How sacral nerve stimulation works in patients with faecal incontinence

[Management of postpartum anal incontinence: A systematic review]

AIM

To analyse the prevalence of postpartum anal incontinence, its risk factors, and its management.

MATERIALS AND METHODS

A comprehensive systematic review of the literature on PubMed, Medline, Embase and Cochrane using: postpartum anal incontinence, postpartum fecal incontinence, perineal rehabilitation, anal surgery.

RESULTS

The prevalence of postpartum anal incontinence varied from 4% (primipare) to 39% (multipare) at 6 weeks postpartum, whereas fecal incontinence can reach respectively 8 to 12% 6 years after delivery. Identified risk factors were: vaginal delivery (OR: 1.32 [95%CI: 1.04-1.68]) compared to cesarean section, instrumental extractions (OR: 1.47 [95%CI: 1.22-1.78]) compared to spontaneous vaginal delivery but it was only with forceps (OR: 1.50 [95%CI: 1.19-1.89]) and not with vaccum (OR: 1.31 [95%CI: 0.97-1.77]). Maternal age over 35 years (OR: 6 [95%CI: 1.85-19.45]), number of births (3 births: OR: 2.91 [95%CI: 1.32-6.41]) and the occurrence of anal-sphincter injury (OR: 2.3 [95%CI: 1.1-5]) were associated with an increased risk of anal incontinence regardless of the type of delivery compared to a group of women without anal incontinence. Perineal rehabilitation should be interpreted with caution because of the lack of randomized controlled trials. A reassessment at 6 months postpartum in order to propose a surgical treatment by sphincteroplasty could be considered if symptoms persist. The results of the sphincteroplasty were satisfactory but with a success rate fading in time (60 to 90% at 6 months against 50 to 40% at 5 and 10 years).

CONCLUSION

Postpartum anal incontinence requires special care. Recommendations for the management of postpartum anal incontinence would be useful.

Acute sacral nerve stimulation reduces visceral mechanosensitivity in Rat through spinal opioid pathway

BACKGROUND

Sacral nerve stimulation (SNS) is an alternative surgical treatment of refractory urge incontinence and/or fecal incontinence. Despite its clinical efficacy, the mechanisms of action of SNS remain poorly understood. The aim of this experimental study was to evaluate the effect of SNS on visceral mechanosensitivity in rats.

METHODS

Anesthetized Sprague-Dawley rats were treated with SNS or sham stimulation. SNS was performed by implanting an electrode close to the sacral nerve root S1. Rats were administered either a non-selective opioid receptor antagonist (naloxone) or a nitric oxide synthase inhibitor (L-NAME). Colonic mechanosensitivity was evaluated using the variation of arterial blood pressure as a spino-bulbar reflex in response to graded isobaric colorectal distension (CRD). C-fos immunoreactive neurons were quantified in spinal and supraspinal sites. μ-opioid receptor (MOR) internalization was counted in the sacral spinal cord with sham or effective SNS in response to CRD.

KEY RESULTS

SNS reduced visceral mechanosensitivity in response to CRD. This effect was reversed by intrathecal and intraveinous naloxone administration. In both models, CRD induced increased c-fos immunoreactivity in the dorsal horn neurons of the sacral spinal cord and supraspinal areas. This increase was prevented by SNS. MOR internalization was significantly higher in stimulated group.

CONCLUSIONS & INFERENCES

SNS impacts on visceral mechanosensitivity by decreasing the spino-bulbar reflex in response to CRD. Spinal opioid receptors are likely involved in this effect.

