNS reversed the increase in bladder capacity. This study indicates that a noninvasive superficial peroneal neuromodulation therapy might be developed to treat bladder underactivity caused by abnormal pudendal nerve somatic afferent activation that is hypothesized to occur in patients with Fowler's syndrome.

Fowler's Syndrome-The Cause of Urinary Retention in Young Women, Often Forgotten, but Significant and Challenging to Treat

Urinary retention in young women is a relatively rare clinical problem and is often underdiagnosed. In particular, functional causes of urinary retention pose a diagnostic challenge. One of them is Fowler’s syndrome, which is associated with impaired urethral relaxation. Fowler’s syndrome is characterized by a large bladder capacity, reduced sensation, increased maximal urethral closure pressure, and detrusor underactivity. Several hypotheses have arisen to explain the cause of urethral relaxation disorders: hormonal changes characteristic of Polycystic Ovary Syndrome (PCOS), causing abnormal stabilization of the muscle membrane, primary failure of relaxation of the striated muscle of the urethra sphincter, and increased urethral afferent activity, inhibiting the bladder afferent signals from reaching the brain by potentiating a spinal mechanism of urinary continence. Currently, sacral neuromodulation is the only intervention that can restore an atypical voiding pattern in women with Fowler’s syndrome. The therapeutic effectiveness exceeds 70%, although the revision rate is relatively high, exceeding 50%. Well-designed, long-term prospective studies comparing sacral neuromodulation (SNM) with other therapies such as pelvic floor muscle physiotherapy are warranted to offer the best patient-tailored treatment.

Sacral neuromodulation to treat voiding dysfunction in patients with previous pelvic surgery for deep infiltrating endometriosis: our centre's experience

Introduction and hypothesis

Voiding symptoms/dysfunctions (VS/Ds) after surgery for deep-infiltrating endometriosis (DIE) are frequent (20% of patients) and, together with bowel dysfunctions, may represent a de novo disorder due to surgical damage of the pelvic plexus or a worsening of pre-existent functional damage. Sacral neuromodulation (SNM) might improve voiding symptoms by treating dysfunctional voiding. The aim of this study is to report our experience with SNM in patients treated with surgery for DIE.

Methods

We retrospectively enrolled 13 patients with VS/Ds after surgery for DIE. All patients were investigated with urodynamic studies (UDS) and agreed to undergo SNM. Pre-existing VS/Ds, bowel disorders and pelvic pain, DIE surgical procedures, UDS and SNM test results were recorded.

Results

After surgery for DIE, functional bladder outflow obstruction and detrusor acontractility were observed in nine and four patients, respectively. Chronic pelvic pain was present in seven cases. Twelve patients developed constipation, whilst one patient had de novo faecal incontinence. After the SNM testing period, nine patients (69.2%) experienced a significant improvement of symptoms that led to definitive implant. Four patients (30.8%) had no symptom relief and the system was removed.

Conclusions

Functional bladder outflow obstruction and urinary retention are the most common VS/Ds after surgery for DIE. SNM may be an effective option for these patients, probably due to its action in improving the dysfunctional voiding, which was likely to be already present as part of the “endometriotic syndrome” and got worse after pelvic surgery. Results for pelvic pain control and gastrointestinal disorders should not be underestimated.

Current concepts of the acontractile bladder

The acontractile bladder (AcB) is a urodynamic-based diagnosis wherein the bladder is unable to demonstrate any contraction during a pressure flow study. Although it is often grouped with underactive bladder, it is a unique phenomenon and should be investigated independently. The purpose of the present review was to examine the current literature on AcB regarding its pathology, diagnosis, current management guidelines, and future developments. We performed a review of the PubMed database, classifying the evidence for AcB pathology, diagnosis, treatment, and potential future treatments. Over the 67 years covered in our review period, 42 studies were identified that met our criteria. Studies were largely poor quality and mainly consisted of retrospective review or animal models. The underlying pathology of AcB is variable with both neurological and myogenic aetiologies. Treatment is largely tailored for renal preservation and reduction of infection. Although future developments may allow more functional restorative treatments, current treatments mainly focus on bladder drainage. AcB is a unique and understudied bladder phenomenon. Treatment is largely based on symptoms and presentation. While cellular therapy and neuromodulation may hold promise, further research is needed into the underlying neuro-urological pathophysiology of this disease so that we may better develop future treatments.

Dysfunctional voiding: the importance of non-invasive urodynamics in diagnosis and treatment

In Dysfunctional voiding, failure of the external sphincter-pelvic floor complex to relax during micturition results in bladder outflow obstruction with a spectrum of presentation from more benign lower urinary tract dysfunction including recurrent urinary tract infections, to significant upper tract pathology and end-stage renal failure. There is no underlying neurological or anatomical cause and the condition is postulated to be a largely learnt behavior. Diagnosis relies on non-invasive urodynamics and in particular uroflowmetry, plus or minus EMG, which is also used in biofeedback, the mainstay of treatment. The etiology, presentation, diagnosis, and treatment with particular emphasis on non-invasive urodynamics are covered.

