Colonosphincteric electromyographic responses to sacral root stimulation: evidence for a somatosympathetic reflex

Association of catechol-O-methyltransferase genetic polymorphism with neuromodulation treatment response in women with fecal or urinary incontinence

BACKGROUND

Prior studies have failed to demonstrate clinical or statistical difference in fecal incontinence (FI) symptom improvement with neuromodulation by percutaneous tibial nerve stimulation vs sham. The results of these studies may be indicative of a placebo or sham effect and led us to investigate possible genetic biomarkers of placebo response among women with FI.

OBJECTIVE

To evaluate the relationship between response to percutaneous tibial nerve stimulation or sham and genetic polymorphisms associated with placebo response in women with FI. Findings were validated using an independent cohort of women treated for urgency urinary incontinence with sacral neuromodulation.

STUDY DESIGN

Blood specimens were utilized from a subset of women in the Neuromodulation for Accidental Bowel Leakage trial who provided blood samples and consented to their use in future studies (N=96). DNA was extracted and genotyping was performed on single nucleotide polymorphisms (previously associated with placebo response in the following genes: catechol-O-methyltransferase, tryptophan hydroxylase-2, brain-derived neurotropic factor, fatty acid amide hydrolase, mu-opiod receptors. An additive linear regression interaction model adjusted for body mass index, race, baseline fecal incontinence episodes or St. Mark's score was used to identify single nucleotide polymorphism by treatment interaction effects significantly associated with change from baseline in St. Mark's score after a 12-week intervention and secondary outcomes. In the absence of significant interaction, single nucleotide polymorphism main effects were tested. Replication of the findings was assessed with an independent cohort of women participating in a randomized trial of urgency urinary incontinence sacral neuromodulation vs onabotulinumtoxinA for treatment of urgency urinary incontinence.

RESULTS

There were no differences in age, body mass index, fecal incontinence episodes, or St. Mark's score at baseline or follow-up between percutaneous tibial nerve stimulation (n=64) vs sham (n=32) participants. There was a significant interaction (P<.1) between the catechol-O-methyltransferase single nucleotide polymorphism and treatment group for improvement in St. Mark's score (interaction P=.02), improvement in fecal incontinence episodes (interaction P=.01), and Patient Global Impression of Improvement (interaction P=.06). Percutaneous tibial nerve stimulation treated participants with the catechol-O-methyltransferase Met allele had the greatest improvements (St. Mark's score improvement: 1.72, 95% confidence interval=[-0.04 to 3.49], P=.06; fecal incontinence episode improvement: 2.36 episodes per week, 95% confidence interval=[0.97-3.75], P=.001; and Patient Global Impression of Improvement: odds ratio (OR)=2.00; 95% confidence interval=[0.96-4.14], P=.06). There was no association between catechol-O-methyltransferase and treatment response in sham treated participants. No significant interaction or main effects were observed for other single nucleotide polymorphisms. In an independent study of urinary incontinence, there were positive significant associations for Patient Global Impression of Improvement urinary leak (OR 2.41, 95% confidence interval =[1.27-4.55], P=.007) and Patient Global Impression of Improvement bladder function (OR 2.10, 95% confidence interval =[1.10-4.01], P=.03 with the Met allele in women treated with sacral neuromodulation . No association was seen in the onabotulinumtoxinA group.

CONCLUSION

Unexpectedly, women who were homozygous for the catechol-O-methyltransferase Met allele (Met/Met) had a significantly higher likelihood of responding to FI treatment via neuromodulation by percutaneous tibial nerve stimulation, but not to sham treatment. This finding was confirmed in a separate study, which found that UI treatment response to neuromodulation by sacral neuromodulation was significantly more likely in women with the catechol-O-methyltransferase Met allele (Met/Met) genotype.

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.

Development of a Remote-Controlled Implantable Rat Sacral Nerve Stimulation System

OBJECTIVES

Sacral nerve stimulation (SNS) is a surgical treatment of urinary and fecal incontinence. Despite its clinical efficacy, the mechanisms of action of SNS are still poorly known. This may be related to the use of acute stimulation models. Up to date, no rodent model of chronic SNS implants has been developed. Therefore, the aim of this study was to create a fully implantable and remotely controllable stimulating device to establish an animal model of chronic SNS.

