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

Bridging the Gap in FDA Approval for Pediatric Neuromodulation Devices

While neuromodulation devices for managing neurological conditions have significantly advanced, there remains a substantial gap in FDA-approved devices specifically designed for pediatric patients. Devices like deep brain stimulators (DBS), vagus nerve stimulators (VNS), and spinal cord stimulators (SCS) are primarily approved for adults, with few options for children. To meet pediatric needs, off-label use is common; however, unique challenges to pediatric device development-such as ethical concerns, small trial populations, and financial disincentives due to the limited market size-continue to hinder progress. This review examines these barriers to pediatric neuromodulation device development and FDA (Food and Drug Administration) approval, as well as the current efforts, such as FDA initiatives and consortia support, that address regulatory and financial challenges. Furthermore, we discuss pathways like the Humanitarian Device Exemptions and Real-World Evidence programs that aim to streamline the approval process and address unmet clinical needs in pediatric care. Addressing these barriers could expand access to effective neuromodulation treatments and improve patient care.

Long-term efficacy and safety of sacral neuromodulation for diarrhoea-predominant and mixed irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is a very common condition worldwide. Treatment options for severe IBS are few. Sacral neuromodulation (SNM) for patients with IBS has been shown to reduce symptoms and improve quality of life in the medium term. This study aimed to evaluate the long-term effectiveness and safety of SNM in diarrhoea-predominant and mixed IBS.

METHODS

A prospective cohort of patients with IBS treated with SNM were evaluated 1, 3, 5, and 10 years after implantation. The primary end-point was a change in the Gastrointestinal Symptom Rating Scale-Irritable Bowel Syndrome version questionnaire (GSRS-IBS) from baseline to 10-year follow-up (FU). Secondary end-points were change in the GSRS-IBS score from baseline to 5-year FU and change in the Irritable Bowel Syndrome-Impact Scale questionnaire (IBS-IS) from baseline to 5- and 10-year FU. Adverse events following SNM were observed.

RESULTS

Of 36 patients treated with SNM, 23 were eligible for 5-year FU and 13 for 10-year FU. The GSRS-IBS score was significantly reduced at both 5-year (p < 0.0001) and 10-year (p = 0.0007) FU. The IBS-IS score was also significantly improved at both 5 years (p < 0.0001) and 10 years (p = 0.0002). Fifty-six adverse events were registered. Five patients were explanted because of adverse events.

CONCLUSION

SNM seems to offer an effective and safe treatment option for highly selected patients with diarrhoea-predominant and mixed IBS.

CLINICAL TRIAL REGISTRATION

The present study has not been registered. The latest founding study was registered at ClinicalTrials.gov, NCT01948973.

Efficacy and Safety of Noninvasive Electrical Neuromodulation for Treatment of Functional Constipation: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Functional constipation (FC) is a prevalent disorder with large disease burden and high associated cost. Noninvasive electrical neuromodulation (NEN) has been studied for treatment of FC, but its overall efficacy and safety remain unclear. This meta-analysis evaluates the efficacy and safety of NEN for treatment of FC.

MATERIALS AND METHODS

A search of PubMed, Cochrane Library, Embase, and Web of Science data bases was completed for randomized controlled studies assessing the efficacy and safety of NEN in patients with FC through June 2024. We performed a meta-analysis using risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes, with 95% CIs.

RESULTS

The analysis included eight randomized controlled trials with 1465 participants. Compared with sham interventions, NEN significantly increased the proportion of patients having ≥three spontaneous bowel movements per week (RR [95% CI] = 2.47 [1.79, 3.40], p < 0.00001), decreased the number of patients using laxative for FC (RR [95% CI] = 0.81 [0.69, 0.95], p = 0.01), decreased the overall constipation severity (MD [95% CI] = -0.58 [-0.81, -0.35], p < 0.00001), and improved the constipation-specific quality of life (MD [95% CI] = -0.24 [-0.32, -0.16], p < 0.00001). There was no significant difference in the frequency of adverse events between NEN and sham interventions (RR [95% CI] = 1.30 [0.77, 2.19], p = 0.32), and participant drop-out rate with NEN was lower (RR [95% CI] = 0.38 [0.17, 0.84], p = 0.02). Mechanistically, NEN was found to modulate the autonomic function (p < 0.00001) and improve the rectal sensation (p = 0.03).

CONCLUSIONS

NEN relieves constipation symptoms, improves quality of life, and reduces use of pharmacologic remedies in adults with FC. These effects seem to be modulated through improved autonomic function and rectal sensation. NEN is safe, well-tolerated, and has a high level of patient compliance.

Management of Fecal Incontinence: Surgical Treatment Options

Background

Fecal incontinence (FI) is a frequent, often underestimated, health issue in adults. Its treatment is primarily nonsurgical. Only if conservative options fail to result in adequate symptom reduction should surgery be considered. We present an overview of historical and current surgical treatment options.

