Long-term results of sacral neuromodulation for women with urinary retention

[Sacral neuromodulation for bladder voiding dysfunction: Experience at a French university center]

OBJECTIVE

To report the experience of a university hospital center with sacral neuromodulation for patients with bladder voiding disorders.

MATERIAL AND METHODS

All patients who underwent sacral neuromodulation between 1998 and 2022 for bladder voiding disorders were included. Medical records were analyzed retrospectively, and population, efficacy and follow-up data were collected.

RESULTS

A total of 134 patients underwent test implantation and 122 patients were analyzed. 68 patients (56%) were implanted with a definitive neuromodulation device. Mean age was 43±16 years and BMI 25.5±5.4kg/m2. 74% were women. Bladder voiding disorder was due to sphincter hypertonia in 51% of cases, with associated bladder hypocontractility in 29%. The spontaneous micturition rate after implantation increased from 34% to 92%. Implantation results appeared to be better in patients with sphincter hypertonia, whether or not associated with bladder hypocontractility. The benefit was most often present with a frequency of 5Hz (54.4%). Side-effects were present in 52% of cases at 5 years, and in 85% of cases were pain in relation to the implanted devices. They resolved under medical treatment or after revision of the device (27% of cases at 5 years).

CONCLUSION

SNM is effective in micturition recovery, but has side effects. Urodynamic mechanism and etiology may provide clues for modulating NMS box settings and determining predictive factors for NMS success. Data from other centers are needed to identify reliable predictive factors.

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.

Statewide Success of Staged Sacral Neuromodulation for the Treatment of Urinary Complaints in California (2005-2011)

PURPOSE

Sacral neuromodulation (SNS) is approved by the Food and Drug Administration as a third-line treatment for refractory overactive bladder, idiopathic urinary retention, and fecal incontinence. Prior to implantation of an implantable pulse generator, all patients undergo a trial phase to ensure symptom improvement. The published success rates of progression from the test phase to permanent implant vary widely (range, 24% to >90%). We sought to characterize success rates using a statewide registry.

METHODS

Using nonpublic data, we identified SNS procedures using the California Office of Statewide Planning and Development ambulatory surgery database from 2005 to 2011. A successful trial was defined as receiving a stage 2 generator implantation after trial lead placement. Multivariable logistic regression was performed to identify factors associated with staged success.

RESULTS

During the study period, 1396 patients underwent a staged SNS procedure, with 962 (69%) subsequently undergoing generator placement. Successful trial rates were 72% for overactive bladder wet, 69% for urgency/frequency, 68% for interstitial cystitis, 67% for neurogenic bladder, and 57% for urinary retention. On multivariate logistic regression, only male sex (odds ratio, 0.51) and urinary retention [odds ratio, 0.54) were significantly associated with lower odds of success, whereas age, race/ethnicity, medical insurance, and placement at an academic or high-volume institution had no association.

CONCLUSIONS

The "real world" success rates for staged SNS implantation in California are less than those observed by some academic centers of excellence but better than previously reported for Medicare beneficiaries. Successful trial rates for interstitial cystitis and neurogenic voiding dysfunction are similar to refractory overactive bladder.

[Sacral neuromodulation as treatment of non-neurological vesical emptying disorders]

GOAL

The goal was to evaluate the results of sacral neuromodulation (SNM) in non-neurological vesical emptying disorders.

PATIENTS AND METHODS

From February 2010 to October 2017, 28 patients presenting voiding symptoms or a non-obstructive chronic urine retention without neurological cause have been operated for an SNM (test phase). The test was positive in case of decreased number of proper intermittent self-catheterization (SC) or post-voiding residual urine (PVR) of at least 50 %. A 100 % positive result meant the return to a spontaneous voiding without SC with a non-significative PVR (<100ml).

