How sacral nerve stimulation works in patients with faecal incontinence

Effects of Posterior Tibial Nerve Stimulation on Fecal Incontinence: An Umbrella Review

PURPOSE

This study aimed to summarize relevant data from previous systematic reviews (SRs) and conduct comprehensive research on the clinical effects of posterior tibial nerve stimulation (PTNS), via the transcutaneous posterior tibial nerve stimulation (TPTNS) or percutaneous posterior tibial nerve stimulation (PPTNS) method on fecal incontinence (FI).

MATERIALS AND METHODS

In adherence to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, a systematic search was conducted on PubMed, Embase, Scopus, and Web of Science databases. We included English-language, full-text SRs reporting outcomes for FI following either PPTNS or TPTNS. The quality of included studies was assessed using the Joanna Briggs Institute checklist. In addition, reanalyzing the meta-analyses was conducted using Comprehensive Meta-Analysis (CMA) software version 3.0 to achieve effect sizes and the level of statistical significance was set at p ≤ 0.05.

RESULTS

From a total of 835 citations, 14 SRs met our inclusion criteria. Four of these also conducted a meta-analysis. Most SRs reported an overall improvement in different study parameters, including bowel habits and quality of life. However, there were major inconsistencies across the results. The most studied outcome was FI episodes, followed by incontinence score. The summary outcomes showed no statistically significant changes in comparing PTNS with sham or sacral nerve stimulation (SNS) for FI (p > 0.05). However, the results of subgroup analysis based on the type of intervention in the control group revealed that FI episodes were significantly fewer than in the PTNS arm, whereas PTNS led to fewer episodes of FI than did the sham. In terms of incontinence score, the results showed that PTNS compared with sham did not change the incontinence score; however, SNS improved the score significantly in one eligible study for reanalysis when compared with PTNS (p < 0.001).

CONCLUSIONS

The findings of the current umbrella review suggest that PTNS can potentially benefit patients with FI. However, this is concluded from studies with a limited population, disregarding the etiology of FI and with limited follow-up duration. Therefore, caution must be taken in contemplating the results.

Visceral symptoms in patients with anterior cutaneous nerve entrapment syndrome (ACNES): expression of viscerosomatic reflexes?

PURPOSE

Anterior cutaneous nerve entrapment (ACNES) is characterized by neuropathic pain in a predictable, circumscript abdominal area. The diagnostic delay is long, with half of ACNES-affected individuals reporting nausea, bloating, or loss of appetite mimicking visceral disease. The aim of this study was to describe these phenomena and to determine whether treatment could successfully reverse the visceral symptoms.

METHODS

This prospective observational study was conducted between July 2017 and December 2020 at SolviMáx, Center of Excellence for Chronic Abdominal Wall and Groin Pain, Máxima Medical Center, Eindhoven. Adult patients who fulfilled published criteria for ACNES and reported at least one visceral symptom at intake were eligible for the study. A self-developed Visceral Complaints ACNES Score (VICAS) questionnaire that scores several visceral symptoms (minimum 1 point, maximum 9 points) was completed before and after therapy. The success of treatment was defined as at least 50% reduction in pain.

RESULTS

Data from 100 selected patients (86 females) aged 39 ± 5 years were available for analysis. Frequently reported symptoms were abdominal bloating (78%), nausea (66%) and altered defecation (50%). Successful treatment significantly reduced the number of visceral symptoms, with a VICAS before of 3 (range 1-8) and after of 1 (range 0-6) (p < 0.001). A low baseline VICAS was associated with successful treatment outcome (OR 0.738, 95% CI 0.546-0.999).

CONCLUSION

Patients with ACNES may report a variety of visceral symptoms. Successful treatment substantially reduces these visceral symptoms in selected patients.

Electroceuticals for Neurogastroenterology and Motility Disorders

PURPOSE OF REVIEW

To provide an updated overview on use of electrostimulation in gastrointestinal motility disorders and obesity, with a focus on gastric electrical stimulation, vagal nerve stimulation and sacral nerve stimulation.

RECENT FINDINGS

Recent studies on gastric electrical stimulation for chronic vomiting showed a decrease in frequency of vomiting, but without significant improvement in quality of life. Percutaneous vagal nerve stimulation shows some promise for both symptoms of gastroparesis and IBS. Sacral nerve stimulation does not appear effective for constipation. Studies of electroceuticals for treatment of obesity have quite varied results with less clinical penetrance of the technology. Results of studies on the efficacy of electroceuticals have been variable depending on pathology but this area remains promising. Improved mechanistic understanding, technology and more controlled trials will be helpful to establish a clearer role for electrostimulation in treatment of various GI disorders.

Update on treatment of abdominal pain in irritable bowel syndrome: A narrative review

The objectives of this narrative review are to update readers on the current state-of-the-art regarding diverse approaches for the treatment of pain, global symptoms, or adequate relief in irritable bowel syndrome (IBS). The article appraises medications, dietary interventions including low fermentable oligosaccharides, disaccharides, and monosaccharides and polyols (FODMAP) diet, fecal microbial transplantation (FMT), electrical approaches, and behavioral therapies including cognitive behavioral therapy (CBT), gut-directed hypnotherapy (GDH), mindfulness, and open-label placebo. Current evidence demonstrates only modest benefit in global IBS symptoms and pain relief. A future approach that identifies pathophysiological mechanisms of IBS through validated biomarkers has the potential to individualize treatment of patients rather than sequential therapeutic trial and error approaches.

Electrical devices for functional visceral pain

Several studies have documented correction of dysmotility in several regions of the gastrointestinal tract based on electrical stimulation of extrinsic nerves supplying those regions. In this issue of Neurogastroenterology and Motility, Ma et al. (2023) document the effect of transcutaneous neuromodulation applied by acustimulation at ST36 for ineffective esophageal motility in patients with gastroesophageal reflux disease. In addition to motor effects, there were also significant effects on GERD symptoms, raising the question whether extrinsic electrical nerve stimulation of the gut can reduce symptoms through effects that target sensation. This brief review summarizes evidence regarding the application of electrical acustimulation, transauricular electrical stimulation, and sacral electrical or magnetic stimulation to reduce abdominal or pelvic pain.

Faecal incontinence is associated with an impaired rectosigmoid brake and improved by sacral neuromodulation

BACKGROUND

The rectosigmoid brake, characterised by retrograde cyclic motor patterns on high-resolution colonic manometry, has been postulated as a contributor to the maintenance of bowel continence. Sacral neuromodulation (SNM) is an effective therapy for faecal incontinence, but its mechanism of action is unclear. This study aims to investigate the colonic motility patterns in the distal colon of patients with faecal incontinence, and how these are modulated by SNM.

