Long-Term Results of Sacral Neuromodulation With the Tined Lead Procedure

Efficacy of sacral neuromodulation and percutaneous tibial nerve stimulation in the treatment of chronic nonobstructive urinary retention: A systematic review

AIM

The aim of this systematic review is to provide an updated report on the efficacy and complications of sacral neuromodulation (SNM) and percutaneous tibial nerve stimulation (PTNS) in the treatment of chronic nonobstructive urinary retention (CNOUR), with a focus on the contemporary technique of SNM utilizing the percutaneous placement of tined leads.

METHODS

This systematic review was conducted with the use of PRISMA guidelines and registered with PROSPERO (CRD42020208052). A systematic literature search was conducted in Embase, PubMed, and Cochrane databases. Inclusion criteria include English language and human participants. Exclusion criteria include SNM studies involving less than 10 CNOUR patients, studies containing data obtained using open, surgical implantation of nontined leads, and studies that only reported the test phase success rate with no long-term efficacy data. The risk of bias assessment was conducted using the National Institutes of Health study quality assessment tool.

RESULTS

A total of 16 papers studies were included (11 SNM and 5 PTNS) in this review. The success rate for SNM ranges between 42.5% and 100% (median = 79.2%) for the test stimulation phase and 65.5%-100% (median = 89.1%) in the long term. Most SNM studies reported revision and explantation rates of lesser than 20%. The success rate was much lower for PTNS, in the 50%-60% range and complications were minimal.

CONCLUSION

SNM using the contemporary percutaneous tined lead implantation technique appears to be an effective treatment for CNOUR and is durable in the long term. Compared to SNM, PTNS appears less efficacious with less evidence supporting its use in CNOUR. Further prospective studies are required to define the role of PTNS in the treatment of CNOUR.

[Functional results and satisfaction in 44 patients after implantation of a NS3-type sacral neurostimulator for refractory idiopathic overactive bladder followed at 43 months, single-center series]

OBJECTIVES

Sacred neuromodulation (SNM) has been used in France since 1997 for the management of non-neurogenic urinary disorders that do not respond to first-line pharmacological treatment. The aim of this study is to analyze the clinical efficacy and satisfaction of patients with refractory idiopathic overactive bladder (OAB) treated with SNM.

METHODS

This single-center retrospective series included 59 patients with refractory OAB of idiopathic origin and eligible for the SNM between January 2010 and December 2017. Demographic data, history of pelvic surgery, complications according to Clavien-Dindo classification, as well as revision and explantation rates were collected. All the patients included underwent a test phase. Therapeutic success for the test phase and definitive implantation was defined by≥50% improvement. Satisfaction was a secondary criteria.

RESULTS

Of the 59 patients tested for SNM, 44 patients had a permanent implantation, of which 36 (82%) were women and 8 (12%) were men. The median age of the study was 55 years old. The median follow-up was 43 months [21,2-66,5]. All of the patients had an idiopathic refractory OAB. The median time between test and final implantation was 28 days [18-35]. The success rate for all patients tested was 60% (34/59). In patients implanted, 34 patients (77%) had clinical improvement. Adverse events had to be managed including multiple re-parameterizations (n=13), device revision (n=16), or even device implantation (n=8). The satisfaction rate was 82% (36/44).

CONCLUSION

With a median follow-up of 43 months, this retrospective study on NMS shows the efficacy of second-line SNM for idiopathic OAB. This technique remains minimally invasive but with significant adverse events when informing our patients.

LEVEL OF EVIDENCE

3.

Long-term Outcomes of Sacral Nerve Stimulation in Pelvic Floor Dysfunctions

Purpose

The aim of this study was to analyze the long-term outcomes of sacral nerve stimulation (SNS) in both idiopathic and neurogenic pelvic floor disorders in patients treated at a referral center.

