Sacral nerve stimulation at subsensory threshold does not compromise treatment efficacy: results from a randomized, blinded crossover study. Ann Surg. 2013;257:219-223. [PMID: 23001079 DOI: 10.1097/sla.0b013e318269d493]

Gastric and sacral electrical stimulation for motility disorders-A clinical perspective

BACKGROUND

Electrical stimulation of the gut has been investigated in recent decades with a view to treating various gastro-intestinal motility disorders including, among others, gastric electrical stimulation to relieve nausea and vomiting associated with gastroparesis and sacral neuromodulation to treat fecal incontinence and/or constipation. Although their symptomatic efficacy has been ascertained by randomized controlled trials, their mechanisms of action are not fully understood.

PURPOSE

This review summarizes the past year's literature on the mechanisms of action of gut electrical stimulation therapies, including their impact on the gut-brain axis.

Importance of some technical aspects of the procedure of percutaneous posterior tibial nerve stimulation in patients with fecal incontinence

INTRODUCTION

The results of percutaneous posterior tibial nerve stimulation (PTNS) in the treatment of fecal incontinence (IF) are modest. The aim of the study is to assess the relationship of some technical aspects with the clinical response: location of the nerve, distal response (motor or sensory) and accommodation.

METHODS

Prospective study of patients with FI undergoing PTNS therapy. The clinical response was assessed using the Wexner scale, defecation diary and anorectal manometry.

RESULTS

32 patients were studied. The intensity of localization (proximity to the nerve) was not correlated with clinical or manometric changes. Motor response was associated with a decrease on the Wexner scale [12.12 (±5.39) to 7.71 (±4.57) P < .005], the number of episodes of passive incontinence [8.78 (±9.64) to 4.11 (±7.11) P = .025], the total number of incontinence episodes [16.11 (±16.03) to 7.78 (±11.34) P = .009] and the number of days with fecal soiling [6.89 (±5.53) to 2.56 (±4.13) P = .002] and with an increase in the length of the manometric anal canal at rest [4.55 (±0.596) to 4.95 (±0.213) P = .004]. The increase in stimulation (accommodation) was inversely correlated with the decrease in the Wexner scale (r = -0.677 P < .005) and the number of days with soiling (r = -0.650 P = .022).

CONCLUSIONS

The motor response during PTNS seems to be related to a better clinical response. The accommodation phenomenon could be associated with worse results. The proximity of the electrode to the nerve does not seem to be important as long as a good distal response is achieved.

Reprogramming Sacral Neuromodulation for Sub-Optimal Outcomes: Evidence and Recommendations for Clinical Practice

Objectives

In some patients treated for urinary or fecal incontinence with sacral neuromodulation (SNM) persistence of symptoms, a reduction in efficacy or adverse effects of stimulation can occur. In such situations, further programming of the SNM device can help resolve problems. Infrequently hardware failure is detected. This article aims to provide practical guidance to solve sub‐optimal outcomes (troubleshooting) occurring in the course of SNM therapy.

Materials and Methods

A systematic literature review was performed. Collective clinical experience from an expert multidisciplinary group was used to form opinion where evidence was lacking.

Results

Circumstances in which reprogramming is required are described. Actions to undertake include changes of electrode configuration, stimulation amplitude, pulse frequency, and pulse width. Guidance in case of loss of efficacy and adverse effects of stimulation, developed by a group of European experts, is presented. In addition, various hardware failure scenarios and their management are described.

Conclusions

Reprogramming aims to further improve patient symptoms or ensure a comfortable delivery of the therapy. Initial changes of electrode configuration and adjustment of stimulation parameters can be performed at home to avoid unnecessary hospital visits. A logical and stepwise approach to reprogramming can improve the outcome of therapy and restore patient satisfaction.

Sacral neuromodulation with the InterStim™ system for faecal incontinence: results from a prospective French multicentre observational study

AIM

The aim of this work was to evaluate the effectiveness, patient satisfaction and quality of life (QoL) and the safety of sacral neuromodulation (SNM) with the InterStim^TM system for the treatment of faecal incontinence (FI) and establish whether results published predominantly by expert sites are generalisable.

METHOD

This is a prospective, multicentre, observational study that invited all French sites treating FI with the InterStim™ system to enrol subjects indicated for an SNM therapy evaluation. Data were collected at three follow-up visits within 1 and 15 months. Therapeutic effectiveness was evaluated by the reduction in leakages per week and improvements over time in the ability to defer defaecation and QoL (as measured with the Faecal Incontinence Quality of Life score). Safety was assessed through reported adverse events.

