A Prospective Randomized Trial Comparing the 1-Stage with the 2-Stage Implantation of a Pulse Generator in Patients with Pelvic Floor Dysfunction Selected for Sacral Nerve Stimulation

Spinal Cord Stimulation for Intractable Visceral Pain Originating from the Pelvic and Abdominal Region: A Narrative Review on a Possible New Indication for Patients with Therapy-Resistant Pain

Aim

Visceral pain, characterized by pain that is diffuse and challenging to localize, occurs frequently and is difficult to treat. In cases where the pain becomes intractable despite optimal medical management, it can affect patients' Quality of Life (QoL). Spinal Cord Stimulation (SCS) has emerged as a potential solution for intractable visceral pain.

Purpose

In this narrative review, we collected all evidence regarding the efficacy of SCS for visceral pain across various underlying conditions.

Methods

A comprehensive literature search was conducted in PubMed, Embase, and Web of Science in which articles published from October 1st, 1963 up to March 7th, 2023 were identified.

Results

Seventy articles were included in this review of which most were retrospective cohort studies, case series and case reports. The studies, often with a small number of participants, reported on SCS for chronic pancreatitis, anorectal pain and bowel disorders, gynaecological diagnoses, visceral pelvic pain, urological disorders and finally general visceral pain. They found positive effects on pain and/or symptom relief, opioid consumption, anxiety and depression and QoL. Complications occurred frequently but were often minor and reversible.

Conclusion

Better screening and selection criteria need to be established to optimally evaluate eligible patients who might benefit from SCS. A positive outcome of a sympathetic nerve block appears to be a potential indicator of SCS effectiveness. Additionally, women receiving SCS for endometriosis had a better outcome compared to other indications. Finally, SCS could also relief functional symptoms such as voiding problems and gastroparesis. Complications could often be resolved with revision surgery. Since SCS is expensive and not always covered by standard health insurance, the incorporation of cost-analyses is recommended. In order to establish a comprehensive treatment plan, including selection criteria for SCS, rigorous prospective, possibly randomized and controlled studies that are diagnosis-oriented, with substantial follow-up and adequate sample sizes, are needed.

Infection Rate of a Prolonged Sacral Neuromodulation Test: A Large Retrospective Study

OBJECTIVES

It is estimated that 3.8% to 12.5% of patients develop a device infection during the two to four weeks of the sacral neuromodulation (SNM) test, leading to removal of the entire system. It is possible to prolong the test phase up to the clinician's decision, particularly when benefits are unclear. The aim of our study is to assess the device infection rate in a prolonged SNM test.

MATERIALS AND METHODS

We retrospectively enrolled patients who performed a prolonged SNM test (at least eight weeks) in the last five years (2017-2021). All procedures were performed using a standardized technique and the same prophylactic antibiotic protocol. In case of a clinical suspicion of infection, all components were explanted. Patient information (age at implantation, medical history of diabetes, metabolic syndrome, immunologic diseases, or chronic immunosuppressive therapy), surgical data (operative time, intraoperative complications), and infection data (timing of onset, symptoms reported, wound culture results) were recorded.

RESULTS

We enrolled 232 patients who underwent a prolonged SNM test (mean duration 65.5 days). A local infection that led to the removal of the entire system occurred in six patients (2.6%). The gluteal pocket was always involved, and in two cases, infection was also extended to the exit point of the extension wire. No significant correlations with clinical data were found. Infection occurred beyond four weeks in two cases, between three and four weeks in three cases, and within two weeks in one case. Intraoperative wound culture was performed in five of six patients, and Staphylococcus aureus (S aureus) was isolated in four cases. One culture test gave negative bacterial growth results.

CONCLUSIONS

The infection rate of a prolonged eight-week SNM test is low and does not differ from that reported in the literature for a two-to-four-week SNM test. S aureus remains the most frequent bacterium involved.

Sacral neuromodulation in the management of non-obstructive urinary retention: Test phase and predictive factors

AIM

The aim of this study is to evaluate the success of the test phase of sacral neuromodulation in management of chronic non-obstructive urinary retention and the factors predictive of good response.

