Buttock placement of the implantable pulse generator: a new implantation technique for sacral neuromodulation--a multicenter study

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.

Factors Associated With Implantable Pulse Generator Site Pain: A Multicenter Cross-Sectional Study

OBJECTIVES

Implantable pulse generator (IPG) site pain following neuromodulation procedures is a recognized complication. The site of the IPG placement varies depending on the neuromodulation type and physician preference. The incidence of IPG site pain as a function of the site of IPG implantation has not been studied systematically.

MATERIALS AND METHODS

We performed a multicenter cross-sectional survey of the incidence, severity, and quality of IPG site pain, location of the IPG, the pain management needs, functional impairment, and cosmetic appearance related to the IPG placement. Contingency table analysis was conducted for categorical variables, and logistic regression analysis and linear regression model was used.

RESULTS

The survey response rate was 60.5% (n = 510). Overall, 31.0% of patients reported pain at the IPG site in the last 72 hours with 31.4% reporting moderate to severe pain and 7.6% reporting severe pain. Older age was inversely associated with IPG-related pain (OR = 0.97, 95% CI = 0.96-0.99, p = 0.001). IPG implantation site did not have a statistically significant interaction with IPG site pain (p > 0.05). The most important factor for IPG site-associated pain was having a spinal cord stimulator implanted as compared to a deep brain stimulator, or sacral nerve stimulator. Most subjects reported no functional impairment related to IPG site pain (91%), found the IPG site pain as expected (80%), and found IPG site cosmetic appearance as expected (96%).

CONCLUSIONS

The incidence of IPG site pain is an important complication of invasive neuromodulation. The anatomic location of the IPG placement does not appear to affect the incidence or severity of IPG site pain. However, the presence of a pre-implant chronic pain disorder does appear to affect the frequency and severity of IPG site pain.

Abdominal Versus Standard Placement of the Sacral Nerve Stimulator Implantable Pulse Generator

OBJECTIVES

To determine patient factors prompting anterior abdominal wall placement of the sacral nerve stimulator implantable pulse generator and investigate revision and infection rates for buttock (standard) and abdominal placement.

METHODS

We retrospectively reviewed records of consecutive sacral nerve stimulation procedures by a single surgeon from 2012 to 2017 at a single institution.

RESULTS

75 patients underwent sacral nerve stimulation--60 with standard and 15 with abdominally placed implantable pulse generators. The mean age and body mass index of the standard group was higher than that of the abdominal group and the majority was female. A greater proportion of patients in the abdominal group had a neurological diagnosis and was wheelchair-dependent. Overall, a total of 20 patients underwent 38 revision surgeries. The indications for revision surgery were pain, loss of efficacy, or lead migration. The standard group accounted for more revisions than the abdominal group (34vs 4 cases, P = .048), with no revisions due to pain in the abdominal group. The infection rate (2% vs 13%, P = .10), average time from implantation to revision, and operative duration were not statistically different between groups.

CONCLUSION

In a subset of patients who were wheelchair-dependent or lacked gluteal fat, placement of the implantable pulse generator in the anterior abdominal wall resulted in no revisions due to pain. Operative duration and infection rates were similar between abdominal and standard placement. Abdominal placement with extended length leads could be considered as a primary or revision option in these select patients.

Results of Sacral Neuromodulation Therapy for Urinary Voiding Dysfunction: Five-Year Experience of a Retrospective, Multicenter Study in China

PURPOSE

This five-year, retrospective, multicenter study evaluated the long-term safety and efficiency of sacral neuromodulation (SNM) in Chinese patients with urinary voiding dysfunction.

PATIENTS AND METHODS

This is a Chinese national, multicenter, retrospective study that included 247 patients (51.2% female) who received an implantable pulse generator (IPG) (InterStim, Medtronic, Minneapolis, MN, USA) between 2012 and 2016. Success was considered if the initial ≥50% improvement in any of primary voiding diary variables persisted compared with baseline. The results were further stratified by identifying patients who showed >50% improvement and those although showed <50% improvement but still wanted to receive IPG; these data were collected and analyzed for general improvement.