MATERIALS AND METHODS

The stimulating device consisted of an implantable pulse generator linked to a platinum electrode. The communication with the device was made through an inductive link which allowed to adjust the stimulation parameters; that is, to turn the device on and off or check the battery status remotely. Rats underwent two surgical procedures. In the first procedure, we achieved chronic sacral stimulation but the implanted electrode was not fixated. In the second procedure, the electrode was fixated in the sacral foramen using dental resin. In both cases, the correct positioning of the electrode was evaluated by computed tomography (CT) imaging and the presence of tail tremor in response to high intensity stimulation. We only tested the function of implanted electrode with fixation using micturition frequency assessment following bipolar or unipolar SNS for three days after recovery.

RESULTS

CT imaging showed that implantation of the electrode required fixation as we found that the second surgical procedure yielded a more precise placement of the implanted electrode. The correct placement of implanted electrode observed with imaging was always correlated with a successful tail tremor response in rats, therefore we pursued our next experiments with the second surgical procedure and only assessed the tail tremor response. We found that both bipolar and unipolar SNS reduced micturition frequency.

CONCLUSION

This stimulating device provides an efficient method to perform chronic SNS studies in rats.

The Efficacy and Safety of Transcutaneous Acupoint Interferential Current Stimulation for Cancer Pain Patients With Opioid-Induced Constipation: A Prospective Randomized Controlled Study

Introduction. Opioid-induced constipation (OIC) is a principal complication secondary to analgesic therapy for cancer pain patients who suffer moderate to severe pain. In this study, we observe the efficacy and safety of transcutaneous acupoint interferential current (IFC) stimulation in those patients with OIC. Methods. A total of 198 patients were randomly allocated to the IFC group and control group in a 1:1 ratio. Finally, 98 patients in the IFC group received 14 sessions administered over 2 weeks, whereas 100 patients in the control group took lactulose orally during the same period. Observation items were documented at management stage and at follow-up stage according to Cleveland Constipation Scales (CCS), pain Numeric Rating Scales (NRS) and Patient Assessment of Constipation Quality of Life (PAC-QoL). Results. The total curative effects of the IFC group and the control group were indistinguishable (76.5% vs 70.0%, P = .299). Regarding CCS and PAC-QoL scores, no significant difference was observed between the 2 groups during the management time and at the follow-up stage of week 3 (P > .05, respectively), but groups were distinguished at the follow-up stage of week 4 (P < .001 and P = .031, respectively). The pain NRS decreased significantly at management stage week 2 and follow-up stage week 3 and week 4 (P = .013, P = .041, P = .011, respectively). Conclusions. Transcutaneous acupoint IFC therapy over acupoints of Tianshu (ST25) and Zhongwan (RN12) may improve constipation and quality of life in cancer patients receiving opiates; further studies are worthwhile.

A pilot study assessing the efficacy of posterior tibial nerve stimulation in the treatment of low anterior resection syndrome

BACKGROUND

Low anterior resection for rectal cancer often results in severe bowel dysfunction, specifically low anterior resection syndrome (LARS), with symptoms such as incontinence, urgency, and frequent bowel movements. Percutaneous tibial nerve stimulation (PTNS) resulted in a high rate of success in patients with fecal incontinence. The aim of this study was to evaluate the effectiveness of treatment with PTNS in LARS and to identify predictors of the outcome of the technique.

METHODS

The study was conducted from May 2012 to April 2015 at the Alvaro Cunqueiro Hospital, University Hospital Complex of Vigo, Spain. Ten patients with LARS were recruited consecutively. All patients underwent 2 sessions per week (30 min each one) for 6 weeks. Patients were followed for 3 weeks, and those who had a significant clinical improvement were recruited to a second phase of PTNS. Some patients presenting with relapse during follow-up underwent an additional phase of PTNS. Outcome measures included Wexner scores, quality of life scores, and urgency of defecation.

