PNE versus 1st stage tined lead procedure: A direct comparison to select the most sensitive test method to identify patients suitable for sacral neuromodulation therapy

Sacral neuromodulation in nursing home residents: Predictors of success and complications in a national cohort of older adults

AIMS

There is limited evidence to support the efficacy of sacral neuromodulation (SNM) for older adults with overactive bladder (OAB). This study aims to report outcomes following SNM among nursing home (NH) residents, a vulnerable population with high rates of frailty and comorbidity.

METHODS

This is a retrospective cohort study of long-stay NH residents who underwent a trial of percutaneous nerve evaluation (PNE) or Stage 1 permanent lead placement (Stage 1) between 2014 and 2016. Residents were identified using the Minimum Data Set linked to Medicare claims. The primary outcome of this study was successful progression from trial to implant. Rates of 1-year device explant/revisions were also investigated.

RESULTS

Trial of SNM was observed in 1089 residents (mean age: 77.9 years). PNE was performed in 66.9% of residents and 33.2% underwent Stage 1. Of Stage 1 procedures, 23.8% were performed with simultaneous device implant (single-stage). Overall, 53.1% of PNEs and 72.4% of Stage 1 progressed to device implant, which was associated with Stage 1 procedure versus PNE (adjusted relative risk [aRR]: 1.34; 95% confidence interval [95% CI]: 1.21-1.49) and female versus male sex (aRR: 1.26; 95% CI: 1.09-1.46). One-year explant/revision was observed in 9.3% of residents (6.3% for PNE, 10.5% for Stage 1, 20.3% single-stage). Single stage procedure versus PNE was significantly associated with device explant/revision (aRR: 3.4; 95% CI: 1.9-6.2).

CONCLUSIONS

In this large cohort of NH residents, outcomes following SNM were similar to previous reports of younger healthier cohorts. Surgeons managing older patients with OAB should use caution when selecting patients for single stage SNM procedures.

Two-Staged Sacral Neuromodulation for the Treatment of Nonobstructive Urinary Retention: A Multicenter Study Assessing Predictors of Success

OBJECTIVES

The aims of this study were to 1) determine the success rate of the tined lead test phase in patients with nonobstructive urinary retention (NOUR), 2) determine predictive factors of a successful test phase in patients with NOUR, and 3) determine long-term treatment efficacy and satisfaction in patients with NOUR.

MATERIALS AND METHODS

The first part was a multicenter retrospective study at two centers in The Netherlands. Patients with NOUR received a four-week tined lead test phase. Success was defined as a ≥50% reduction of clean intermittent catheterization frequency or postvoid residual. We analyzed possible predictors of success with multivariable logistic regression. Second, all patients received a questionnaire to assess efficacy, perceived health (Patient Global Impression of Improvement), and treatment satisfaction.

RESULTS

This study included 215 consecutive patients (82 men and 133 women) who underwent a tined lead test phase for the treatment of NOUR. The success rate in women was significantly higher than in men, respectively 62% (83/133) and 22% (18/82, p < 0.001). In women, age per ten years (odds ratio [OR] 0.74, 95% CI: 0.59-0.93) and a history of psychiatric illness (OR 3.92, 95% CI: 1.51-10.2), including posttraumatic stress disorder (PTSD), significantly predicted first stage sacral neuromodulation (SNM) success. In men, age per ten years (OR 0.43, 95% CI: 0.25-0.72) and previous transurethral resection of the prostate and/or bladder neck incision (OR 7.71, 95% CI: 1.43-41.5) were significant predictors of success. Conversely, inability to void during a urodynamic study (for women, OR 0.79, 95% CI: 0.35-1.78; for men, OR 3.06, 95% CI: 0.83-11.3) was not predictive of success. Of the patients with a successful first stage, 75% (76/101) responded to the questionnaire at a median follow-up of three years. Of these patients, 87% (66/76) continued to use their SNM system, and 92% (70/76) would recommend SNM to other patients.

CONCLUSIONS

A history of psychiatric illness, including PTSD, in women with NOUR increased the odds of first stage SNM success 3.92 times. A previous transurethral resection of the prostate and/or bladder neck incision in men increased the odds of success 7.71 times. In addition, a ten-year age increase was associated with an OR of 0.43 in men and 0.74 in women, indicating a 2.3- and 1.3-times decreased odds of success, respectively.

Novel electrode design reduces sensory threshold current drift during peripheral nerve evaluation in patients considered for sacral nerve stimulation

Objective:

To retrospectively compare the efficacy and technical performance of a novel lead used for percutaneous nerve evaluation (PNE) during the testing phase for sacral nerve neuromodulation with the existing lead currently used.