RESULTS

Following test stimulation, 187 patients (43%) declined implantation and 247 (57%) underwent implantation using InterStim®. Among 247 patients, 34 (13.7%) had overactive bladder (OAB), 59 (23.8%) had interstitial cystitis/bladder pain syndrome (IC/BPS), 47 (19%) had idiopathic urinary retention (IUR), and 107 (44.1%) had neurogenic bladder (NB). IPG efficiency rate for OAB, interstitial cystitis/bladder pain syndrome, idiopathic urinary retention, and neurogenic bladder were 42.5, 72.4, 51.6, and 58.8%, respectively. The mean duration of follow-up was 20.1 ± 12.8 months.

CONCLUSIONS

SNM appears effective in the long term, with a total IPG implantation rate of approximately 57% (ranging between 42.5 and 72.4% depending on indication). Interstitial cystitis/bladder pain syndrome appear to be the best indication for stage I testing. Chinese neurogenic bladder patients are most inclined to choose SNM. SNM is relatively safe, with low postoperation adverse events of 16.1% and reoperation rate of 3.2% during the follow-up period.

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.

The effect of sacral neuromodulation on pregnancy: a systematic review

INTRODUCTION AND HYPOTHESIS

To evaluate the effects of sacral neuromodulation (SNM) on pregnancy and the impact of delivery on SNM function.

METHODS

A systematic search was conducted through January 2016. We selected studies including women who had SNM and a subsequent pregnancy.

RESULTS

Out of 2,316, eight studies were included, comprising 22 patients (26 pregnancies). SNM indications were Fowler's syndrome in 11, urinary retention in 6, fecal incontinence in 1, fecal and urinary urgency in 1, overactive bladder in 1, intractable interstitial cystitis in 1, and myelodysplasia in 1. SNM stayed on in 8 pregnancies. In the remaining 18 pregnancies in which the device was deactivated, 7 had recurrent urinary tract infections, including 1 with pyelonephritis and 2 who requested reactivation owing to recurrent symptoms. Outcomes were reported in 25 pregnancies, 16 had Cesarean section (CS) and 9 had vaginal delivery, including 2 operative deliveries. Out of 25, two infants had pilonidal sinus and motor tic disorder (exhibited at the age of 2 years), both from the same mother. After delivery, SNM was functioning in 15 (60%), 4 required reprogramming, and 3 required replacement (1 had recurrence of fecal incontinence after her operative delivery with evidence of displaced leads and 1 patient reported decreased SNM effects after her two CS), and 3 decided to remove the device (2 out of 3 patients were free of symptoms after SNM deactivation and requested removal).

CONCLUSION

Within the current limited evidence, the decision regarding SNM activation or deactivation should be individualized. A registry for those patients is recommended.

Sacral neuromodulation in overactive bladder: a review and current perspectives

Overactive bladder (OAB) symptoms of urgency, frequency, and urge incontinence currently affect a substantial portion of the population, especially as age increases. Sacral neuromodulation has become a popular option for refractory OAB symptoms over the past 2 decades. Studies have demonstrated that it is an effective treatment for OAB and urge incontinence as indicated by decreased number of voids, increased bladder capacity, and fewer leakage events. In addition, the effects have proved to be durable to multiple years following implantation. These benefits come at the expense of a high rate of adverse events, although with comparable long-term cost-effectiveness to botulinum toxin A. We aimed to review the literature that demonstrates that sacral neuromodulation continues to be an efficacious treatment for refractory OAB wet and dry patients, with continuously expanding indications.

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.

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.

Sacral nerve stimulation for fecal incontinence

Fecal incontinence (FI), which can severely affect a person's quality of life, is a difficult problem to treat. For some patients, limited management options exist. Sacral nerve stimulation, also known as sacral neuromodulation, although long established for urinary incontinence, has gained acceptance in treating FI. One unique aspect is that the procedure is performed in two stages. During the first stage, a temporary lead is inserted into the S3 sacral foramen and the patient can monitor improvement before a permanent device is implanted. While this procedure has proven to be effective for treating FI, it is also attractive owing to the low morbidity and low infection risk reported in the literature.