RESULTS

Three patients did not complete the treatment due to poor response in the first phase. Incontinence was reduced in the remaining seven of ten patients. The median Wexner score at initial patient evaluation was 14 (IQR 10.75-18.5), which decreased to 10 (IQR 6.5-18) after treatment (p = 0.034). A statistically significant improvement was demonstrated in quality of life scale, lifestyle, depression, and daily defecation urgency (p < 0.05). LARS Score improvement was observed in five patients (50%) with a total resolution of LARS in 2 (20%).

CONCLUSIONS

PTNS is an ambulatory treatment that could play an important role in the context of a multimodal treatment approach in patients with LARS. It could be a first-line treatment to identify non-responders to conservative management who need different and more invasive treatments.

Acute sacral nerve stimulation reduces visceral mechanosensitivity in a cross-organ sensitization model

BACKGROUND

Sacral nerve stimulation (SNS) is a surgical treatment of fecal and urinary incontinence that consists of inserting a stimulating electrode into one of the s3 or s4 sacral holes. In addition to the benefit of SNS in the treatment of incontinence, recent studies showed that SNS is effective in the treatment of irritable bowel syndrome as well as bladder pain syndrome. The aim of this study was to evaluate the effect of SNS on visceral mechanosensitivity in a cross-organ sensitization rat model.

METHODS

Hypersensitive model was obtained by instillation of acetic acid into the bladder of rats during 5 minutes, 30 minutes before the start of the experiments. Visceral sensitivity was assessed by monitoring the change in mean arterial pressure in response to graded isobaric colorectal distension series. To decipher the mechanisms underlying SNS effect, rats were administered intravenously either a nonselective opioid receptor antagonist (naloxone) or a nitric oxide synthesis antagonist (L-NAME). Neuronal activation in the dorsal horn of the sacral spinal cord was measured by counting c-fos immunoreactive cells in response to colorectal distension and NMS.

KEY RESULTS

Intravesical acetic acid instillation increased mean arterial pressure variation in response to colorectal distension when compared to saline group. SNS reduced the variation in arterial pressure. Colorectal distension induced a rise in c-fos immunoreactive cells in the dorsal horn of the spinal cord. This effect was reduced by SNS.

CONCLUSIONS & INFERENCES

SNS reduces visceral mechanosensitivity in a cross-organ sensitization model.

Electroneurostimulation for the management of bladder bowel dysfunction in childhood

Both non-invasive and invasive electroneurostimulation (ENS) modalities for bladder bowel dysfunction have been studied and reported in children. A summary of the proposed mechanism of actions and the more commonly used and recently reported techniques and outcomes are described. This includes transcutaneous electrical nerve stimulation, functional electrical nerve stimulation, intravesical electrical nerve stimulation, percutaneous tibial nerve stimulation and sacral neuromodulation in conditions including overactive bladder, enuresis, dysfunctional voiding, constipation, combined bladder bowel dysfunction and neuropathic bladder and bowel dysfunction. There is a need for further high quality randomised trials as well as long-term outcomes to establish whether ENS is able to alter the long-term trajectory for an individual child with bladder bowel dysfunction.

Faecal incontinence: Current knowledges and perspectives

Faecal incontinence (FI) is a disabling and frequent symptom since its prevalence can vary between 5% and 15% of the general population. It has a particular negative impact on quality of life. Many tools are currently available for the treatment of FI, from conservative measures to invasive surgical treatments. The conservative treatment may be dietetic measures, various pharmacological agents, anorectal rehabilitation, posterior tibial nerve stimulation, and transanal irrigation. If needed, patients may have miniinvasive approaches such as sacral nerve modulation or antegrade irrigation. In some cases, a surgical treatment is proposed, mainly external anal sphincter repair. Although these different therapeutic options are available, new techniques are arriving allowing new hopes for the patients. Moreover, most of them are non-invasive such as local application of an α1-adrenoceptor agonist, stem cell injections, rectal injection of botulinum toxin, acupuncture. New more invasive techniques with promising results are also coming such as anal magnetic sphincter and antropylorus transposition. This review reports the main current available treatments of FI and the developing therapeutics tools.

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.

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.

Interferential therapy: a new treatment for slow transit constipation. a pilot study in adults

AIM

The study aimed to assess, for the first time, the effectiveness of interferential therapy (IFT) in the treatment of slow transit constipation in adults and its impact on the quality of life.