Treatment of fecal incontinence: state of the science summary for the National Institute of Diabetes and Digestive and Kidney Diseases workshop

This is the second of a two-part summary of a National Institutes of Health conference on fecal incontinence (FI) that summarizes current treatments and identifies research priorities. Conservative medical management consisting of patient education, fiber supplements or antidiarrheals, behavioral techniques such as scheduled toileting, and pelvic floor exercises restores continence in up to 25% of patients. Biofeedback, often recommended as first-line treatment after conservative management fails, produces satisfaction with treatment in up to 76% and continence in 55%; however, outcomes depend on the skill of the therapist, and some trials are less favorable. Electrical stimulation of the anal mucosa is ineffective, but continuous electrical pulsing of sacral nerves produces a ≥50% reduction in FI frequency in a median 73% of patients. Tibial nerve electrical stimulation with needle electrodes is promising but remains unproven. Sphincteroplasty produces short-term clinical improvement in a median 67%, but 5-year outcomes are poor. Injecting an inert bulking agent around the anal canal led to ≥50% reductions of FI in up to 53% of patients. Colostomy is used as a last resort because of adverse effects on quality of life. Several new devices are under investigation but not yet approved. FI researchers identify the following priorities for future research: (1) trials comparing the effectiveness, safety, and cost of current therapies; (2) studies addressing barriers to consulting for care; and (3) translational research on regenerative medicine. Unmet patient needs include FI in special populations (e.g., neurological disorders and nursing home residents) and improvements in behavioral treatments.

A systematic review of sacral nerve stimulation mechanisms in the treatment of fecal incontinence and constipation

BACKGROUND

Sacral nerve stimulation (SNS) is now well established as a treatment for fecal incontinence (FI) resistant to conservative measures and may also have utility in the management of chronic constipation; however, mechanism of action is not fully understood. End organ effects of SNS have been studied in both clinical and experimental settings, but interpretation is difficult due to the multitude of techniques used and heterogeneity of reported findings. The aim of this study was to systematically review available evidence on the mechanisms of SNS in the treatment of FI and constipation.

METHODS

Two systematic reviews of the literature (performed in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses framework) were performed to identify manuscripts pertaining to (a) clinical and (b) physiological effects of SNS during the management of hindgut dysfunction.

KEY RESULTS

The clinical literature search revealed 161 articles, of which 53 were deemed suitable for analysis. The experimental literature search revealed 43 articles, of which nine were deemed suitable for analysis. These studies reported results of investigative techniques examining changes in cortical, gastrointestinal, colonic, rectal, and anal function.

CONCLUSIONS & INFERENCES

The initial hypothesis that the mechanism of SNS was primarily peripheral motor neurostimulation is not supported by the majority of recent studies. Due to the large body of evidence demonstrating effects outside of the anorectum, it appears likely that the influence of SNS on anorectal function occurs at a pelvic afferent or central level.

Novel treatment options for fecal incontinence

Fecal incontinence (FI) is a devastating condition affecting a substantial portion of the population. The etiologies of FI are wide ranging, as are the treatment options. When conservative measures fail, often surgical intervention is required. As in any area where a wide range of treatment options exist, there is no one perfect solution. Fortunately, novel treatment options for FI are becoming available, namely, posterior tibial nerve stimulation, magnetic anal sphincter, stem cell transplant, pyloric transplantation, and acupuncture.

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.

A randomised, controlled study of small intestinal motility in patients treated with sacral nerve stimulation for irritable bowel syndrome

Background

Irritable bowel syndrome (IBS) is among the most common gastrointestinal disorders worldwide. In selected patients with severe diarrhoea-predominant or mixed IBS subtypes sacral nerve stimulation (SNS) alleviates IBS-specific symptoms and improves quality of life. The mode of action, however, remains unknown. The present study aimed to evaluate the effect of SNS on small intestinal motility in IBS patients.

Methods

Twenty patients treated with SNS for severe diarrhoea-predominant or mixed IBS were included in a randomised, controlled, crossover study. The neurostimulator was turned ON or OFF for the first one month and then to the opposite setting for the next month. Gastrointestinal transit patterns were investigated with the Motility Tracking System-1 (MTS-1) at the end of each the ON and OFF period. Primary endpoint was change in the velocity of the magnetic pill within the small intestine. Statistical testing was performed with Wilcoxon’s rank sum test and Fisher’s exact test.