RESULTS

The median follow-up was of 53.2±21.2 months. Twenty-four (85.7%) tests were positive, from which twenty-two (78.6%) were 100% positive. 16 (84.2%) out of 19 patients with SC had spontaneous voiding without PVR. The number of daily SC decreased from 4.6±1.5 to 0.4±1.2 in post-operative (P<0.001). The PVR was of 287.1±170.4ml vs. 30.4±48.6ml in post-operative (P<0.001). Fourteen patients (58.3%) underwent at least one chirurgical revision or a removal of material ; mainly for loss of efficiency, end of battery, electrode migration and pain on material. At the end of the follow-up, 70.8% of the responding patients had their device still efficient.

CONCLUSION

Results showed that SNM appears to be an efficient treatment of non-neurological emptying vesical troubles. Nevertheless, the re-operation rate was still significant.

LEVEL OF EVIDENCE

3.

Progress in research of sacral nerve stimulation

Sacral nerve stimulation (SNS) is well-known as a minimally invasive treatment. Originally, it was mainly used to treat urinary system diseases such as urge urinary incontinence. Gradually, it is used to treat digestive system diseases such as fecal incontinence and chronic constipation. SNS is a method in which electrical pulse signals are sent out through pulse generators to stimulate the sacral nerve directly or indirectly, thus modulating the nerve reflex of the bladder, urethra, anus, colon, and rectum and improving abnormal nerve regulation to achieve the therapeutic effect. The regulation of the sacral nerve is often carried out by inserting electrodes into the sacral spinal canal S_2-4 (mostly S₃), and the symptoms are improved by complex regulation of spinal reflex and supraspinal reflex. However, the exact mechanism is still unclear. Many studies have shown that SNS plays a key role in the treatment of many diseases of the urinary system and digestive system. This paper reviews the progress in the research of SNS.

Sacral neuromodulation for symptomatic chronic urinary retention in females: do age and comorbidities make a difference?

OBJECTIVES

To evaluate if age and medical comorbidities are associated with progression to implantation of sacral neuromodulation devices in women with symptomatic chronic urinary retention.

METHODS

This multisite retrospective cohort included women with symptomatic chronic urinary retention who had a trial phase of sacral neuromodulation. The primary outcome was progression to implantation. Post-implantation outcomes were assessed as stable response versus decreased efficacy. A sub-analysis of catheter-reliant (intermittent-self catheterization or indwelling) patients was performed. Age was analyzed by 10-year units (decades of age). Multivariate logistic regression determined odds ratios for outcomes of implantation and for post-implantation stable response.

RESULTS

Implantation occurred in 86% (243/284) women across six academic institutions. Most patients (160/243, 66%) were catheter reliant at the time of trial phase. Increased decade of age was associated with reduced implantation in all women [OR 0.54 (95% CI 0.42, 0.70)] and in the subgroup of catheter-reliant women [OR 0.52 (95% CI 0.37, 0.73)]. Post-implantation stable response occurred in 68% (193/243) of women at median follow-up of 2 years (range 0.3-15 years). Medical comorbidities present at the time of trials did not impact progression to implantation or post-implantation success.

CONCLUSIONS

Increasing decade of age is associated with reduced implantation in women with symptomatic chronic urinary retention. There is no age cutoff at which outcomes change. Post-implantation stable response was not associated with age or medical comorbidities.

Sacral nerve stimulation for refractory OAB and idiopathic urinary retention: Can phenotyping improve the outcome for patients: ICI-RS 2019?

AIMS

Sacral nerve stimulation (SNS) is widely used to treat refractory idiopathic overactive bladder (OAB) and idiopathic urinary retention. However, clinical outcomes are variable and understanding predictive factors for success or side-effects would enable personalization of therapy and optimization of outcomes. At the International Consultation on Incontinence-Research Society meeting 2019, a Think Tank was convened to discuss how advances in the basic science study of SNS may be translatable into clinical practice to improve outcomes of patients undergoing SNS treatment.

METHODS

We conducted a literature review and expert consensus meeting focusing on current methods of phenotyping patients and specifically, how advances in basic science research of the mechanism of action of SNS can be translated into clinical practice to improve patient selection for therapy.