Methods

This retrospective observational study analyzed the records of 106 patients tested at our department from December 1999 to January 2017. The efficacy variables evaluated were the Global Response Assessment (range, 0%–100%) and, according to the clinical indication, other specific variables such International Consultation on Incontinence QuestionnaireShort Form, number of catheterizations or pads/day, and the numerical pain scale. The safety variables analyzed were complications (pain, migration, infection), reinterventions and explants. Patients’ quality of life (QoL) and satisfaction with the procedure were evaluated through telephone interviews.

Results

The clinical indications were overactive bladder (OAB) (n=36), urinary retention (UR) (n=37), bladder pain syndrome/interstitial cystitis (BPS/IC) (n=19), fecal incontinence (FI) (n=8), and double incontinence (DI) (n=6). The implant rates according to the clinical indication were as follows: OAB, 55.6%; UR, 56.8%; BPS/IC, 63.15%; FI, 87.5%; and DI, 66.7%. Clinical and/or statistically significant improvements in all efficacy variables were observed. Loss of therapeutic effect at 75 months of follow-up was observed in 34% of patients. Device-related pain appeared in 25 patients (39%); in 20 patients, it was resolved by reprogramming and 5 patients required device removal. An overall improvement in QoL and high levels of satisfaction with the procedure were observed. More than 90% of patients would recommend SNS to a friend or relative.

Conclusions

SNS is a minimally invasive procedure that offers a real alternative to patients with refractory pelvic floor dysfunction. Its safety profile is very favorable and it provides a long-lasting improvement in symptoms and QoL.

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.

Recent advances in managing overactive bladder

Overactive bladder syndrome (OAB) is defined as urinary urgency, usually accompanied by frequency and nocturia, with or without urgency incontinence, in the absence of urinary tract infection or other obvious pathology. In this review, we focus on recent advances in the management of OAB. We examine the evidence on the effect of anticholinergic load on OAB patients. Advances in medical treatment include a new beta-3 agonist, vibegron, which is thought to have fewer drug interactions than mirabegron. Treatment of genitourinary syndrome of the menopause with oestrogens and ospemifene have also shown promise for OAB. Botulinum toxin has been shown to be an effective treatment option. We discuss the new implantable neuromodulators that are on the market as well as selective bladder denervation and laser technology.

Stimulation Parameters for Sacral Neuromodulation on Lower Urinary Tract and Bowel Dysfunction-Related Clinical Outcome: A Systematic Review

Objective

Sacral neuromodulation (SNM) has been used to treat patients with lower urinary tract dysfunction and bowel dysfunction for many years. Success rates vary between 50% and 80%, indicating that there is much room for improvement. Altering stimulation parameters may result in improved outcome. This paper reports a systematic review of the clinical efficacy of nonconventional stimulation parameters on urinary tract and bowel dysfunction.

Materials and Methods

Three databases were used for the literature search: Ovid (Medline, Embase) and PubMed. Papers were screened by two independent reviewers, who also extracted data from these papers. Clinical papers studying SNM stimulation parameters, that is, intermittent stimulation, frequency, pulse width, and amplitude, in urinary tract and bowel dysfunction were included. Quality of included papers was assessed using standardized guidelines.

Results

Out of 5659 screened papers, 17 papers, studying various stimulation parameters, were included. Overall quality of these papers differed greatly, as some showed no risk of bias, whereas others showed high risk of bias.

Stimulation parameters included intermittent stimulation, frequency, pulse width, amplitude, and unilateral vs. bilateral stimulation. Especially high frequency SNM and either a narrow or wide pulse width seem to improve efficacy in patients with bowel dysfunction. Additionally, implementation of short cycling intervals is promising to improve quality of life for patients with urinary tract or bowel dysfunction.

Conclusion

The results of our systematic review indicate that stimulation parameters may improve efficacy of SNM in treatment of both urinary tract dysfunction and bowel dysfunction.