METHODS

A high-resolution fibreoptic colonic manometry catheter, containing 36 sensors spaced at 1-cm intervals, was positioned in patients with faecal incontinence undergoing stage 1 SNM. One hour of pre- and post meal recordings were obtained followed by pre- and post meal recordings with suprasensory SNM. A 700-kcal meal was given. Data were analysed to identify propagating contractions.

RESULTS

Fifteen patients with faecal incontinence were analysed. Patients had an abnormal meal response (fewer retrograde propagating contractions compared to controls; p = 0.027) and failed to show a post meal increase in propagating contractions (mean 17 ± 6/h premeal vs. 22 ± 9/h post meal, p = 0.438). Compared to baseline, SNM significantly increased the number of retrograde propagating contractions in the distal colon (8 ± 3/h premeal vs. 14 ± 3/h premeal with SNM, p = 0.028). Consuming a meal did not further increase the number of propagating contractions beyond the baseline upregulating effect of SNM.

CONCLUSION

The rectosigmoid brake was suppressed in this cohort of patients with faecal incontinence. SNM may exert a therapeutic effect by modulating this rectosigmoid brake.

Neuromodulation Strategies to Reduce Inflammation and Improve Lung Complications in COVID-19 Patients

Since the outbreak of the COVID-19 pandemic, races across academia and industry have been initiated to identify and develop disease modifying or preventative therapeutic strategies has been initiated. The primary focus has been on pharmacological treatment of the immune and respiratory system and the development of a vaccine. The hyperinflammatory state ("cytokine storm") observed in many cases of COVID-19 indicates a prognostically negative disease progression that may lead to respiratory distress, multiple organ failure, shock, and death. Many critically ill patients continue to be at risk for significant, long-lasting morbidity or mortality. The human immune and respiratory systems are heavily regulated by the central nervous system, and intervention in the signaling of these neural pathways may permit targeted therapeutic control of excessive inflammation and pulmonary bronchoconstriction. Several technologies, both invasive and non-invasive, are available and approved for clinical use, but have not been extensively studied in treatment of the cytokine storm in COVID-19 patients. This manuscript provides an overview of the role of the nervous system in inflammation and respiration, the current understanding of neuromodulatory techniques from preclinical and clinical studies and provides a rationale for testing non-invasive neuromodulation to modulate acute systemic inflammation and respiratory dysfunction caused by SARS-CoV-2 and potentially other pathogens. The authors of this manuscript have co-founded the International Consortium on Neuromodulation for COVID-19 to advocate for and support studies of these technologies in the current coronavirus pandemic.

Understanding the physiology of human defaecation and disorders of continence and evacuation

The act of defaecation, although a ubiquitous human experience, requires the coordinated actions of the anorectum and colon, pelvic floor musculature, and the enteric, peripheral and central nervous systems. Defaecation is best appreciated through the description of four phases, which are, temporally and physiologically, reasonably discrete. However, given the complexity of this process, it is unsurprising that disorders of defaecation are both common and problematic; almost everyone will experience constipation at some time in their life and many will develop faecal incontinence. A detailed understanding of the normal physiology of defaecation and continence is critical to inform management of disorders of defaecation. During the past decade, there have been major advances in the investigative tools used to assess colonic and anorectal function. This Review details the current understanding of defaecation and continence. This includes an overview of the relevant anatomy and physiology, a description of the four phases of defaecation, and factors influencing defaecation (demographics, stool frequency/consistency, psychobehavioural factors, posture, circadian rhythm, dietary intake and medications). A summary of the known pathophysiology of defaecation disorders including constipation, faecal incontinence and irritable bowel syndrome is also included, as well as considerations for further research in this field.

Electrophysiological Responses in the Human S3 Nerve During Sacral Neuromodulation for Fecal Incontinence

Intra-operative electrode placement for sacral neuromodulation (SNM) relies on visual observation of motor contractions alone, lacking complete information on neural activation from stimulation. This study aimed to determine whether electrophysiological responses can be recorded directly from the S3 sacral nerve during therapeutic SNM in patients with fecal incontinence, and to characterize such responses in order to better understand the mechanism of action (MOA) and whether stimulation is subject to changes in posture. Eleven patients undergoing SNM were prospectively recruited. A bespoke stimulating and recording system was connected (both intraoperatively and postoperatively) to externalized SNM leads, and electrophysiological responses to monopolar current sweeps on each electrode were recorded and analyzed. The nature and thresholds of muscle contractions (intraoperatively) and patient-reported stimulation perception were recorded. We identified both neural responses (evoked compound action potentials) as well as myoelectric responses (far-field potentials from muscle activation). We identified large myelinated fibers (conduction velocity: 36–60 m/s) in 5/11 patients, correlating with patient-reported stimulation perception, and smaller myelinated fibers (conduction velocity <15 m/s) in 4/11 patients (not associated with any sensation). Myoelectric responses (observed in 7/11 patients) were attributed to pelvic floor and/or anal sphincter contraction. Responses varied with changes in posture. We present the first direct electrophysiological responses recorded from the S3 nerve during ongoing SNM in humans, showing both neural and myoelectric responses. These recordings highlight heterogeneity of neural and myoelectric responses (relevant to understanding MOA of SNM) and confirm that electrode lead position can change with posture.

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.

Design of a Randomized Controlled Trial of Percutaneous Posterior Tibial Nerve Stimulation for the Treatment of Refractory Fecal Incontinence in Women: The NeurOmodulaTion for Accidental Bowel Leakage Study

OBJECTIVES

High-level evidence for second-line noninvasive treatments for fecal incontinence in women is limited. We present the rationale for and design of the NeuromOdulaTion for Accidental Bowel Leakage trial, a randomized controlled trial of percutaneous tibial nerve stimulation (PTNS) and validated sham stimulation in women with refractory accidental bowel leakage.

METHODS

The rationale and goals for a 2-part study with a run-in phase, use of a generic pulse generator for PTNS and sham stimulation, masking, participant inclusion, primary and secondary outcome measures, and adverse event collection are described. A superiority design will be used to compare change from baseline in St. Mark's score after 12 weekly stimulation sessions between PTNS and sham. Responders to initial treatment (PTNS or sham) will be assigned to scheduled or "as needed" intervention for up to 1 year. Secondary outcome measures include incontinence episodes and other bowel events recorded in a 14-day electronic bowel diary, general and condition-specific quality of life instruments, adaptive behavior, global impression of improvement, symptom control, and sexual function.

RESULTS

Sample size calculations determined that 165 participants (110 PTNS and 55 sham) would provide 90% power to detect greater than or equal to 4-point difference between PTNS and sham in change from baseline in St. Mark's score at 12 weeks.