METHOD

All consecutive patients with slow transit constipation diagnosed by symptomology and a colonic transit time (CTT) of > 100 h measured with radiopaque markers were included in this prospective study. IFT was performed for 1 h/day over 3 months. Clinical improvement was based on the stool diary and the Knowles-Eccersley-Scott Symptom and Cleveland Clinic Constipation Scores. Quality of life was assessed with the Gastrointestinal Quality of Life Index questionnaire.

RESULTS

Eleven patients with a median age of 51 years were included. At the end of the follow-up period, seven (63.6%) had significantly improved after IFT with a median of 0.66 stools per week [interquartile range (IQR) 0.33-0.66] before treatment and 1.66 (IQR 1.33-1.66) after (P = 0.007). The Knowles-Eccersley-Scott Symptom score changed from 30 (IQR 27-33) before treatment to 19 (IQR 17-26) after treatment (P = 0.005) and the Cleveland Clinic Constipation Score from 26 (IQR 25-28) to 17 (IQR 13-24; P = 0.005). The CTT improved from 103 h (IQR 101-113) to 98 h (IQR 94-107; P = 0.02). The Gastrointestinal Quality of Life Index score improved from 60 (IQR 57-63) to 95 (IQR 68-100; P = 0.005).

CONCLUSION

IFT is a new non-invasive treatment for slow transit constipation. Further studies to confirm these results with longer follow-up are necessary.

Electrical stimulation of the dorsal clitoral nerve reduces incontinence episodes in idiopathic faecal incontinent patients: a pilot study

AIM

Faecal incontinence (FI) has a significant impact on quality of life. This study investigates whether stimulation of the dorsal genital nerve (DGN) improves FI symptoms.

METHOD

Ten female patients suffering from idiopathic FI (median age 60 years) were included in the study. Stimulation was applied twice daily for 3 weeks at the maximal tolerable stimulation amplitude (pulse width, 200 μs; pulse rate, 20 Hz). Patients kept a 3-week bowel diary prior to stimulation, during stimulation and after the final stimulation. FI severity scores, FI Severity Visual-Analogue Score (VAS), FI Quality of Life Score (FIQL), sphincter function and rectal volume tolerance were assessed at baseline, immediately after stimulation and 3 weeks after stimulation.

RESULTS

Nine patients completed the study. The Wexner score (P=0.027) and the St Mark's score (P=0.035) improved after stimulation in seven and six of the patients and improvement was maintained 3 weeks after stimulation (P=0.048 and P=0.049, respectively). The number of incontinent episodes was reduced in seven out of nine patients (P=0.025). Improvement was maintained for 3 weeks after stimulation (P=0.017). Subjective assessments of FI severity using the VAS score and the FIQl score did not improve during stimulation. Sphincter function and rectal volume tolerability were unaffected.

CONCLUSION

DGN stimulation reduced the number of FI episodes in most patients suffering from idiopathic FI. Sphincter function and rectal volume tolerability were not affected. DGN stimulation may represent a new treatment for idiopathic FI.

How sacral nerve stimulation works in patients with faecal incontinence

AIM

Sacral nerve stimulation (SNS) reduces incontinence episodes and improves the quality of life of patients treated for faecal incontinence. However, the exact mechanism of action of this technique remains unclear. The present article reviews the pertinent neuroanatomy and neurophysiology related to SNS and provides explanations for potential mechanisms of action.

METHOD

A systematic review of the literature was performed for studies of the potential mechanisms of action of SNS, using MEDLINE, PubMed, Embase and the Cochrane Library. Articles dealing with the technique, adverse events and economic evaluations of SNS, as well as literature reviews, were excluded, except for reviews dealing with the mechanisms of action of SNS. The following inclusion criteria were used to select articles: (i) articles in English, (ii) randomized, double-blinded, sham-controlled studies, and (iii) cohort studies. Case-control studies or retrospective studies were cited only when randomized or cohort studies could not be found.

RESULTS

We propose three hypotheses to explain the mechanism of action of SNS: (i) a somato-visceral reflex, (ii) a modulation of the perception of afferent information, and (iii) an increase in external anal sphincter activity.