Materials and methods:

Sixty-three PNE leads were inserted in 45 consecutive patients who underwent PNE with the novel helical electrodes, and the intra-operative and return clinic sensory threshold currents were recorded. This resulted in current measurements for 63 individual electrodes. Measurements were compared with 46 consecutive patients who previously underwent PNE using the standard lead with measurements for 63 individual electrodes. Current difference distributions for the two leads were compared using a Wilcoxon signed-rank test.

Results:

There was a statistically significant difference observed between the two types of PNE electrode. The new PNE lead demonstrated less drift in sensory threshold current during a 12-day test period in comparison to the old lead.

Conclusion:

The novel helical PNE electrodes demonstrate a significant improvement in current drift compared with the old style leads over a 12-day test period.

Level of evidence:

Level III

Prospective, multicenter study to evaluate performance and safety of a re-engineered temporary lead for InterStim™ therapy evaluation

AIMS

The basic evaluation or percutaneous nerve evaluation (PNE) is a method to assess pre-implantation therapeutic response in patients considering sacral neuromodulation for the treatment of refractory overactive bladder. A new PNE lead with a more robust design and greater distensibility designed to reduce the possibility of lead migration has recently been introduced to the market. The aim of this prospective, multicenter, global, postmarket study was to evaluate the clinical performance and safety of the new InterStim PNE lead with the foramen needle.

METHODS

Patients with overactive bladder were enrolled in this study. The primary objective of this study was to determine the proportion of subjects who demonstrated motor or sensory response(s) during lead placement using the InterStim PNE lead. Additional measures included the Patient Global Impression of Improvement (PGI-I), patient satisfaction at the end of therapy evaluation, and change in bladder symptoms from baseline to the end of therapy evaluation (1-week follow-up visit).

RESULTS

One-hundred and ten subjects met the inclusion and exclusion criteria and underwent a lead implant procedure. Of those, 108 had a successful procedure and 107 completed the 1-week follow-up visit. Ninety-nine percent of subjects (109/110) had a motor or sensory response during needle placement (95% confidence interval [CI]: 95%-100%) and 97% of subjects (107/110) had a motor or sensory response during lead placement (95% CI: 92%-99%). The majority of subjects (88%, 95/108) reported their bladder condition was better at the follow-up visit compared to before the PNE implant procedure, as reported in PGI-I. Subjects reported being satisfied with how the therapy impacted their voiding symptoms (82%, 88/108) and that they would recommend this therapy (87%, 94/108) to other patients. Symptom improvement was demonstrated with urinary urge incontinence subjects having an average of 4.2 ± 3.4 urinary incontinence episodes/day at baseline and 2.2 ± 2.5 at follow-up, and urinary frequency subjects having an average of 12.5 ± 4.4 voids/day at baseline and 10.5 ± 4.3 voids/day at follow-up. Lead removal was deemed to be easy and safe by the implanting physician, with a total of three adverse device effects in 3/110 subjects. No event was categorized as serious and all were resolved without sequelae.

CONCLUSIONS

The updated InterStim PNE lead with a more robust design and greater distensibility designed to reduce migration was shown to have a high rate of motor or sensory response during lead placement. Furthermore, subjects reported high rates of global improvements and amelioration of symptoms, and the lead was easy to remove with minimal morbidity.

An overview of sacral neuromodulation: a treatment for patients with symptoms of lower urinary tract dysfunction

This article provides an introduction to patient selection for, and the processes involved in, sacral neuromodulation (SNM) device implantation as a treatment for urinary symptoms. SNM has been an option to treat lower urinary tract dysfunction for more than 20 years and is a treatment for both overactive bladder syndrome (OAB) and female non-obstructed chronic urinary retention (FCUR). It is recognised by the National Institute for Health and Care Excellence as a therapeutic option for OAB and FCUR. SNM has its place in the pathway for the treatment of both conditions and, in the correctly assessed patient, can be the last option before considering major surgical intervention.

Predictive Factors in Sacral Neuromodulation: A Systematic Review

INTRODUCTION

Sacral neuromodulation (SNM) is an effective treatment in patients with overactive bladder syndrome or nonobstructive urinary retention when conservative treatment fails. Several factors that could impact outcome with SNM have been studied. This systematic review investigated these predictive factors and their relevance for clinical practice.

METHODS

Systematic review according to the PRISMA guidelines was conducted. This review is registered in the PROSPERO register (CRD42015016256).