Urology as rehabilitation medicine: a literature review

As a urologist, we usually encounter with two representative functional behaviors, namely, voiding and sexual function. These are not only important but also complex and synchronized so if these functions are impaired, patients need active functional rehabilitation to recover. These functional impairments should be recognized and corrected early because they could not only cause direct damage to the affected functions but also have harmful consecutive consequences such as kidney damage due to voiding abnormality and self-esteem damage due to decreased sexual function. Numerous rehabilitative methods are currently available, which help minimize the negative effects of these functional impairments. In terms of voiding function, pelvic floor muscle exercise, biofeedback, functional magnetic stimulation, neuromodulation, and clean intermittent self-catheterization are representative rehabilitation modalities. In case of children, extra-attention should be paid because this might affect their entire life. In impairment of sexual function, early intervention to maintain male erection is the main target of rehabilitation to prevent corporal fibrosis and penile deformity and increase recovery chance in patients who underwent radical prostatectomy or major surgery. In this review, we will elucidate various rehabilitation methods in urology to further increase our understanding of the rehabilitative characteristics of urology and widen our view of rehabilitation medicine.

Management of Idiopathic Overactive Bladder Syndrome: What Is the Optimal Strategy After Failure of Conservative Treatment?

CONTEXT

A considerable number of patients affected by the overactive bladder syndrome (OAB) do not respond to pharmacotherapy and bladder training due to unsatisfactory response or intolerability.

OBJECTIVE

To review the available literature assessing therapeutic effect of the available third-line treatment modalities for OAB.

EVIDENCE ACQUISITION

PubMed, Medline, and Cochrane databases were searched for all studies comparing outcomes of the available third-line treatment modalities for OAB.

EVIDENCE SYNTHESIS

Several minimally invasive surgical procedures are available for patients with refractory OAB. These therapies include intravesical botulinum toxin type A, posterior tibial nerve stimulation, and sacral neuromodulation.

CONCLUSIONS

None of the mentioned therapeutic modalities shows strong superiority over another. If the results of one therapy are not satisfactory, switching to another third-line treatment can be attempted. The treatment algorithm is dependent on several factors, including age, comorbidity, patient preference, surgical expertise, and financial concerns. All these factors should be taken into consideration before initiation of treatment.

PATIENT SUMMARY

In the management of drug-resistant overactive bladder syndrome, the different minimally invasive treatments that are available are equal. If the results of one therapy are not satisfactory, switching to another treatment can be attempted. The treatment algorithm is dependent on several factors, including age, comorbidity, patient preference, surgical expertise, and financial concerns.

Predicting a successful outcome in sacral neuromodulation testing: Are urodynamic parameters prognostic?

AIMS

To assess whether the urodynamic parameters of mean voided volume, peak detrusor overactivity (DO) pressure, bladder compliance, capacity, and volume at first detrusor overactivity during filling cystometry can predict a successful outcome at first stage tined lead placement (FSTLP).

METHODS

Ninty-nine consecutive patients with urodynamically proven idiopathic detrusor overactivity (IDO) refractory to medical treatment and opting for Sacral Nerve Stimulation (SNS), were assessed pre and post FSTLP. Data from 3-day frequency-volume charts, and patient reported (subjective) outcomes were used to assess success or failure after FSTLP. Success was defined as improvement in symptoms >50%. Binary logistic regression analysis was used to ascertain whether key parameters at filling cystometrogram were predictors for success prior to FSTLP.

RESULTS

Binary logistic regression analysis did not demonstrate any significant relationship between the five parameters at urodynamics and outcome at FSTLP (B < 0.01, P > 0.16) for all parameters.

CONCLUSIONS

The results from this prospective analysis on patients with IDO refractive to medical therapy referred for SNS would suggest that aside from proving DO at urodynamics as a pre-requisite for intervention as per NICE and EAU guidelines, no parameter is predictive for a successful outcome at FSTLP.

Long-Term Functional Outcomes of S3 Sacral Neuromodulation for the Treatment of Idiopathic Overactive Bladder

OBJECTIVES

To assess the long-term functional outcomes of sacral neuromodulation (SNM) in the treatment of refractory idiopathic overactive bladder (IOAB) and to determine predictive factors for success.