Summary

Well-known sphincter replacement techniques such as dynamic graciloplasty and the artificial bowel sphincter are no longer used because of their invasiveness and relevant comorbidity. Today, sphincteroplasty and sacral neuromodulation (SNM) are the most common procedures recommended in current guidelines. The therapeutic choice is based on diagnostic findings. Sphincteroplasty is an option only in patients with an anal sphincter lesion and has only moderate long-term success. SNM has become the established first choice in multiple pathophysiological conditions resulting in FI, as it has proved highly successful with minimal invasiveness. Over time, the spectrum of indications has evolved and the technique is now successful in morphological sphincter defects as well.

Key Messages

The spectrum of surgical options to treat FI is limited. Owing to its efficacy and low comorbidity, SNM is now considered the gold standard in multiple pathophysiological and morphological conditions, whereas sphincteroplasty remains an option in patients with FI from a defined sphincter lesion.

Efficacy of Traditional Acupuncture Compared to Biofeedback Therapy in Fecal Incontinence: A Randomized Controlled Trial

BACKGROUND

Fecal incontinence has a devastating impact on quality of life and imposes a substantial socioeconomic burden. Best medical therapy, including biofeedback therapy, improves mild symptoms with minimal impact on moderate to severe symptoms. Surgical management for incontinence carries a degree of morbidity, resulting in low uptake and acceptability. Although acupuncture is common practice in Singapore for numerous medical conditions, its role in fecal incontinence is relatively novel. In our local context, however, acupuncture is accessible, inexpensive, and potentially well accepted as a treatment strategy.

OBJECTIVE

To determine the effectiveness of traditional Chinese medicine acupuncture, compared to biofeedback therapy, in the treatment of fecal incontinence. The secondary aim is to investigate the differences in quality of life after treatment.

DESIGN

Randomized controlled trial.

SETTING

Prospective, single-institution study.

PATIENTS

Patients with 2 or more episodes of fecal incontinence per week or St. Mark's incontinence score of 5 or higher were recruited. Patients were randomly assigned into biofeedback therapy, which included 3 sessions over 10 weeks, or 30 sessions of acupuncture over 10 weeks.

MAIN OUTCOME MEASURES

Incontinence episodes, St. Mark's score, and fecal incontinence quality-of-life scale.

RESULTS

Eighty-five patients were randomly assigned to biofeedback therapy (n = 46) or acupuncture (n = 39). Demographics and baseline clinical characteristics were not different ( p > 0.05). Overall median incontinence episodes were reduced in both, with the acupuncture arm reporting significantly fewer episodes at week 15 ( p < 0.001). Acupuncture also improved quality of life, with improvement in lifestyle, coping, depression, and embarrassment at week 15 ( p < 0.05). Although the St. Mark's score was significantly reduced in both arms at week 15 ( p < 0.001), the acupuncture arm's score was significantly lower ( p = 0.002).

LIMITATIONS

Longer follow-up is required.

CONCLUSIONS

Acupuncture is clinically effective and improves the quality of life in patients with fecal incontinence. See Video Abstract .

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov : NCT04276350.

EFICACIA DE LA ACUPUNTURA TRADICIONAL COMPARADA CON LA TERAPIA DE BIORRETROALIMENTACIN EN LA INCONTINENCIA FECAL UN ENSAYO CONTROLADO ALEATORIO

ANTECEDENTES:La incontinencia fecal tiene un impacto devastador en la calidad de vida e impone una carga socioeconómica sustancial. La mejor terapia médica, incluida la terapia de biorretroalimentación, mejora los síntomas leves, con un impacto mínimo sobre los síntomas moderados a graves. El tratamiento quirúrgico de la incontinencia conlleva un grado de morbilidad que resulta en una baja aceptación y aceptabilidad. Si bien la acupuntura es una práctica común en Singapur para numerosas afecciones médicas, su papel en la incontinencia fecal es relativamente novedoso. Sin embargo, en nuestro contexto local, la acupuntura es accesible, económica y potencialmente bien aceptada como estrategia de tratamiento.OBJETIVO:Determinar la efectividad de la acupuntura de la Medicina Tradicional China, en comparación con la terapia de biorretroalimentación en el tratamiento de la incontinencia fecal. El objetivo secundario es investigar las diferencias en la calidad de vida después del tratamiento.DISEÑO:Ensayo controlado aleatorio.AJUSTE:Estudio prospectivo de una sola institución.PACIENTES:Se reclutaron pacientes con >2 episodios de incontinencia fecal/semana o una puntuación de incontinencia de St. Mark's >5. Los pacientes fueron asignados aleatoriamente a una terapia de biorretroalimentación que incluyó 3 sesiones durante 10 semanas o 30 sesiones de acupuntura durante 10 semanas.PRINCIPALES MEDIDAS DE RESULTADO:Episodios de incontinencia, puntuación de St. Mark's y escala de calidad de vida de incontinencia fecal.RESULTADOS:Ochenta y cinco pacientes fueron asignados aleatoriamente a terapia de biorretroalimentación (n = 46) o acupuntura (n = 39). Las características demográficas y clínicas iniciales no fueron diferentes ( p > 0,05). La mediana general de episodios de incontinencia se redujo en ambos, y el grupo de acupuntura informó significativamente menos en la semana 15 ( p <0,001). La acupuntura también mejoró la calidad de vida, con mejoras en el estilo de vida, el afrontamiento, la depresión y la vergüenza en la semana 15 ( p <0,05). Mientras que la puntuación de St Mark se redujo significativamente en ambos brazos en la semana 15 ( p < 0,001), la puntuación del brazo de acupuntura fue significativamente menor (p = 0,002).LIMITACIONES:Se requiere un seguimiento más prolongado.CONCLUSIONES:La acupuntura es clínicamente efectiva y mejora la calidad de vida en pacientes con incontinencia fecal. (Traducción-Dr Yolanda Colorado ).