Results

The median velocity of the magnetic pill through the small intestine in the fasting state was not significantly different between periods with and without SNS (Group ON-OFF: median change 0 m/h (range -1.07, 0.63), Group OFF-ON: median change 0.27 m/h (range -0.59, 1.12)) (p = 0.25). Neither, was the median velocity of the magnetic pill through the small intestine in the postprandial state significantly different between periods with and without SNS (Group ON-OFF: median change -0.13 m/h (range -0.46, 0.23), Group OFF-ON: median change 0.015 m/h (range -0.48, 0.59)) (p = 0.14).

Conclusion

Even though SNS may reduce symptoms of diarrhoea-predominant and mixed IBS, it has no detectable effect on small intestinal transit patterns.

Trial registration

Clinical.trials.gov, (NCT00919672).

A pilot study of chronic pudendal nerve stimulation for faecal incontinence for those who have failed sacral nerve stimulation

BACKGROUND

Sacral nerve stimulation (SNS) is used as a first-line treatment for faecal incontinence when conservative measures have failed. However, one-third of patients fail to benefit from this treatment. We hypothesised that sacral afferent stimulation can be maximised using pudendal nerve stimulation (PNS) and this may be of benefit in this patient group. The aim of this study was to assess chronic PNS for those who failed to improve with SNS.

METHODS

Ten patients who had failed SNS were recruited. All underwent percutaneous insertion of a stimulation lead with four-electrode array adjacent to the pudendal nerve. Continuous bipolar stimulation was administered using an external pulse generator over a 3-week period. Those who experienced a ≥50% reduction in the frequency of incontinent episodes over this period proceeded to chronic stimulation with an implantable pulse generator.

RESULTS

Five patients experienced a ≥50% reduction of incontinent episodes during test stimulation and proceeded to chronic stimulation. In these five patients, at a median (range) follow-up of 24 (6-36) months, the median (inter quartile range) frequency of incontinent episodes reduced from 5 (18.25) to 2.5 (3) per week (p = 0.043). Three patients maintained a ≥50% improvement in soiling. There was an improvement in the St Mark's continence Score from 19 (15-24) to 16 (13-19), p = 0.042. There were no significant changes in ability to defer defecation or in quality of life scores.

CONCLUSIONS

Pudendal nerve stimulation failed to improve the symptoms in the majority of patient who had failed SNS. Only a third experienced any improvement.

Predictive factors for successful sacral nerve stimulation in the treatment of fecal incontinence: lessons from a comprehensive treatment assessment

BACKGROUND

Sacral nerve stimulation has a place in the treatment algorithm for fecal incontinence, but the predictive factors of its midterm and long-term success are unknown.

OBJECTIVE

The purpose of this study was to investigate the effect of a 3-year sacral nerve stimulation treatment of fecal continence and to identify specific predictive factors from the pretreatment and per-treatment assessments for the midterm success of sacral nerve stimulation.

DESIGN

A cohort analysis of consecutive patients treated with sacral nerve stimulation for fecal incontinence over a period of 3 years was performed.

SETTINGS

This study was conducted at an academic colorectal unit in a tertiary care center.

PATIENTS

Sixty patients were available for the assessment of 3-year outcomes.

MAIN OUTCOME MEASURES

Clinical outcome (including Cleveland Clinic score) and anorectal physiological data were collected prospectively before and after treatment.

RESULTS

At the 3-year follow-up, 33 of the 60 implanted patients had an improved outcome as defined by a ≥30% improvement in the Cleveland Clinic score from baseline (37.1% on intention to treat and 55.0% per protocol), whereas 22 had an unsuccessful outcome as defined by a <30% improvement in the Cleveland Clinic score from baseline (24.7% on intention to treat and 36.7% per protocol), of whom 7 had their device explanted or switched off permanently before the 3-year assessment, and 3 were lost at follow-up. At 3 years, we failed to identify any factors that could predict the 3-year clinical outcome of sacral nerve stimulation based on preimplantation and postimplantation assessments.