MATERIALS AND METHODS

To obtain long-term data, all consecutive patients suffering from IOAB and treated by SNM at a single tertiary care center between December 1996 and December 2004 were included. Data regarding patient demographics, past medical, and surgical history, bladder diary, complications as well as device revision and removal rates were collected. Success was defined as an improvement ≥ 50% of any clinical parameter.

RESULTS

Overall, 34 patients, with a median age of 57.8 years (IQR 44.8-65.7) were included. Immediately after definitive implantation, 2 (6%) patients were lost to follow-up. After a median follow-up of 9.7 years (IQR 4.7-12.0), SNM was considered successful in 20 (63%) patients. Mean amount of protections used per 24 hours significantly decreased (4.1 preoperatively vs. 1.8 at the last follow-up visit, p = 0.02). Devices were removed in 2 (6%) patients due to pain and lack of efficacy. Twenty-two revision surgeries were performed in 15 (47%) patients. First revision surgery occurred after a mean of 6.2 years (± 3.1). Revision surgeries were mainly performed for end of battery life/device dysfunction (n = 18, 82%). No significant predictor for success was identified.

CONCLUSIONS

With a median follow-up time of 9.7 years, this retrospective SNM study reports a 63% efficacy rate (≥ 50% improvement) for the treatment of refractory IOAB. Moreover, it is a well-tolerated and minimally invasive therapy.

Real-Time Changes in Brain Activity during Sacral Neuromodulation for Overactive Bladder

PURPOSE

We performed functional magnetic resonance imaging to identify changes in brain activity during sacral neuromodulation in women with overactive bladder who were responsive to therapy.

MATERIALS AND METHODS

Women recruited into the study had nonneurogenic refractory overactive bladder, responded to sacral neuromodulation and had had a stable program for at least 3 months with no subsequent overactive bladder treatment. Enrolled patients completed validated symptom and quality of life instruments before functional magnetic resonance imaging. Stimulus settings were recorded, devices were switched off for a 5-day washout and instruments were repeated. Three functional magnetic resonance imaging scans with simultaneous sacral neuromodulation stimulation were performed below, at and above stimulus sensory threshold using a block design. This yielded brain activity maps represented by changes in blood oxygenation level dependence. A total of 5 stimulator off and 4 stimulator on cycles of 42 seconds each were imaged. Group analysis was done using a single voxel p value of 0.05 with a false-positive error of 0.05 on cluster analysis.

RESULTS

Six of the 13 patients enrolled completed functional magnetic resonance imaging. Median age was 52 years (range 36 to 64). Urinary symptoms and voiding diary data worsened with washout. Overall brain activation generally progressed with increasing stimulation amplitude. However, activation of the right inferior frontal gyrus remained stable while deactivation of the pons and the periacqueductal gray matter only occurred with subsensory stimulation. Sensory stimulation activated the insula but deactivated the medial and superior parietal lobes. Suprasensory stimulation activated multiple structures and the expected S3 somatosensory region. All devices had normal impedance after functional magnetic resonance imaging.

CONCLUSIONS

Functional magnetic resonance imaging confirmed that sacral neuromodulation influences brain activity in women with overactive bladder who responded to therapy. These changes varied with stimulus intensity.

Impact of ao-dake-humi, Japanese traditional bamboo foot stimulator, on lower urinary tract symptoms, constipation and hypersensitivity to cold: a single-arm prospective pilot study

Background

Ao-dake-humi is a traditional Japanese bamboo foot stimulator consisting of a half-pipe-shaped step made of bamboo used to stimulate the foot by stepping on it, and is commonly used to promote general health among the elderly in Japan. However, its efficacy has not been reported in the scientific literature. This study was performed to investigate the role of ao-dake-humi focusing on lower urinary tract symptoms (LUTS), constipation, and hypersensitivity to cold (HC).