MATERIALS AND METHODS

This is a retrospective study carried out on a cohort of patients followed up in a tertiary University Hospital in France. Fifty-two patients with chronic non-obstructive urinary retention were included in this study. These patients were seen over the past 20 years, from the year 2000 to 2020. The initial evaluation of patients included a summary of medical and surgical history, age, BMI, history of pelvic floor disorders, initial voiding pattern, physical examination, voiding diary, initial uroflowmetry and a urodynamic study. Postoperative follow-up and analysis of complications were also carried out.

RESULTS

A total of 52 patients were included in this study, 13 males and 39 females. Out of these patients, 17 patients (32.7%) with a median age of 47.3 years±18.1 benefited from definitive implantation of the sacral neuromodulation. The univariate analysis showed that age was the only significant variable in this study and the optimal age threshold was<58.5 years.

CONCLUSION

SNM is a therapy with significant clinical benefits and low morbidity for patients with chronic non-obstructive urinary retention. The results obtained need to be confirmed with a prospective study with a larger number of patients.

LEVEL OF EVIDENCE: 4

Review of the rechargeable sacral neuromodulation system to treat refractory overactive bladder

Overactive bladder is a medical condition that requires management. If left untreated, it may severely affect quality of life. When first- and second-line treatments fail, sacral neuromodulation can be a safe and effective option for patients with refractory overactive bladder. This article reviews the rechargeable sacral neuromodulation (Axonics).

Bioelectronic medicine for the autonomic nervous system: clinical applications and perspectives

Bioelectronic medicine (BM) is an emerging new approach for developing novel neuromodulation therapies for pathologies that have been previously treated with pharmacological approaches. In this review, we will focus on the neuromodulation of autonomic nervous system (ANS) activity with implantable devices, a field of BM that has already demonstrated the ability to treat a variety of conditions, from inflammation to metabolic and cognitive disorders. Recent discoveries about immune responses to ANS stimulation are the laying foundation for a new field holding great potential for medical advancement and therapies and involving an increasing number of research groups around the world, with funding from international public agencies and private investors. Here, we summarize the current achievements and future perspectives for clinical applications of neural decoding and stimulation of the ANS. First, we present the main clinical results achieved so far by different BM approaches and discuss the challenges encountered in fully exploiting the potential of neuromodulatory strategies. Then, we present current preclinical studies aimed at overcoming the present limitations by looking for optimal anatomical targets, developing novel neural interface technology, and conceiving more efficient signal processing strategies. Finally, we explore the prospects for translating these advancements into clinical practice.

Recent advances in managing fecal incontinence

Fecal incontinence (FI) is the uncontrolled passage of feces or gas in an individual who previously had control. The prevalence of the problem varies but can be as high as 50% of institutionalized individuals. The severity varies among individuals, but the negative impact on self-esteem and quality of life can have devastating effects. The goals of treatment are to decrease the frequency and severity of episodes as well as to improve quality of life. At present, several therapies, ranging from medical management to more invasive surgical interventions, are offered for the management of FI. In this article, we review the most recent advances in the management of FI.

What uro-gynecologists should know about sacral neuromodulation (SNM) for the treatment of refractory overactive bladder

PURPOSE

To inform uro-gynecologists about the current standards and latest developments of sacral neuromodulation (SNM) in women with overactive bladder (OAB).

METHODS

Literature search in the PubMed database for articles published between 1988 and 2019 on SNM for OAB in women.

RESULTS

In total, 361 articles were identified and 51 articles retrieved for the review. SNM shows an objective success rate of 70-80%, OAB cure rate of 17-47% and a subjective satisfaction rate of 80-90%. These benefits have to be weighed against an adverse event rate of approx. 40%. SNM is significantly more successful than switching to another antimuscarinic after failed antimuscarinic drug therapy. Efficacy of SNM is slightly lower compared to bladder wall injections with 200 U botulinum toxin in the first months but efficacy of both treatments appears to be similar after 24 months. MRI examinations of patients with a sacral neurostimulator should only be performed after radiologist consultation. Sacral neurostimulators in patients with another pacemaker system should only be implanted after interdisciplinary consultation. The sacral neuromodulator should be turned off during pregnancy and delivery. SNM for OAB in patients with concomitant female sexual dysfunction or fecal incontinence seems to be beneficial.