LIMITATIONS

This study involved a relatively small number of patients. There was a lack of consistency in the tool used to evaluate the efficacy of the test and permanent stimulations.

CONCLUSIONS

Based on per-protocol assessments, 55% of the patients had improved outcomes at the 3-year follow-up. No predictor was identified by the pretreatment and posttreatment assessments (see Video, Supplemental Digital Content 1, http://links.lww.com/DCR/A133).

Emerging surgical therapies for faecal incontinence

Faecal incontinence is a common condition and is associated with considerable morbidity and economic cost. The majority of patients are managed with conservative interventions. However, for those patients with severe or refractory incontinence, surgical treatment might be required. Over the past 20 years, numerous developments have been made in the surgical therapies available to treat such patients. These surgical therapies can be classified as techniques of neuromodulation, neosphincter creation (muscle or artificial) and injection therapy. Techniques of neuromodulation, particularly sacral nerve stimulation, have transformed the management of these patients with a minimally invasive procedure that offers good results and low morbidity. By contrast, neosphincter procedures are characterized by being more invasive and associated with considerable morbidity, although some patients will experience substantial improvements in their continence. Injection of bulking agents into the anal canal can improve symptoms and quality of life in patients with mild-to-moderate incontinence, and the use of autologous myoblasts might be a future therapy. Further research and development is required not only in terms of the devices and procedures, but also to identify which patients are likely to benefit most from such interventions.

Treatments of faecal incontinence: recommendations from the French national society of coloproctology

Faecal incontinence is common and significantly affects quality of life. Its treatment involves dietary manipulation, medical treatments, perineal rehabilitation or surgery. In this paper, the French National Society of Coloproctology offers recommendations based on the data in the current literature, including those on recently developed treatments. There is a lack of high quality data and most of the recommendations are therefore based either on grade of recommendation B or expert recommendation (Level 4). However, the literature supports the construction of an algorithm based on the available scientific evidence and expert recommendation which may be useful in clinical practice. The French National Society of Coloproctology proposes a decision-making algorithm that includes recent developments of treatment. The current recommendations support sacral nerve modulation as the key treatment for faecal incontinence. They do not support the use of sphincter substitutions except in certain circumstances. Transanal irrigation is a novel often successful treatment of faecal incontinence due to neurological disorders.

Sacral nerve stimulation for the treatment of refractory voiding and bowel dysfunction

Sacral nerve stimulation, sometimes referred to as a "pacemaker for the bladder and bowels" delivers nonpainful, electrical pulses to the sacral nerves to improve or restore function. A relatively simple procedure works via a complex mechanism to modulate the reflexes that influence the bladder, bowels, sphincters, and pelvic floor. Current approved indications include urinary urge incontinence, urgency-frequency, nonobstructive urinary retention, and fecal incontinence. The history, mechanism of action, evolution, and landmark literature for this treatment modality are reviewed.

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.

Percutaneous posterior tibial nerve stimulation (PPTNS) in faecal incontinence associated with an anal sphincter lesion: results of a prospective study

PURPOSE

Establish the efficacy of posterior tibial nerve stimulation in treating faecal incontinence associated to sphincter defect.

METHODS

Prospective study that included patients with faecal incontinence associated to sphincter lesions between 90 and 180°. Clinical anamnesis, physical examination, reverse visual analogic scale, incontinence diary and Wexner score were recorded at baseline and 6 months. Anal manometry was realized at baseline and 6 months. Subjects underwent one 30-min session every week for 12 consecutive weeks and was continued with 6 additional sessions every 2 weeks.

RESULTS

Sixteen patients were analysed, 15 women and 1 men, with a mean age of 56.5 years. The incontinence were obstetric origin (50%) and perineal surgeries (50%). Four patients who did not continue with the second stage. Referring to the retention time, at baseline 12 patients (75%) did not bear even 1 min. At 6 months the retention time was <1 min in only 2 patients (p = 0.008). Median Wexner baseline values were 10; at 6 months decrease to 5 (p = 0.006). The visual analogical scale (VAS) increased from 6 to 7.5 (p > 0.05). After 6 months, maximum resting pressure increased from 40.9 to 51 mmHg (p < 0.001) and maximum squeeze pressure from 82.5 to 94 mmHg (p < 0.001).