RESULTS

The terms "Idiopathic OAB" and "idiopathic urinary retention" encompass several underlying pathophysiological phenotypes. Commonly, phenotyping is based on clinical and urodynamic factors. Animal studies have demonstrated that high-frequency stimulation can produce rapid onset, reversible conduction block in peripheral nerves. Altering stimulation parameters may potentially enable personalization of therapy depending upon the clinical indication in the future. Similarly, advances in conditional and closed-loop stimulation may offer greater efficacy for certain patients. Phenotyping based on psychological comorbidity requires further study to potentially optimize patient selection for therapy.

CONCLUSIONS

Idiopathic OAB and idiopathic urinary retention are heterogenous conditions with multiple potential underlying phenotypes. Tailoring stimulation parameters to the needs of each individual according to phenotype could optimize outcomes. Assessing psychological comorbidity may improve patient selection. Areas for further research are proposed.

Management of functional neurological disorder

Functional neurological disorder (FND) is a common cause of persistent and disabling neurological symptoms. These symptoms are varied and include abnormal control of movement, episodes of altered awareness resembling epileptic seizures and abnormal sensation and are often comorbid with chronic pain, fatigue and cognitive symptoms. There is increasing evidence for the role of neurologists in both the assessment and management of FND. The aim of this review is to discuss strategies for the management of FND by focusing on the diagnostic discussion and general principles, as well as specific treatment strategies for various FND symptoms, highlighting the role of the neurologist and proposing a structure for an interdisciplinary FND service.

Clinical outcomes of sacral neuromodulation in non-neurogenic, non-obstructive dysuria: A 5-year retrospective, multicentre study in China

BACKGROUND

Management of non-neurogenic, non-obstructive dysuria represents one of the most challenging dilemmas in urological practice. The main clinical symptom is the increase in residual urine. Voiding dysfunction is the main cause of dysuria or urinary retention, mainly due to the decrease in bladder contraction (the decrease in contraction amplitude or duration) or the increase in outflow tract resistance. Sacral neuromodulation (SNM) has been used for > 10 years to treat many kinds of lower urinary tract dysfunction. It has become increasingly popular in China in recent years. Consequently, studies focusing on non-neurogenic, non-obstructive dysuria patients treated by SNM are highly desirable.

AIM

To assess the outcome of two-stage SNM in non-neurogenic, non-obstructive dysuria.

METHODS

Clinical data of 54 patients (26 men, 28 women) with non-neurogenic, non-obstructive dysuria treated by SNM from January 2012 to December 2016 in ten medical centers in China were retrospectively analyzed. All patients received two or more conservative treatments. The voiding diary, urgency score, and quality of life score before operation, after implantation of tined lead in stage I (test period), and during short-term follow-up (latest follow-up) after implantation of the implanted pulse generator in stage II were compared to observe symptom improvements.

RESULTS

Among the 54 study patients, eight refused to implant an implanted pulse generator because of the unsatisfactory effect, and 46 chose to embed the implanted pulse generator at the end of stage I. The conversion rate of stage I to stage II was 85.2%. The average follow-up time was 18.6 mo. There were significant differences between baseline (before stage I) and the test period (after stage I) in residual urine, voiding frequency, average voiding amount, maximum voiding amount, nocturia, urgency score, and quality of life score. The residual urine and urgency score between the test period and the latest follow-up time (after stage II) were also significantly different. No significant differences were observed for other parameters. No wound infection, electrode breakage, or other irreversible adverse events occurred.

CONCLUSION

SNM is effective for patients with non-neurogenic, non-obstructive dysuria showing a poor response to traditional treatment. The duration of continuous stimulation may be positively correlated with the improvement of residual urine.

Sacral neuromodulation for female pelvic floor disorders

Objective: To systematically review available studies on the effectiveness and safety of sacral neuromodulation (SNM) in women with various pelvic floor disorders not responding to more conservative treatment, as SNM is indicated in such women.