CONCLUSIONS

SNM is a successful and recommended second-line treatment of OAB. Sacral neurostimulators should preferably be implanted in SNM-centers because complications and the frequency of revisions are significantly reduced with increasing experience of the surgeon.

[Chronic sacral nerve electrostimulation in treatment of neurogenic pelvic organ dysfunction in children]

Myelodysplasia is the most common cause of congenital pelvic abnormalities in children. The causes of acquired neurogenic pelvic dysfunctions in children include spinal cord injury, myelitis, and neurodegenerative diseases. Urination impairments in children with neurological disorders are a serious clinical problem. In most cases, the capabilities of conservative treatment of pelvic organ dysfunctions are limited. One of the most promising directions in treatment of neurogenic urination disorders is modeling of a lost urination mechanism using direct or mediated electrostimulation of the nerve fibers of the sacral plexus - neuromodulation.

AIM

the review aim is to describe the technique and results of chronic sacral neurostimulation in treatment of pelvic organ disorders in children, which have been reported in the international literature. An obligatory condition for application of chronic sacral neurostimulation (CSNS) is a positive clinical response to test electrostimulation of the S3 nerve root. The test period duration is 1-3 weeks. In the case of a positive effect, a permanent system is implanted for neurostimulation of the S3 nerve root. On treatment with CSNS, children with severe urinary incontinence had a significant decrease in the rate of incontinence episodes, and patients with urinary retention had no or reduced need for periodic catheterization. Therefore, the accumulated experience of using CSNS in children with spinal cord diseases indicates the need in further study of the technique capabilities for correction of pelvic organ dysfunctions.

Electrical neuromodulation in the management of lower urinary tract dysfunction: evidence, experience and future prospects

Lower urinary tract dysfunction (LUTD) is common and causes a spectrum of morbidity and decreased quality of life (QoL) for patients. LUTD can range from urinary retention to urge incontinence, and includes a variety of syndromes, with the most common and widely recognized being overactive bladder (OAB). The classic treatments of LUTD and OAB comprise different strategies including behavioral therapies, medications and minimally invasive or invasive surgical procedures. Generally, once patients have tried behavioral modifications and oral medical therapy, and have not experienced adequate relief of their symptoms, the next step is to consider minimally invasive therapies. In the last two decades since FDA approval, sacral nerve stimulation (SNS) has become an accepted intervention, with increasing use and evidence of effectiveness for LUTD, specifically OAB and non-obstructive urinary retention. SNS has shown both objective and subjective improvement in voiding symptoms in several randomized controlled trials (RCTs) when compared to sham or standard medical therapy. The main limitations for more extensive use include relatively high cost, implantation of a device and possibly reoperation secondary to adverse events (AE). Percutaneous tibial nerve stimulation (PTNS) is a less invasive, less direct and less expensive method for neuromodulation, which has also shown effectiveness in several randomized and non-randomized trials, including comparable improvement rates to anticholinergics in OAB management. However, the efficacy of PTNS is only maintained for a short period after the stimulation is delivered. This technique has a much lower rate of AE compared to SNS, but with the inconvenience of weekly visits for stimulation, although implantable devices are on the horizon. In this article we review the mechanism of action, indications, effectiveness and complications related to SNS and PTNS therapy for LUTD.

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

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

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

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

Objectives:

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

Materials and Methods:

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

Results:

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

Conclusion:

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

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.

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.

The role of electrical stimulation techniques in the management of the male patient with urgency incontinence

PURPOSE OF REVIEW

Overactive bladder affects 10-27% of men, a significant portion of whom report urge urinary incontinence that is inadequately treated with first-line and second-line treatments. There is thus a substantial need to critically evaluate the alternative means of clinical management.

RECENT FINDINGS

This review presents the current evidence for the use of sacral neuromodulation and percutaneous tibial nerve stimulation in the treatment of men with urge incontinence, as well as evaluates the financial implications of these treatments. Other alternative modes of electrical stimulation for urge incontinence are also briefly reviewed.

SUMMARY

Both sacral neuromodulation and percutaneous tibial nerve stimulation prove to be viable, durable options for treating patients with refractory urge incontinence. Alternative modes of stimulation are also beginning to show promise.