Sacral nerve stimulation leads to long-term improvement in fecal incontinence and quality of life for children with functional and organic defecation disorders

BACKGROUND

Our objective was to evaluate long-term outcomes of sacral nerve stimulation (SNS) for children with functional and organic defecation disorders.

METHODS

We performed a prospective study of children <21 years of age who started SNS treatment between 2012 and 2018. We recorded demographics, medical history, and diagnostic testing. We obtained measures of symptom severity and quality of life at baseline and follow up at 1, 6, 12, 24, 36, 48, and ≥60 months. Successful response was defined as bowel movements >2 times/week and fecal incontinence (FI) <1 time/week. Families were contacted to administer the Glasgow Children's Benefit Inventory and to evaluate patient satisfaction.

KEY RESULTS

We included 65 patients (59% female, median age at SNS 14 years, range 9-21) with median follow-up of 32 months. Thirty patients had functional constipation (FC), 15 had non-retentive FI (NRFI), and 16 had an anorectal malformation (ARM). The percentage with FI <1 time/week improved from 30% at baseline to 64% at 1 year (p < 0.001) and 77% at most recent follow-up (p < 0.001). Patients with FC, NRFI, and ARM had sustained improvement in FI (p = 0.02, p < 0.001, p = 0.02). Patients also reported fewer hard stools (p = 0.001). Bowel movement frequency did not improve after SNS. At most recent follow-up, 77% of patients with a functional disorder and 50% with an organic disorder had responded (p = 0.03). Nearly all families reported benefit.

CONCLUSIONS AND INFERENCES

SNS led to sustained improvement in FI regardless of underlying etiology, but children with functional disorders were more likely to respond than those with organic disorders.

Patient Satisfaction With Long-term Sacral Neuromodulation for Fecal Incontinence: Experience From a Single Tertiary Center

BACKGROUND

Sacral neuromodulation is an effective treatment for fecal incontinence in the long term. Efficacy is typically assessed using bowel diary, symptom severity, and quality-of-life questionnaires, and "success" is defined as more than 50% improvement in these measures. However, patient satisfaction may be a more meaningful and individualized measure of treatment efficacy.

OBJECTIVE

To assess patient-reported satisfaction with long-term sacral neuromodulation and compare it to the frequently applied efficacy measures.

DESIGN

An observational study of a prospectively maintained database.

SETTING

A single tertiary pelvic floor referral unit.

PATIENTS

Data from 70 patients (68 women, median age 69 [60-74] years) were available. The median time since implantation was 11 (9-14) years. Nineteen patients reported inactive neuromodulation devices.

MAIN OUTCOME MEASURES

Bowel diaries, the Manchester Health Questionnaire, and the St. Mark's Incontinence Score were recorded at baseline, after percutaneous nerve evaluation, and at the last follow-up. Patient-reported satisfaction, using a 0% to 100% visual analog scale, with treatment since implantation (overall) and in the 2 weeks preceding completion of the last outcome measures (current) were also assessed.

RESULTS

Satisfaction was significantly higher in those with active sacral neuromodulation devices (75% vs 20%, p < 0.001) at follow-up. No significant relationships exist between symptom improvement using conventional measures and patient-reported satisfaction. Current satisfaction was not associated with changes in bowel diary data after percutaneous nerve evaluation. Despite improvements in the St. Mark's Incontinence Score and Manchester Health Questionnaire below the 50% improvement threshold used to define "success," patients reported high (80%) satisfaction.

LIMITATIONS

Retrospective design with gaps in the available data.

CONCLUSIONS

High patient satisfaction with sacral neuromodulation can be achieved; however, the response to percutaneous nerve evaluation may not predict treatment satisfaction in the long term. The change in questionnaire results, which measure the use of compensatory behaviors and quality-of-life impact, may better correspond to treatment satisfaction.