CONCLUSION

PTNS is an effective treatment for faecal incontinence associated to sphincter lesions because the number of incontinence episodes per week, the Wexner Score, the ability to defer defaecation and the manometric determinations improved significantly.

Neuromodulation for fecal incontinence: an effective surgical intervention

Fecal incontinence is a disabling symptom with medical and social implications, including fear, embarrassment, isolation and even depression. Most patients live in seclusion and have to plan their life around the symptom, with secondary impairment of their quality of life. Conservative management and biofeedback therapy are reported to benefit a good percentage of those affected. However, surgery must be considered in the non-responder population. Recently, sacral nerve electrostimulation, lately named neuromodulation, has been reported to benefit patients with fecal incontinence in randomized controlled trials more than placebo stimulation and conservative management, by some unknown mechanism. Neuromodulation is a minimally invasive procedure with a low rate of adverse events and apparently favorable cost-efficacy profile. This review is intended to expand knowledge about this effective intervention among the non-surgically skilled community who deals with this disabled group of patients.

Bilateral transcutaneous posterior tibial nerve stimulation for the treatment of fecal incontinence

BACKGROUND

Unilateral posterior tibial nerve stimulation has been shown to improve fecal incontinence in the short term. Posterior tibial nerve stimulation is believed to work by stimulation of the ascending afferent spinal pathways. Bilateral stimulation may activate more of these pathways. This may lead to an improved therapeutic effect.

OBJECTIVE

The aim of this study was to assess the efficacy of bilateral transcutaneous posterior tibial nerve stimulation for fecal incontinence.

DESIGN

This was a single-group pilot prospective study.

SETTING

The study was conducted from June 2012 to September 2012 at the authors' institution.

PATIENTS

Twenty patients with fecal incontinence were recruited consecutively. Conservative therapy had failed to improve the fecal incontinence in all 20 patients.

INTERVENTION

All patients received 30 minutes of daily bilateral stimulation for 6 weeks. The bilateral stimulation was administered by each patient at home. No further stimulation was given after 6 weeks, and the patients were followed up until their symptoms returned to the prestimulation state (baseline).

MAIN OUTCOME MEASURE

The primary outcome measure was a change in the frequency of incontinent episodes per week.

RESULTS

Seventeen patients completed 6 weeks of treatment. Two patients achieved complete continence. Ten (59%) achieved a ≥50% reduction in frequency of incontinent episodes. Overall, there was a significant reduction in median (interquartile range) frequency of incontinent episodes per week of 6 (8.25) to 2 (7.25) (p = 0.03). There was a significant improvement in the ability to defer defecation from 3 (4) to 5 (8) minutes (p = 0.03). There was no change in the St Mark's incontinence score. One domain of the Rockwood fecal incontinence quality-of-life score and of the Medical Outcomes Study Short Form 36 score improved significantly.

LIMITATIONS

This study was limited by its small size and its lack of blinding and control.

CONCLUSIONS

Bilateral transcutaneous posterior tibial nerve stimulation appears to be a cheap and effective treatment for fecal incontinence. It can easily be used by the patient at home.

A review of posterior tibial nerve stimulation for faecal incontinence

AIM

This review aimed to assess the published results of posterior tibial nerve stimulation (PTNS) for faecal incontinence.

METHOD

A search was performed of PubMed, MEDLINE and Embase to identify studies describing the clinical outcome of PTNS for faecal incontinence.