CONCLUSIONS

The methods for the NeuromOdulaTion for Accidental Bowel Leakage trial will provide high-level evidence of the effectiveness and optimal maintenance therapy schedule of a low-cost PTNS protocol in community-dwelling women seeking second-line intervention for refractory accidental bowel leakage.

Neurogenic Bowel Dysfunction in Children and Adolescents

Neurogenic/neuropathic bowel dysfunction (NBD) is common in children who are affected by congenital and acquired neurological disease, and negatively impacts quality of life. In the past, NBD received less attention than neurogenic bladder, generally being considered only in spina bifida (the most common cause of pediatric NBD). Many methods of conservative and medical management of NBD are reported, including relatively recently Transanal Irrigation (TAI). Based on the literature and personal experience, an expert group (pediatric urologists/surgeons/gastroenterologists with specific experience in NBD) focused on NBD in children and adolescents. A statement document was created using a modified Delphi method. The range of causes of pediatric NBD are discussed in this paper. The various therapeutic approaches are presented to improve clinical management. The population of children and adolescents with NBD is increasing, due both to the higher survival rate and better diagnosis. While NBD is relatively predictable in producing either constipation or fecal incontinence, or both, its various effects on each patient will depend on a wide range of underlying causes and accompanying comorbidities. For this reason, management of NBD should be tailored individually with a combined multidisciplinary therapy appropriate for the status of the affected child and caregivers.

Japanese Practice Guidelines for Fecal Incontinence Part 3 -Surgical Treatment for Fecal Incontinence, Fecal Incontinence in a Special Conditions- English Version

In Japan, the surgical treatment for fecal incontinence (FI) can be performed using minimally invasive surgery, such as anal sphincteroplasty and sacral neuromodulation (SNM), as well as antegrade continence enema (ACE), graciloplasty, and stoma construction. In addition, currently, several other procedures, including biomaterial injection therapy, artificial bowel sphincter (ABS), and magnetic anal sphincter (MAS), are unavailable in Japan but are performed in Western countries. The evidence level of surgical treatment for FI is generally low, except for novel procedures, such as SNM, which was covered by health insurance in Japan since 2014. Although the surgical treatment algorithm for FI has been chronologically modified, it should be sequentially selected, starting from the most minimally invasive procedure, as FI is a benign condition. Injuries to the neural system or spinal cord often cause disorders of the sensory and motor nerves that innervate the anus, rectum, and pelvic floor, leading to the difficulty in controlling bowel movement or FI and/or constipation. FI and constipation are closely associated; when one improves, the other tends to deteriorate. Patients with severe cognitive impairment may present with active soiling, referred to as "incontinence" episodes that occur as a consequence of abnormal behavior, and may also experience passive soiling.

Management of Fecal Incontinence

Nine percent of adult women experience episodes of fecal incontinence at least monthly. Fecal incontinence is more common in older women and those with chronic bowel disturbance, diabetes, obesity, prior anal sphincter injury, or urinary incontinence. Fecal incontinence negatively affects quality of life and mental health and is associated with increased risk of nursing home placement. Fewer than 30% of women with fecal incontinence seek care, and lack of information about effective solutions is an important barrier for both patients and health care professionals. Even among women with both urinary and fecal incontinence presenting for urogynecologic care, the rate of verbal disclosure of fecal incontinence symptoms remains low. This article provides an overview of the evaluation and management of fecal incontinence for the busy obstetrician-gynecologist, incorporating existing guidance from the American College of Obstetricians and Gynecologists, the American College of Gastroenterology, and the American Society of Colon and Rectal Surgeons. The initial clinical evaluation of fecal incontinence requires a focused history and physical examination. Recording patient symptoms using a standard diary or questionnaire can help document symptoms and response to treatment. Invasive diagnostic testing and imaging generally are not needed to initiate treatment but may be considered in complex cases. Most women have mild symptoms that will improve with optimized stool consistency and medications. Additional treatment options include pelvic floor muscle strengthening with or without biofeedback, devices placed anally or vaginally, and surgery, including sacral neurostimulation, anal sphincteroplasty, and, for severely affected individuals for whom other interventions fail, colonic diversion.

Comparison of long-term outcome of sacral nerve stimulation for constipation and faecal incontinence with focus on explantation rate, additional visits, and patient satisfaction

BACKGROUND

The aim of the present study was to compare sacral nerve stimulation (SNS) for constipation (SNS-C) with SNS for idiopathic faecal incontinence (SNS-IFI) regarding explantation rate, additional visits, and improvement of patient satisfaction 5 years after implantation.

METHODS

From our prospective database (launched in 2009), we extracted all SNS-C patients 5 years post-implantation, and the SNS-IFI patients implanted just before and just after each SNS-C patient. We retrospectively evaluated the explantation rate, number of additional visits, and patient satisfaction using a visual analogue scale (VAS). We hypothesized that compared with those in the SNS-IFI group: (1) the explantation rate would be higher in SNS-C patients, (2) the number of additional visits would be higher in SNS-C patients, and (3) in patients with an active implant at 5 years, the improvement in VAS would be the same.

RESULTS

We included 40 SNS-C patients and 80 SNS-IFI patients. In the SNS-C group 7/40 (17.5%), patients were explanted, compared to 10/80 (12.5%) patients in the SNS-IFI group (p = 0.56). The mean number of additional visits in the SNS-C group was 3.5 (95% CI 2.8-4.1)) and 3.0 (95% CI 2.6-3.6)) in the SNS-IFI group (p = 0.38). Additional visits due to loss of efficacy were significantly higher in the SNS-C patients (p = 0.03). The reduction in VAS score (delta VAS) at 5 years was 37.1 (95% CI 20.9-53.3) in the SNS-C group, and 46.0 (95% CI 37.9-54.0) in the SNS-IFI group (p = 0.27).

CONCLUSIONS

No significant difference was found regarding explantation rate, number of additional visits, or improvement of VAS at 5 years after SNS implantation between SNS-C patients and SNS-IFI patients.