RESULTS

A total of 221 subjects with a mean age of 62.1 years were tested (184 women) and 178 received a permanent implant. For all implanted subjects with diary data at baseline and follow-up, a reduction in leakage of more than 50% was observed in 80%, 76% and 83% at 1-3, 4-8 and 9-15 months, respectively. The mean number of leakage episodes and urgency improved significantly compared with the baseline (p < 0.0001). Subjects showed improvements in QoL and time to defer defaecation and were generally satisfied with their therapy. The main device-related adverse event was the requirement to undertake reprogramming (in 52% of subjects with actions following an event). The rates of infection (in 6% of subjects) and surgical revision (in 10% of subjects) were in agreement with literature reports.

CONCLUSION

This study confirms the clinical effectiveness, safety and positive effect of SNM on QoL as well as high patient satisfaction for the treatment of FI in real-life.

Clinical efficacy of transcutaneous tibial nerve stimulation (TTNS) versus sham therapy (part I) and TTNS versus percutaneous tibial nerve stimulation (PTNS) (part II) on the short term in children with the idiopathic overactive bladder syndrome: protocol for part I of the twofold double-blinded randomized controlled TaPaS trial

Background

Transcutaneous tibial nerve stimulation (TTNS) and percutaneous tibial nerve stimulation (PTNS) are effective and safe therapies for overactive bladder (OAB) syndrome in adults. However, few randomized sham-controlled trials have been conducted in a pediatric population. To our knowledge, both therapies never have been compared in children.

Aim

The aim of the complete study is twofold: (1) to assess the efficacy of TTNS therapy on bladder symptoms after 12 weeks of treatment in a pediatric population with idiopathic overactive bladder syndrome (iOAB) and/or nocturnal enuresis (part I) and (2) to assess the effect of TTNS compared to PTNS (part II). In this article, we aim to present the protocol of the first part of the TaPaS trial (TTNS, PTNS, sham therapy).

Methods

Part I of the TaPaS trial is set up as a single-center randomized-controlled trial. Children, aged from 5 to 12 years with iOAB and/or nocturnal enuresis, are assigned to two groups by computer-generated randomization: TTNS therapy (intervention) and sham therapy (control). The primary outcome is the percentage difference in average voided volume (AVV) between baseline and after 12 weeks of treatment. Secondary endpoints are the percentage difference in supervoid volumes, number of urinary incontinence episodes/24 h and in voiding frequency, the difference in parent reported outcomes between baseline and after 12 weeks of treatment, and the duration of clinical response.

Discussion

We hypothesize that TTNS is a non-inferior treatment for iOAB in children compared to PTNS therapy. Since literature is inconclusive about the efficacy of TTNS in a pediatric population, a sham-controlled RCT on TTNS will be conducted (part I). A protocol for a prospective randomized sham-controlled trial has been developed. Enrolment has started in November 2018. Study completion of part I is expected by August 2021.

Trial registration

ClinicalTrials.gov NCT 04256876. Retrospectively registered on February 5, 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05117-8.

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.

Tools for fecal incontinence assessment: lessons for inflammatory bowel disease trials based on a systematic review

BACKGROUND

Fecal incontinence is a disabling condition affecting up to 20% of women.

OBJECTIVE

We investigated fecal incontinence assessment in both inflammatory bowel disease and non-inflammatory bowel disease patients to propose a diagnostic approach for inflammatory bowel disease trials.

METHODS

We searched on Pubmed, Embase and Cochrane Library for all studies on adult inflammatory bowel disease and non-inflammatory bowel disease patients reporting data on fecal incontinence assessment from January 2009 to December 2019.

RESULTS

In total, 328 studies were included; 306 studies enrolled non-inflammatory bowel disease patients and 22 studies enrolled inflammatory bowel disease patients. In non-inflammatory bowel disease trials the most used tools were the Wexner score, fecal incontinence quality of life questionnaire, Vaizey score and fecal incontinence severity index (in 187, 91, 62 and 33 studies). Anal manometry was adopted in 41.2% and endoanal ultrasonography in 34.0% of the studies. In 142 studies (46.4%) fecal incontinence evaluation was performed with a single instrument, while in 64 (20.9%) and 100 (32.7%) studies two or more instruments were used. In inflammatory bowel disease studies the Wexner score, Vaizey score and inflammatory bowel disease quality of life questionnaire were the most commonly adopted tools (in five (22.7%), five (22.7%) and four (18.2%) studies). Anal manometry and endoanal ultrasonography were performed in 45.4% and 18.2% of the studies.