SATISFACCIN A LARGO PLAZO EN LOS PACIENTES CON LA NEUROMODULACIN SACRA PARA LA INCONTINENCIA FECAL EXPERIENCIA DE UN NICO CENTRO TERCIARIO

ANTECEDENTES:La neuromodulación sacra es un tratamiento eficaz para la incontinencia fecal a largo plazo. La eficacia suele evaluarse mediante cuestionarios sobre la frecuencia diaria intestinal, la gravedad de los síntomas o la calidad de vida, y el "éxito" se define como una mejoría >50% en estas medidas. Sin embargo, la satisfacción del paciente puede ser una medida más significativa e individualizada de la eficacia del tratamiento.OBJETIVO:Evaluar la satisfacción a largo plazo de los pacientes con la neuromodulación sacra y compararla con las medidas de eficacia aplicadas con frecuencia.DISEÑO:Estudio observacional de una base de datos mantenida prospectivamente.LUGAR:Unidad terciaria única de referencia de suelo pélvico.PACIENTES:Se dispuso de datos de 70 pacientes (68 mujeres, mediana de edad 69 [60-74]). La mediana de tiempo transcurrido desde la implantación fue de 11 (9-14) años. Diecinueve pacientes informaron de dispositivos de neuromodulación inactivos.PRINCIPALES MEDIDAS DE VALORACIÓN:Diarios intestinales, el Cuestionario de Salud de Manchester y la Puntuación de Incontinencia de St Marks registrados al inicio, tras la evaluación percutánea del nervio y en el último seguimiento. Los pacientes informaron de su satisfacción, utilizando una escala analógica visual de 0%-100%, con el tratamiento desde la implantación (global) y en las dos semanas anteriores a la realización de las últimas medidas de resultado (actual).RESULTADOS:La satisfacción fue significativamente mayor en los pacientes con dispositivos de neuromodulación sacra activos (75% frente a 20%, p < 0,001) durante el seguimiento. No existen relaciones significativas entre la mejoría de los síntomas mediante medidas convencionales y la satisfacción comunicada por el paciente. La satisfacción actual no se asoció con los cambios en los datos de la frecuencia diaria intestinal tras la evaluación percutánea de los nervios. A pesar de que las mejoras en la puntuación de incontinencia de St Mark y el Cuestionario de Salud de Manchester se situaron por debajo del umbral de mejora del 50% utilizado para definir el "éxito", los pacientes declararon un alto grado de satisfacción (80%).LIMITACIONES:Retrospectivo con lagunas en los datos disponibles.CONCLUSIONES:Puede lograrse una alta satisfacción de los pacientes con la neuromodulación sacra; sin embargo, la respuesta a la evaluación percutánea del nervio puede no predecir la satisfacción con el tratamiento a largo plazo. El cambio en los resultados del cuestionario, que mide el uso de conductas compensatorias y el impacto en la calidad de vida, puede corresponder mejor a la satisfacción con el tratamiento. (Traducción-Dr. Ingrid Melo ).

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.

Recent advances in treating constipation in children

INTRODUCTION

Functional constipation (FC) is a common childhood condition, diagnosed via the Rome IV criteria. Standard therapy includes lifestyle and dietary modification followed by initiation of osmotic laxative therapy. About 30% of children continue to experience symptoms related to FC despite appropriate management. New pharmacologic, surgical, and neuromodulatory therapies for FC are now available for use in adult and pediatric populations. In 2023, the first pharmacologic agent, linaclotide, obtained FDA approval for treatment of FC in children 6-17 years old.

AREAS COVERED

This article reviews current and emerging pharmacologic, surgical, and neuromodulation therapies for the management of FC in pediatric patients. Efficacy and safety data regarding each of these modalities was reviewed and discussed.

EXPERT OPINION

Advancements in therapeutics available for the management of FC necessitate further investigation on safety and efficacy in pediatric populations. Careful consideration should be taken in choosing an available treatment with limited pediatric evidence as adult and pediatric FC have different underlying pathophysiology and require a different therapeutic approach. Standardization of methodology and pediatric endpoints are needed to optimize ability to compare efficacy of different treatments. We predict the future of pediatric FC management will include a personalized approach to care, resulting in improved outcomes.

Treatment of anterior resection syndrome: A systematic review and network meta-analysis

INTRODUCTION

There has been a lack of research comparing the efficacy of various treatments for low anterior resection syndrome (LARS).

METHODS

We conducted a comprehensive search across six electronic databases and a paired meta-analysis was undertaken to assess the effectiveness of the interventions. Furthermore, a network meta-analysis was utilized to compare the efficacy of different treatments for LARS.