Methods: Data source: We did a systematic review through the PubMed and the Cochrane Library according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement from 1998 to 2018 in English using the keywords ‘Sacral Neuromodulation’ and ‘Sacral Nerve Stimulation’.

Study selection: Randomised controlled trials and prospective studies were selected, with a minimum sample size of 20 patients and ≥6 months of follow-up.

Results: We identified 19 articles. A ≥50% reduction in symptoms qualifies the patient for a permanent implant. Several advances have been introduced into SNM to decrease the invasiveness of the procedure, including a smaller implantable pulse generator battery (improved comfort) and better localisation of the lead wire (improved outcome). The literature reports success for overactive bladder (OAB) to range between 56% and 68% (up to 80%). We report a 5-year therapeutic success rate of 67%. In our previous studies, 38% of our patients with urge urinary incontinence achieved complete continence at 60-months follow-up, with a therapeutic response rate of 57%. Effectiveness in patients with urinary retention and faecal incontinence are about 70% and 85%, respectively. Effectiveness in interstitial cystitis/bladder pain syndrome appears to be lower compared with OAB.

Conclusion: SNM is a safe and effective therapy for women with various pelvic floor disorders.

Abbreviations: BONT: botulinum toxin; FDA: USA Food and Drug Administration; FS: Fowler’s syndrome; FI: faecal incontinence; IC/BPS: interstitial cystitis/bladder pain syndrome; ICIQ-OABqol: International Consultation on Incontinence Modular Questionnaire-Overactive Bladder Symptoms Quality of Life; INS: implantable neurostimulator; OAB: overactive bladder; PET: positron emission tomography; PNE: peripheral nerve evaluation; PRISMA: Preferred Reporting Items for Systematic Reviews and Meta-Analyses; PTNM: posterior tibial nerve modulation; PVR: post-void residual urine; QoL: quality of life; RCT: randomised controlled trial; SNM: sacral neuromodulation; (U)UI: (urgency) urinary incontinence

Role of sacral neuromodulation in modern urogynaecology practice: a review of recent literature

Sacral neuromodulation (SNM) offers promise in the therapy of many pelvic floor disorders. This innovative treatment has slowly gained popularity. A review of recent literature is presented in relation to its efficacy and complications in various pelvic floor conditions: overactive bladder and urge urinary incontinence, chronic urinary retention, painful bladder syndrome, pelvic pain and double incontinence. It is a minimally invasive, completely reversible safe procedure with good long-term outcomes. However, the treatment is costly, the revision rate is high and patients require life-long follow-up. SNM should always be considered in suitable patients before offering bladder augmentation procedures or urinary diversion or permanent catheterization for bladder dysfunction. SNM should also be considered in patients with double incontinence, after discussion in a urogynaecology/colorectal multidisciplinary team.

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.

Initial experience with sacral neuromodulation for the treatment of lower urinary tract dysfunction in Brazil

Objectives:

We report on the short-term outcomes of sacral neuromodulation (SNM) for treatment of idiopathic lower urinary tract dysfunction in Brazil (procedures performed before 2014).

Materials and Methods:

Clinical data and surgical outcomes of patients who underwent SNM staged procedures were retrospective evaluated. Urological assessment included a focused medical history and physical examination, measurement of postvoid residual volumes, urodynamics, and bladder diaries. A successful test phase has been defined by improvement of at least 50% of the symptoms, based on bladder diaries.

Results:

From January 2011 to December 2013, eighteen consecutive patients underwent test phase for SNM due to refractory overactive bladder (15 patients), non-obstructive chronic urinary retention (2 patients), and bladder pain syndrome/interstitial cystitis (1 patient). All patients underwent staged procedures at four outpatient surgical centers. Mean age was 48.3±21.2 (range 10-84 years). There were 16 women and 2 men. Median follow-up was 3 months. Fifteen patients (83.3%) had a successful test phase and underwent implantation of the pulse generator (IPG). Median duration of the test phase was 7 days (range 5–24 days). Mean age was 45.6±18.19 years in responders versus 61.66±34.44 years in non-responders (p=0.242). Mean operative time (test phase) was 99±33.12 min in responders versus 95±35 min for non-responders (p=0.852). No severe complications were reported.