Functional segregation within the pelvic nerve of male rats: a meso- and microscopic analysis

The pelvic splanchnic nerves are essential for pelvic organ function and have been proposed as targets for neuromodulation. We have focused on the rodent homologue of these nerves, the pelvic nerves. Our goal was to define within the pelvic nerve the projections of organ-specific sensory axons labelled by microinjection of neural tracer (cholera toxin, subunit B) into the bladder, urethra or rectum. We also examined the location of peptidergic sensory axons within the pelvic nerves to determine whether they aggregated separately from sacral preganglionic and paravertebral sympathetic postganglionic axons travelling in the same nerve. To address these aims, microscopy was performed on the major pelvic ganglion (MPG) with attached pelvic nerves, microdissected from young adult male Sprague-Dawley rats (6-8 weeks old) and processed as whole mounts for fluorescence immunohistochemistry. The pelvic nerves were typically composed of five discrete fascicles. Each fascicle contained peptidergic sensory, cholinergic preganglionic and noradrenergic postganglionic axons. Sensory axons innervating the lower urinary tract (LUT) consistently projected in specific fascicles within the pelvic nerves, whereas sensory axons innervating the rectum projected in a complementary group of fascicles. These discrete aggregations of organ-specific sensory projections could be followed along the full length of the pelvic nerves. From the junction of the pelvic nerve with the MPG, sensory axons immunoreactive for calcitonin gene-related peptide (CGRP) showed several distinct patterns of projection: some projected directly to the cavernous nerve, others projected directly across the surface of the MPG to the accessory nerves and a third class entered the MPG, encircling specific cholinergic neurons projecting to the LUT. A subpopulation of preganglionic inputs to noradrenergic MPG neurons also showed CGRP immunoreactivity. Together, these studies reveal new molecular and structural features of the pelvic nerves and suggest functional targets of sensory nerves in the MPG. These anatomical data will facilitate the design of experimental bioengineering strategies to specifically modulate each axon class.

Effects of sacral nerve electrical stimulation on 5‑HT and 5‑HT3AR/5‑HT4R levels in the colon and sacral cord of acute spinal cord injury rat models

Spinal cord injury (SCI) often leads to defecation dysfunction. Sacral nerve electrical stimulation (SNS) therapy could improve defecation function. The present study aimed to assess SNS therapy, with regard to the levels of serotonin (5-HT) and its receptors (5-HT3AR and 5-HT4R) in the colon and sacral cord, a rat model of acute severe SCI was used. This rat model was made using the New York University Impactor device. Model rats were randomized to the SCI and SNS (electrical stimulation on the S3 nerve) groups. After 14 days of treatment, enteric transmission function was assessed. 5-HT and 5-HT3AR/5-HT4R were measured by ELISA, quantitative PCR, immunohistochemistry and western blotting. In SCI rats, SNS significantly increased the quantity of feces, shortened the time to the first fecal passage, and improved fecal texture and colon histology. SNS elevated 5-HT contents in the colon and spinal cord, and enhanced 5-HT3AR/5-HT4R protein expression and distribution in the colonic myenteric plexus and mucosa, sacral intermediolateral nucleus and dorsal horn. SNS upregulated the relative expression levels of 5-HT3AR/5-HT4R mRNA and protein in the colon and spinal cord. SNS can improve defecation and accelerate the recovery of colonic transmission functions in rat models of acute SCI. These effects involved upregulation of the 5-HT/5-HT3AR/5-HT4R axes.

Anorectal angle at rest predicting successful sacral nerve stimulation in idiopathic fecal incontinence-a cohort analysis

PURPOSE

Sacral nerve stimulation is an effective treatment for patients suffering from fecal incontinence. However, less is known about predictors of success before stimulation. The purpose of this study was to identify predictors of successful sacral nerve stimulation in patients with idiopathic fecal incontinence.

METHODS

Consecutive female patients, receiving peripheral nerve evaluation and sacral nerve stimulation between September 2008 and October 2014, suffering from idiopathic fecal incontinence were included in this study. Preoperative patient's characteristics, anal manometry, and defecography results were collected prospectively and investigated by retrospective analysis. Main outcome measures were independent predictors of treatment success after sacral nerve stimulation.

RESULTS

From, all in all, 54 patients suffering from idiopathic fecal incontinence receiving peripheral nerve evaluation, favorable outcome was achieved in 23 of 30 patients after sacral nerve stimulation (per protocol 76.7%; intention to treat 42.6%). From all analyzed characteristics, wide anorectal angle at rest in preoperative defecography was the only independent predictor of favorable outcome in multivariate analysis (favorable 134.1 ± 13.9° versus unfavorable 118.6 ± 17.1°).

CONCLUSIONS

Anorectal angle at rest in preoperative defecography might present a predictor of outcome after sacral nerve stimulation in patients with idiopathic fecal incontinence.

Sacral neuromodulation versus onabotulinumtoxinA for refractory urgency urinary incontinence: impact on fecal incontinence symptoms and sexual function

BACKGROUND

Women with refractory urgency urinary incontinence can be treated with onabotulinumtoxinA or sacral neuromodulation. Little data exists on the comparative effects of treatment of refractory urgency urinary incontinence on other pelvic floor complaints, such as bowel and sexual function.

OBJECTIVE

The objective of this study was to compare the impact of these treatments on fecal incontinence and sexual symptoms.

METHODS

This was a planned supplemental analysis of a randomized trial in women with refractory urgency urinary incontinence treated with onabotulinumtoxinA (n = 190) or sacral neuromodulation (n = 174). Fecal incontinence and sexual symptoms were assessed at baseline and at 6, 12, and 24 months. Fecal incontinence symptoms were measured using the St Mark's (Vaizey) Fecal Incontinence severity scale. Sexual symptoms were measured using the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire-12 (PISQ-12) and the Pelvic Organ Prolapse/Incontinence Sexual Questionnaire, IUGA-Revised (PISQ-IR). The PISQ-IR allows measurement of sexual symptoms in both sexually active and non-sexually active adults. Primary outcomes were change in Vaizey and PISQ-12 scores between baseline and 6 months. Secondary outcomes were change in PISQ-IR total and subscores between baseline and 6 months and change in Vaizey, PISQ-12, and PISQ-IR scores between baseline and 12 and 24 months. Intent-to-treat analysis was performed using repeated measures mixed model to estimate change in all parameters from baseline while adjusting for the baseline score. A subgroup analysis of women with clinically significant bowel symptoms was conducted based on baseline Vaizey score of ≥12.