RESULTS

This study encompassed nine randomized controlled trials, involving a total of 450 patients. Compared to routine care, 5-HT3 receptor antagonists (follow-up<3 months) and percutaneous tibial nerve stimulation (3 months ≤ follow-up <6 months) were effective in reducing the LARS score. Pelvic floor rehabilitation (follow-up≤3 months) was effective in decreasing daily number of bowel movements when compared to routine care. The network meta-analysis indicated that 5-HT3 receptor antagonists (follow-up<3 months) were the most effective in reducing both the LARS score and the daily number of bowel movements. Transanal irrigation (3 months ≤ follow-up ≤ 12 months) was most effective in reducing the LARS score. Additionally, 5-HT3 receptor antagonists demonstrated relative efficacy in improving patients' quality of life (follow-up ≤ 1 month).

CONCLUSIONS

This review indicates that 5-HT3 receptor antagonists and anal irrigation show significant promise in the treatment of LARS. Nevertheless, the contributions of percutaneous tibial nerve stimulation and pelvic floor rehabilitation to LARS treatment should not be overlooked. Given the clinical heterogeneity observed among the studies, the results should be interpreted with caution.

Functional Constipation and Obstructed Defecation

Constipation encompasses symptoms of decreased colonic motility or difficulty with the defecation process. As a broad definition, this can be inclusive of functional constipation (FC) or colonic inertia, obstructed defecation (OD), and irritable bowel syndrome-constipation type (IBS-CS). After excluding IBS-C, FC and OD diagnosis and management require a multidisciplinary approach often involving nutritionists, pelvic floor therapists, urogynecologists, and colon and rectal surgeons. Differentiating the presence or absence of each can direct therapy and prognosticate chances for improvement in this often complex combination of disorders.

Short-term clinical and manometric outcomes of percutaneous tibial nerve stimulation for faecal incontinence: a large single-centre series

BACKGROUND

Faecal incontinence (FI) is common, with a significant impact on quality of life. Percutaneous tibial nerve stimulation (PTNS) is a therapy for FI; however, its role has recently been questioned. Here we report the short-term clinical and manometric outcomes in a large tertiary centre.

METHODS

A retrospective review of a prospective PTNS database was performed, extracting patient-reported FI outcome measures including bowel diary, the St Marks's Incontinence Score (SMIS) and Manchester Health Questionnaire (MHQ). Successful treatment was > 50% improvement in symptoms, whilst a partial response was 25-50% improvement. High-resolution anorectal manometry (HRAM) results before and after PTNS were recorded.

RESULTS

Data were available from 135 patients [119 (88%) females; median age: 60 years (range: 27-82years)]. Overall, patients reported a reduction in urge FI (2.5-1) and passive FI episodes (2-1.5; p < 0.05) alongside a reduction in SMIS (16.5-14) and MHQ (517.5-460.0; p < 0.001). Some 76 (56%) patients reported success, whilst a further 20 (15%) reported a partial response. There were statistically significant reductions in rectal balloon thresholds and an increase in incremental squeeze pressure; however, these changes were independent of treatment success.

CONCLUSION

Patients report PTNS improves FI symptoms in the short term. Despite this improvement, changes in HRAM parameters were independent of this success. HRAM may be unable to measure the clinical effect of PTNS, or there remains the possibility of a placebo effect. Further work is required to define the role of PTNS in the treatment of FI.

Sacral neuromodulation for constipation and fecal incontinence in children and adolescents - study protocol of a prospective, randomized trial on the application of invasive vs. non-invasive technique

BACKGROUND

A therapeutic effect of sacral neuromodulation (SNM) on fecal incontinence (FI) and quality of life has been proven in adults. SNM is, however, rarely used in pediatric cases. The aim of the study is to investigate effects of SNM in pediatric constipation in a prospective parallel-group trial.

METHODS

A monocentric, randomized, unblinded, parallel-group trial is conducted. SNM is conducted in the invasive variant and in an innovative, external approach with adhesive electrodes (enteral neuromodulation, ENM). We include patients with constipation according to the ROME IV criteria and refractory to conventional options. Patients with functional constipation and Hirschsprung's disease are able to participate. Participants are allocated in a 1:1 ratio to either SNM or ENM group. Clinical data and quality of life is evaluated in regular check-ups. Neuromodulation is applied continuously for 3 months (end point of the study) with follow-up-points at 6 and 12 months. Findings are analyzed statistically considering a 5% significance level (p ≤ 0.05). Outcome variables are defined as change in (1) episodes of abdominal pain, (2) episodes of FI, (3) defecation frequency, (4) stool consistency. Improvement of proprioception, influence on urinary incontinence, quality of life and safety of treatment are assessed as secondary outcome variables. We expect a relevant improvement in both study groups.

DISCUSSION

This is the first trial, evaluating effects of neuromodulation for constipation in children and adolescents and comparing effects of the invasive and non-invasive application (SNM vs. ENM).

TRIAL REGISTRATION

The study is registered with clinicaltrials.gov, Identifier NCT04713085 (date of registration 01/14/2021).