CONCLUSION

Based on prior validation and experience, we propose to use the Wexner score as the first step for fecal incontinence assessment in inflammatory bowel disease trials. Anal manometry and/or endoanal ultrasonography should be taken into account in the case of positive questionnaires.

Importance of some technical aspects of the procedure of percutaneous posterior tibial nerve stimulation in patients with fecal incontinence

INTRODUCTION

The results of percutaneous posterior tibial nerve stimulation (PTNS) in the treatment of fecal incontinence (IF) are modest. The aim of the study is to assess the relationship of some technical aspects with the clinical response: location of the nerve, distal response (motor or sensory) and accommodation.

METHODS

Prospective study of patients with FI undergoing PTNS therapy. The clinical response was assessed using the Wexner scale, defecation diary and anorectal manometry.

RESULTS

32 patients were studied. The intensity of localization (proximity to the nerve) was not correlated with clinical or manometric changes. Motor response was associated with a decrease on the Wexner scale [12.12 (± 5.39) to 7.71 (± 4.57) p < 0.005], the number of episodes of passive incontinence [8.78 (± 9.64) to 4.11 (± 7.11) p = 0.025], the total number of incontinence episodes [16.11 (± 16.03) to 7.78 (± 11.34) p = 0.009] and the number of days with faecal soiling [6.89 (± 5.53) to 2.56 (± 4.13) p = 0.002] and with an increase in the length of the manometric anal canal at rest [4.55 (± 0.596) to 4.95 (± 0.213) p = 0.004]. The increase in stimulation (accommodation) was inversely correlated with the decrease in the Wexner scale (r = -0.677 p < 0.005) and the number of days with soiling (r = -0.650 p = 0.022).

CONCLUSIONS

The motor response during PTNS seems to be related to a better clinical response. The accommodation phenomenon could be associated with worse results. The proximity of the electrode to the nerve does not seem to be important as long as a good distal response is achieved.

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.

Programming Algorithms for Sacral Neuromodulation: Clinical Practice and Evidence-Recommendations for Day-to-Day Practice

Background

In sacral neuromodulation (SNM), stimulation programming plays a key role to achieve success of the therapy. However to date, little attention has been given to the best ways to set and optimize SNM programming during the test and chronic stimulation phases of the procedure.

Objective

Standardize and make SNM programming easier and more efficient for the several conditions for which SNM is proposed.

Methods

Systematic literature review and collective clinical experience report.

Results

The basic principles of SNM programming are described. It covers choice of electrode configuration, stimulation amplitude, pulse frequency and pulse widths, while use of cycling is also briefly discussed. Step‐by‐step practical flow charts developed by a group of 13 European experts are presented.

Conclusions

Programming of SNM therapy is not complex. There are few programming settings that seem beneficial or significantly impact patient outcomes. Only four basic electrode configurations could be identified according to four different options to define the cathode. In a majority of patients, the proposed stimulation parameters will allow a satisfactory improvement for long periods of time. A regular follow‐up is, however, necessary to assess and eventually optimize results, as well as to reassure patients.

Improved longevity and efficacy of sacral nerve stimulation by simple adjustments at follow-up

AIM

Sacral nerve stimulation (SNS) for faecal incontinence (FI) at subsensory amplitudes as low as 50% of the sensory threshold has been found to be effective at 3 months' follow-up. Furthermore, alternative pacemaker settings may improve functional outcome in patients with suboptimal treatment efficacy. In this work we aim to explore if sub-sensory stimulation as low as 50% of sensory threshold is effective at 1-year follow-up. We also aimed to investigate if 31 Hz (frequency) or 90 µs (pulse width) stimulation improved treatment efficacy in dissatisfied patients.

METHOD

All patients in whom the stimulation was effective in controlling FI (satisfied group) were encouraged to have the stimulation amplitude reduced. Those in whom the device was less effective (dissatisfied group) were offered alternative frequency settings or pulse width (31 Hz or 90 µs). Patients were follow-up after 12 months and evaluated by a visual analogue scale (VAS) for patient satisfaction, the Cleveland Clinic Continence Score (CCCS), Rockwood Faecal Incontinence Quality of Life Scale (QoL) and a bowel habit diary.