Sacral neuromodulation blocks pudendal inhibition of reflex bladder activity in cats: insight into the efficacy of sacral neuromodulation in Fowler's syndrome

This study tested the hypothesis that sacral neuromodulation, i.e., electrical stimulation of afferent axons in sacral spinal root, can block pudendal afferent inhibition of the micturition reflex. In α-chloralose-anesthetized cats, pudendal nerve stimulation (PNS) at 3-5 Hz was used to inhibit bladder reflex activity while the sacral S1 or S2 dorsal root was stimulated at 15-30 Hz to mimic sacral neuromodulation and to block the bladder inhibition induced by PNS. The intensity threshold (T) for PNS or S1/S2 dorsal root stimulation (DRS) to induce muscle twitch of anal sphincter or toe was determined. PNS at 1.5-2T intensity inhibited the micturition reflex by significantly ( P < 0.01) increasing bladder capacity to 150-170% of control capacity. S1 DRS alone at 1-1.5T intensity did not inhibit bladder activity but completely blocked PNS inhibition and restored bladder capacity to control level. At higher intensity (1.5-2T), S1 DRS alone inhibited the micturition reflex and significantly increased bladder capacity to 135.8 ± 6.6% of control capacity. However, the same higher intensity S1 DRS applied simultaneously with PNS, suppressed PNS inhibition and significantly ( P < 0.01) reduced bladder capacity to 126.8 ± 9.7% of control capacity. S2 DRS at both low (1T) and high (1.5-2T) intensity failed to significantly reduce PNS inhibition. PNS and S1 DRS did not change the amplitude and duration of micturition reflex contractions, but S2 DRS at 1.5-2T intensity doubled the duration of the contractions and increased bladder capacity. These results are important for understanding the mechanisms underlying sacral neuromodulation of nonobstructive urinary retention in Fowler's syndrome.

The underactive bladder: diagnosis and surgical treatment options

The underactive bladder (UAB)/detrusor underactivity (DU) is a relatively common condition. It is difficult to diagnose and can be difficult to manage. The aim of this review is to provide a review of the diagnosis and different surgical treatment options for UAB/DU. A comprehensive literature review using medical search engines was performed. The search included a combination of the following terms, UAB, DU, TURP, reduction cystoplasty, bladder diverticulectomy and sacral neuromodulation (SNM). Search results were assessed for their overall relevance to this review. Definitions, general overview and management options were extracted from the relevant medical literature. DU affects up to 45% of men and women >70 years of age. The symptoms of DU overlap significantly with overactive bladder (OAB) and bladder outlet obstruction (BOO). Urodynamic findings include low voiding pressure combined with slow intermittent flow and incomplete bladder emptying. Non-operative management for DU is acceptable; only 1 in 6 male patients may need a TURP and acute urinary retention (AUR) is rare. TURP for DU is feasible and is associated with good short and medium term outcomes, but over time, there is a return to baseline symptoms. Bladder diverticulectomy can also improve DU, but there is a paucity of guidelines on patient selection. SNM provides excellent outcomes for DU, but patient selection is important.

Surgical management of recurrent urinary tract infections: a review

There are many causes of recurrent urinary tract infections (rUTI) which are amenable to surgical management. This usually follows a lengthy trial of conservative management. Aetiological classification of rUTI requiring surgical management may be divided into congenital or acquired. Predisposing factors are classified into two groups; those providing a source for organisms, or by maintaining favourable conditions for the proliferation of organisms. Sources of infections include calculi, fistulae or abscesses. Conditions which predispose to bacterial proliferation include malignancies, foreign bodies, high post void residuals, and neuropathic bladders. Removal of identified sources, treating the obstruction, and improving urinary drainage, are all goals of surgical management. Surgical options for rUTI management can range from minimally invasive procedures such as endoscopic or percutaneous, through to more invasive requiring laparoscopic or an open approach. Surgery remains a very important and viable solution.

Urethral Sphincter Injection of Botulinum Toxin A: A Review of Its Application and Outcomes

The first reported application of Botulinum toxin-A (BTX-A) into the urethral sphincter predates the first documented use in the bladder. The aim of this review is to describe the clinical indications of BTX-A injection into the urethral sphincter and its clinical efficacy. This review of the literature includes the larger more significant published studies that have reported on this use of BTX-A. Case reports and articles not published in English were excluded. There have been many published clinical studies describing the use of BTX-A in the urethral sphincter, four of which are randomized placebo controlled trials. These studies tend to include patients either in urinary retention or with obstructed voiding, both in the neuropathic and non-neuropathic populations. Studies tend to demonstrate improvements in urodynamic parameters and quality of life after injection. There have been many small clinical studies in this area, however larger placebo-controlled trials are needed to evaluate this treatment at higher levels of evidence.