Percutaneous tibial nerve stimulation versus sacral nerve stimulation for the treatment of faecal incontinence

Introduction

Faecal incontinence (FI) is a common condition with a significant impact on quality of life (QoL). Neuromodulation treatments delivered by members of the multidisciplinary team including sacral nerve stimulation (SNS) and percutaneous tibial nerve stimulation (PTNS) are options for FI refractory to conservative management. The aim of this study was to assess whether a successful treatment with one neuromodulation modality corresponds with success in the other.

Methods

A retrospective review of a prospectively managed neuromodulation database identified 15 patients who had undergone both PTNS and SNS. The definition of success of each treatment was a >50% improvement in any of The St. Mark's Incontinence Score, Manchester Health Questionnaire, or weekly faecal urgency or FI episodes.

Results

Complete data from 12 patients was available for assessment and PTNS was delivered as the first treatment in nine patients. Overall, seven patients (58%) had successful PTNS treatment, with 10 (83%) having a successful SNS trials. Of the seven patients who had successful PTNS treatment, six patients (85.4%) went on to have success with SNS. Of the five patients who failed PTNS, four (80%) went on to have SNS success. Five (71%) of those who had positive PTNS outcomes had permanent SNS implantation as their final treatment decision.

Conclusion

This study suggests that there is no clear relationship between successful PTNS treatment and an SNS trial period which may be explained by differing mechanisms of action or the potential placebo effect of PTNS. Further work is required to investigate any association in larger studies to inform clinical practice.

Tissue-Matchable and Implantable Batteries Toward Biomedical Applications

Implantable electronic devices can realize real-time and reliable health monitoring, diagnosis, and treatment of human body, which are expected to overcome important bottlenecks in the biomedical field. However, the commonly used energy supply devices for them are implantable batteries based on conventional rigid device design with toxic components, which both mechanically and biologically mismatch soft biological tissues. Therefore, the development of highly soft, safe, and implantable tissue-matchable flexible batteries is of great significance and urgency for implantable bioelectronics. In this work, the recent advances of tissue-matchable and implantable flexible batteries are overviewed, focusing on the design strategies of electrodes/batteries and their biomedical applications. The mechanical flexibility, biocompatibility, and electrochemical performance in vitro and in vivo of these flexible electrodes/batteries are then discussed. Finally, perspectives are provided on the current challenges and possible directions of this field in the future.

Does Rectoanal Intussusception Limit Improvements in Clinical Outcome and Quality of Life After Sacral Nerve Stimulation for Fecal Incontinence?

BACKGROUND

Sacral nerve stimulation is a treatment option for severe, medically refractory fecal incontinence, although its use in patients with anatomic abnormalities remains controversial.

OBJECTIVE

This study aimed to determine whether patients with rectoanal intussusception achieve similar benefits from device implantation to patients without rectoanal intussusception.

DESIGN

Retrospective review of a prospectively maintained database. Demographics and clinical data were collected for each patient, including preoperative pelvic floor testing. Defecographies were reanalyzed in a blinded manner. Preoperative rectoanal intussusception was determined on the basis of the Oxford system (grade III-IV vs not; grade V excluded).

SETTINGS

Academic-affiliated pelvic health center.

PATIENTS

All patients undergoing sacral nerve stimulation for fecal incontinence between July 2011 and July 2019.

MAIN OUTCOME MEASURES

Cleveland Clinic Florida Incontinence/Wexner Scores, Fecal Incontinence Severity Indices, and Fecal Incontinence Quality of Life Indices at 1 year.

RESULTS

One hundred sixty-nine patients underwent sacral nerve stimulation for fecal incontinence during the study period. The average age was 60.3 years and 91% were female. Forty-six patients (27.2%) had concomitant rectoanal intussusception (38 patients [22.5%] grade III and 8 patients [4.7%] grade IV). Before surgery, patients reported an average of 10.8 accidents per week and a Wexner score of 15.7, with no difference between patients with and without rectoanal intussusception ( p = 0.22 and 0.95). At 1 year after surgery, the average Wexner score was 9.5. There was no difference in postoperative Wexner scores (10.4 vs 9.2, p = 0.23) or improvement over time between patients with and without rectoanal intussusception (-6.7 vs -5.7, p = 0.40). Similarly, there was no difference in quality of life or frequency of incontinence to liquid or solid stool.

LIMITATIONS

Single-institution, moderate sample size, incomplete survey response.

CONCLUSIONS

Concomitant rectoanal intussusception does not appear to affect clinical outcomes or quality of life after sacral nerve stimulation for fecal incontinence. Appropriate patients with fecal incontinence and rectoanal intussusception can be considered for sacral nerve stimulation placement. See Video Abstract at http://links.lww.com/DCR/C192 .