Conclusion:

SNM is a minimally invasive treatment option for patients with refractory idiopathic lower urinary tract dysfunction. Our initial experience with staged technique showed that tined-lead electrodes yielded a high rate of responders and favorable clinical results in the short-term follow-up.

Neuromodulation for the Treatment of Endometriosis-Related Symptoms

Sacral and pudendal neuromodulation have been advocated for the treatment of refractory pelvic pain, urinary urgency and retention, as well as fecal incontinence or constipation, all of which are commonly related to endometriosis and/or its surgical treatment.

In this review, the mechanisms of action and different routes of neuromodulation will be detailed, as well as all the studied applications of neuromodulation on ameliorating symptoms related to endometriosis and/or its treatment.

Electrical stimulation for the treatment of lower urinary tract dysfunction after spinal cord injury

Electrical stimulation for bladder control is an alternative to traditional methods of treating neurogenic lower urinary tract dysfunction (NLUTD) resulting from spinal cord injury (SCI). In this review, we systematically discuss the neurophysiology of bladder dysfunction following SCI and the applications of electrical stimulation for bladder control following SCI, spanning from historic clinical approaches to recent pre-clinical studies that offer promising new strategies that may improve the feasibility and success of electrical stimulation therapy in patients with SCI. Electrical stimulation provides a unique opportunity to control bladder function by exploiting neural control mechanisms. Our understanding of the applications and limitations of electrical stimulation for bladder control has improved due to many pre-clinical studies performed in animals and translational clinical studies. Techniques that have emerged as possible opportunities to control bladder function include pudendal nerve stimulation and novel methods of stimulation, such as high frequency nerve block. Further development of novel applications of electrical stimulation will drive progress towards effective therapy for SCI. The optimal solution for restoration of bladder control may encompass a combination of efficient, targeted electrical stimulation, possibly at multiple locations, and pharmacological treatment to enhance symptom control.

Outcome of sacral nerve stimulation for fecal incontinence at 5 years

OBJECTIVE

This study aimed to evaluate the outcome of sacral nerve stimulation (SNS) for fecal incontinence at 5 years after implantation and to identify predictors of sustained efficacy.

BACKGROUND

There is a lack of knowledge about the long-term outcome of SNS for fecal incontinence.

METHODS

Prospectively collected data from patients who underwent implantation of an SNS device between 2001 and 2006 were reviewed.

RESULTS

One hundred and one patients were available for outcome evaluation at 5 years. Sixty of 101 patients [42.6% on intention-to-treat (ITT) and 55.6% per protocol (PP)] reported a favorable outcome, 41 patients (ITT 29.1%; PP 38.0%) reported an unfavorable outcome, of whom 24 patients (ITT 17.0%; PP 22.2%) had their device explanted or permanently switched off before 5 years. Wexner incontinence scores improved significantly from a baseline median of 16 (range 6-20) to a median of 6 (range 0-20) at 3 months (P < 0.0001), and the improvement compared with baseline was maintained throughout the 5-year follow-ups (P < 0.0001).Age was a negative predictive factor [odds ratio (OR): 0.96 each year increase, 95% confidence interval (CI): 0.92-0.99; P = 0.016]. Positive predictors included improvement of urge incontinence episodes during percutaneous nerve evaluation (OR: 10.8; 95% CI: 1.72-132; P = 0.036), improvement of incontinence scores at 6 months from baseline (OR: 6.29; 95% CI: 1.33-34.3; P = 0.025), particularly improvement of incontinence scores from 3 to 6 months (OR: 41.5; 95% CI: 3.51-811; P = 0.007). Overall, 521 reportable events were recorded from 94 patients (93.1%).