Methods

Participants with LUTS, constipation, or HC were enrolled in this study. Ao-dake-humi was used twice a day for 28 days. Before and 28 days after starting ao-dake-humi use, international prostate symptom score (IPSS), quality-of-life (QoL) score, and overactive bladder symptom score (OABSS) were measured to evaluate the efficacy of ao-dake-humi on LUTS. To evaluate the objective efficacy of ao-dake-humi on LUTS, a frequency-volume chart (FVC) was plotted in LUTS patients for 3 days. A visual analogue scale (VAS) was used to evaluate the efficacy of ao-dake-humi on constipation (VAS-constipation) and HC (VAS-HC) in the participants with constipation or HC.

Results

A total of 24 participants were enrolled in this study. Twenty-one participants had LUTS, 11 had constipation, and 17 participants had HC. IPSS, especially storage-subscore, QoL score and OABSS, decreased significantly after use of ao-dake-humi. The use of ao-dake-humi increased maximal bladder capacity, resulting in a significant decrease in urinary frequency as determined from the FVC. In accordance with the results of VAS-constipation and VAS-HC, both constipation and HC were significantly relieved after ao-dake-humi use.

Conclusion

The results of this prospective pilot study indicated that ao-dake-humi is safe and has therapeutic efficacy in cases of LUTS, constipation and HC. The possibility of using ao-dake-humi as physical neuromodulation therapy was shown in the management of LUTS, constipation and HC.

Trial registration

UMIN000019333 (UMIN-CTR, Registered October-15-2015) retrospectively registered.

OnabotulinumtoxinA in the treatment of overactive bladder: a cost-effectiveness analysis versus best supportive care in England and Wales

The cost-effectiveness of onabotulinumtoxinA (BOTOX(®)) 100 U + best supportive care (BSC) was compared with BSC alone in the management of idiopathic overactive bladder in adult patients who are not adequately managed with anticholinergics. BSC included incontinence pads and, for a proportion of patients, anticholinergics and/or occasional clean intermittent catheterisation. A five-state Markov model was used to estimate total costs and outcomes over a 10-year period. The cohort was based on data from two placebo-controlled trials and a long-term extension study of onabotulinumtoxinA. After discontinuation of initial treatment, a proportion of patients progressed to downstream sacral nerve stimulation (SNS). Cost and resource use was estimated from a National Health Service perspective in England and Wales using relevant reference sources for 2012 or 2013. Results showed that onabotulinumtoxinA was associated with lower costs and greater health benefits than BSC in the base case, with probabilistic sensitivity analysis indicating an 89 % probability that the incremental cost-effectiveness ratio would fall below £20,000. OnabotulinumtoxinA remained dominant over BSC in all but two scenarios tested; it was also economically dominant when compared directly with SNS therapy. In conclusion, onabotulinumtoxinA appears to be a cost-effective treatment for overactive bladder compared with BSC alone.

Predictors of reoperation after sacral neuromodulation: A single institution evaluation of over 400 patients

AIMS

To explore factors that may predispose patients to reoperation after sacral neuromodulation (SNM).

METHODS

Patients enrolled in our longitudinal neuromodulation database were reviewed. Medical records data, and voiding diaries, Interstitial Cystitis Symptom-Problem Indices (ICSI-PI), and Overactive Bladder Questionnaires (OAB-q) at baseline and 3 months were analyzed with Pearson's χ² , Fisher's Exact test, Wilcoxon rank tests, and multivariable logistic regression.