LA INTUSUSCEPCIN RECTOANAL LIMITA LAS MEJORAS EN EL RESULTADO CLNICO Y LA CALIDAD DE VIDA DESPUS DE LA NEUROESTIMULACION SACRA PARA LA INCONTINENCIA FECAL

ANTECEDENTES:La neuroestimulación sacra es una opción de tratamiento para la incontinencia fecal grave refractaria al tratamiento médico, aunque su uso en pacientes con anomalías anatómicas sigue siendo controvertido.OBJETIVO:Determinar si los pacientes con intususcepción rectoanal logran beneficios similares de la implantación del dispositivo a los pacientes sin intususcepción rectoanal.DISEÑO:Revisión retrospectiva de una base de datos mantenida prospectivamente. Se recopilaron datos demográficos y clínicos de cada paciente, incluidas las pruebas preoperatorias del piso pélvico. Las defecografías se volvieron a analizar de forma ciega. La intususcepción rectoanal preoperatoria se determinó según el sistema de Oxford (grado III-IV vs. no; grado V excluido).ESCENARIO:Centro académico de salud pélvica.PACIENTES:Todos los pacientes sometidos a neuroestimulación sacra por incontinencia fecal entre julio de 2011 y julio de 2019.PRINCIPALES MEDIDAS DE RESULTADO:Cleveland Clinic Florida Incontinence/Wexner Scores, Índices de gravedad de la incontinencia fecal, Índices de calidad de vida de la incontinencia fecal al año.RESULTADOS:169 pacientes se sometieron a neuroestimulación sacra por incontinencia fecal durante el período de estudio. La edad promedio fue de 60.3 años y el 91% eran mujeres. Cuarenta y seis pacientes (27.2%) tenían intususcepción rectoanal concomitante (38 [22.5%] grado III y 8 [4.7%] grado IV). Antes de la cirugía, los pacientes informaron un promedio de 10.8 accidentes por semana y una puntuación de Wexner de 15.7 sin diferencia entre pacientes con y sin intususcepción rectoanal (p = 0.22 y 0.95). Un año después de la cirugía, la puntuación promedio de Wexner fue de 9.5. No hubo diferencia en las puntuaciones de Wexner posoperatorias (10.4 frente a 9.2, p = 0.23) o mejoría con el tiempo entre los pacientes con y sin intususcepción rectoanal (-6.7 frente a -5.7, p = 0.40). De manera similar, no hubo diferencia en la calidad de vida o la frecuencia de incontinencia de heces líquidas o sólidas.LIMITACIONES:Institución única, tamaño de muestra moderado, respuesta de encuesta incompleta.CONCLUSIÓN:La intususcepción rectoanal concomitante no parece afectar los resultados clínicos o la calidad de vida después de la neuroestimulación sacra para la incontinencia fecal. Los pacientes apropiados con incontinencia fecal e intususcepción rectoanal pueden ser considerados para la neuroestimulación sacra. Consulte Video Resumen en http://links.lww.com/DCR/C192(Traducción-Dr. Jorge Silva Velazco ).

[Sacral Neuromodulation for Fecal Incontinence and Constipation: Evidence, Programming and Long-term Management]

BACKGROUND

Over the last two decades, sacral neuromodulation (SNM) has established its role in the treatment of functional pelvic organ-/pelvic floor disorders. Even though the mode of action is not fully understood, SNM has become the preferred surgical treatment of fecal incontinence.

METHODS AND RESULTS

A literature search was carried out on programming sacral neuromodulation and long-term outcomes in treating fecal incontinence and constipation.Sacral neuromodulation was found to be successful in the long term. Over the years, the spectrum of indications has expanded, and now includes patients presenting with anal sphincter lesions. The use of SNM for low anterior resection syndrome (LARS) is currently under clinical investigation. Findings of SNM for constipation are less convincing. In several randomised crossover studies, no success was demonstrated, even though it is possible that subgroups may benefit from the treatment. Currently the application cannot be recommended in general.The pulse generator programming sets the electrode configuration, amplitude, pulse frequency and pulse width. Usually pulse frequency and pulse width follow a default setting (14 Hz, 210 s), while electrode configuration and stimulation amplitude are adjusted individually to the patient need and perception of stimulation.Despite low infection rates and few electrode-/pulse generator dysfunctions, up to 65% of patients require surgical reintervention during long term follow-up - in 50% of cases because of battery depletion, which is an expected event. At least one reprogramming is necessary in about 75% of the patients during the course of the treatment, mostly because of changes in effectiveness, but rarely because of pain. Regular follow-up visits appear to be advisable.

CONCLUSION

Sacral neuromodulation can be considered to be a safe and effective long-term therapy of fecal incontinence. To optimise the therapeutic effect, a structured follow-up regime is advisable.

High-Frequency Repetitive Magnetic Stimulation at the Sacrum Alleviates Chronic Constipation in Parkinson's Patients

Objective

This study was to investigate the therapeutic effect of high-frequency repetitive magnetic stimulation (HF-rMS) at the sacrum for chronic constipation in Parkinson's patients (PD).