CONCLUSIONS

On an ITT analysis, 42.6% of patients reported favorable outcomes at 60 months. Patient's age, improvement of urge incontinence during PNE, and sustained efficacy during the first 6 months after implantation are some of the predictors identified.

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.

Pregnancy in women with Fowler's syndrome treated with sacral neuromodulation

INTRODUCTION AND HYPOTHESIS

Our aim was to determine the impact of pregnancy on sacral neuromodulation (SNM) and vice versa in patients with Fowler's syndrome (FS), which is typified by chronic urinary retention (CUR).

METHODS

We performed a retrospective study of pregnancy in patients with FS who underwent a two-stage SNM implantation. Data were obtained using a standard questionnaire and clinical interview.

RESULTS

There were a total of ten patients with 13 pregnancies. The SNM was switched off in ten of the 13 pregnancies, with CUR recurring in nine of the ten pregnancies and recurrent urinary tract infections (UTI) occurring in four of these pregnancies (more than three UTI in the pregnancy). Those in whom the device was left on continued to void normally. One woman had a first trimester miscarriage, eight pregnancies went to term, and four deliveries were premature. Caesarean section was performed in eight pregnancies for obstetric reasons. Four pregnancies resulted in a vaginal delivery. There were no congenital anomalies reported. Following delivery, four of nine women experienced dysfunction of their SNM device when it was switched back on.

CONCLUSION

Turing off the SNM during pregnancy results in recurrence of CUR, with an increased risk of recurrent UTI associated with preterm delivery. This did not impact foetal well-being. The option of keeping the SNM on during pregnancy should therefore be considered, and as caesarean section affects the SNM device, we advise that caesarean section should only be performed for obstetric reasons.

Implant-Driven Tibial Nerve Stimulation in the Treatment of Refractory Overactive Bladder Syndrome: 12-Month Follow-up

Objectives.  To investigate feasibility and safety of implant-driven tibial nerve stimulation. Materials and Methods.  Eight patients with refractory overactive bladder were successfully treated with implanted percutaneous tibial nerve stimulation (PTNS). Patients were evaluated with bladder diaries, quality of life questionnaires, and physical examination before implantation, and at 3, 6, and 12 months of follow-up. The primary objective was ≥ 50% reduction of the number of incontinence episodes and/or voids on bladder diary. The Wilcoxon signed ranks test was used. Results.  At 3, 6 and 12 months, respectively five, six, and four patients met the primary objective. At 3- and 6-month follow-up, voiding and quality of life parameters had significantly (p < 0.05) improved. Urinary tract infection, temporarily walking difficulties, and spontaneous radiating sensations were reported as adverse events and no local infection, erosion, or dislocation. Conclusions.  Implant-driven tibial nerve stimulation seems to be feasible and safe.

Postoperative issues of sacral nerve stimulation for fecal incontinence and constipation: a systematic literature review and treatment guideline

BACKGROUND

There is a lack of knowledge on the incidence and management of suboptimal therapeutic effect and the complications associated with sacral nerve stimulation for fecal incontinence and constipation.

OBJECTIVE

This study aimed to review current literature on postoperative issues and to propose a treatment algorithm.

DATA SOURCE

PubMed, MEDLINE, and EMBASE were searched using the keywords "sacral nerve stimulation," "sacral neuromodulation," "fecal incontinence," and "constipation" for English-language articles published from January 1980 to August 2010. A further search was conducted on a wider literature using the keywords "complication," "adverse effect," "treatment failure," "equipment failure," "infection," "foreign-body migration," "reoperation," "pain," and "algorithm."

STUDY SELECTION

Four hundred sixty-one titles were identified, and after a title and abstract review, 135 were subjected to full article review; 89 were finally included in this review. Five articles were added by manual search and consensus.