Long-term outcome of sacral neuromodulation in patients with idiopathic nonobstructive urinary retention: Single-center experience

OBJECTIVE

The objective of this study was to determine the safety and efficacy of sacral neuromodulation (SNM) in patients with idiopathic nonobstructive urinary retention.

MATERIALS AND METHODS

We retrospectively reviewed the files of patients who underwent staged neuromodulation for idiopathic nonobstructive urinary retention from 2004 to 2016 at our hospital. Patients who had a 50% improvement in symptoms after 1 week of stage 1 procedure were qualified for permanent device implantation. Patient data were assessed on efficacy and need for intermittent self-catheterization, complications, and operative revision rates.

RESULTS

Twenty-seven female patients who underwent SNM therapy were analyzed. The mean age of the patients was 32.5 ± 10.8 years. The mean duration of urinary retention was 3.2 ± 1.7 years. All patients were doing intermittent self-catheterization, but few were able to void <100 ml. Twenty-four (88.8%) of the 27 patients demonstrated a >50% improvement in symptoms and underwent permanent device placement. At a median follow-up of 5.7 ± 3.2 years, 20 (83.3%) of the 24 patients demonstrated sustained improvement rates of >50%. Seventeen (70.83%) of 24 patients could void spontaneously with a mean residual urine of 28.1 ± 24.4 ml (P < 0.001). Three (12.5%) were voiding with significant mean decreasing number of catheterizations from 5.6 ± 2.4 to 1.4 ± 2.1 (P < 0.001). Four (16.6%) had their device explanted. Ten (41.6%) of the 24 patients underwent surgical revision. Most of the adverse events were managed by device reprograming.

CONCLUSION

SNM is a highly effective and safe procedure in this subset of the female population with idiopathic refractory nonobstructive urinary retention.

Evaluation of the axonics modulation technologies sacral neuromodulation system for the treatment of urinary and fecal dysfunction

INTRODUCTION

Sacral neuromodulation (SNM) remains one of the few effective treatments for refractory bladder and bowel dysfunction. However, SNM is associated with frequent need for surgical intervention, in many cases because of a failed battery. A rechargeable SNM system, with a manufacturer-reported battery life of 15 years or more, has entered post-market clinical testing in Europe but has not yet been approved for clinical testing in the United States. Areas covered: We review existing neuromodulation technologies for the treatment of lower urinary tract and bowel dysfunction and explore the limitations of available technology. In addition, we discuss implantation technique and device specifications and programming of the rechargeable SNM system in detail. Lastly, we present existing evidence for the use of SNM in bladder and bowel dysfunction and evaluate the anticipated trajectory of neuromodulation technologies over the next five years. Expert commentary: A rechargeable system for SNM is a welcome technological advance. However surgical revision not related to battery changes is not uncommon. Therefore, while a rechargeable system would be expected to reduce costs, it will not eliminate the ongoing maintenance associated with neuromodulation. No matter the apparent benefits, all new technologies require extensive post-market monitoring to ensure safety and efficacy.

Chronic pudendal neuromodulation using an implantable microstimulator improves voiding function in diabetic rats

Objective

Few studies have investigated the feasibility of using chronic pudendal neuromodulation for improving voiding function in patients with diabetes who are also experiencing urinary retention. The present study investigated the effects of chronic electrical stimulation (ES) of the sensory branch of the pudendal nerve on voiding function in diabetic rats.

Approach

A custom-made implantable microstimulation system was designed and manufactured for chronic implantation in normal control (NC) and diabetic rats. After three or six weeks of pudendal neuromodulation, the intravesical pressure, external urethral sphincter electromyograms (EUS-EMGs), and urine flow rate (UFR) of all rats were simultaneously recorded to assess the effects of chronic pudendal ES on voiding function. Morphological changes in pudendal axons were assessed through hematoxylin and eosin (H&E) staining.

Significance

This study demonstrated the feasibility of using chronic pudendal neuromodulation for improving voiding function in diabetic rats. These results may facilitate the development of an advanced neural prosthesis for restoring bladder function in clinical settings.

Pharmacologic management of non-neurogenic functional obstruction in women

INTRODUCTION

Impaired bladder emptying in women without neurologic disease may be related to urethral obstruction and/or impaired bladder contractility. Mechanical obstruction generally requires surgical management and options are limited for impaired bladder contractility. However, functional obstruction from voiding dysfunction or primary bladder neck obstruction may present an opportunity for pharmacologic intervention.

AREAS COVERED

In this review, the authors extensively reviewed available literature regarding the use of off-label medications for functional bladder outlet obstruction in women. In addition, side effect profiles and pharmacology of these medications determined from on-label indications are reviewed. Specific medications reviewed include vaginal diazepam, baclofen, urethral botulinum toxin injection, and alpha-adrenergic blockers.