RESULTS

Thirteen studies were identified. These described the outcome of PTNS for faecal incontinence in 273 patients. Four described transcutaneous PTNS, eight percutaneous PTNS and one compared both methods of PTNS with a sham transcutaneous group. One investigated patients with faecal incontinence and spinal cord injury and another with inflammatory bowel disease. There was marked heterogeneity of the treatment regimens and of the end points used. All reported that PTNS improved faecal incontinence. A > 50% improvement was reported in episodes of faecal incontinence in 63-82% of patients. An improvement was seen in urgency (1-5 min). Improvement was also described in the Cleveland Clinic faecal incontinence score in eight studies. Patients with urge and mixed incontinence appear to benefit more than those with passive incontinence. Treatment regimens ranged in duration from 1-3 months. A residual therapeutic effect is seen after completion of treatment. Follow-up ranged from 1-30 months.

CONCLUSION

PTNS is effective for faecal incontinence. However, many of the published studies are of poor quality. Comparison between studies is difficult owing to differences in the outcome measures used, technique of PTNS and the timing and duration of treatment.

Sacral nerve stimulation (SNS), posterior tibial nerve stimulation (PTNS) or acupuncture for the treatment for fecal incontinence: a clinical commentary

Sacral nerve stimulation (SNS) has become an established therapy worldwide for the treatment for fecal incontinence. A large number of papers have been published over the years, and SNS is generally considered very effective with improved continence and quality of life for most patients. However, the results are mostly expressed in the semi-quantitative terms, that is, patients' diaries translated into score points. The clinical value of SNS is questionable, especially as the patient groups are usually small and/or etiologically heterogenic and the follow-up period mostly short. The Health Technology Assessment organization in the west region of Sweden has recently evaluated the SNS with regard to evidence, efficacy and risks. Economic and ethical aspects raise serious questions on this expensive and not entirely risk-free treatment in routine medical care. Similar criticism has also been raised by other reviewers proposing a more thorough scientific assessment with well-designed randomized trials and comparison with other similar methods of treatment.

Sacral nerve stimulation for constipation

BACKGROUND

For over 10 years sacral nerve stimulation (SNS) has been used for patients with constipation resistant to conservative treatment. A review of the literature is presented.

METHODS

PubMed, MEDLINE and Embase databases were searched for studies demonstrating the use of SNS for the treatment of constipation.

RESULTS

Thirteen studies have been published describing the results of SNS for chronic constipation. Of these, three were in children and ten in adults. Test stimulation was successful in 42-100 per cent of patients. In those who proceeded to permanent SNS, up to 87 per cent showed an improvement in symptoms at a median follow-up of 28 months. The success of stimulation varied depending on the outcome measure being used. Symptom improvement correlated with improvement in quality of life and patient satisfaction scores.

CONCLUSION

SNS appears to be an effective treatment for constipation, but this needs to be confirmed in larger prospective studies with longer follow-up. Improved outcome measures need to be adopted given the multiple symptoms that constipation may be associated with. Comparison with other established surgical therapies also needs consideration.

Sacral nerve stimulation in the treatment of fecal incontinence - the experience of a pelvic floor center : short term results

OBJECTIVES

The aim of this paper is to present the data pertinent to the experiences of our Pelvic Floor Center on the utilisation of SNS in the treatment of fecal incontinence and compare these data to the data of current literature.

METHODS

All patients who had had SNS treatment for fecal incontinence between the dates of 1st April 2008 and 1st April 2011 were enrolled in the study. We considered a 50% reduction of fecal incontinence episodes as a success of the test phase. The score used for assessment was the Cleveland Clinic Florida-Fecal Incontinence score (CCF-FI).

RESULTS

The 21 patients treated for fecal incontinence (19 ♀ and 2 ♂, average age 59.7 [ 26-73] years) were sub-divided on the basis of the presence or absence of sphincter damage (group A1 had damage while group A2 did not). A patient (group A1) was excluded from the study as the result of the external connector breaking during the test phase. Of the 20 remaining patients (9 from group A1 and 11 from A2), 14 (70%) felt benefit and subsequently underwent definitive stimulator implantation. The variation between the pre-operative CCF-FI and the value at 6 months was statistically significant both in group A1 (p=0.009) and in group A2 (p=0.003). The only complication reported was one case (7.1%) of infection of the definitive stimulator.