RESULTS

At baseline, mean Vaizey scores were indicative of mild fecal incontinence symptoms and were not different between onabotulinumtoxinA and sacral neuromodulation groups (7.6 ± 5.3 vs 6.6 ± 4.9, P = .07). The proportion of sexually active women (56% vs 63%, P = .25), mean PISQ-12 score (33.4 ± 7.5 vs 32.7 ± 6.7, P = .55), or PISQ-IR subscores were also not different between the onabotulinumtoxinA and sacral neuromodulation groups at baseline. There was no difference between women treated with onabotulinumtoxinA and those treated with sacral neuromodulation at 6 months in terms of improvement in fecal incontinence symptom score (Vaizey: -1.9, 95% confidence interval -2.6 to -1.2 vs -0.9, 95% confidence interval -1.7 to -0.2, P = .07) or sexual symptoms score (PISQ-12: 2.2, 95% confidence interval 0.7 to 3.7 vs 2.2, 95% confidence interval 0.7 to 3.7, P = .99). There was no difference in improvement between groups in the sexual symptom subscores in sexually active and non-sexually active women at 6 months. Similar findings were noted at 12 and 24 months. In a subgroup (onabotulinumtoxinA = 33 and sacral neuromodulation = 22) with clinically significant fecal incontinence at baseline (Vaizey score ≥12), there was a clinically meaningful improvement in symptoms in both groups from baseline to 6 months, with no difference in improvement between the onabotulinumtoxinA and sacral neuromodulation groups (-5.1, 95% confidence interval -7.3 to -2.8 vs -5.6, 95% confidence interval -8.5 to -2.6, P = .8).

CONCLUSION

There were no differences in improvement of fecal incontinence and sexual symptoms in women with urgency urinary incontinence treated with onabotulinumtoxinA or sacral neuromodulation. Women with significant fecal incontinence symptoms at baseline had clinically important improvement in symptoms, with no difference between the treatments. Our findings can help clinicians counseling women considering treatment for refractory urgency urinary incontinence.

Sacral nerve stimulation improves colonic inflammation mediated by autonomic-inflammatory cytokine mechanism in rats

BACKGROUND

Vagal nerve stimulation (VNS) was reported to have a therapeutic potential for inflammatory bowel disease (IBD). This study was designed to determine effects and mechanisms of SNS on colonic inflammation of in rodent models of IBD and compare the difference among SNS, VNS, and SNS plus VNS.

METHODS

Intestinal inflammation in rats was induced by intrarectal administration of TNBS (2,4,6-Trinitrobenzenesulfonic acid) on the first day. Five days after intrarectal TNBS, the rats were treated with sham-VNS, VNS, Sham-SNS, SNS, and SNS + VNS for 10 days. In another experiment, after 10 days of 4% DSS (dextran sodium sulfate) in drinking water, rats were treated with 10-day sham-SNS and SNS. Various inflammatory responses were assessed; mechanisms involving autonomic functions and inflammatory cytokines were investigated.

KEY RESULTS

(a) VNS, SNS, and VNS + SNS significantly and equally decreased the disease activity index and macroscopic scores, and normalized colon length; (b) IL-10 was decreased by TNBS but increased with SNS, VNS, and SNS + VNS; pro-inflammatory cytokines, IL-6, IL-17A, MCP-1 and TNF-α, were increased by TNBS but decreased with SNS, VNS, and SNS + VNS (P < .05); MPO activity was decreased by SNS, VNS, and SNS + VNS; (c) SNS, VNS, and SNS + VNS remarkably increased vagal activity that was suppressed by TNBS (P < .05); (d) smilar SNS effects were noted in rats with DSS-induced colitis.

CONCLUSIONS & INFERENCES

SNS presents similar anti-inflammatory effects as VNS by inhibiting pro-inflammatory cytokines and increasing anti-inflammatory cytokines via the autonomic pathway. Similar to VNS, SNS may also have a therapeutic potential for colonic inflammation.

Sacral nerve modulation for faecal incontinence: influence of age on outcomes and complications. A multicentre study

AIM

Faecal incontinence is frequent in the elderly. Little is currently known about the efficacy of sacral nerve modulation (SNM) in the elderly. The present study aimed to assess the impact of age on the outcome of SNM and on the surgical revision and explantation rates by comparing the results of a large data set of patients.

METHOD

Prospectively collected data from patients who underwent an implant procedure between January 2010 and December 2015 in seven French centres were retrospectively evaluated. In total, 352 patients [321 women; median age (range): 63 (24-86) years] were included. Clinically favourable and unfavourable outcomes, and surgical revision and explantation rates, were compared according to the age of the patients.

RESULTS

A similar outcome was observed when comparing patients < 70 years and ≥ 70 years (a favourable outcome in 79.2% and 76.2%, respectively, P = 0.89). The probability of a successful treatment as a function of time was similar for the two age groups (< 70 years and ≥ 70 years, P = 0.54). The explantation and revision rates were not influenced by age (explantation rate: 17% in patients < 70 years vs 14% in patients ≥ 70 years, P = 0.89; and revision rate: 42% in patients < 70 years vs 40% in patients ≥ 70 years, P = 0.89). The probability of explantation as a function of time was similar for the two age groups (P = 0.82). The limitations of this study were its retrospective status, the rate of loss at follow-up and different durations of patient follow-up.

CONCLUSIONS

Our results suggest that patients ≥ 70 years suffering from faecal incontinence benefit from SNM with a similar risk as a younger population.

Sacral nerve modulation for irritable bowel syndrome: A randomized, double-blinded, placebo-controlled crossover study

BACKGROUND

Irritable bowel syndrome (IBS) is among the most common gastrointestinal disorders, and a substantial proportion of patients have an insufficient response to treatment. In a single-blinded study, sacral nerve modulation (SNM) significantly reduced symptoms of IBS. The aim of the present double-blinded, randomized, placebo-controlled study was to evaluate the effect of SNM for IBS.

METHODS

We included patients with diarrhea-predominant or mixed IBS and a minimum baseline IBS-specific symptom score of 40 points (Gastrointestinal Symptom Rating Scale-IBS version). Patients underwent a 6-week period of SNM. In the first 4 weeks, the patients were randomized 1:1 to have the neurostimulator set subsensory or OFF for 2 weeks and then the opposite for another 2 weeks. Patients and investigators were blinded to settings. In the remaining 2 weeks, the stimulation was set suprasensory. IBS-specific symptoms and quality of life were assessed with validated questionnaires and bowel diaries.

KEY RESULTS

Twenty-one patients were randomized and eligible for analysis. The IBS-specific symptom score was reduced with borderline significance during stimulation (subsensory-OFF median change -1 (-26, 9), OFF-subsensory median change 8 (-11, 36); P = 0.0572). Pain was significantly reduced during stimulation (subsensory-OFF median change -1.5 (-4, 1), OFF-subsensory median change 1 (-4, 3); P = 0.0188), along with the number of daily bowel movements (subsensory-OFF median change 0 (-1.8, 0.2), OFF-subsensory median change 0.2 (-0.5, 1.1); P = 0.0373). The median placebo effect was 14% (0, 55).

CONCLUSION AND INFERENCES

Sacral nerve modulation for IBS seems promising but should be considered experimental until larger multicenter studies have been performed.

Success and Complication Rates After Sacral Neuromodulation for Fecal Incontinence and Constipation: A Single-center Follow-up Study

Background/Aims

The aim of this study was to evaluate the sustainability of sacral neuromodulation (SNM) success in patients with fecal incontinence (FI) and/or constipation.