EXPERT OPINION

Alpha-blockers in particular have demonstrated promise in women with demonstrable or suspected bladder outlet obstruction with side effect profiles similar to those observed in men. However, lack of quality data hinders informed decision making with alpha-blockers or any of the other agents studied in women with non-neurogenic functional outlet obstruction. In the absence of well-designed, placebo-controlled multi-institutional trials, those prescribing these medications must be aware of special considerations and side effects associated with relatively unfamiliar treatments in the context of uncertain benefit.

Diagnosis and Management of Bladder Outlet Obstruction in Women

Bladder outlet obstruction (BOO) should be considered when a woman complains of voiding difficulty, abdominal straining to void, or refractory storage symptoms. Diagnosis of female BOO is not straightforward and usually requires invasive (video)urodyanmic study. A diagnostic algorithm is recommended for making optimal diagnosis. Female BOO can be classified as having anatomical and functional origins, and each contains several sub-classifications. Literatures published between 1988 and 2013 were reviewed and summarized for the diagnosis and therapy in each subtype of female BOO.

Neural stimulators: a guide to imaging and postoperative appearances

Implantable neural stimulators have been developed to aid patients with debilitating neurological conditions that are not amenable to other therapies. The aim of this article is to improve understanding of correct anatomical placement as well as the relevant imaging methods used to assess these devices. Potential complications following their insertion and an overview of the current indications and potential mechanism of action of these devices is provided.

Sacral nerve stimulation: Interstim®therapy

Sacral nerve stimulation is a young but promising technique in the treatment of chronic voiding dysfunctions. Electrical stimulation of the S3 nerve--using a pacemaker device--is able to treat a wide range of pelvic floor dysfunctions. This article gives a brief review on the indications, mechanisms of action and possible complications of this technique. Furthermore, new evolutions in the domain of sacral nerve modulation are discussed.

Posterior tibial nerve stimulation as treatment for the overactive bladder

OBJECTIVE

To evaluate the efficacy of posterior tibial nerve stimulation (PTNS) as a treatment for the overactive bladder (OAB) resistant to medical treatment.

PATIENTS AND METHODS

The study included 60 patients, comprising 55 women (92%) and five men (8%) with a mean (SD) age of 41.4 (10.8) years, who presented to the Urology Department of Benha University Hospital from June 2010 to October 2012. All patients were assessed initially by taking a history, a physical examination, urine analysis, routine laboratory investigations, and a urodynamic evaluation in the form of flowmetry, cystometry, and a pressure-flow study in some cases. A voiding diary (daytime and night-time frequency, voiding volume, and leakage episodes) was completed by all patients, and all underwent 12 sessions of PTNS using a personal computer-based system, and were reassessed after the sixth session, at the end of the course, and at 3 and 6 months after the last session, using the same methods as in the baseline visit.

RESULTS

There was a statistically significant improvement in all the variables assessed. No infection or failure of the PTNS mechanism was detected while using the technique, but there were rare instances of minor bleeding and a temporary painful feeling at the insertion site.

CONCLUSION

PTNS is safe, and gives statistically significant improvements in the patient's assessment of OAB symptoms.

Optimizing the duration of assessment of stage-1 sacral neuromodulation in nonobstructive chronic urinary retention

OBJECTIVES

The duration of test stimulation using two-stage sacral neuromodulation (SNM) is not studied. This study will determine the restoration of normal bladder sensation and resultant voiding in chronic urinary retention (CUR) after stage-1 SNM.

MATERIALS AND METHODS

Two-stage SNM used in 24 female patients with CUR. After stage-1 SNM, patients were assessed over an eight-week period and asked to record the restoration of normal bladder sensation and voiding. Qualitative and quantitative statistics were used to assess the outcomes and the influence of prognostic factors.

RESULTS

The mean age of patients was 37.0 ± 9.7 years. Normal bladder sensation was restored on the same day as switching on the battery after stage-1 in seven patients (29.2%), while in 17 patients it occurred between day 2-31 (mean: nine days). Similarly, the mean onset of voiding was also nine days (range: 2-31 days). After day 15, 21% of patients voided. The mean lag time between the restoration of bladder sensation and voiding was 3.6 days. By day 17, a cumulative percentage of 90% of patients had a normalized bladder sensation and 80% had commenced voiding. Infection of the externalized lead occurred in only one case. There were no correlations between the outcome parameters with age (p > 0.05), symptom duration, or concomitant diagnosis of overactive bladder or chronic pelvic pain (p = 0.418, p = 0.114).

CONCLUSION

Stage-1 SNM may be left in situ for up to four weeks to ensure the maximum chance of restoring normal bladder function in this complex group of patients.