RESULTS

Seventy-eight studies (of which 11 abstracts) were included. Females, younger patients, and a tined lead procedure tend to be predictive in successful SNM outcome. Factors that did not influence SNM outcome were prior back surgery, surgery for stress urinary incontinence, affective symptoms, and duration of complaints. Reduced detrusor contractility is associated with a lower success rate. The level of evidence of most studies (graded according to the Centre for Evidence-Based Medicine) was 3b.

CONCLUSION

Even though this systematic review investigated predictive factors (gender, age, type of procedure, type of lead, and detrusor contractility), no general consensus on predictive factors could be made. Most studies are small, retrospective, and involve a heterogeneous population. Therefore, prospective research in larger specific patient groups remains necessary to find predictors of SNM outcome.

Long-term outcomes of sacral neuromodulation for lower urinary tract dysfunction: A 23-year experience

AIMS

To evaluate the long-term outcomes of sacral neuromodulation (SNM), and patient characteristics that may predict long-term success or complications.

METHODS

A single-center retrospective cohort study was performed of all patients who underwent SNM testing and implantation. Outcome results, resolution of symptoms, and device removal were reported. Multivariable logistic regression was used to identify predictors of success. Cox proportional hazards model was used to identify predictors for device removal.

RESULTS

Four hundred and thrity four patients underwent SNM test phase of which 241 (median age 48.0 years, 91.7% [221/241] female) had device implantation and were followed up for median [range] time of 4.0 (3 months-20.5 years) years. Multivariable logistic regression showed that male gender (odds ratio: 0.314; 95% confidence interval: 0.164-0.601, p = .0005) was independently associated with decreased peripheral nerve evaluation success. At final follow-up for patients who originally had device implantation, median (interquartile range) percent of symptoms resolution of all patients was 60.0% (0%-90%) and 69.3% (167/241) had SNM successful outcomes. Cox proportional hazards model showed no difference for time to SNM device removal with respect to patient age, gender, or diagnosis. 69.3% (167/241) patients had at least 1 surgical re-intervention. The most common reason at first surgical re-intervention was lead change only (26.3%, 44/167).

CONCLUSION

SNM is a minimally invasive procedure with good long-term success rates. There is a high revision rate but overall, SNM has a good safety profile and excellent long-term outcomes.

Five-year single center experience of sacral neuromodulation for isolated fecal incontinence or fecal incontinence combined with low anterior resection syndrome

PURPOSE

Sacral neuromodulation (SNM) has proven to be a safe and effective treatment for fecal incontinence (FI). For low anterior resection syndrome (LARS), however, SNM efficacy is still poorly documented. The primary aim of this study was to report on efficacy of SNM therapy for patients with isolated FI or LARS. Furthermore, we evaluated the safety of the procedure and the relevance of adequate follow-up.

METHODS

A retrospective analysis was performed upon a prospectively maintained database of all patients who underwent SNM therapy for isolated FI or LARS between January 2014 and January 2019. The Wexner and LARS scores were evaluated at baseline, during test phase, after definitive implantation and annually during follow-up. Treatment success was defined as at least 50% improvement of the Wexner score or a reduction to minor or no LARS.

RESULTS

Out of 89 patients with isolated FI or LARS who had a SNM test phase, 62 patients were eligible for implantation of the permanent SNM device. At baseline, 3 weeks, and 1, 2, 3, 4 and 5 years after definitive implantation the median Wexner score of all patients was 18, 2, 4.5, 5, 5, 4 and 4.5, respectively, and 18, 4, 5.5, 5, 4, 3 and 4, respectively, for patients with FI and LARS. Patients with LARS more frequently required changes in program settings.

CONCLUSIONS

SNM therapy is a safe and effective treatment for patients with isolated FI and patients with FI and LARS. Adequate follow-up is essential to ensure long-term effectivity, especially for LARS patients.

Acute effect of sacral neuromodulation for treatment of detrusor overactivity on urodynamic parameters

Aim

The aim of this study is to evaluate the acute effects of sacral neuromodulation (SNM) on various urodynamic parameters.

Methods

Patients with overactive bladder and detrusor overactivity (DO) who were planned for percutaneous nerve evaluation (PNE) were included. Directly after the PNE, a urodynamic study (UDS) was performed. The stimulation was turned off during the first UDS (UDS 1), and during the second filling cycle, stimulation was turned on (UDS 2). The UDS was followed by a test phase of 1 week and the bladder diaries were evaluated during an outpatient clinic visit. Primary outcome measures were the differences in UDS parameter values with SNM off and on.