RESULTS

Of 407 patients, 134 (33%) had at least one reoperation over median 28.9 months follow-up (range 1.6-121.7); 78/407 (19%) were revised, and 56/407 (14%) were explanted. The most common reason for reoperation was lack of efficacy/worsening symptoms (n = 87). The reoperations group had a higher proportion of women (P = 0.049), lower mean body mass index (BMI; P = 0.010), more reprogramming events (P < 0.0001), longer median follow-up (P = 0.0008), and higher proportions with interstitial cystitis (P = 0.013), using hormone replacement therapy (P = 0.0004), and complications (P < 0.0001). Both reoperations/no reoperations groups had similar improvements in ICSI-PI (P < 0.0001 for both), OAB-q severity (P < 0.0001 for both) and quality of life (P < 0.0001 for both). On multivariate analysis, only longer follow-up (P = 0.0011; OR 1.048; CI 1.019, 1.078) and having a complication (P < 0.0001; OR 23.2; CI 11.47, 46.75) were significant predictors of reoperations. In women only, using HRT at time of implant was also predictive of reoperation (P = 0.0027; OR 3.09; CI 1.48, 6.46).

CONCLUSIONS

In this largest known series to date, one third of the patients required reoperation and the most common reason was lack of efficacy/worsening symptoms. Ongoing study is needed as the technology continues to evolve. Neurourol. Urodynam. 36:354-359, 2017. © 2015 Wiley Periodicals, Inc.

Conjoint Urological Society of Australia and New Zealand (USANZ) and Urogynaecological Society of Australasia (UGSA) Guidelines on the management of adult non-neurogenic overactive bladder

Due to the myriad of treatment options available and the potential increase in the number of patients afflicted with overactive bladder (OAB) who will require treatment, the Female Urology Special Advisory Group (FUSAG) of the Urological Society of Australia and New Zealand (USANZ), in conjunction with the Urogynaecological Society of Australasia (UGSA), see the need to move forward and set up management guidelines for physicians who may encounter or have a special interest in the treatment of this condition. These guidelines, by utilising and recommending evidence-based data, will hopefully assist in the diagnosis, clinical assessment, and optimisation of treatment efficacy. They are divided into three sections: Diagnosis and Clinical Assessment, Conservative Management, and Surgical Management. These guidelines will also bring Australia and New Zealand in line with other regions of the world where guidelines have been established, such as the American Urological Association, European Association of Urology, International Consultation on Incontinence, and the National Institute for Health and Care Excellence guidelines of the UK.

CT evaluation of acupuncture needles inserted into sacral foramina

OBJECTIVE

To use CT scanning to evaluate the precision with which acupuncture needles can be inserted into sacral foramina to establish sacral nerve modulation by electroacupuncture.

METHODS

The subjects were five adult women (mean age 71.6 years). These five cases were divided into two groups. In the first three subjects (group A) the intention was to insert acupuncture needles in the S3 and S4 foramina; in the remaining two subjects (group B) the intention was to insert acupuncture needles in the S2 and S3 foramina.

RESULTS

CT scanning showed that in subject 1 of group A, the acupuncture needle intended for insertion in S3 was actually in the S4 foramen, and the acupuncture needle intended for insertion in S4 was actually distal to the sacral body. In subjects 2 and 3, the acupuncture needles were inserted accurately in the S3 and S4 foramina. In the three subjects who had acupuncture needles inserted in the S4 foramen, the tip of the acupuncture needle was an average distance of 6.0 mm from the rectum. The acupuncture needles inserted in subjects 4 and 5 of group B were inserted accurately into the S2 and S3 foramina.

CONCLUSIONS

Inserting acupuncture needles into the sacral foramina of S2 and S3 at an angle of about 60° has the potential to be used for sacral nerve modulation by repeated electroacupuncture stimulation. Needling may be less accurate in subjects with higher body mass index. Because of the potential risk of perforating the rectum with the needle, this technique must be used by specialists only.

TRIAL REGISTRATION NUMBER

2013-026.

Economic evaluation of sacral neuromodulation in overactive bladder: A Canadian perspective

INTRODUCTION

Refractory overactive bladder (OAB) with urge incontinence is an underdiagnosed condition with substantial burden on the healthcare system and diminished patient's quality-of-life. Many patients will fail conservative treatment with optimized medical-therapy (OMT) and may benefit from minimally invasive procedures, including sacral-neuromodulation (SNM) or botulinum-toxin (BonT-A). The goal of this study was to estimate the cost-efectiveness of SNM vs. OMT and BonT-A as important parameters from coverage and access to a therapy.