Sacral neuromodulation for bowel dysfunction: a consensus statement from the Italian group

BACKGROUND

Representatives from the Italian centers experienced in sacral neuromodulation (SNM) for the treatment of bowel dysfunction met in order to define the current clinical practice in Italy and to produce a consensus statement regarding indications for this therapy and patient management.

METHODS

Fifty Italian colonproctologists were asked to complete a questionnaire concerning their clinical practice in SNM (290 questions, grouped within 4 broad areas). Physicians expressed their opinion by completing the questionnaire, assigning to each statement their level of agreement according to the 5-point Likert scale; the data were analyzed by attributing to each expert's answers a weight proportional to the degree of experience. During a meeting held 2 months later, the critical aspects of the therapy were re-examined and discussions held with the goal of reaching an agreement on controversial topics. The available literature was reviewed.

RESULTS

Patient selection criteria, etiology, diagnostic investigations, test procedures and implantation, follow-up and evaluation of results have been reviewed. The aim was to achieve an algorithm for patient management, showing the place of SNM in the treatment of bowel dysfunction. The approach in case of treatment failure was also discussed.

CONCLUSIONS

Analysis of the data collected reveals substantial consensus at the national level concerning all the main points with regard to the therapy. The recommendations expressed in this article can be considered as national guidelines and taken into account by the principal international implantation centers.

Sacral neuromodulation with an implantable pulse generator in children with lower urinary tract symptoms: 15-year experience

PURPOSE

Sacral nerve modulation with an implantable pulse generator is not an established treatment in children. This therapy has been described for dysfunctional elimination syndrome and neurogenic bladder. We report 2 new indications for this approach in children, ie bladder overactivity and Fowler syndrome. The aim of this study was to improve the results of future treatment for sacral neuromodulation in children by describing factors favorable for good outcomes with this method.

MATERIALS AND METHODS

A total of 18 children 9 to 17 years old were studied. Mean ± SD followup was 28.8 ± 43.8 months. Of the patients 16 underwent S3 sacral neuromodulation and 7 underwent pudendal stimulation (5 as a revision, 2 from the beginning).

RESULTS

Initial full response was achieved in 9 of 18 patients (50%) and partial response in 5 (28%). In patients presenting with incontinence mean ± SD number of incontinence episodes weekly improved significantly from 23.2 ± 12.4 to 1.3 ± 2.63 (p <0.05). In patients requiring clean intermittent catheterization there was a significant decrease in mean ± SD daily frequency of catheterization from 5.2 ± 1.6 to 2.0 ± 1.9 (p <0.05). At the end of the study 6 of 15 patients (40%) had a full response and 5 (33%) had a partial response, while 4 implantable pulse generator devices (27%) were explanted because of failure.

CONCLUSIONS

Sacral neuromodulation is feasible in the pediatric population, with good short-term (78% full or partial response) and satisfactory long-term results (73%). Sacral neuromodulation can offer good results for overactive bladder, dysfunctional elimination syndrome and Fowler syndrome. Pudendal nerve stimulation is a feasible salvage treatment that can be useful in cases when S3 implantation is impossible or unsuccessful.

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.

Pelvic electrical neuromodulation for the treatment of overactive bladder symptoms

Overactive bladder syndrome negatively affects the daily life of many people. First-line conservative treatments, such as antimuscarinics, do not always lead to sufficient improvement of the complaints and/or are often associated with disabling adverse effects leading to treatment failure. Electrical stimulation of the sacral nerves has emerged as an alternative and attractive treatment for refractory cases of bladder overactivity. Few theories attempted to explain its mechanism of action which remains elusive. It involves percutaneous posterior tibial nerve stimulation and more commonly sacral neuromodulation. For the latter, temporary sacral nerve stimulation is the first step. If the test stimulation is successful, a permanent device is implanted. The procedure is safe and reversible. It carries a durable success rate. The technique should be combined with careful followup and attentive adjustments of the stimulation parameters in order to optimize the clinical outcomes. This paper provides a review on the indications, possible mechanisms of action, surgical aspects and possible complications, and safety issues of this technique. The efficacy of the technique is also addressed.