Methods

This is a retrospective analysis of a prospective database of patients who received SNM therapy for FI and/or constipation between 2006 and 2015. Success rates, complications and reintervention rates were assessed after up to 10 years of follow-up.

Results

Electrodes for test stimulation were implanted in 101 patients, of whom 79 (78.2%) received permanent stimulation. The mean follow-up was 4.4 ± 3.0 years. At the end of follow-up, 57 patients (72.2%) were still receiving SNM. The 5-year success rate for FI and isolated constipation was 88.2% (95% confidence interval [CI], 80.1-97.0%) and 31.2% (95% CI, 10.2-95.5%), respectively (P ＜ 0.001). In patients with FI, involuntary evacuations per week decreased ＞ 50% in 76.1% of patients (95% CI, 67.6-86.2%) after 5 years. A lead position at S3 was associated with an improved outcome (P = 0.04). Battery exchange was necessary in 23 patients (29.1%), with a median battery life of 6.2 years. Reinterventions due to complications were necessary in 24 patients (30.4%). For these patients, the 5-year success rate was 89.0% (95% CI, 75.3-100.0%) compared to 78.4% (95% CI, 67.2-91.4%) for patients without reintervention.

Conclusions

SNM offers an effective sustainable treatment for FI. For constipation, lasting success of SNM is limited and is thus not recommended. Reinterventions are necessary but do not impede treatment success.

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.

Efficacy of Percutaneous Posterior Tibial Nerve Stimulation for the Management of Fecal Incontinence in Multiple Sclerosis: A Pilot Study

BACKGROUND

Fecal incontinence is a debilitating and highly prevalent problem among multiple sclerosis patients. Conservative therapies often fail to provide benefit. Posterior tibial nerve stimulation is a minimally invasive neuromodulatory therapy with proven efficacy for fecal incontinence in non-neurological settings.

OBJECTIVE

To evaluate the efficacy of posterior tibial nerve stimulation in treating multiple sclerosis-related fecal incontinence.

METHODS

Consecutive multiple sclerosis patients with fecal incontinence that had failed conservative therapy received posterior tibial nerve stimulation between 2012 and 2015. All patients had previously undergone anorectal physiology tests and endoanal ultrasound. Patients whose Wexner incontinence score reduced below 10 post-therapy or halved from baseline were deemed responders.

RESULTS

Thirty-three patients (25 female, median age 43 years) were included. Twenty-three (70%) had urge, 4 (12%) passive, and 9 (27%) mixed fecal incontinence. Twenty-six (79%) were classified as responders. The majority of subjects had relapsing-remitting multiple sclerosis (67%); those had a significantly higher response rate (95% vs. 67% and 50% in primary and secondary progressive respectively, P < 0.05). Responders tended to be more symptomatic at baseline and had greater improvements in bowel symptom scores and quality of life scores with therapy.

CONCLUSION

Posterior tibial nerve stimulation demonstrates potential as an effective therapy for fecal incontinence in multiple sclerosis. These findings provide the basis for future more definitive controlled studies.

The "rectosigmoid brake": Review of an emerging neuromodulation target for colorectal functional disorders

The regulation of gastrointestinal motility encompasses several overlapping mechanisms including highly regulated and coordinated neurohormonal circuits. Various feedback mechanisms or "brakes" have been proposed. While duodenal, jejunal, and ileal brakes are well described, a putative distal colonic brake is less well defined. Despite the high prevalence of colonic motility disorders, there is little knowledge of colonic motility owing to difficulties with organ access and technical difficulties in recording detailed motor patterns along its entire length. The motility of the colon is not under voluntary control. A wide range of motor patterns is seen, with long intervals of intestinal quiescence between them. In addition, the use of traditional manometric catheters to record contractile activity of the colon has been limited by the low number of widely spaced sensors, which has resulted in the misinterpretation of colonic motor patterns. The recent advent of high-resolution (HR) manometry is revolutionising the understanding of gastrointestinal motor patterns. It has now been observed that the most common motor patterns in the colon are repetitive two to six cycles per minute (cpm) propagating events in the distal colon. These motor patterns are prominent soon after a meal, originate most frequently in the rectosigmoid region, and travel in the retrograde direction. The distal prominence and the origin of these motor patterns raise the possibility of them serving as a braking mechanism, or the "rectosigmoid brake," to limit rectal filling. This review aims to describe what is known about the "rectosigmoid brake," including its physiological and clinical significance and potential therapeutic applications.

Efficacy of Bilateral Transcutaneous Posterior Tibial Nerve Stimulation for Fecal Incontinence

CONTEXT

Posterior tibial nerve stimulation is a new second-line treatment for refractory fecal incontinence.

OBJECTIVE

To assess the efficacy of bilateral transcutaneous posterior tibial nerve stimulation (BTPTNS) for treatment of fecal incontinence in Japanese patients and its impact on quality of life.

DESIGN

A prospective observational-interventional study was conducted from May 2015 to June 2017 in patients with fecal incontinence in whom conservative treatment had failed. All patients received a 30-minute session of stimulation twice weekly for 6 consecutive weeks. Evaluation at baseline and at 6 weeks involved the Wexner score, Fecal Incontinence Quality of Life (FIQL) questionnaire, and anal manometry. Patients recorded episodes of incontinence in a weekly diary.

MAIN OUTCOME MEASURES

Reduction of 50% or greater in incontinence episodes, decreased Wexner score, and improved FIQL scores.

RESULTS

Twenty-two patients with a median age of 64.1 years (range, 26-81 years) and men:women ratio of 9:13 completed BTPTNS. Mean episodes of fecal incontinence were significantly reduced from 4.7 to 1.5 (p < 0.05). An improvement of 50% or better in episodes of fecal incontinence was achieved in 77.2% of patients. The median Wexner score significantly decreased from 10.2 to 6.9 (p < 0.05). The median FIQL score improved from 2.7 to 3.1 (p = 0.06), and significant improvement was seen in the embarrassment domain (2.2 vs 2.8, p < 0.05). Resting and squeezing anal pressures revealed no significant changes.

CONCLUSION

Our findings suggest that BTPTNS is safe and well tolerated and may improve symptoms of fecal incontinence. This technique offers an additional noninvasive, less expensive form of treatment.