Results

Ten female patients were included in the study and completed the study protocol. Eight patients showed ≥50% improvement of symptoms following a test phase. There were no differences between UDS 1 and UDS 2 in the UDS parameters; bladder volume at first sensation, bladder volume at first DO, highest DO pressure, bladder capacity, maximum flow rate, and pressure at maximum flow rate.

Discussion

None of the aforementioned urodynamic parameters was influenced by acute SNM in patients who responded to SNM. To the best of our knowledge, this is the first study investigating the acute effects of SNM on bladder function.

International Continence Society best practice statement for use of sacral neuromodulation

AIMS

Sacral neuromodulation (SNM) is an accepted therapy for a variety of conditions. However, despite over 20 years of experience, it remains a specialized procedure with a number of subtleties. Here we present the recommendations issued from the International Continence Society (ICS) SNM Consensus Panel.

METHODS

Under the auspices of the ICS, eight urologists, three colorectal surgeons and two urogynecologists, covering a wide breadth of geographic and specialty interest representation, met in January 2017 to discuss best practices for neuromodulation. Suggestions for statements were submitted in advance and specific topics were assigned to committee members, who prepared and presented supporting data to the group, at which time each topic was discussed in depth. Best practice statements were formulated based on available data. This document was then circulated to multiple external reviewers after which final edits were made and approved by the group.

RESULTS

The present recommendations, based on the most relevant data available in the literature, as well as expert opinion, address a variety of specific and at times problematic issues associated with SNM. These include the use of SNM for a variety of underlying conditions, need for pre-procedural testing, use of staged versus single-stage procedures, screening for success during the trial phase, ideal anesthesia, device implantation, post-procedural management, trouble-shooting loss of device function, and future directions for research.

CONCLUSIONS

These guidelines undoubtedly constitute a reference document, which will help urologists, gynecologists, and colorectal surgeons optimize their use of SNM for refractory urinary urgency and frequency, UUI, NOR, and FI.

Clinical utility of neurostimulation devices in the treatment of overactive bladder: current perspectives

Objectives

This review describes the evidence from established and experimental therapies that use electrical nerve stimulation to treat lower urinary tract dysfunction.

Methods

Clinical studies on established treatments such as percutaneous posterior tibial nerve stimulation (P-PTNS), transcutaneous electrical nerve stimulation (TENS), sacral nerve stimulation (SNS) and sacral anterior root stimulation (SARS) are evaluated. In addition, clinical evidence from experimental therapies such as dorsal genital nerve (DGN) stimulation, pudendal nerve stimulation, magnetic nerve stimulation and ankle implants for tibial nerve stimulation are evaluated.

Results

SNS and P-PTNS have been investigated with high-quality studies that have shown proven efficacy for the treatment for overactive bladder (OAB). SARS has proven evidence-based efficacy in spinal cord patients and increases the quality of life. TENS seems inferior to other OAB treatments such as SNS and P-PTNS but is noninvasive and applicable for ambulant therapy. Results from studies on experimental therapies such as pudendal nerve stimulation seem promising but need larger study cohorts to prove efficacy.

Conclusion

Neurostimulation therapies have proven efficacy for bladder dysfunction in patients who are refractory to other therapies.

Significance

Refinement of neurostimulation therapies is possible. The aim should be to make the treatments less invasive, more durable and more effective for the treatment of lower urinary tract dysfunction.

Percutaneous Nerve Evaluation Test Versus Staged Test Trials for Sacral Neuromodulation: Sensitivity, Specificity, and Predictive Values of Each Technique

Purpose

InterStim device is an U.S. Food and Drug Administration approved minimal invasive therapy for sacral neuromodulation for lower urinary tract dysfunction. Before InterStim implantation, a trial with the appropriate screening tests is required to determine patient therapy eligibility. There are two different techniques for patient screening: percutaneous nerve evaluation (PNE) test and staged test. Few studies have reported success and failure rates for each technique. However, test sensitivity and predictive values of either test have not been studied. The aim of our study was to determine the sensitivity and specificity of each test and to establish a decision algorithm for the most appropriate testing method to be used as a screening test.

Methods

This cross-sectional study was conducted from August 2009 to February 2012 and included patients with lower urinary tract dysfunction who participated in the stimulation test trial. Patients underwent PNE as the first stimulation test, while those who encountered technical difficulty during PNE or electrode migration underwent staged testing.

Results

A total of 213 patients, including 172 female and 41 male subjects, underwent PNE. The patients’ diagnoses included refractory overactive bladder (47.9%), nonobstructive urinary retention (29.6%), and frequency urgency syndrome (22.1%). A total of 202 patients were screened with PNE and 10 patients with staged testing. Overall sensitivity of PNE was 87.3%, and it was 90% for staged test. PNE specificity was 98.5% as compared to 92.9% for staged test. Positive and negative predictive values for PNE were 99% and 82.1% and for staged test were 90% and 92.9%, respectively.