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.

Fifteen years of sacral nerve stimulation: from an open procedure to a minimally invasive technique

AIM

This historical review describes the development of InterStim™ therapy from an open procedure to a minimally invasive technique for the treatment of pelvic floor disorders. The latest technological and surgical evaluations of sacral nerve stimulation (SNS) are presented with their impact on the therapy's success and safety.

METHOD

A search for relevant literature on SNS in the PubMed database was carried out for this review, which focuses on technical modifications and related clinical outcomes.

RESULTS

InterStim™ therapy for faecal incontinence was introduced in Europe in 1995. Since its introduction, technical improvements in devices and leads have progressed SNS from an open one-stage procedure to a minimally invasive two-stage technique. A smaller neurostimulator and particularly the new tined lead allow InterStim™ therapy to be performed under local anaesthesia and in an outpatient setting. Additionally, the use of the self-anchoring tined lead has reduced the number of technical failures and improved the test phase significantly, from 60% to 80%. The new smaller-in-size neurostimulator facilitates the implant procedure and further improves patient comfort.

CONCLUSION

By using new technical achievements over the past 15 years, InterStim™ therapy has become a highly effective and safe procedure for selected patients with faecal incontinence.

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 with implanted devices for urinary storage and voiding dysfunction in adults

BACKGROUND

The neural control of storage and voiding of urine is complex and dysfunction can be difficult to treat. One treatment for people with refractory symptoms is continuous electrical nerve stimulation of the sacral nerve roots using implanted electrodes and an implanted pulse generator.

OBJECTIVES

To determine the effects of implantable electrical stimulation devices in the treatment of urine storage and voiding problems.

SEARCH STRATEGY

We searched the Cochrane Incontinence Group Specialised Register (searched 10 February 2009), CENTRAL (The Cochrane Library 2008, Issue 1), MEDLINE (January 1980 to March 2008), EMBASE (January 1980 to March 2008), CINAHL (January 1982 to March 2008) and the reference lists of relevant articles.

SELECTION CRITERIA

Trials that tested implanted electronic stimulators connected to electrodes attached to the nerves and providing continuous electrical stimulation for neuromodulation.

DATA COLLECTION AND ANALYSIS

Both authors selected studies, assessed quality, and extracted data.

MAIN RESULTS

Eight reports of randomised studies that evaluated implants which provided continuous stimulation were included. It was unclear whether some reports included patients who also appeared in other reports, so no data were pooled. In spite of this, it seems clear that continuous stimulation offers benefits for carefully selected people with overactive bladder syndrome and for those with urinary retention but no structural obstruction.Many of the implants did not work and many required revision operations. Many questions remain about patient selection and the best way to use these devices.

AUTHORS' CONCLUSIONS

In spite of methodological problems, it would appear that some people benefit from implants which provide continuous nerve stimulation. More research is needed on the best way to improve patient selection, carry out the implant, and to find why so many fail. The effectiveness of implants should be tested against other interventions, particularly in people with an overactive bladder.

Long-term outcome of sacral nerve stimulation for fecal incontinence

PURPOSE

Sacral nerve stimulation is a safe and effective procedure for fecal incontinence. We investigated whether its efficacy is maintained long term.

PATIENTS AND METHODS

Sixty patients with fecal incontinence underwent permanent sacral nerve stimulation. Patients' data were prospectively recorded in the national registry of the Italian Group of sacral nerve stimulation. The severity of fecal incontinence was evaluated by the Wexner score, and data were collected in a bowel function diary. Quality of life was evaluated by the Italian version of the Medical Outcomes Survey Short Form (SF-36) questionnaire.