METHODS

A Markov model with Monte-Carlo simulation was used to assess the incremental cost effectiveness ratio (ICER) of SNM vs. BonT-A and OMT both in deterministic and probabilistic analysis from a provincial payer perspective over a 10-year time horizon with 9-month Markov-cycles. Clinical data, healthcare resource utilization, and utility scores were acquired from recent publications and an expert panel of 7 surgeons. Cost data (2014-Dollars) were derived from provincial health insurance policy, drug benefit formulary, and hospital data. All cost and outcomes were discounted at a 3% rate.

RESULTS

The annual (year 1-10) incremental quality-adjusted life years for SNM vs. BonT-A was 0.05 to 0.51 and SNM vs. OMT was 0.19 to 1.76. The annual incremental cost of SNM vs. BonT-A was $7237 in year 1 and -$9402 in year 10 and was between $8878 and -$11 447 vs. OMT. In the base-case deterministic analysis, the ICER for SNM vs. BonT-A and OMT were within the acceptable range ($44 837 and $15 130, respectively) at the second year of therapy, and SNM was dominant in consequent years. In the base-case analysis the probability of ICER being below the acceptability curve (willingness-to-pay $50 000) was >99% for SNM vs. BonT-A at year 3 and >95% for OMT at year 2.

CONCLUSION

SNM is a cost-effective treatment option to manage patients with refractory OAB when compared to either BonT-A or OMT. From a Canadian payers' perspective, SNM may be considered a first-line treatment option in management of patients with OAB with superior long-term outcomes. Similar to all economic analysis, this study has limitations which are based on the assumptions of the used model.

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.

Male incontinence: onabotulinum toxin A and sacral nerve stimulation

PURPOSE OF REVIEW

Overactive bladder affects 10-12% of men, of which 13% are refractory to medical therapy and seek second-line treatment. This places a substantial clinical and economic burden on the National Health Service United Kingdom.

RECENT FINDINGS

This review identifies current evidence for the use of onabotulinum toxin A and sacral nerve neuromodulation for the treatment of overactive bladder in patients who do not respond to optimal medical treatment. Posterior tibial nerve stimulation is not covered here. Clinical and financial implications of the treatments are reviewed.

SUMMARY

The focus will remain on recently published evidence, which may be useful to clinicians managing refractory patients.

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.

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.

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

OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

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

OBJECTIVE

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Sacral nerve stimulator revision due to somatic growth

PURPOSE

Sacral nerve modulation is a Food and Drug Administration approved treatment for refractory urgency, frequency, urge incontinence and nonobstructive urinary retention in adults. The sparse literature on sacral nerve modulation in children focuses on its initial efficacy in patients with neurogenic bladder and dysfunctional elimination. We describe our initial experience with sacral nerve modulation and the phenomenon of growth spurts associated with lead malfunction that necessitates revision.

MATERIALS AND METHODS

After receiving institutional review board approval we retrospectively reviewed the charts of pediatric patients who underwent sacral nerve modulation surgery at our institution. Charts were examined for patient demographics, subjective success, the need for further surgery and success after revision.

RESULTS

Four patients underwent sacral nerve modulation at an average age of 12.1 years. All patients reported initial success, defined as greater than 50% symptom improvement. Subsequently 3 patients required a total of 5 revisions due to lead malfunction with an average of 1.5 years between surgeries. In those requiring revision the average somatic growth between revisions was 8.1 cm. Return of efficacy was reported after each revision. All patients had functioning nerve stimulators in place and continued to have a positive subjective response.

CONCLUSIONS

The sparse data on sacral nerve modulation in children shows efficacy and safety similar to those in adults. Somatic growth may be associated with lead malfunction and require surgical revision. We report a small series showing that revision can be done successfully and safely. Informed consent for sacral nerve modulation in pediatric patients should include a discussion of somatic growth as a possible cause of lead malfunction necessitating revision.