Conclusions

PNE test has high specificity and positive predictive value. We recommend PNE, a simple office-based, less expensive procedure as the first option for screening.

Outcomes of Sacral Neuromodulation in a Privately Insured Population

OBJECTIVE

In this study, we analyzed claims data from the Ingenix data base to analyze outcomes of sacral neuromodulation with respect to both provider and patient factors.

MATERIALS AND METHODS

We used the Ingenix (I3) data base to determine demographic, diagnosis, and procedure success information for years 2002-2007 for privately insured patients. Demographic information was obtained, as were the diagnoses given and procedures performed, based on ICD-9 diagnosis codes and Current Procedural Terminology procedure codes. Multivariate analysis was performed to identify specific predictors of success, as measured by progression to implantation of a pulse generator.

RESULTS

Overall success, as defined by battery placement, was 49.1%. Fifty-one percent of staged procedures were followed by battery placement compared with 24.1% of percutaneous cases (p < 0.0001). Among the patient variables analyzed, women were more likely than men to progress to battery placement. After Stage I testing, patients treated by urologists were overall more likely than gynecologists to proceed to battery placement (I3: 54% vs. 47%, p < 0.0001). Unlike previous findings in other claims-based data sets, we did not observe a provider-volume relationship in the i3 data set.

CONCLUSIONS

Success of sacral neuromodulation, as defined by proceeding to battery placement, was much better after formal staged procedures, which leads us to question the utility of percutaneous techniques. Outcomes were also better among female patients and among those treated by a urologist. Specialty differences will likely diminish over time as more gynecologists adopt sacral neuromodulation.

Overactive bladder - 18 years - Part II

Traditionally, the treatment of overactive bladder syndrome has been based on the use of oral medications with the purpose of reestablishing the detrusor stability. The recent better understanding of the urothelial physiology fostered conceptual changes, and the oral anticholinergics - pillars of the overactive bladder pharmacotherapy - started to be not only recognized for their properties of inhibiting the detrusor contractile activity, but also their action on the bladder afference, and therefore, on the reduction of the symptoms that constitute the syndrome. Beta-adrenergic agonists, which were recently added to the list of drugs for the treatment of overactive bladder, still wait for a definitive positioning - as either a second-line therapy or an adjuvant to oral anticholinergics. Conservative treatment failure, whether due to unsatisfactory results or the presence of adverse side effects, define it as refractory overactive bladder. In this context, the intravesical injection of botulinum toxin type A emerged as an effective option for the existing gap between the primary measures and more complex procedures such as bladder augmentation. Sacral neuromodulation, described three decades ago, had its indication reinforced in this overactive bladder era. Likewise, the electric stimulation of the tibial nerve is now a minimally invasive alternative to treat those with refractory overactive bladder. The results of the systematic literature review on the oral pharmacological treatment and the treatment of refractory overactive bladder gave rise to this second part of the review article Overactive Bladder - 18 years, prepared during the 1st Latin-American Consultation on Overactive Bladder.

The technique of sacral nerve modulation

AIM

The aim of this review was to summarize current knowledge and recommendations regarding the technique of implantation of the electrode in performing sacroneuromodulation (SNM) and the available information on programming parameters and implantation algorithms.

METHOD

All English-language articles published from January 1985 to December 2013 that reported the SNM surgical technique and results were considered for inclusion. Data were considered useful for the present review only if related to: (i) peripheral nerve evaluation; (ii) temporary nerve stimulation; (iii) definitive impulse generator placement; and (iv) parameters programming.

RESULTS

The literature search revealed 193 potentially relevant studies from initial electronic search terms and eligibility criteria, and these studies were evaluated in detail. In total, 41 studies were included in the final analysis. Of the studies reviewed, the majority (n = 37) were prospective or retrospective case series. Only three randomized clinical trials were eligible for inclusion.

CONCLUSION

Although the technique seems to be standardized, several steps still need to be clarified in order to define the best way to perform the procedure and then to maximize the outcome.

Tined lead versus percutaneous nerve evaluation for sacral nerve stimulator assessment

Purpose:

We compared the outcomes of percutaneous nerve evaluation (PNE) with first-stage tined lead placement (FSTLP) for the testing phase of sacral nerve neuromodulation (SNM), and we assessed the outcomes of these two techniques following implantation of a (second-stage) permanent sacral nerve stimulator (SNS).