RESULTS

Fifty-two patients were available for long-term follow-up lasting at least 5 years. Compared with baseline, the Wexner score decreased significantly after definitive implantation (from 15 +/- 4 to 5 +/- 5, P < 0.001). At least 50 percent improvement in continence was achieved in 74 percent of the patients, and at least 70 percent improvement (median value) was achieved in 50 percent. The mean number of solid/liquid incontinence episodes decreased significantly from 0.5 (+/-0.5) to 0.1 (+/-0.3) per day (P = 0.004). Quality of life improved in all domains. The overall mean improvement in SF-36 scores was 39.8 percent. Both mean resting and squeeze anal pressures increased significantly, and maximum volume tolerated decreased significantly.

CONCLUSIONS

Sacral nerve stimulation maintains its efficacy long term, not only in regard to control of symptoms but also regarding quality of life.

Neuromodulation for the treatment of urinary incontinence

Neuromodulation has been reported to be effective for the treatment of stress and urgency urinary incontinence. The cure and improvement rates of pelvic floor neuromodulation in urinary incontinence are 30-50% and 60-90%, respectively. In clinical practice, vaginal, anal and surface electrodes are used for external, short-term stimulation, and sacral nerve stimulation for internal, chronic (long-term) stimulation. The effectiveness of neuromodulation has been verified in a randomized, placebo-controlled study. However, the superiority to other conservative treatments, such as pelvic floor muscle training has not been confirmed. A long-term effect has also been reported. In conclusion, pelvic floor exercise with adjunctive neuromodulation is the mainstay of conservative management for the treatment of stress incontinence. For urgency and mixed stress plus urgency incontinence, neuromodulation may therefore be the treatment of choice as an alternative to drug therapy.

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.

Subcutaneous tunneling of the temporary testing electrode significantly improves the success rate of subchronic sacral nerve modulation (SNM)

Sacral nerve modulation (SNM) is an effective way to treat non-neurogenic dysfunctions of pelvic organs. For over 20 years, this technique has been used for the treatment of overactive bladder, urinary retention, pelvic pain and even more recently, fecal incontinence and constipation. The objective of the study is to improve the fixation of the temporary testing electrode (TTE) in order to obtain more reliable results in the testing phase which should lead to have a comparable success rate as the two-stage implant for a chronic implant. Twenty-eight patients (ratio of sex women:men = 3:1; with overactive bladder, urinary retention, pelvic pain syndrome and fecal incontinence) were evaluated by the modified temporary test electrode (TTE) placement. With the subcutaneous tunneling technique (mean time of evaluation 8.3 days), it is possible to perform percutaneous nerve evaluation (PNE) more effectively with an objective, reliable and less expensive outcome prior to the implantation of the implantable sacral nerve stimulator in almost 80% of the evaluated patients. Because the costs of therapy are not covered by health insurance in all countries, there is a need for an effective and inexpensive way to test and select patients appropriately. The tunneled TTE maintains its place for consistent amplitude during the entire test duration. The modification of placing the TTE produces repayable results. This technique can be performed on an outpatient basis to evaluate sacral nerve modulation as an early treatment option for non-dysfunctions of pelvic organs before they are forwarded to a specialized center for a chronic SNM implantation.

Results of sacral neuromodulation therapy for urinary voiding dysfunction: outcomes of a prospective, worldwide clinical study

PURPOSE

This 5-year, prospective, multicenter trial evaluated the long-term safety and efficacy of sacral neuromodulation in patients with refractory urge incontinence, urgency frequency and retention.

MATERIALS AND METHODS

A total of 17 centers worldwide enrolled 163 patients (87% female). Following test stimulation 11 patients declined implantation and 152 underwent implantation using InterStim. Of those treated with implantation 96 (63.2%) had urge incontinence, 25 (16.4%) had urgency frequency and 31 (20.4%) had retention. Voiding diaries were collected annually for 5 years. Clinical success was defined as 50% or greater improvement from baseline in primary voiding diary variable(s).