RESULTS

Two hundred and nineteen patients were contacted, with a response rate of 71% (n = 155). Those who were successfully contacted comprised 110 (71%) patients classed as satisfied and 45 (29%) as dissatisfied. Seventy-five (68%) of the satisfied patients agreed to have their stimulation amplitude reduced. At 1-year follow-up the median amplitude had reduced from 1.5 V [interquartile range (IQR) 0.85-2.0 V] to 0.75 V (IQR 0.45-1.4 V) (P-value < 0.001) representing an overall reduction of 39% (6.6-62.5%). There were no significant differences in VAS, CCCS or QoL despite subsensory stimulation at 1-year follow-up. In 28% of the dissatisfied patients alternative pacemaker settings improved VAS to satisfactory levels.

CONCLUSION

Subsensory stimulation is as effective as stimulation at or above the sensory threshold. High-frequency stimulation (31 Hz) can improve functional outcome in patients with loss of efficacy.

Efficacy and mechanism of sub-sensory sacral (optimised) neuromodulation in adults with faecal incontinence: study protocol for a randomised controlled trial

Background

Faecal incontinence (FI) is a substantial health problem with a prevalence of approximately 8% in community-dwelling populations. Sacral neuromodulation (SNM) is considered the first-line surgical treatment option in adults with FI in whom conservative therapies have failed. The clinical efficacy of SNM has never been rigorously determined in a trial setting and the underlying mechanism of action remains unclear.

Methods/design

The design encompasses a multicentre, randomised, double-blind crossover trial and cohort follow-up study. Ninety participants will be randomised to one of two groups (SNM/SHAM or SHAM/SNM) in an allocation ratio of 1:1. The main inclusion criteria will be adults aged 18–75 years meeting Rome III and ICI definitions of FI, who have failed non-surgical treatments to the UK standard, who have a minimum of eight FI episodes in a 4-week screening period, and who are clinically suitable for SNM. The primary objective is to estimate the clinical efficacy of sub-sensory SNM vs. SHAM at 32 weeks based on the primary outcome of frequency of FI episodes using a 4-week paper diary, using mixed Poisson regression analysis on the intention-to-treat principle. The study is powered (0.9) to detect a 30% reduction in frequency of FI episodes between sub-sensory SNM and SHAM stimulation over a 32-week crossover period.

Secondary objectives include: measurement of established and new clinical outcomes after 1 year of therapy using new (2017 published) optimised therapy (with standardised SNM-lead placement); validation of new electronic outcome measures (events) and a device to record them, and identification of potential biological effects of SNM on underlying anorectal afferent neuronal pathophysiology (hypothesis: SNM leads to increased frequency of perceived transient anal sphincter relaxations; improved conscious sensation of defaecatory urge and cortical/subcortical changes in afferent responses to anorectal electrical stimulation (main techniques: high-resolution anorectal manometry and magnetoencephalography).

Discussion

This trial will determine clinical effect size for sub-sensory chronic electrical stimulation of the sacral innervation. It will provide experimental evidence of modifiable afferent neurophysiology that may aid future patient selection as well as a basic understanding of the pathophysiology of FI.

Trial registration

International Standard Randomised Controlled Trial Number: ISRCTN98760715. Registered on 15 September 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2689-1) contains supplementary material, which is available to authorized users.

Systematic Review of Surgical Treatments for Fecal Incontinence

BACKGROUND

No systematic review has examined the collective randomized and nonrandomized evidence for fecal incontinence treatment effectiveness across the range of surgical treatments.

OBJECTIVE

The purpose of this study was to assess the efficacy, comparative effectiveness, and harms of surgical treatments for fecal incontinence in adults.

DATA SOURCES

Ovid MEDLINE, EMBASE, Physiotherapy Evidence Database, Cumulative Index to Nursing and Allied Health Literature, Allied and Complementary Medicine, and the Cochrane Central Register of Controlled Trials, as well as hand searches of systematic reviews, were used as data sources.

STUDY SELECTION

Two investigators screened abstracts for eligibility (surgical treatment of fecal incontinence in adults, published 1980-2015, randomized controlled trial or observational study with comparator; case series were included for adverse effects). Full-text articles were reviewed for patient-reported outcomes. We extracted data, assessed study risk of bias, and evaluated strength of evidence for each treatment-outcome combination.

INTERVENTIONS

Surgical treatments for fecal incontinence were included interventions.

MAIN OUTCOME MEASURES

Fecal incontinence episodes/severity, quality of life, urgency, and pain were measured.