CONCLUSION

The mechanism of action of SNS in patients with faecal incontinence almost certainly depends on the modulation of spinal and/or supraspinal afferent inputs. Further research on humans and animals will be required to gain a better understanding of the mechanisms of action of SNS.

The influence of sacral nerve stimulation on gastrointestinal motor function in patients with fecal incontinence

BACKGROUND

Sacral nerve stimulation (SNS) is a well-established treatment for fecal incontinence of various etiologies. However, the mechanism of action remains unclear. The aim of the present study was to determine whether SNS affects gastric emptying, small intestinal transit or colonic transit times.

METHODS

Seven patients with a permanently implanted sacral nerve stimulator participated in a double-blind randomized cross-over study. The patients were allocated to stimulation ON or OFF for two 7-day periods separated by at least 1week. On days 4-7 of each 7-day period, the patients were examined by gamma camera imaging to measure gastric emptying, small intestinal transit and colonic transit parameters of a radiolabeled, 1600 kJ mixed solid and liquid meal ingested on day 4.

KEY RESULTS

Sacral nerve stimulation did not change gastric retention at 15 min, gastric mean emptying time, gastric half emptying time, small intestinal mean transit time or colonic geometric center after 24, 48 and 72 h.

CONCLUSIONS & INFERENCES

  Sacral nerve stimulation does not induce major changes in the propulsive capacity of the gastrointestinal tract in patients successfully treated for fecal incontinence with permanent sacral nerve stimulator.

Predictive factors for successful sacral nerve stimulation in the treatment of faecal incontinence: results of trial stimulation in 200 patients

AIM

Sacral nerve stimulation (SNS) has a place in the treatment algorithm for faecal incontinence (FI). However, after implantation, 15-30% of patients with FI fail to respond for unknown reasons. We investigated the effect of SNS on continence and quality of life (QOL) and tried to identify specific predictive factors of the success of permanent SNS in the treatment of FI.

METHOD

Two hundred consecutive patients (six men; median age = 60; range 16-81) underwent permanent implantation for FI. The severity of FI was evaluated by the Cleveland Clinic Score. Quality of life was evaluated by the French version of the American Society of Colon and Rectal Surgeons (ASCRS) quality of life questionnaire (FIQL). All patients underwent a preoperative evaluation. After permanent implantation, severity and QOL scores were reevaluated after six and 12 months and then once a year.

RESULTS

The severity scores were significantly reduced during SNS (P = 0.001). QOL improved in all domains. At the 6-month follow-up, the clinical outcome of the permanent implant was not affected by age, gender, duration of symptoms, QOL, main causes of FI, anorectal manometry or endoanal ultrasound results. Only loose stool consistency (P = 0.01), persistent FI even though diarrhoea was controlled by medical treatment (P = 0.004), and low stimulation intensity (P = 0.02) were associated with improved short-term outcomes. Multivariate analysis confirmed that loose stool consistency and low stimulation intensity were related to a favourable outcome.

CONCLUSION

Stool consistency and low stimulation intensity have been identified as predictive factors for the short-term outcome of SNS.

Neuromodulation and the role of electrodiagnostic techniques

Electrodiagnostic techniques have been utilized in surgery since the early 1960s. These techniques have been primarily used in neurosurgery; however, with the introduction of neuromodulation for voiding dysfunction, these techniques have now found their way into the field of female pelvic medicine. This article will review techniques applicable to evaluate pelvic floor function as it relates to neuromodulation. It will also review the literature describing how these techniques are used to help determine appropriate candidates as well as improve surgical outcomes. A PubMed search was conducted using the terms neuromodulation, Interstim, electrodiagnosis, electrodiagnostic techniques, electromyography with limits to the pelvic floor, and voiding dysfunction. Eight articles and three abstracts were found that directly related to the use of electrodiagnostic techniques as they apply to neuromodulation. Electrodiagnostic techniques may play a role in helping predict appropriate candidates for neuromodulation as well as improve surgical outcomes.

[Neurostimulation techniques in the therapeutic management of chronic pelvic and perineal pain]

INTRODUCTION

Neuromodulation is a nonspecific analgesic treatment whose mechanism of action has not yet been elucidated. The purpose of this article is to review the techniques and results of neuromodulation in the management of chronic pelvic and perineal pain.