RESULTS

Data for all implanted cases were reported. For patients with urge incontinence mean leaking episodes per day decreased from 9.6 +/- 6.0 to 3.9 +/- 4.0 at 5 years. For patients with urgency frequency mean voids per day decreased from 19.3 +/- 7.0 to 14.8 +/- 7.6, and mean volume voided per void increased from 92.3 +/- 52.8 to 165.2 +/- 147.7 ml. For patients with retention the mean volume per catheterization decreased from 379.9 +/- 183.8 to 109.2 +/- 184.3 ml, and the mean number of catheterizations decreased from 5.3 +/- 2.8 to 1.9 +/- 2.8. All changes were statistically significant (p <0.001). No life threatening or irreversible adverse events occurred. In 102 patients 279 device or therapy related adverse events were observed. At 5 years after implantation 68% of patients with urge incontinence, 56% with urgency frequency and 71% with retention had successful outcomes.

CONCLUSIONS

This long-term study demonstrates that InterStim therapy is safe and effective for restoring voiding in appropriately selected cases refractory to other forms of treatment.

Efficacy and safety of sacral nerve stimulation for urinary urge incontinence: a systematic review

PURPOSE

We systematically reviewed the evidence on the efficacy and safety of sacral nerve stimulation (SNS) for severe urge incontinence.

MATERIALS AND METHODS

A systematic review was performed of primary studies of SNS for urge incontinence published in English between 1966 and May 2003, and identified in major electronic databases. Two reviewers independently selected studies, assessed their methodological quality and extracted data.

RESULTS

Four randomized controlled trials and 30 case series were identified. Evidence from the randomized controlled trials, involving approximately 120 patients, showed that about 80% achieved continence or greater than 50% improvement in their main incontinence symptoms after SNS compared with about 3% of controls receiving conservative treatments while waiting for an implant. While case series were larger, they were methodologically less reliable. However, they showed similar results with 67% of patients becoming dry or achieving a greater than 50% improvement in symptoms after implantation. Incontinence episodes, leakage severity, voiding frequency and pad use were significantly lower after implantation. Benefits were reported to persist 3 to 5 years after implantation. Adverse events were documented in 27 studies. Overall the reoperation rate in implanted cases was 33%. The most common reason for surgical revision was relocation of the generator because of pain and infection. Common complications were pain at the implant or lead site in 25% of patients, lead related problems such as lead migration in 16%, replacement and repositioning of the implanted pulse generator in 15%, wound problems in 7%, adverse effects on bowel function in 6%, infection in 5% and generator problems in 5%. Permanent removal of the electrodes was reported in 9% of patients. Technical changes with time have been associated with decreased complication rates.

CONCLUSIONS

There is evidence indicating that SNS is effective for decreasing symptoms in patients with urge incontinence. Adverse events occurred in about half of the implanted cases and surgical revision was performed in 33%. No major irreversible complications were reported in the studies reviewed. Further research is required on the long-term effects of and quality of life in patients with SNS.

Long Term Results of Neuromodulation by Sacral Nerve Stimulation for Lower Urinary Tract Symptoms: A Retrospective Single Center Study

OBJECTIVE

To analyse the influence of technical improvements of Sacral Nerve Stimulation (SNS) on the incidence of surgical interventions and subjective long-term results of SNS.

METHODS

Retrospective, transversal study analyzing records of implanted patients at our department of Urology.

RESULTS

Of 149 patients analyzed, 107 had overactive bladder symptoms and 42 had urinary retention. Mean follow-up was 64,2 (sd = 38,5) months. In the whole group 194 adverse events occurred. 6 Patients had infection in their implanted system, one was explanted for infection. Most events could be solved by giving advice or by reprogramming the stimulator. 129 reoperations have been performed and 21 patients had their system explanted. Analysis of the data shows a striking difference in the incidence of reoperations, but small differences in subjective results in the groups of patients implanted before or after 1996, suggesting that a proactive approach towards adverse events is worthwhile.

CONCLUSIONS

SNS gives lasting benefit in patients with refractory symptoms of overactive bladder and non-obstructive urinary retention. The differences in outcomes and incidence of reoperation can be attributed to the learning curve and technical and surgical improvements in the application of SNS.