RESULTS

Forty-eight studies were identified as cohort studies reporting on postoperative issues, including 1661 patients who underwent percutaneous nerve evaluation and 1600 patients who proceeded to sacral nerve stimulation therapy. Pooled data showed that the most common problem during percutaneous nerve evaluation was lead displacement (5.3%). The incidence of suboptimal outcome, pain, and infection after implantation was 12.1%, 13.0%, and 3.9%.

LIMITATIONS

There was significant underreporting of untoward events, because 60% of the studies did not report complications during percutaneous nerve evaluation, and suboptimal outcome after implantation was not disclosed in 44% of the studies.

CONCLUSIONS

The incidence of untoward events associated with sacral nerve stimulation appears to be low. However, there is a significant underreporting of the incidence. Using the information from the structured and systematic literature review, we formulated a clinically relevant guideline for reporting and managing postoperative issues. The guideline can provide a framework for clinical practice.

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.

Advances in the role of sacral nerve neuromodulation in lower urinary tract symptoms

Sacral neuromodulation has been developed to treat chronic lower urinary tract symptoms, resistant to classical conservative therapy. The suspected mechanisms of action include afferent stimulation of the central nervous system and modulation of activity at the level of the brain. Typical neuromodulation is indicated both in overactivity and in underactivity of the lower urinary tract. In the majority of patients, a unilateral electrode in a sacral foramen and connected to a pulse generator is sufficient to achieve significant clinical results also on long term. In recent years, other urological indications have been explored.

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.

Long-term outcome and surgical interventions after sacral neuromodulation implant for lower urinary tract symptoms: 14-year experience at 1 center

PURPOSE

Few reports address the reoperation rate after sacral neuromodulation implants. We report our long-term results and reoperations during our 14-year experience with sacral neuromodulation at our center.

MATERIALS AND METHODS

We retrospectively reviewed the patient database at our center to assess the long-term outcome, incidence and cause of surgical re-intervention after InterStim® sacral neuromodulation implantation for lower urinary tract dysfunction between 1994 and 2008.

RESULTS

A total of 96 sacral neuromodulation devices were implanted in 88 women and 8 men. Indications for implantation were bladder pain syndrome in 47.9% of cases, urgency urinary incontinence in 35.4% and idiopathic urinary retention in 16.7%. The explantation rate was 20.8% and median time to removal was 18.5 months. Reasons for explantation in all subgroups were poor result in 12 patients, painful stimulation in 6 and radiation of stimulation to the leg in 2. Median long-term followup was 50.7 months. The long-term success rate was 87.5%, 84.8% and 73% in patients with idiopathic urinary retention, urgency urinary incontinence and bladder pain syndrome, respectively. Overall 39% of patients needed revision of the sacral neuromodulation implant. The main reason for revision was loss of stimulation in 58.5% of cases. The revision rate decreased with the introduction of the tined lead technique from 50% using lead Model 3092 to 31% using lead Model 3893 (Medtronic, Minneapolis, Minnesota). The battery was changed in 8 patients. Mean battery life was 101.8 months.

CONCLUSIONS

Sacral neuromodulation is a minimally invasive procedure with a good long-term outcome. The reoperation rate has improved with advances in surgical technique and equipment.

Sacral neuromodulation in diabetic patients: success and complications in the treatment of voiding dysfunction

AIMS

We compared success rates, subsequent complications, and possible indications for success of sacral neuromodulation (SNM) for urinary voiding dysfunction in diabetic and non-diabetic patients.

METHODS

Thirty-two diabetic patients (mean age 61.8 years, range 27-83) with urge incontinence, urgency-frequency syndrome, and/or urinary retention refractory to non-surgical treatment were retrospectively evaluated along with 211 non-diabetic patients (mean age 54.1 years, range 20-86) with similar symptoms. All patients who experienced >or=50% reduction in urinary symptoms following a 7- to 21-day test period went on to permanent SNM device implantation.