RESULTS

Twenty-two studies met inclusion criteria (13 randomized trials and 9 observational trials); 53 case series were included for harms. Most patients were middle-aged women with mixed FI etiologies. Intervention and outcome heterogeneity precluded meta-analysis. Evidence was insufficient for all of the surgical comparisons. Few studies examined the same comparisons; no studies were high quality. Functional improvements varied; some authors excluded those patients with complications or lost to follow-up from analyses. Complications ranged from minor to major (infection, bowel obstruction, perforation, and fistula) and were most frequent after the artificial bowel sphincter (22%-100%). Major surgical complications often required reoperation; few required permanent colostomy.

LIMITATIONS

Most evidence is intermediate term, with small patient samples and substantial methodologic limitations.

CONCLUSIONS

Evidence was insufficient to support clinical or policy decisions for any surgical treatments for fecal incontinence in adults. More invasive surgical procedures had substantial complications. The lack of compliance with study reporting standards is a modifiable impediment in the field. Future studies should focus on longer-term outcomes and attempt to identify subgroups of adults who might benefit from specific procedures.

Acute lumbosacral nerve stimulation does not affect anorectal motor function in a rodent model

BACKGROUND

Sacral nerve stimulation has become a first line treatment for fecal incontinence, however, its effect on the motor function of the anorectum is uncertain. The aim of this study was to apply acute lumbosacral nerve stimulation in an animal model and to determine its effect on the external and internal anal sphincter forces, the rectoanal inhibitory and excitatory reflexes, and the slow wave frequency of the internal anal sphincter.

METHODS

Lumbosacral nerve stimulation was applied to 16 nulliparous female rats. A novel in vivo preparation was designed to allow simultaneous monitoring of external and internal anal sphincter forces. The effect of rectal distension on the two anal sphincters was also studied.

KEY RESULTS

Lumbosacral nerve stimulation delivered at either S1 or L6 in rodents did not affect sphincter forces, rectoanal reflexes or slow wave frequency of anal canal smooth muscle.

CONCLUSIONS & INFERENCES

The absence of effect on the motor pathways of continence suggests that the mechanism of action is predominantly on sensory feedback mechanisms from the anorectum, thereby increasing cortical awareness of the pelvic floor.

Cost-effectiveness analysis of sacral nerve stimulation as treatment for severe irritable bowel syndrome

AIM

Early results from sacral nerve stimulation (SNS) for severe irritable bowel syndrome (IBS) are promising but estimates of cost-effectiveness are lacking. Our object was to perform a cost-effectiveness analysis for SNS as an alternative to no treatment of IBS.

METHOD

This retrospective analysis was based on the results from a randomized controlled crossover study with a cost-utility analysis performed on patient-level data and modelling of censored data over a projected period of time of up to 20 years. The analysis was conducted on an intention-to-treat approach. For estimation of the uncertainty of the incremental cost-effectiveness ratio a bias corrected bootstrap analysis was performed.

RESULTS

Cost-effectiveness was not reached for 4 years after permanent implantation (£31 270 per quality-adjusted life years), which was the upper limit for patient follow-up, but our data imply a cost-effectiveness from a 7-year perspective onwards.

CONCLUSION

The study indicates the SNS treatment for IBS is cost effective from a 7-year perspective onwards.

Impact of fecal incontinence and its treatment on quality of life in women

Fecal incontinence (FI) is a physically and psychosocially debilitating disorder which negatively impacts quality of life (QOL). It bears a significant burden not only on patients but also on their families, caretakers as well as society as a whole. Even though it is considered a somewhat common condition, especially as women age, the prevalence is often underestimated due to patients' reluctance to report symptoms or seek care. The evaluation and treatment of FI can be also hindered by lack of understanding of the current management options among healthcare providers and how they impact on QOL. This article provides a comprehensive review on the impact of FI and its treatment on QOL in women.

Sacral nerve stimulation for faecal incontinence and constipation in adults

BACKGROUND

Faecal incontinence (FI) and constipation are both socially-embarrassing and physically-disabling conditions that impair quality of life. For both, surgery may be required in a minority of people when more conservative measures fail. However, the invasiveness and irreversible nature of direct surgery on bowel and sphincter muscles, poor long-term outcomes and well-established compIications makes such procedures unappealing for these benign conditions. A less-invasive surgical option to treat faecal incontinence and constipation is direct, low-voltage stimulation of the sacral nerve roots, termed sacral nerve stimulation (SNS). SNS has become the first line surgical treatment for FI in people failing conservative therapies. Its value in the treatment of constipation is less clear.