Prospective randomized double-blind study of temporary sacral nerve stimulation in patients with rectal evacuatory dysfunction and rectal hyposensitivity

OBJECTIVE

Prospective randomized double-blind placebo-controlled crossover trial of 14 female patients (median age 52 [30-69] years) with proctographically defined evacuatory dysfunction (ED) and demonstrable rectal hyposensitivity (elevated thresholds to balloon distension in comparison with age- and sex-matched controls).

BACKGROUND

Sacral nerve stimulation (SNS) is an evolving treatment for constipation. However, variable outcomes might be improved by better patient selection. Evidence that the effect of SNS may be mediated by modulation of afferent signaling promotes a role in patients with ED associated with rectal hyposensation.

METHODS

SNS was performed by the standard 2-stage technique (temporary then permanent implantation). During a 4-week period of temporary stimulation, patients were randomized ON-OFF/OFF-ON for two 2-week periods. Before insertion (PRE), and during each crossover period, primary (rectal sensory thresholds) and secondary (bowel diaries, constipation, and GIQoL [gastrointestinal quality of life] scores) outcome variables were blindly assessed.

RESULTS

Thirteen patients completed the trial. Following stimulation, defecatory desire volumes to rectal balloon distension were normalized in 10 of 13 patients (PRE: mean 277 mL [234-320] vs ON: 163 mL [133-193] vs OFF: 220 mL [183-257 mL]; P = 0.006) and maximum tolerable volume in 9 of 13 (PRE: mean 350 mL [323-377] vs ON: 262 mL [219-305] vs OFF: 298 mL [256-340 mL]; P = 0.012). There was a significant increase in the percentage of successful bowel movements (PRE: median 43% [0-100] vs ON: 89% [11-100] vs OFF: 83% [11-100]; P = 0.007) and Wexner constipation scores improved (PRE: median 19 [9-26] vs ON: 10 [6-27] vs OFF: 13 [5-29]; P = 0.01). There were no significant changes in disease-specific or generic quality of life measures. Eleven patients progressed to permanent stimulation (9/11 success at 19 months).

CONCLUSIONS

Most patients with chronic constipation secondary to ED with rectal hyposensitivity responded to temporary SNS. The physiological results presented support a mechanistic role for rectal afferent modulation.

Percutaneous tibial nerve stimulation for fecal incontinence: a video demonstration

BACKGROUND

Fecal incontinence is an increasingly common condition with significant negative impact on quality on life and health care resources. It frequently presents a therapeutic challenge to clinicians. Emerging evidence suggests that percutaneous tibial nerve stimulation is an effective treatment for fecal incontinence with the added benefit of being minimally invasive and cost effective.

METHOD

Pursuant to the preliminary report of our early experience of percutaneous tibial nerve stimulation in patients with fecal incontinence published in this journal in 2010, in this dynamic article, we now describe and demonstrate the actual technique that can be performed in a nurse-led clinic or outpatient or community setting.

CONCLUSION

Percutaneous tibial nerve stimulation is a technically simple procedure that can potentially be performed in an outpatient or community setting. The overall early success rate of 68% following its use reported by our unit compares favorably with the success rate following other forms of neuromodulation, including sacral nerve stimulation. When completed, our long-term outcome data will provide further information on the efficacy of tibial nerve stimulation in a larger cohort of patients (n > 100). Future studies, including our currently planned randomized controlled trial of percutaneous tibial nerve stimulation vs sham stimulation, will provide controlled efficacy data and may provide information on its exact mechanism of action.

Sacral neuromodulation for lower urinary tract dysfunction

OBJECTIVES

To review the technique, indications, results and working mechanisms of sacral neuromodulation (SNM) for lower urinary tract dysfunction.

METHODS

The available literature on SNM for lower urinary tract dysfunction was searched. Based on the information available in the literature and also based on personal experience, the urological indications, technique, mechanisms of action and results of SNM are presented and discussed.

RESULTS

SNM for lower urinary tract dysfunction involves stimulation of the 3rd sacral nerve with an electrode implanted in the sacral foramen and connected to a pulse generator. The technique is accepted by the FDA since 1997. Currently, SNM for lower urinary tract dysfunction has been successfully used in about 26,000 patients with various forms of lower urinary tract dysfunction, including urgency, frequency and urgency incontinence as well as non-obstructive urinary retention. The actual procedure of SNM consists of a minimal invasive technique and is effective in about 70% of the patients who have been implanted with a permanent system. Also, in pelvic pain, interesting results have been described. SNM modulates the micturition reflexes at different levels in the central nervous system.

CONCLUSIONS

Sacral neuromodulation is a safe and effective therapy for various forms of lower urinary tract dysfunction, including urgency, frequency and urgency incontinence as well as non-obstructive urinary retention. It should be the first choice after failure of maximal conservative therapy.