Methods:

Seventy consecutive patients had either PNE ( n = 35) or FSTLP ( n = 35) evaluation, and conversion to a permanent SNS implant according to response. Primary outcomes were assessed using frequency-volume charts, pad testing, ICIQ/EQ5D questionnaires and global health perception visual analogue scale (VAS). Success was considered if they achieved greater than 50% improvement in their urinary symptoms. Success and failure rates were compared during the test phase and after implantation of the SNS.

Results:

Mean follow-up for the FSTLP group was 14 months (nine to 20) and for the PNE group was 22 months (eight to 27). Sixteen (46%) of the PNE tests and 20 (57%) of the FSTLP patients were converted to permanent implant. A significant correlation was noted between patients’ general health (VAS score) and a successful test phase ( r = 0.297, p = 0.013). Eighteen of 19 (95%) of tined lead patients have successful SNS implants, whereas five of 16 (31%) of PNE evaluations failed to convert test efficacy to the permanent SNS implant ( p = 0.042). Furthermore, two of PNE-SNS patients were successfully salvaged by the implantation of a second tined lead.

Conclusions:

FSTLP-SNS has a significantly higher success rate than PNE-SNS in converting the test phase to SNS implantation. This may be due in part to difficulties retaining accurate lead placement with the two-lead (PNE-SNS) approach. These findings have important cost and logistical implications for SNS services.

Understanding clinic options for overactive bladder

Overactive bladder (OAB) is a symptom complex of urinary frequency, nocturia and urgency with or without urgency incontinence that adversely impacts patient's quality of life. Conservative management begins in the outpatient clinic, often with significant improvement and patient satisfaction. In this review we will discuss the evaluation of OAB and review treatment options focusing on behavioral modification, medical therapy, and neuromodulation. These treatment options are offered in a stepwise fashion, remembering that more than one may be needed and can be used concomitantly.

Long-term follow-up of sacral neuromodulation for lower urinary tract dysfunction

OBJECTIVE

To report our long-term experience of sacral neuromodulation (SNM) for various lower urinary tract dysfunctions but with a focus on efficacy, safety, re-interventions and degree of success.

PATIENTS AND METHODS

This is a single tertiary referral centre study that included 217 patients (86% female) who received an implantable pulse generator (IPG) (Interstim™, Medtronic, Minneapolis, USA) between 1996 and 2010. Success was considered if the initial ≥50% improvement in any of primary voiding diary variables persisted compared with baseline, but was further stratified.

RESULTS

The mean duration of follow-up was 46.88 months. Success and cure rates were ≈70% and 20% for urgency incontinence, 68% and 33% for urgency frequency syndrome and 73% and 58% for idiopathic retention. In those patients with an unsuccessful therapy outcome, the mean time to failure was 24.6 months after implantation. There were 88 (41%) patients who had at least one device or treatment related surgical re-intervention. The re-intervention rate was 1.7 per patient with most of them (47%) occurring ≤2 years of follow-up.

CONCLUSIONS

SNM appears effective in the long-term with a success rate after definitive IPG implant of ≈70% and complete cure rates ranging between 20% and 58% depending on indication. Patients with idiopathic retention appear to do best. The re-intervention rate is high with most occurring ≤2 years of implantation. It is likely that with the newer techniques used, efficacy and re-intervention rates will improve.

Defining response and non-response to treatment in patients with overactive bladder: a systematic review

OBJECTIVE

There is currently a lack of formal guidance for assessing treatment response and non-response in patients with overactive bladder (OAB). Such guidance would be useful for both clinical practice and the design of clinical trials. Our purpose was to review and assess definitions of treatment response and non-response used in patients with OAB.

METHODS

We conducted a systematic review of articles published between January 1, 2005 and August 8, 2013 using PubMed. Search terms included (overactive bladder) AND ('treatment response' OR responder OR success OR satisfied OR goal OR refractory OR nonresponder OR fail OR persistent OR dissatisfied). Limits were 'humans' and 'English'. Studies conducted in subjects with neurogenic detrusor overactivity, conditions other than OAB, or OAB symptoms following lower urinary tract/pelvic surgery were excluded; case reports and letters were also excluded.