OBJECTIVES

To assess the effects of sacral nerve stimulation using implanted electrodes for the treatment of faecal incontinence and constipation in adults.

SEARCH METHODS

We searched the Cochrane Incontinence Group Specialised Register, which contains trials identified from the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, MEDLINE In-Process, ClinicalTrials.gov, the World Health Organization (WHO) ICTRP and handsearched journals and conference proceedings (searched 5 February 2015), EMBASE (1 January 1947 to 2015 Week 5), and the reference lists of retrieved relevant articles.

SELECTION CRITERIA

All randomised or quasi-randomised trials assessing the effects of SNS for faecal incontinence or constipation in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the search results, assessed the methodological quality of the included trials, and undertook data extraction.

MAIN RESULTS

Six crossover trials and two parallel group trials were included.Six trials assessed the effects of SNS for FI. In the parallel group trial conducted by Tjandra, 53 participants with severe FI in the SNS group experienced fewer episodes of faecal incontinence compared to the control group who received optimal medical therapy (mean difference (MD) -5.20, 95% confidence interval (CI) -9.15 to -1.25 at 3 months; MD -6.30, 95% CI -10.34 to -2.26 at 12 months). Adverse events were reported in a proportion of participants: pain at implant site (6%), seroma (2%) and excessive tingling in the vaginal region (9%).In the parallel group trial carried out by Thin, 15 participants with FI in the SNS group experienced fewer episodes of FI compared with the percutaneous tibial nerve stimulation (PTNS) group (MD -3.00, 95% CI -6.61 to 0.61 at 3 months; MD -3.20, 95% CI -7.14 to 0.74 at 12 months). Adverse events were reported in three participants: mild ipsilateral leg pain during temporary testing (n = 1); and stimulator-site pain following insertion of neurostimulator (n = 2).In the crossover trial by Leroi 7 of 34 recruited participants were excluded from the crossover due mainly to complications or immediate device failure. Twenty-four of the remaining 27 participants while still blinded chose the period of stimulation they had preferred. Outcomes were reported separately for 19 participants who preferred the 'on' and five who preferred the 'off' period. For the group of 19, the median (range) episodes of faecal incontinence per week fell from 1.7 (0 to 9) during the 'off' period to 0.7 (0 to 5) during the 'on' period; for the group of five, however, the median (range) rose from 1.7 (0 to 11) during the 'off' period compared with 3.7 (0 to 11) during the 'on' period. Four of 27 participants experienced an adverse event resulting in removal of the stimulator.In the crossover trial by Sørensen and colleagues, participants did not experience any FI episodes in either the one-week 'on' or 'off' periods.In the crossover trial by Vaizey, participants reported an average of six, and one, episodes of faecal incontinence per week during the 'off' and 'on' periods respectively in two participants with FI. Neither study reported adverse events.In the crossover trial by Kahlke, 14 participants with FI experienced significantly lower episodes of FI per week during the stimulator 'on' (1 (SD, 1.7)) compared with the 'off' period (8.4 (SD, 8.7)). Adverse events reported include: haematoma formation (n = 3); misplacement of tined lead (1); and pain at stimulator site (n = 1).Two trials assessed SNS for constipation. In the Kenefick trial, the two participants experienced an average of two bowel movements per week during the 'off' crossover period, compared with five during the 'on' period. Abdominal pain and bloating occurred 79% of the time during the 'off' period compared with 33% during the 'on' period. No adverse events occurred. In contrast, in the trial by Dinning with 59 participants, SNS did not improve frequency of bowel movements and 73 adverse events were reported, which included pain at site of the implanted pulse generator (32), wound infection (12), and urological (17) events.

AUTHORS' CONCLUSIONS

The limited evidence from the included trials suggests that SNS can improve continence in a proportion of patients with faecal incontinence. However, SNS did not improve symptoms in patients with constipation. In addition, adverse events occurred in some patients where these were reported. Rigorous high quality randomised trials are needed to allow the effects of SNS for these conditions to be assessed with more certainty.

Sacral nerve stimulation for faecal incontinence and constipation: a European consensus statement

AIM

In Europe during the last decade sacral nerve stimulation (SNS) or sacral neuromodulation (SNM) has been used to treat faecal incontinence (FI) and constipation. Despite this, there is little consensus on baseline investigations, patient selection and operative technique. A modified Delphi process was conducted to seek consensus on the current practice of SNS/SNM for FI and constipation.