Urinary retention in women and sacral neuromodulation

The remit of this article is to provide an overview of urinary retention in women, taking into account the predisposing factors, aetiology, investigations and treatments. The information presented is based on a widespread search of the English literature using multiple library sites on the internet and on personal experience. Urinary retention occurs when there is impaired bladder emptying, resulting in a high post-void urinary residual. It is often associated with restricted voiding. The aetiology is manifold and thus the symptomatic patient may present to the urologist, gynaecologist, neurologist or physician. Once the problem is identified, and predisposing factors excluded (e.g. opiates), the patient has to be investigated fully. In the Department of Uro-Neurology at the National Hospital for Neurology and Neurosurgery in the UK, we advocate the use of urethral sphincter assessments, including urethral pressure studies, ultrasound volume assessment and electromyography. This article will take a detailed look at all aspects of assessing these patients. In those in whom diagnosis is reached, sacral neuromodulation (SNM) is the treatment of choice. As a modality, SNM has its supporters but also its detractors. Thus, it is essential that all patients are fully counselled before undergoing this surgery. Urinary retention in women is still poorly understood. This article serves to demystify the issues raised in having this condition, by looking closely at the currently known science. It is clear that some patients may be diagnosed with Fowler's syndrome and may thus be more treatable by SNM than others, but this still leaves a significant proportion of patients with no diagnosis and no satisfactory therapy. A great deal of work still needs to be done on the understanding of the pathogenesis, the provision of more distinct investigations and the development of better treatment modalities.

[The primary disorder of sphincter relaxation or Fowler's syndrome]

The primary disorder of sphincter relaxation or Fowler's syndrome constitutes the first cause of urinary retention in young women after ruling neurological, iatrogenic and local origins out. It includes painless urinary retention, polycystic ovaries in more than 50% of the cases, high maximum urethral closure pressure, increase in sphincter volume and striated urethral sphincter electromyography abnormalities. So far, the only treatment restoring micturation in this condition is sacral neuromodulation.

Retention test in sacral nerve stimulation for fecal incontinence

INTRODUCTION

Sacral nerve stimulation has become an established treatment for patients with fecal incontinence. However, the mechanism of its action remains obscure. We aim to assess whether sacral nerve stimulation improves patients' ability to retain rectal content.

METHODS

Patients who had been treated successfully with sacral nerve stimulation underwent four retention tests during which the stimulator was turned either on or off. Both the patients and investigators were blinded to the status of the stimulator. The retention test results were assessed for interassessment agreement and for any differences between the on and off phases. Wexner scores, anorectal physiology tests, and patients' perceptions of stimulator settings were also recorded.

RESULTS

Nineteen patients (16 women; mean age, 57.5 years) took part in the study. Retention tests showed moderate interassessment agreement (weighted Cohen's kappa index, 0.45). There were no sharp differences in retained volume between the stimulator's on and off phases (median 50 (range, 0-300) mL vs. 50 (range, 0-300) mL; P = 0.85).

CONCLUSION

Sacral nerve stimulation does not alter patients' ability to retain rectal content. Further studies are needed to investigate the mechanism of sacral nerve stimulation.

A functional magnetic resonance imaging study of the effect of sacral neuromodulation on brain responses in women with Fowler's syndrome

STUDY TYPE

Aetiology (case series).

LEVEL OF EVIDENCE

4.

OBJECTIVE

To examine brain responses to bladder filling in young women with Fowler's syndrome (FS, a sphincter abnormality manifested by impaired voiding and bladder sensation), treated with sacral neuromodulation (SNM).

PATIENTS AND METHODS

Six women, aged 18-39 years with FS underwent functional brain magnetic resonance imaging (fMRI) immediately after SNM and when untreated (baseline). Data were collected at four sessions: after SNM with an empty and a full bladder, and at baseline with an empty and a full bladder. In each session, 280 whole-brain scans were acquired while repeatedly infusing and withdrawing 50 mL of saline, using push-buttons to report changing desire to void. Data were analysed using Statistical Parametric Mapping.

RESULTS

At baseline with an empty bladder, extensive responses (contrast = infusion-withdrawal) were almost exclusively negative ('deactivations'), e.g. in the right insula, seat of visceral sensation. Increased bladder volume and/or SNM treatment reduced deactivations and strengthened normal (positive) responses, e.g. in the periaqueductal grey (PAG) terminus of ascending spinal afferents. At baseline, there was significant correlation of brain responses with maximum urethral closure pressure.

CONCLUSION

These data show that brain responses to bladder filling are abnormal in FS. The explanation for this that best explains the evidence is that the primary abnormality is an overactive urethra that generates abnormally strong inhibitory afferent signals, so effectively blocking bladder afferent activity at the sacral level and deactivating the PAG and higher centres, with consequent loss of bladder sensation and ability to void. Apparently, a normal mechanism for suppression of incontinence involving the striated urethral sphincter becomes exaggerated in FS and prevents voiding. SNM seems to act at the sacral level, by blocking inhibition by urethral afferents.