Sacral Neuromodulation for Fecal Incontinence: A Review of the Central Mechanisms of Action

OBJECTIVE

Fecal incontinence (FI) has a devastating effect on the quality of life and results in social isolation. Sacral neuromodulation (SNM) is proven to be an effective, minimal invasive treatment modality for FI. Despite the increasing application of SNM, the exact mechanisms of action remain unclear. The initial assumption of peripheral motor neurostimulation is not supported by increasing evidence, which report effects of SNM outside the pelvic floor. A new hypothesis states that afferent signals to the brain are essential for a successful therapy. This study aimed to review relevant studies on the central mechanism of SNM in FI.

METHODS

Clinical and experimental studies on the central mechanisms, both brain and spinal cord, of SNM for FI up to December 2015 were evaluated.

RESULTS

In total, 8 studies were found describing original data on the central mechanism of SNM for FI. Four studies evaluated the central effects of SNM in a clinical setting and 4 studies evaluated the central effects of SNM in an experimental animal model. Results demonstrated a variety of (sub)cortical and spinal changes after induction of SNM.

CONCLUSION

Review of literature demonstrated evidence for a central mechanism of action of SNM for FI. The corticoanal pathways, brainstem, and specific parts of the spinal cord are involved.

Increase of n-NOS and i-NOS in Rat Colon After Sacral Neuromodulation

OBJECTIVE

Sacral neuromodulation (SNM) is proposed to treat different anorectal dysfunctions but its mechanism of action is not yet known. Our previous study demonstrated how SNM can significantly increase neuronal nitric oxide synthase NOS (n-NOS) and inducible NOS (i-NOS) expression in the anus and rectum of rats. There are no reports regarding the relation between SNM and NOS in colonic cells: our aim was to assess NOS expression in colonic rat model after SNM.

MATERIALS AND METHODS

Twenty-six female Sprangue-Dawley rats were considered: group I, normal control rats; group II, sham treatment rats, in whom electrodes for electrical stimulation were placed in S1 foramen bilaterally and left in place, without performing neuromodulation; group III, rats in whom SNM was performed. After 14 days, the rats were sacrificed and we evaluated n-NOS and i-NOS in colonic specimens by immunohistochemistry and Western Blot analysis.

RESULTS

Western Blot analysis showed that levels of n-NOS and i-NOS were higher in colon of the III group rats respect to the others; in particular, immunohistochemistry revealed that, after neuromodulation, n-NOS expression in the muscle cells and i-NOS expression in glandular epithelium and nervous cells were highly represented (p < 0.05).

CONCLUSION

Our study showed that in colon, SNM is able to influence NO synthesis, activating n-NOS expression in muscle cells and i-NOS expression in glandular epithelium and nervous cells. Our study showed a complex colonic response to SNM. This experimental model could be applied to better understand the mechanism of action of SNM in bowel dysfunction.

Faecal incontinence in patients with a sphincter defect: comparison of sphincteroplasty and sacral nerve stimulation

AIM

Sphincteroplasty (SP) is used to treat faecal incontinence (FI) in patients with a sphincter defect. Although sacral nerve stimulation (SNS) is used in patients, its outcome in patients with a sphincter defect has not been definitively evaluated. We compared the results of SP and SNS for FI associated with a sphincter defect.

METHOD

Patients treated by SNS or SP for FI with an associated sphincter defect were retrospectively identified from an Institutional Review Board approved prospective database. Patients with ultrasound evidence of a sphincter defect were matched by age, gender and body mass index. The main outcome measure was change in the Cleveland Clinic Florida Faecal Incontinence Score (CCF-FIS).

RESULTS

Twenty-six female patients with a sphincter defect were included in the study. The 13 patients in each group were similar for age, body mass index, initial CCF-FIS and the duration of follow-up. No differences were observed in parity (P = 1.00), the rate of concomitant urinary incontinence (P = 0.62) or early postoperative complications. Within-group analysis showed a significant reduction of the CCF-FIS among patients having SNS (15.9-8.4; P = 0.003) but not SP (16.9-12.9; P = 0.078). There was a trend towards a more significant improvement in CCF-FIS in the SNS than in the SP group (post-treatment CCF-FIS 8.4 vs 12.9, P = 0.06). Net improvement in CCF-FIS was not significantly different between the groups (P = 0.06).

CONCLUSION

Significant improvement in CCF-FIS was observed in patients treated with SNS but not SP patients. A trend towards better results was seen with SNS.

Sacral neurostimulation for low anterior resection syndrome after radical resection for rectal cancer: evaluation of treatment with the LARS score

PURPOSE

Sacral neurostimulation (SNS) has proven to be an effective treatment modality for low anterior resection syndrome (LARS). The primary aim of this study is to investigate the impact of SNS on all symptoms of LARS, not merely on fecal incontinence. Furthermore, we wanted to evaluate whether the LARS score could be useful as a tool to evaluate SNS treatment.

METHODS

All patients diagnosed with minor or major LARS, unresponsive to conservative therapy for fecal incontinence, who underwent sacral neuromodulation for LARS at Groeninge Hospital, Kortrijk, Belgium, were prospectively enrolled in the study. The primary endpoint was the reduction in the severity of LARS. This was assessed by validated questionnaires: the LARS score and the Wexner score.

RESULTS

Eleven patients underwent definite implantation of the SNS device. All patients showed a substantial decrease in their Wexner scores: The mean score was reduced from 17.7 to 4.6 (Z: 2.93; p: 0.0033). Additionally, the mean LARS score dropped from 36.9 to 11.4 (Z: 2.93; p: 0.0033). Furthermore, there was a significant amelioration of all symptoms of LARS.

CONCLUSIONS

Our study shows that SNS is effective for all symptoms of LARS. The authors believe that in patients who receive SNS for LARS, it could be useful to determine the LARS score to evaluate the complexity of the symptoms and their response to treatment.

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.

Pathophysiology and Therapeutic Options for Fecal Incontinence

Fecal incontinence (FI), defined as the involuntary loss of solid or liquid feces through the anus is a prevalent condition with significant effects on quality of life. FI can affect individuals of all ages and in many cases greatly impairs quality of life but, incontinent patients should not accept their debility as either inevitable or untreatable. The severity of incontinence can range from unintentional elimination of flatus to the complete evacuation of bowel contents. It is reported to affect up to 18% of the population, with a prevalence reaching as high as 50% in nursing home residents. However, FI is often underreported, thus obscuring its true prevalence in the general population. The options for treatment vary according to the degree and severity of the FI. Treatment can include dietary and lifestyle modification, certain medications, biofeedback therapy, bulking agent injections, sacral nerve stimulation as well as various types of surgery. In this article, we aim to provide a comprehensive review on the diagnosis and management of FI.

Sacral nerve stimulation--hidden costs (uncovered)

AIM

The aim of this study is to determine the occurrence of surgical revision in a cohort of patients treated with sacral nerve stimulation (SNS) for faecal incontinence and constipation and to establish the types of procedures performed and indications for surgery.