MATERIAL AND METHODS

A comprehensive review of the literature was performed by searching PUBMED for articles on the various neuromodulation techniques used in the management of chronic pelvic and perineal pain.

RESULTS

Several levels of neuromodulation of the somatic nervous system have been evaluated in the management of pelvic pain: transcutaneous electrical nerve stimulation (TENS), percutaneous nerve stimulation (PNS), nerve root or nerve trunk stimulation, spinal cord stimulation. An improvement was obtained in an average of two thirds of cases, but with declining efficacy over time. The various studies were difficult to compare due to the heterogeneous study populations and very diverse endpoints. Interesting studies on the value of autonomic nervous system intervention have been described, but with no specific trials of neuromodulation.

CONCLUSION

The place of neuromodulation in the management of patients with chronic pelvic and perineal pain has yet to be defined, as it is too frequently used as a last resort. It appears important to develop and analyse this treatment modality in large-scale, randomized, prospective studies.

Transcutaneous electrical posterior tibial nerve stimulation for faecal incontinence: effects on symptoms and quality of life

PURPOSE

Faecal incontinence is a disabling symptom which may be particularly difficult to treat. Recent studies showed that transcutaneous electrical posterior tibial nerve stimulation may improve faecal continence. In this study, we aimed to evaluate the effectiveness of this technique and tried to individualize predictive factors of success.

METHODS

Twenty-four patients suffering from faecal incontinence were treated 20 min per day by applying transcutaneous electrical posterior tibial nerve stimulation for 3 months. A clinical evaluation was performed at the end of treatment, with Wexner's score and analogical scales for symptoms. After 3 months, if the treatment was successful, patients were proposed to continue on the treatment. Predictive factors such as age, symptom duration, proctologic history, obstetrical history, ano-rectal manometric data and quality-of-life score were also analysed.

RESULTS

At 3 months, 13 patients (54%) reported a significant symptomatic improvement with a significant modification in the Wexner's score (14 vs 12, p < 0.025). At a median follow-up of 15 months, there were still 11 patients whose condition was improved.

CONCLUSION

This study shows encouraging mid-term results, and even if further randomized studies are necessary, transcutaneous electrical posterior tibial nerve stimulation may be a new and easy-to-use therapeutic option to treat faecal incontinence.

Sacral nerve stimulation in faecal incontinence: position statement based on a collective experience

OBJECTIVE

Since the first paper published by Matzel et al., in 1995, on the efficacy of sacral nerve stimulation (SNS) in patients with faecal incontinence, the indications, the contraindications, the stimulation technique and follow up of implanted patients have changed. The aim of this article was to provide a consensus opinion on the management of patients with faecal incontinence treated with SNS.

METHOD

Recommendations were based on a critical review of the literature when available and on expert opinions in areas with insufficient evidence.

RESULTS

We have reviewed the indications and contraindications, proposed an algorithm for patient management showing the place of SNS. The temporary test technique, the implantation technique, the patient follow up and the approach in case of treatment failure were discussed.

CONCLUSION

We hope not only to provide a guide on patient management to clinical practitioners interested in SNS but also to harmonize our practices.

Does magnetic stimulation of sacral nerve roots modify colonic motility? Results of a randomized double-blind sham-controlled study

Although sacral nerve root stimulation (SNS) can result in a symptomatic improvement of faecal incontinence, the mechanism of action remains unknown. The aim of this study was to assess whether short-term magnetic SNS can inhibit pharmacologically induced propulsive colonic contractions. Twelve healthy volunteers (median age: 43.5 years old) were studied on two separate occasions and randomized into either active (15 Hz, 100% output intensity for 5 s min(-1) for 30 min) or sham rapid rate lumbosacral magnetic stimulation (rLSMS). Colorectal motility was recorded with a manometric catheter located at the most proximal transducer in the left colon and the most distal, in the rectum. Colonic contractions were provoked by instilling Bisacodyl. The effects of rLSMS on colonic, sigmoid and rectal contractions were monitored and recorded after Bisacodyl instillation. The appearance of high-amplitude contractions propagated or not (HAC/HAPC) provoked by Bisacodyl instillation was significantly delayed during active compared to sham stimulation (P = 0.03). There was no difference in the characteristics of HAC/HAPC (i.e. frequency, amplitude, duration, velocity of propagation) or the motility index with active or sham stimulation. The perception of urgency tended to be decreased with rLSMS following Bisacodyl instillation. The catheter was expulsed within a median of 16.5 min (range 8-39) after Bisacodyl administration during active stimulation compared to 14 min (range 5-40) during sham stimulation (P = 0.03). This study suggests that rLSMS could delay the appearance of the first Bisacodyl-induced colonic contractions.