CONCLUSION

SNS represents an effective treatment for patients with fecal incontinence. The results have been encouraging, and in line with current literature.

Turning off sacral nerve stimulation does not affect gastric and small intestinal motility in patients treated for faecal incontinence

AIM

Sacral nerve stimulation (SNS) reduces symptoms in up to 80% of patients with faecal incontinence (FI). Its effects are not limited to the distal colon and the pelvic floor. Accordingly, spinal or supraspinal neuromodulation have been suggested as part of the mode of action. The effect of SNS on gastric and small-intestinal motility was studied.

METHOD

Using the magnet tracking system, MTS-1, a small magnetic pill was tracked twice through the upper gastrointestinal tract of eight patients with FI successfully treated with SNS. Following a randomized double-blind crossover design, the stimulator was either left active or was turned off for 1 week before investigations with MTS-1.

RESULTS

The median (range) frequency of gastric con-tractions was 3.05 (2.83-3.40) per min during SNS and 3.04 (2.79?-3.76) per min without (P=NS). The median (range) frequency of contractions in the small intestine during the first 2h after pyloric passage was 10.005 (9.68-10.70) per min during SNS and 10.09 (9.79-10.29) per min without SNS (P=NS). The median (range) velocity of the magnetic pill during the first 2h in the small intestine was 1.6 (1.2-2.8) cm/min during SNS and 1.7 (0.8-3.7) cm/min without SNS (P=NS). Small-intestinal propagation mainly occurred during very fast movements (>15cm/min), accounting for 51% (42-60%) of the distance 3% (2-4%) of the time during SNS and for 53% (18-73%) of the distance 3% (1-8%) of the time without SNS (P=NS).

CONCLUSION

Turning off SNS for 1week did not affect gastric or small-intestinal motility patterns.

Sacral nerve stimulation for fecal incontinence related to external sphincter atrophy

BACKGROUND

Atrophy of the external anal sphincter, a pathologic muscle volume anomaly associated with fecal incontinence, has been shown to be a negative predictor of the outcome of surgery for defects of the external anal sphincter. It is unclear whether external anal sphincter atrophy also affects the outcome of sacral nerve stimulation for fecal incontinence.

OBJECTIVE

Our aim was to assess the effectiveness of sacral nerve stimulation in patients with fecal incontinence and external anal sphincter atrophy and to determine whether severity of atrophy and concomitant presence of a sphincter defect are negative predictors of outcome.

DESIGN

This was a prospective observational study of treatment outcome.

SETTING

The study was conducted from November 2004 through November 2010 at a regional hospital in Italy.

PATIENTS

Consecutive patients with fecal incontinence and external anal sphincter atrophy were included. By means of MRI, patients were determined to have either moderate (<50%) or severe (≥ 50%) thinning of and/or replacement of sphincter muscle by fat. The concomitant presence of defects of the external anal sphincter was also detected by MRI.

INTERVENTION

All patients underwent sacral nerve stimulation through a staged implantation procedure.

MAIN OUTCOME MEASURES

The main outcome measures were improvement in the Cleveland Clinic Florida Fecal Incontinence Scale (Wexner score), number of episodes of incontinence per week, and the Fecal Incontinence Quality of Life Scale.

RESULTS

A total of 28 patients underwent definitive implantation of the sacral nerve stimulation device. Wexner scores decreased from a median of 16 (range, 10-20) at baseline to 3 (range, 0-8) at 6-month follow-up (p < 0.001). Weekly incontinence episodes decreased from a mean (SD) of 14.7 (12.5) to 0.40 (0.82); p < 0.001. Improvement was significantly related to severity of fecal incontinence (r = 0.86; p < 0.001). Overall quality-of-life scores improved from a mean of 1.8 (0.6) to 3.8 (0.4);p < 0.001. Sacral nerve stimulation was effective in both moderate (n = 16) and severe (n = 12) atrophy and in patients with (n = 8) or without (n = 20) external anal sphincter defects.