Re-operation rates after permanent sacral nerve stimulation for refractory voiding dysfunction in women

OBJECTIVES

To describe the development of screening tests and to identify re-operation rates after the permanent implant phase, and its characteristics, of the Interstim (Medtronic, Inc., Minneapolis, MI, USA) device for sacral nerve stimulation (SNS).

PATIENTS AND METHODS

We retrospectively reviewed the charts of women who had SNS between January 1998 and December 2005; their demographic, clinical and surgical information was abstracted. Descriptive statistics, chi-square and analysis of variance were used to compare the results.

RESULTS

In all, 95 patients had 105 test procedures; 30 peripheral nerve evaluation (PNE) and 75 staged tined leads. Response rates were lower in the PNE than in the tined lead (40% vs 67%, P = 0.01). The indication for SNS was associated with the response rate, with urinary retention having the highest response (71%, P = 0.01). For the 55 implanted devices, there were 18 revisions (33%) and eight explants (15%). The main reasons for revision or explants were loss of efficacy (16/26) and pain at the implant site (six of 26). The median (range) time to intervention after implantation was 17 (1.2-75.0) months, and this was significantly associated with the indication. Revisions due to pain at the implant site were within the first year, and re-operations due to loss of efficacy after 1-2 years, whereas battery replacement was required on average 4 years after initial implantation.

CONCLUSIONS

This study confirms the higher response rates of the tined-lead staged technique over PNE. Unobstructive urinary retention had the highest response rates. The reason for revision appeared to be largely predicted by the length of time since implantation.

Sacral nerve stimulation: neuromodulation for voiding dysfunction and pain

Voiding dysfunction, which includes incontinence, retention, and chronic pelvic pain, is a relatively frequent problem that can be difficult to manage. Neuromodulation via stimulation of the sacral nerves has been shown to improve these symptoms, although the exact mechanisms remain elusive. Techniques for nerve stimulation may vary, depending on the disease, location of pain, and the patient's anatomy. In addition to placement of electrodes on the sacral nerve roots, modulation has also been reported by peripheral branches of the sacral nerves including the pudendal and posterior tibial nerves. Newer surgical techniques have significantly decreased the morbidity of the procedures and increased the probability of a successful outcome.

Sacral neurostimulation for urinary retention: 10-year experience from one UK centre

OBJECTIVES

To report our 10-year experience of sacral neurostimulation (SNS) for women in urinary retention, comparing the original one-stage with the newer two-stage technique, as SNS therapy is a well-established treatment for urinary retention secondary to urethral sphincter overactivity (Fowler's syndrome).

PATIENTS AND METHODS

Between 1996 and 2006, 60 patients with urinary retention had a SNS device inserted; their case records were reviewed and data on efficacy, follow-up, need for continued clean intermittent self-catheterization (CISC), complications and operative revision rate were assessed.

RESULTS

Overall, 43 of 60 (72%) women were voiding spontaneously, with a mean postvoid residual volume of 100 mL; 30 (50%) no longer needed to use CISC. During a total of 2878 months of SNS experience, adverse event episodes included lead migration in 20, 'box-site' pain in 19, leg pain/numbness in 18 and loss of response/failure in 18 patients; 53% of the women required a surgical revision related to their implanted stimulator. The efficacy of the two-stage was similar to that of the one-stage procedure (73% vs 70%). Women with a normal urethral sphincter electromyogram had worse outcomes than women with an abnormal test (43% vs 76%). Although the efficacy was no different in those taking analgesia/antidepressant medication, this group of women had a higher surgical revision rate. Failure and complications for the one-stage procedure were not restricted to the early follow-up period. The mean battery life of the implant was 7.31 years.

CONCLUSIONS

SNS has sustained long-term efficacy but the procedure has a significant complication rate. At present, the two-stage technique has comparable efficacy to the one-stage technique but a longer-term follow-up is required. The National Institute of Clinical Excellence recommended the use of SNS in women with urinary incontinence who fail to respond adequately to anticholinergic therapy, but patients choosing this treatment should be made aware of the high complication rate associated with the procedure.

Sacral neuromodulation for nonobstructive urinary retention--is success predictable?

PURPOSE

We investigated whether there are factors which can predict successful stage II (permanent) sacral nerve stimulator (InterStim) implantation for patients with nonobstructive urinary retention.

MATERIALS AND METHODS

We retrospectively reviewed our sacral neuromodulation database from January 1, 1999 to January 1, 2006. A total of 29 patients were referred to the William Beaumont Hospital Department of Urology for nonobstructive urinary retention. All patients completed a 3-day voiding log followed by test stimulation. Patients underwent test stimulation for a 2-week trial period. Those who experienced 50% improvement in void volume and/or catheterization frequency subsequently underwent permanent implantation. We reviewed patient charts with respect to age, sex, duration of retention, underlying diagnosis for retention and voiding ability.