Transcutaneous posterior tibial nerve stimulation for fecal incontinence in inflammatory bowel disease patients: a therapeutic option?

BACKGROUND

Fecal incontinence associated with inflammatory bowel disease (IBD) may be particularly difficult to treat. Two recent studies showed that transcutaneous posterior tibial nerve stimulation may improve fecal continence. In this pilot study, we tested the usefulness of this noninvasive technique to treat fecal incontinence in IBD.

METHODS

Twelve patients with IBD (7 Crohn's disease, 2 undetermined colitis, 3 ulcerative colitis) were treated by applying transcutaneous posterior tibial nerve electrical stimulation daily for 3 months. A clinical evaluation was performed at the end of treatment, with Wexner's score and Harvey-Bradshaw index and analog scales to assess symptoms and quality of life.

RESULTS

At 3 months, 5 patients (41.6%) reported a significant symptomatic and quality of life improvement, although only 1 reported a significant modification in the Wexner score.

CONCLUSION

These preliminary results are encouraging, although further studies are necessary. Posterior tibial nerve electrical stimulation may represent a new therapeutic option to treat the difficult problem of fecal incontinence in patients with IBD.

Sacral nerve stimulation and rectal function: results of a prospective study in faecal incontinence

The mechanisms of action of sacral nerve stimulation (SNS) to treat faecal incontinence remain poorly understood.

THE AIMS OF OUR STUDY WERE

(i) to measure the effect of SNS on rectal function and (ii) to evaluate rectal function as a predictive factor of clinical response to SNS. Rectal function was studied before and 3 months after permanent SNS in 18 patients (17 women, mean age 58.5 years) with faecal incontinence, using an electronic barostat. Rectal sensitivity and volume variations were recorded during isobaric distensions. Three months after SNS, 14 patients had a significant improvement of faecal incontience symptoms and four had not. Baseline 'maximal tolerated volume' was significantly lower in the positive response group (210 +/- 56 vs 286 +/- 30 mL, P = 0.02). Baseline rectal compliance was lower in patients with a positive response than those without, although this difference did not reach significance (6.2 +/- 3.2 vs 9.2 +/- 2.9 mL mmHg(-1),P = 0.10). Rectal compliance was not significantly modified by SNS. Our results suggest that an increased rectal capacity as measured by the maximal tolerated volume may be a predictive factor of poor response to SNS in faecal incontinence. SNS does not significantly modify rectal function.

Sacral nerve stimulation can improve continence in patients with Crohn's disease with internal and external anal sphincter disruption

PURPOSE

Sacral nerve stimulation is a technique commonly used for the treatment of idiopathic incontinence. This study was designed to assess the efficiency of sacral nerve stimulation as a means of treating fecal incontinence in patients with Crohn's disease with disrupted internal and external anal sphincters.

METHODS

Five patients (3 women) with fecal incontinence suffering from Crohn's disease-related anoperineal lesions were treated by applying three weeks of sacral nerve stimulation and then by permanent sacral nerve stimulation implantation. Endoanal ultrasonography showed that all of these patients had disrupted external and internal anal sphincters.

RESULTS

Continence was improved in all treated patients. The median follow-up time was 14 (range, 3-36) months. At the end of the follow-up period, the median Wexner's score significantly improved from 15 to 6 and the median number of daily stools decreased from 7 to 2. The patients' quality of life also increased significantly.

CONCLUSIONS

Sacral nerve stimulation improves fecal continence in patients suffering from Crohn's anoperineal lesions with internal and external anal sphincters disruption.