LIMITATIONS

The study was limited by its observational nature and relatively small sample size.

CONCLUSIONS

Sacral nerve stimulation can be effective in restoring continence and improving quality of life in patients with fecal incontinence related to atrophy of the external anal sphincter, regardless of the severity of atrophy. Moreover, the presence of EAS atrophy does not influence the success of the outcome of SNS in patients with a sphincter defect. These findings are consistent with the hypothesis that the effects of SNS are not achieved solely by its action on the anal sphincter complex.

Sacral nerve stimulation in faecal incontinence associated with an anal sphincter lesion: a systematic review

AIM

The long-term results of sphincteroplasty for faecal incontinence due to an anal sphincter lesion have been disappointing. Initially sacral nerve stimulation was used only in faecal incontinence of neurogenic origin but subsequently the indications have been extended to other conditions. The aim of this review was to evaluate sacral nerve stimulation for incontinence in the presence of a sphincter defect.

METHOD

The MEDLINE, Embase and Cochrane Library databases for the period between 1995 and 2011 were searched for studies in English, with no limitations concerning the study size or the length of follow-up. The major endpoints were clinical efficacy, changes in anorectal manometry and quality of life.

RESULTS

Ten reports (119 patients) satisfied the inclusion criteria. The quality of the studies was low (nine were retrospective, one was prospective). All reported a lesion of the external anal and/or internal anal sphincter on endoanal ultrasound. A definitive implant was performed on 106 (89%) of the 119 patients who underwent a peripheral nerve evaluation test. The weighted average number of incontinent episodes per week decreased from 12.1 to 2.3, the weighted average Cleveland Clinic Score decreased from 16.5 to 3.8, and the ability to defer defaecation, when evaluated, increased significantly. The features at anorectal manometry did not change. The quality of life improved significantly in almost all studies.

CONCLUSION

Sacral nerve stimulation could be a therapeutic option for faecal incontinence in patients with an anal sphincter lesion. However, the quality of the published studies is low. A randomized clinical trial comparing sacral nerve stimulation with other classical surgical procedures at long-term follow-up, although beset with difficulties, should be conducted.

Sacral nerve stimulation enhances epithelial barrier of the rectum: results from a porcine model

BACKGROUND

The mechanism of action of sacral nerve stimulation (SNS) remains largely elusive. The aims of this study were to develop a clinically relevant animal model for percutaneous SNS and to describe its effect on the epithelial barrier of the rectum.

METHODS

Under general anesthesia and after percutaneous electrode placement for S3 nerve root stimulation, six pigs underwent unilateral stimulation and six bilateral stimulation. Animals were stimulated for 3 h using an external pulse generator (1-2.5 V; 14 Hz; 210 μs). Six animals underwent electrode implantation without stimulation and served as controls. Full-thickness rectal biopsies were performed prior to and after stimulation. Paracellular permeability was evaluated by measuring sulfonic acid flux across the rectal mucosa in Ussing chambers. Histological assessment of mucosal thickness, epithelial desquamation, and mucus expression were performed.

KEY RESULTS

Percutaneous stimulation resulted in successful anal contractions whose amplitude and uniformity was enhanced following bilateral compared with unilateral stimulation. In controls, paracellular permeability significantly increased during the stimulation period whereas it remained unchanged following unilateral stimulation. In contrast, permeability was significantly reduced by bilateral stimulation. This effect was associated with a concomitant reduction in mucosal thickness and a trend toward increased amount of mucus on surface epithelium compared with controls.

CONCLUSIONS & INFERENCES

The development of a porcine model of percutaneous SNS revealed the ability of neuromodulation to reinforce rectal epithelial barrier. Furthermore, our results suggest that SNS could be used for treatment of gastrointestinal pathologies with reduced rectal mucosal barrier functions.