RESULTS

Of the 29 patients 15 were men and 14 were women. Mean patient age was 58.8+/-16 years (range 18 to 82). The mean age of the men in the study was 55.5+/-18 years while the mean age of the women was 62.3+/-14 years. Although all the patients performed intermittent self-catheterization 18 were able to void (more than 50 cc per void). The remaining 11 patients had minimal (50 cc or less) or no ability to void. Of the 18 patients who were able to void 12 (67%) underwent successful permanent implantation. However, voiding improved after test stimulation in only 2 of the 11 patients (18%) who had been unable to void. This difference was statistically significant (p=0.02) and suggests that pre-implantation ability to void can predict success of test stimulation.

CONCLUSIONS

Patient ability to void predicts success of first stage test stimulation. Although we would still offer a trial of sacral neuromodulation to those with nonobstructive urinary retention and the inability to void, this study would allow better counseling regarding the likelihood of successful outcome.

Chapitre L - Troubles vésico-sphinctériens et vessie neurogène non neurogène ou “dysfonctions mictionnelles”

Some patients can present severe lower urinary tract dysfunction but assessment does not reveal any anatomical or neurological lesion. Initially called "non-neurogenic neurogenic bladder", the disorders encountered in this context are now called "dysfunctional voiding". In this article, the authors describe the characteristics of the main syndromes, the assessment that should be performed and the various treatment options to be considered.

Sacral nerve stimulation for voiding dysfunction: One institution's 11-year experience

AIM

The purpose of this study was to review our institution's 11-year experience with SNS for the treatment of refractory voiding dysfunction. Dating back to 1993, it covers a span of time which describes the evolution of SNS as it includes PNE trials, non-tined (bone-anchored or fascial-anchored) leads, percutaneous tined leads with two-staged procedures, and even percutaneous pudendal trials.

METHODS

A retrospective review was performed on SNS patients who received an implantable pulse generator (IPG) in our practice from 12/1993 to 12/2004. After Institutional Review Board approval, consents for chart review were obtained from 104 patients, representing 44% of this neuromodulatory patient population.

RESULTS

Of our population, 87% were female and 13% were male. Average age at implant was 50 years +/- 13.4 years. Duration of symptoms before implantation was 116 months (range 9-600 months). Eighty percent were implanted for a predominant complaint of urinary urgency and frequency (U/F). Overall, 22% had U/F only, 38% had concomitant urge incontinence (UI), and 20% had concomitant mixed incontinence (MI). Twenty percent were treated for non-obstructive urinary retention (UR), with half of these associated with a neurogenic etiology. Additionally, 46.2% had pelvic pain, 58.6% had bowel complaints, and 51% reported sexual dysfunction. In patients with U/F, mean voiding parameters as described by pre-implant voiding diaries revealed the following: 12.4 (+/-5.1) voids per 24 hr; 2.3 (+/-1.8) voids per night; 5.0 (+/-4.7) leaks per 24 hr; and 2.3 (+/-2.6) pads per 24 hr. Statistically significant improvements post-implantation were noted with mean decreases in the following: 4.3 voids per 24 hr; 1.0 void per night; 4.4 leaks per 24 hr; and 2.3 pads per 24 hr (all P < 0.05). In the UR group a statistically significant improvement post-implantation was noted only in voids per night, with a mean decrease of 0.8 (P < 0.05). With a mean follow up of 22 months (range 3-162 months), sustained subjective improvement was >50%, >80%, and >90% in 69%, 50%, and 35% of patients, respectively. By quality of life survey, 60.5% of patients were satisfied and 16.1% were dissatisfied with current urinary symptoms. Only 13% (14 patients) abandoned therapy, making up a significant portion of those dissatisfied with current urinary symptoms. Good overall lead durability was seen (mean 22 months, range 1-121 months), with the first successful lead proving to be the most durable (mean 28 months, range 1.4-120 months). Lead durability decreased progressively with subsequent trials. Overall, 53% of patients experienced at least one reportable event (RE) attributable to either lead or IPG. A total of 126 REs were noted, with 97% mild-to-moderate in severity. REs included lack of efficacy, loss of efficacy, infection, hematoma/seroma, migration, pain, undesirable change in sensation, and device malfunction. In this population, 47.1% of leads were tined while 52.9% were non-tined. Tined leads had an overall lower RE rate as compared to non-tined leads: 28% and 73%, respectively.

CONCLUSIONS

SNS is an effective method for treating certain types of voiding dysfunction. Although 53% of patients experienced at least one RE, 97% were mild-to-moderate and did not appear to affect the continued use of this therapy. With improved technology, such as percutaneous tined leads, the RE rate is decreasing. Further analyses of subsets of this population are currently underway.