METHOD

From the years 2002 to 2014, 125 patients were identified who had undergone permanent SNS therapy with 36 (28.8 %) patients requiring surgical intervention postimplantation. These cases were retrospectively reviewed (range of follow-up 1-99 months).

RESULTS

Over a total of 1512 months of SNS treatment, 51 unplanned surgical procedures were required in 36 patients. At present, 48 procedures have been performed at an average of 2.6 years following implantation and three patients are awaiting surgery. Lead-related problems accounted for 30 (58.8 %) procedures at an average of 1.7 years affecting 22 patients. Battery and implantable pulse generator-related problems attributed to 13 procedures (25.5 %) in 12 patients at an average of 5.0 years. Battery depletion occurred in seven patients at an average of 5.4 years. Surgical revision was required to replace, remove, or resite various components of the SNS system. Indications for surgery included lead damage, pain and loss or lack of SNS efficacy. Explantation was warranted in six patients due to poor SNS efficacy, pain, infection and facilitation of a magnetic resonance imaging scan. This was performed at an average of 1.6 years.

CONCLUSION

A considerable proportion of patients treated with SNS therapy require surgical revision. These unplanned procedures are associated with substantial unexpected costs that financially burden SNS services.

Sacral neuromodulation for persistent faecal incontinence after laparoscopic ventral rectopexy for high-grade internal rectal prolapse

AIM

Internal rectal prolapse is recognized as an aetiological factor in faecal incontinence. Patients found to have a high-grade internal rectal prolapse on routine proctography are offered a laparoscopic ventral rectopexy after failed maximum medical therapy. Despite adequate anatomical repair, faecal incontinence persists in a number of patients. The aim of this study was to evaluate the outcome of sacral neuromodulation in this group of patients.

METHOD

Between August 2009 and January 2012, 52 patients who underwent a laparoscopic ventral rectopexy for faecal incontinence associated with high-grade internal rectal prolapse had persistent symptoms of faecal incontinence and were offered sacral neuromodulation. Symptoms were evaluated before and after the procedure using the Fecal Incontinence Severity Index (FISI) and the Gastrointestinal Quality of Life Index (GIQLI).

RESULTS

Temporary test stimulation was successful in 47 (94%) of the patients who then underwent implantation of a permanent pulse generator. The median FISI score 1 year after sacral neuromodulation was lower than the median score before [34 (28-59) vs. 19 (0-49); P < 0.01], indicating a significant improvement in faecal continence. Quality of life (GIQLI) was significantly better after starting sacral neuromodulation [78 (31-107) vs. 96 (55-129); P < 0.01].

CONCLUSION

Patients may benefit from sacral neuromodulation for persisting faecal incontinence after laparoscopic ventral rectopexy.

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.

Do endoflip assessments of anal sphincter distensibility provide more information on patients with fecal incontinence than high-resolution anal manometry?

BACKGROUND

Anal manometry is the standard technique for evaluating anal sphincter function. However, the functional lumen imaging probe (EndoFLIP(®) ) can be used to measure sphincter distensibility during volume-controlled distensions. Our aims were (i) to assess anal distensibility in patients with fecal incontinence (FI) and in healthy subjects using the EndoFLIP(®) and (ii) to compare the results with anal pressures measured by 3D high-resolution manometry (3D-HRM) to determine whether the EndoFLIP(®) was more sensitive and specific for diagnosing FI than 3D-HRM.

METHODS

EndoFLIP(®) and 3D-HRM assessments of 34 female FI patients and 40 healthy female subjects were performed. Anal distensibility was measured as the median cross-sectional area at the narrowest point divided by the corresponding intra-bag pressure at rest and during peak voluntary contraction and was expressed in mm(2) /mmHg.

KEY RESULTS

A 40-mL anal distensibility index was selected for further comparisons as it provided the best discrimination between the FI patients and the healthy subjects. The index was significantly higher in the FI patients than in the healthy subjects at rest (p = 1.10(-4) ) and during voluntary contraction (p = 1.10(-4) ). The index at rest and during voluntary contraction appeared to be more appropriate than anal pressures for discriminating between FI patients and healthy subjects.

CONCLUSIONS & INFERENCES

The present study confirmed that FI is associated with an abnormally high distensibility index at rest and during voluntary contraction. The ability of the distensibility index to discriminate between FI patients and healthy subjects was significantly better than anal pressure.

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.

Management of patients with faecal incontinence

Faecal incontinence, defined as the involuntary loss of solid or liquid stool, is a common problem affecting 0.8-8.3% of the adult population. Individuals suffering from faecal incontinence often live a restricted life with reduced quality of life. The present paper is a clinically oriented review of the pathophysiology, evaluation and treatment of faecal incontinence. First-line therapy should be conservative and usually include dietary adjustments, fibre supplement, constipating agents or mini enemas. Biofeedback therapy to improve external anal sphincter function can be offered but the evidence for long-term effect is poor. There is good evidence that colonic irrigation can reduce symptoms and improve quality of life, especially in patients with neurogenic faecal incontinence. Surgical interventions should only be considered if conservative measures fail. Sacral nerve stimulation is a minimally invasive procedure with high rate of success. Advanced surgical procedures should be restricted to highly selected patients and only performed at specialist centres. A stoma should be considered if other treatment modalities fail.

Lack of effect of sacral nerve stimulation for incontinence in patients with systemic sclerosis

AIM

Systemic sclerosis (SSc) is a multisystem disorder of unknown aetiology leading to the deposition of excessive connective tissue in the skin, blood vessels and internal organs. Gastrointestinal involvement occurs in 90% of cases and the prevalence of faecal incontinence (FI) is 38%. This study comprises the largest case series assessing the efficacy of sacral nerve stimulation (SNS) treatment for incontinence in this patient group.

METHOD

A retrospective analysis on prospectively collected data was performed on all SSc patients from our two centres who had undergone SNS for FI.

RESULTS

Ten female patients of mean age of 54 (37-72) years had temporary SNS performed. The mean duration of FI was 13 (2-25) years. All had passive FI. Each patient had preprocedure anorectal physiology and endoanal ultrasound examinations documenting internal sphincter atrophy/fragmentation or reduced anal resting pressure. Overall there was no statistically significant difference (P = 0.57) in the total Wexner incontinence scores before (mean 15.1 ± 2.6 SD) and during temporary SNS procedures (mean 13.1 ± 3.6 SD). Two patients with a significant improvement went on to have permanent SNS with only one achieving a favourable outcome at 1 year.

CONCLUSION

This study showed that SNS failed to reduce episodes of leakage in nine out of 10 patients with systemic sclerosis affected with incontinence.