METHOD

A systematic literature search of SNS for FI and constipation was conducted using PubMed. A set of questions derived from the search and expert opinion were answered on-line on two occasions by an international panel of specialists from Europe. A 1-day face-to-face meeting of the experts finalized the discussion.

RESULTS

Three hundred and ninety-three articles were identified from the literature search, of which 147 fulfilled the inclusion criteria. Twenty-two specialists in FI and constipation from Europe participated. Agreement was achieved on 43 (86%) of 50 domains including the set-up of service, patient selection, baseline investigations, operative technique and programming of the device. The median of agreement was 95% (35-100%).

CONCLUSION

Consensus was achieved on the majority of domains of SNS/SNM for FI and constipation. This should serve as a benchmark for safe and quality practice of SNS/SNM in Europe.

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 modulation for fecal incontinence: results of a prospective single-center randomized crossover study

BACKGROUND

Although sacral nerve modulation has become an important tool for the treatment of fecal incontinence, prospective, randomized data are still rare.

OBJECTIVE

To determine the effectiveness of sacral nerve modulation in a prospective randomized crossover study

DESIGN

: Prospective randomized crossover study

SETTING

: Proctological Office and Department of Surgical Proctology at a private hospital.

PATIENTS

A total of 31 consecutive patients (31 women) aged 55 ± 12 years (median ± SD) with fecal incontinence were enrolled between February 2012 and December 2012.

INTERVENTIONS

All patients underwent sacral nerve modulation through a staged implantation procedure between 2009-2011. After a median of 26.8 months following implantation, 16 of the 31 patients agreed to be randomized in a crossover design to stimulation ON or OFF, each for a 3-week period. After the two periods (ie, 6 weeks), while still blinded to the stimulator status, the patients chose which stimulation period (first or second) they preferred. The mode of stimulation corresponding to the selected period was then continued for 3 months (final period).

MAIN OUTCOME MEASURES

Frequency of bowel movements, frequency of fecal incontinence and urgency episodes, severity scores, preference for ON or OFF.

RESULTS

The frequency of fecal incontinence episodes and Cleveland Clinic Incontinence Score (CCIS) were both significantly lower in the ON period than the OFF period (p < 0.005) during the crossover phase of the study. All patients decided to stay in the ON mode for the final period and have continued in the ON mode until now.

LIMITATIONS

Small patient numbers.

CONCLUSIONS

The significant improvement in fecal incontinence during the ON period, as compared to the OFF period, makes it unlikely that the observed benefits of sacral nerve modulation are due to a placebo effect.

Sacral nerve stimulation changes rectal sensitivity and biomechanical properties in patients with irritable bowel syndrome

BACKGROUND

Sacral nerve stimulation (SNS) has been demonstrated to alleviate symptoms and improve quality of life in selected patients with irritable bowel syndrome (IBS). The mechanisms of action, however, remain unknown. The aim of the study was to evaluate the effects of SNS on rectal sensitivity and biomechanical properties in patients with IBS.

METHODS

Twenty patients with diarrhea-predominant (n = 11) or mixed (n = 9) IBS were treated with SNS in a controlled, randomized crossover trial. They were randomized to either 1 month of SNS (ON) or placebo (OFF) with the opposite setting for the next month. Sensory and biomechanical parameters were assessed by multimodal rectal stimulation at the end of each period. IBS-specific symptoms were evaluated at baseline and at the end of each treatment period.

KEY RESULTS

Cold stimuli were better tolerated in the ON period (19.9 °C[± 0.6]) compared to the OFF period (21.8 °C[± 0.6]; p = 0.03). Significantly lower cross-sectional areas were needed to elicit sensory responses in the ON period (1545 mm(2) [± 95]) compared to the OFF period (1869 mm(2) [± 92]; p = 0.015). The association between reduced sensory threshold and improvement of constipation was of borderline significance (p = 0.05). Wall stiffness was significantly lower in the ON period (192 mmHg[± 10]) compared to the OFF period (234 mmHg[± 10]; p = 0.004). Reduced wall stiffness was significantly associated with improved overall GSRS-IBS symptom score (p = 0.01). Reduced sensory threshold to stretch (p = 0.02) and reduced wall stiffness (p < 0.001) were predictors of the GSRS-IBS symptom score.