RESULTS

The literature search returned 423 articles, of which 75 met the inclusion criteria and defined a specific threshold by which treatment response or non-response was determined for patients receiving behavioral therapy and/or treatment with an antimuscarinic, β3-agonist, botulinum toxin, or neural stimulation. One published abstract from congress proceedings and three additional articles that were not identified by the search were included; thus, a total of 79 records were included. A wide variety of symptom-based definitions and patient-reported outcomes (PROs) were used. Symptom-based definitions frequently used a threshold of 50-100% improvement in general or specific symptoms; urgency urinary incontinence (UUI) was often used in studies with incontinent patients. Definitions based on PROs frequently used measures of satisfaction, general improvement, or goal achievement. Studies of patients with refractory OAB often referred to a failure to respond to ≥1 other therapy, or to poor efficacy or unacceptable tolerability, without further specification. Limitations of this review are that only English language articles were included and that only the PubMed database was used for the literature search.

CONCLUSIONS

There is considerable heterogeneity in the definitions of treatment response and non-response in trials of patients with OAB; some standardization would be beneficial. However, there is also heterogeneity among patients of what constitutes treatment success or failure, and conceptualizations of treatment response and non-response in both clinical trials and clinical practice must take patient characteristics into account. For patients with UUI, it is recommended that the criteria for treatment response include this symptom, as measured by change in the absolute number of UUI episodes or achievement of continence, given its impact on patients' lives and associated bother. PROs provide important information that confirm symptom-based measures by demonstrating that observed changes in symptoms are meaningful to the patient. In clinical practice, measures of treatment satisfaction and goal achievement can be highly useful.

Electrical and mechanical office-based neuromodulation

Overactive bladder (OAB) is commonly encountered in urologic practice. Treatment algorithms begin with conservative therapy and pharmacotherapy with antimuscarinics. Some patients do not receive adequate relief from these methods or they do not tolerate side effects from pharmacotherapy. A test stimulation for sacral neuromodulation and percutaneous tibial nerve stimulation are office-based techniques that are commonly used as the next step in the algorithm of care in patients with OAB. These techniques are efficacious and approved by the Food and Drug Administration for treatment of overactive bladder and its associated symptoms.

Predictors of implantable pulse generator placement after sacral neuromodulation: who does better?

OBJECTIVES

Numerous studies have documented a relationship between provider variables, including surgeon volume and specialty, and outcomes for surgical procedures. In this study we analyzed claims data from a Medicare database to analyze outcomes of sacral neuromodulation (SNM) with respect to both provider and patient factors.

MATERIALS AND METHODS

A 5% random sample of Medicare beneficiaries from 1997 to 2007 was the data source. Data retrieved included demographic information, ICD-9 diagnosis codes, and CPT procedure codes. Multivariate analysis was performed to identify predictors of progression to implantable pulse generator (IPG) implantation.

RESULTS

After stage I testing, urologists were more likely than gynecologists to proceed to IPG placement (Center for Medicare and Medicaid Services: 49% vs. 43%, p < 0.0001). After percutaneous testing, gynecologists were more likely than urologists to proceed to battery placement (63% vs.44%, p = 0.005). Among the patient variables analyzed, women were more likely than men to progress to battery placement. Patients treated by high-volume providers had higher rates of IPG placement after formal stage I trials (71% vs. 33%, p < 0.0001).

CONCLUSIONS

The rate of IPG implantation after SNM was greater among high-volume providers. Women had better outcomes than men. Further research may better define the relationship between outcomes of sacral neuromodulation and specific etiology of voiding dysfunction.

Sacral neuromodulation in patients with idiopathic overactive bladder after initial botulinum toxin therapy

PURPOSE

We evaluated whether patients with overactive bladder and incontinence who discontinued intravesical botulinum toxin therapy can be successfully treated with sacral neuromodulation.

MATERIALS AND METHODS

All patients who were referred to our center after discontinuation of botulinum toxin-A between 2005 and 2010 were included in this observational study. All patients underwent test stimulation with sacral neuromodulation and were evaluated with voiding diaries. Success was defined as more than 50% improvement in leakage episodes. Successful test stimulation was subsequently followed by a definitive implant. Patient satisfaction with sacral neuromodulation therapy was evaluated 1 year after the definitive implant.

RESULTS

A total of 20 patients were included in the study. Of these patients 17 (85%) had discontinued botulinum toxin-A because of lack of efficacy and 3 had been treated successfully with botulinum toxin-A but requested a more permanent solution. The mean interval between the botulinum toxin-A and the sacral neuromodulation test stimulation was 23 months. In 14 patients (70%) the test stimulation was successful and they received a definitive implant. Of the 14 patients 5 even showed a decrease of greater than 90% in leakage episodes. One year after implantation 11 patients (79%) were satisfied with the sacral neuromodulation treatment.