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.

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.

Sacral neuromodulation and peripheral nerve stimulation in patients with anal incontinence: an overview of techniques, complications and troubleshooting

Sacral neuromodulation (SNM) therapy has revolutionized the management of many forms of anal incontinence, with an expanded use and a medium-term efficacy of 75% overall. This review discusses the technique of SNM therapy, along with its complications and troubleshooting and a discussion of the early data pertaining to peripheral posterior tibial nerve stimulation in incontinent patients. Future work needs to define the predictive factors for neurostimulatory success, along with the likely mechanisms of action of their therapeutic action.

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.

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.

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.

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.

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 and refractory overactive bladder: an emerging tool for an old problem

Overactive bladder (OAB) syndrome negatively affects the daily life of many people. Conservative treatments, such as antimuscarinics, do not always lead to sufficient improvement of the complaints and are often associated with considerable side effects resulting in treatment failure. In the case of failure or intolerable side effects, sacral neuromodulation (SNM) and botulinum toxin intravesical injections are minimally invasive and reversible alternatives. Currently, both SNM and botulinum toxin injection have FDA approval for use in OAB patients. This mini-review attempts to provide an update on SNM as a second-line management of adults with refractory OAB, based on the available clinical evidence concerning the efficacy and safety.

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.

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

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

Urinary retention in women and sacral neuromodulation

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

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.

Contrasting the percutaneous nerve evaluation versus staged implantation in sacral neuromodulation

Sacral neuromodulation is increasingly used for the treatment of voiding dysfunction, pelvic pain syndromes, and gastrointestinal disorders. While increased use of this technology has led to a greater understanding of its potential as well as its limitations, difficulty persists in identifying the patients that will benefit most. Either of two trial stimulation techniques is performed before placement of a permanent neuromodulator: the monopolar percutaneous nerve evaluation and the tined quadripolar staged trial. The preponderance of recent literature asserts the superior sensitivity of the staged trial over percutaneous nerve evaluation. However, the techniques offer disparate advantages, and other issues, such as cost-effectiveness, remain largely unexplored. The role of sacral neuromodulation will continue to expand as physicians and patients become increasingly aware of its therapeutic potential. Widespread adoption of this clinically superior technique will most rapidly help the greatest number of patients.

Selection of ideal candidates for neuromodulation in refractory overactive bladder

Sacral neuromodulation is a minimally invasive, reversible treatment option that has been approved by the US Food and Drug Administration for patients with urgency/frequency and urge incontinence. While long-term success rates are high, the high treatment cost and the need for operative revision or explantation in cases of failure make the selection of ideal candidates particularly important. Because predictive factors for success and the exact mechanism of action are not known, physicians must rely on a preimplantation test procedure, either in the office or in the operating room, to select patients for implantation of a pulse generator. In this paper, we review the recent literature on performing a test procedure with both temporary and permanent leads and the selection of optimal candidates for sacral neuromodulation therapy.

Sacral nerve stimulation for treatment of intractable pain associated with cauda equina syndrome

Sacral nerve stimulation (SNS) is an effective treatment for bladder and bowel dysfunction, and also has a role in the treatment of chronic pelvic pain. We report two cases of intractable pain associated with cauda equina syndrome (CES) that were treated successfully by SNS. The first patient suffered from intractable pelvic pain with urinary incontinence and fecal incontinence after surgery for a herniated lumbar disc. The second patient underwent surgery for treatment of a burst fracture and developed intractable pelvic area pain, right leg pain, excessive urinary frequency, urinary incontinence, voiding difficulty and constipation one year after surgery. A SNS trial was performed on both patients. Both patients' pain was significantly improved and urinary symptoms were much relieved. Neuromodulation of the sacral nerves is an effective treatment for idiopathic urinary frequency, urgency, and urge incontinence. Sacral neuromodulation has also been used to control various forms of pelvic pain. Although the mechanism of action of neuromodulation remains unexplained, numerous clinical success reports suggest that it is a therapy with efficacy and durability. From the results of our research, we believe that SNS can be a safe and effective option for the treatment of intractable pelvic pain with incomplete CES.