CONCLUSIONS & INFERENCES

SNS for diarrhea-predominant and mixed IBS relaxes the rectal wall, while making it more sensitive to stretch and less sensitive to cold. Reduced wall stiffness and increased sensitivity to stretch are associated with improved GSRS-IBS symptom score.

A randomized, controlled, crossover study of sacral nerve stimulation for irritable bowel syndrome

OBJECTIVE

To investigate whether sacral nerve stimulation reduces irritable bowel syndrome (IBS)-specific symptoms by a randomized, controlled, crossover study.

BACKGROUND

IBS affects 3% to 22% of the population worldwide, but most patients continue to have symptoms despite treatment.

METHODS

Patients included from our tertiary center had diarrhea-predominant or mixed IBS, with a minimum baseline IBS symptom score (Gastrointestinal Syndrome Rating Scale-IBS questionnaire) of 40 points reduced by a minimum of 30% during the percutaneous nerve evaluation before permanent implantation. Patients were randomized (1:1) to have the stimulator ON or OFF for 1 month and then the opposite for another month. Investigators and patients were not informed of the setting. IBS-specific symptoms and quality of life were assessed through bowel diaries and validated questionnaires. Primary endpoint was the IBS-specific symptom score.

RESULTS

Twenty-one patients were randomized. Ten were eligible for analysis in each group. IBS-specific symptom scores were significantly reduced during stimulation: the median difference in the ON-OFF group was 12 (range, -22 to 44) and in the OFF-ON group -17.5 (range, -48 to -1) (P = 0.0009). IBS-specific quality-of-life scores improved significantly during stimulation: the median difference in the ON-OFF group was 16 (range, -24 to 69) and in the OFF-ON group -42.5 (range, -77 to 0) (P = 0.0003). At 1-year follow-up, the median IBS-specific symptom score (25; range, 13-65) was significantly lower than that at baseline (62; range, 45-80) (P = 0.0001).

CONCLUSIONS

Sacral nerve stimulation significantly reduces symptoms and improves quality of life of highly selected patients with IBS.

Surgical therapies for fecal incontinence

PURPOSE OF REVIEW

Fecal incontinence is a significant source of morbidity and decreased quality of life (QOL) for many. Until recent years, few therapies beyond medical management were available for patients. Surgical treatment of fecal incontinence has evolved from colostomy and direct repair of muscle defects to interventional techniques such as nerve stimulation and bulking agents. We review the most recent surgical options for the treatment of fecal incontinence within the context of established therapies.

RECENT FINDINGS

Overlapping sphincteroplasty is an established therapy that improves continence and QOL, although results deteriorate over time. Implanted artificial bowel sphincter has a 100% complication rate and 80% are explanted over time. Sacral nerve stimulation has minimal risk and more durable long-term improvement in continence. Less invasive versions of nerve stimulation are being researched. Injectable biomaterials have shown some promise, although durability of results is not clear. Novel therapies, including muscle cell transfer and pelvic slings are currently being investigated.

SUMMARY

Surgical therapies for fecal incontinence continue to evolve and show promise in improving QOL with a lower risk profile. Effective valuation of these therapies is currently limited by heterogeneous studies, short duration of follow up, and inconsistent outcome measures.

Current management of fecal incontinence: Choosing amongst treatment options to optimize outcomes

The severity of fecal incontinence widely varies and can have dramatic devastating impacts on a person’s life. Fecal incontinence is common, though it is often under-reported by patients. In addition to standard treatment options, new treatments have been developed during the past decade to attempt to effectively treat fecal incontinence with minimal morbidity. Non-operative treatments include dietary modifications, medications, and biofeedback therapy. Currently used surgical treatments include repair (sphincteroplasty), stimulation (sacral nerve stimulation or posterior tibial nerve stimulation), replacement (artificial bowel sphincter or muscle transposition) and diversion (stoma formation). Newer augmentation treatments such as radiofrequency energy delivery and injectable materials, are minimally invasive tools that may be good options before proceeding to surgery in some patients with mild fecal incontinence. In general, more invasive surgical treatments are now reserved for moderate to severe fecal incontinence. Functional and quality of life related outcomes, as well as potential complications of the treatment must be considered and the treatment of fecal incontinence must be individualized to the patient. General indications, techniques, and outcomes profiles for the various treatments of fecal incontinence are discussed in detail. Choosing the most effective treatment for the individual patient is essential to achieve optimal outcomes in the treatment of fecal incontinence.