CONCLUSIONS

Despite the small sample size, this study indicates that patients who are dissatisfied with or in whom botulinum toxin-A treatment fails can respond successfully to sacral neuromodulation. The success rate of the test stimulation was comparable to that of patients who have never been treated with botulinum toxin-A. The 1-year satisfaction rate was comparable that of patients without a history of botulinum toxin-A treatment.

Neuromodulation for overactive bladder

Overactive bladder (OAB) affects millions of people worldwide yet first-line treatments are often poorly tolerated and compliance rates are low. Neuromodulation works via afferent nerve modulation and offers a minimally invasive and reversible alternative treatment option for patients with OAB who have failed first-line therapy. Neuromodulation has revolutionized the management of OAB and is now well established as a safe and effective treatment for those refractory to conservative treatments. Multiple neuroanatomical pathways have been described for sacral neuromodulation including the S3 nerve root, pudendal nerve and tibial nerve. The S3 nerve root is currently the main treatment target and has the most long-term data on safety and efficacy to support its use. However, studies on neuromodulation at the pudendal nerve or posterior tibial nerve have been positive and their role in treatment continues to evolve. Most urologists who are experienced in voiding dysfunction can become proficient in each technique. Patient selection, surgical techniques and postoperative management differ slightly between approaches and urologists should familiarize themselves with these differences. Treatment of OAB should progress from the least to most invasive modality, and neuromodulation provides an attractive option owing to its minimally invasive approach, tolerability, positive outcomes and reversibility.

Sacral nerve stimulation for urinary dysfunction: the first year of the Scottish national service

Sacral nerve stimulation (SNS) has become an established treatment option for patients with intractable detrusor overactivity and non-obstructive urinary retention. The Scottish Sacral Nerve Stimulation service was established in April 2010 to provide a service for the population of Scotland. We report our experience from the first year of this new national service. All patients referred for SNS from the inception of the service in April 2010 until the end of March 2011 were studied. During the one-year period, there were 50 referrals. Thirty-three percutaneous nerve evaluations, eight tined lead tests and 16 permanent implantation procedures were performed during this period. Morbidity was low and both incontinence and quality-of-life questionnaires demonstrated statistically significant improvements (International Consultation on Incontinence Questionnaire [ICIQ-SF], P = 0.005; Incontinence Impact Questionnaire [IIQ 7], P = 0.0007; Urogenital Distress Inventory [UDI 6], P = 0.0002). Referral pattern was skewed towards the west of Scotland with some health boards producing no referrals during the year. Results from the first year of the service have shown that it is a safe and efficient procedure with significant improvement in incontinence, voluntary voiding and quality-of-life parameters. The limitation of funding for permanent implants inevitably impacts on the role of the technique as a management option in these patients.

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.

Does patient age impact outcomes of neuromodulation?

AIMS

We evaluated whether patients stratified by age have the same level of risks/benefits after a staged neuromodulation procedure for refractory voiding symptoms.

METHODS

Urologic diagnosis, complications, and revisions were collected from medical records of adults enrolled in our prospective observational study. Symptoms were assessed over 2 years with diaries, Interstitial Symptom-Problem Indices (ICSI-PI), and the Overactive Bladder Questionnaire-SF (OAB-q SF). 12-item Short-Form Health Survey (SF-12v2®) mental (MCS) and physical (PCS) component summaries evaluated quality of life. Data were examined with Pearson Chi-square or Fisher's Exact test, Kruskal-Wallis tests, and repeated measures analyses.

RESULTS

Patients (83% female) were grouped by age (years): <40 (n = 46), 40-64 (n = 146), and ≥65 (n = 136). Urge incontinence was predominant in the older groups and more patients <40 had interstitial cystitis/painful bladder syndrome (IC/PBS). In the <40, 40-64, and ≥65 groups, respectively, generator implant (91%, 88%, and 89%) and explant (15%, 12%, and 10%) rates were similar. Complications (24%, 14%, and 9%; P = 0.031) and revisions (20%, 5%, and 6%; P = 0.0025) differed. For the three respective groups, urinary frequency (P < 0.0001 for all), nocturia (P < 0.0001 for all), incontinence episodes (P < 0.0001 for all), urgency (P = 0.0474, P < 0.0001, P = 0.0020), ICSI-PI (P = 0.0015, P < 0.0001, P < 0.0001), and OAB-q scores improved over time. Incontinence severity improved in those >65 (P = 0.0015). SF-12 PCS improved in those 40-64 (P = 0.0482) and MCS scores improved in the <40 and 40-64 age groups (P = 0.013 and P = 0.0440, respectively).

CONCLUSIONS

These data suggest that neuromodulation success is not age dependent, however continued study is needed to confirm findings.