RESULTS

No significant difference was found with respect to successful conversion rates from the test period to permanent implantation between diabetic and non-diabetic patients. Long-term success rates at a mean followup of 29.3 months following permanent device implantation for diabetic patients were 69.2% of those with urge incontinence, 85.7% of those with urgency-frequency, and 66.7% of those with urinary retention. The non-diabetic cohort had success rates of 67.0% for urge incontinence, 67.8% for urgency/frequency, and 58.2% for urinary retention (P = 0.823, 0.157, and 0.631, respectively). No patient experienced intraoperative complications. Nine of 24 (37.5%) devices were explanted postoperatively in diabetic patients compared with 36 of 141 (25.5%) in non-diabetic patients (P = 0.224). The number of explants due to infection was higher in diabetic patients (16.7%) versus non-diabetic patients (4.3%; P = 0.018).

CONCLUSIONS

No difference in long-term success rates was seen in diabetic patients when compared with similar, non-diabetic patients. Diabetic patients did, however, have a higher incidence of device explantation due to infection.

Suboptimal outcome following sacral nerve stimulation for faecal incontinence

BACKGROUND

The aim of the study was to identify the incidence of suboptimal therapeutic responses and adverse events associated with sacral nerve stimulation (SNS) for faecal incontinence, and to determine their influence on treatment outcome.

METHODS

Prospectively collected data from 176 patients who underwent SNS were reviewed retrospectively. Patient variables and reportable events were analysed by binary regression to identify the predictors of treatment outcome.

RESULTS

Overall, 592 reportable events were recorded from 150 patients (85·2 per cent) at a median of 11 (interquartile range (i.q.r.) 4-26) months. Loss of efficacy (212 events, 87 patients), lack of efficacy (186 events, 68 patients) and pain/discomfort (126 events, 67 patients) accounted for 88·5 per cent of reportable events. Loss of efficacy (odds ratio (OR) 2·52, 95 per cent confidence interval 1·33 to 4·79; P = 0·007), lack of efficacy (OR 2·80, 1·46 to 5·36; P = 0·002) and pain in the leg (OR 4·07, 1·34 to 12·33; P = 0·013) were predictors of unfavourable outcome in the medium to long term. At a median follow-up of 33 (i.q.r. 20-52) months, 31 patients (17·6 per cent) had explantation of the device or discontinued treatment.

CONCLUSION

Suboptimal therapeutic responses and adverse events are not uncommon when SNS is employed for faecal incontinence. They have a negative impact on treatment outcome.

[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.

Botulinum toxin: An emerging therapy in female bladder outlet obstruction

INTRODUCTION

We evaluated the utility of botulinum toxin in functional female bladder outlet obstruction.

MATERIALS AND METHODS

A total of 7 consecutive female patients with bladder outlet obstruction were included. Patients with neurogenic bladder were excluded. All were previously treated with periodic dilations. Diagnosis was based on symptomatology, cystometry, and micturating cystograms. A total of 2 patients had been in chronic retention with residual volumes more than 400 ml. All were managed with an injection of botulinum toxin, 100 units in 2 ml of saline injected with a flexible cystoscopic needle. The site of the injection was deep submucosally, 0.5 ml in each quadrant at the level of the most prominent narrowing seen endoscopically. All the procedures were done as day care procedures under local anaesthesia. After the procedure, no catheter was placed. Patients were followed up for changes in IPSS scores and post void residual urine measurements. In all cases, multiple injections were used.

RESULTS

The follow-up period ranged from 48-52 weeks. The IPSS reduced by an average of 12 points. Post void residual urine reduced by 62%. Improvements commenced 4.85 days (average) after the procedure and lasted for an average of 16.8 weeks (range: 10.8-28 weeks).

DISCUSSION

There is a gradual improvement in symptoms over time and the maximal effect occurred at 10-14 days. The duration of improvement was approximately 16.8 weeks. All patients were satisfied by the degree of improvement felt.

CONCLUSIONS

Botulinum toxin proved successful in improving the voiding characteristics. It possibly acts at the zone of hypertonicity at the bladder neck or midurethra. The only disadvantage is the high cost of the drug.

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.