Materials and Methods

Eventually 48 PD patients were enrolled from July 2019 to October 2020, and randomly divided into the HF-rMS group (the intervention group, n = 24) and the sham HF-rMS group (the control group, n = 24). The intervention group received HF-rMS at the sacrum, whereas the control group received ineffective magnetic stimulation. We performed clinical evaluation before and after HF-rMS treatment, including constipation score scale (KESS questionnaire), Unified Parkinson's Disease Rating Scale (UPDRS-III exercise examination), Hoehn-Yahr (H-Y) stage of motor function; simple mental status scale (MMSE), anxiety/depression table (HAD-A/HAD-D), the activity of daily living (ADL), and quality of life scale for patients with constipation (PAC-QOL) to evaluate symptoms and satisfaction of PD patients with chronic constipation.

Results

There was no significant difference in the clinical characteristics between the two groups. As compared to the control group, the HF-rMS group displayed a larger change (pre and posttreatment) in the KESS scores of PD patients with chronic constipation, suggesting a significant improvement. Moreover, HF-rMS significantly promoted the mood, activity of daily living, and quality of life of PD patients when comparing the alteration of HAD-A/HAD-D scores, ADL scores, and PAC-QOL scores between the two groups. Finally, there was no significant difference in the change of the UPDRS III score and the MMSE score between the two groups.

Conclusion

HF-rMS at the sacrum can improve chronic constipation in PD 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.

Development of prediction model of low anterior resection syndrome for colorectal cancer patients after surgery based on machine-learning technique

BACKGROUND

Low anterior resection syndrome (LARS) is a common postoperative complication in patients with colorectal cancer, which seriously affects their postoperative quality of life. At present, the aetiology of LARS is still unclear, but some risk factors have been studied. Accurate prediction and early management of medical intervention are keys to improving the quality of life of such high-risk patients.

OBJECTIVES

Based on machine-learning methods, this study used the follow-up results of postoperative patients with colorectal cancer to develop prediction models for LARS and conducted a comparative analysis between the different models.

METHODS

A total of 382 patients diagnosed with colorectal cancer and undergoing surgery at West China Hospital from April 2017 to December 2020 were retrospectively selected as the development cohort. Logistic regression, support vector machine, decision tree, random forest and artificial neural network algorithms were used to construct the prediction models of the obtained dataset. The models were internally validated using cross-validation. The area under the curve and Brier score measures were used to evaluate and compare the differentiation and calibration degrees of the models. The sensitivity, specificity, positive predictive value and negative predictive value of the different models were described for clinical use.

RESULTS

A total of 342 patients were included, the incidence of LARS being 47.4% (162/342) during the six-month follow-up. After feature selection, the factors influencing the occurrence of LARS were found to be location, distance, diverting stoma, exsufflation and surgical type. The prediction models based on five machine-learning methods all showed acceptable performance.

CONCLUSIONS

The five models developed based on the machine-learning methods showed good prediction performance. However, considering the simplicity of clinical use of the model results, the logistic regression model is most recommended. The clinical applicability of these models will also need to be evaluated with external cohort data.

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.

Psychological stress in inflammatory bowel disease: Psychoneuroimmunological insights into bidirectional gut–brain communications

Inflammatory bowel disease (IBD), mainly including ulcerative colitis (UC) and Crohn’s disease (CD), is an autoimmune gastrointestinal disease characterized by chronic inflammation and frequent recurrence. Accumulating evidence has confirmed that chronic psychological stress is considered to trigger IBD deterioration and relapse. Moreover, studies have demonstrated that patients with IBD have a higher risk of developing symptoms of anxiety and depression than healthy individuals. However, the underlying mechanism of the link between psychological stress and IBD remains poorly understood. This review used a psychoneuroimmunology perspective to assess possible neuro-visceral integration, immune modulation, and crucial intestinal microbiome changes in IBD. Furthermore, the bidirectionality of the brain–gut axis was emphasized in the context, indicating that IBD pathophysiology increases the inflammatory response in the central nervous system and further contributes to anxiety- and depression-like behavioral comorbidities. This information will help accurately characterize the link between psychological stress and IBD disease activity. Additionally, the clinical application of functional brain imaging, microbiota-targeted treatment, psychotherapy and antidepressants should be considered during the treatment and diagnosis of IBD with behavioral comorbidities. This review elucidates the significance of more high-quality research combined with large clinical sample sizes and multiple diagnostic methods and psychotherapy, which may help to achieve personalized therapeutic strategies for IBD patients based on stress relief.

Pediatric gastrointestinal neuromodulation: A review

Neuromodulation, also known as bioelectric neuromodulation or neurostimulation, is the therapeutic use of electrical stimulation of nerves or brain centers. Neuromodulation has been trialed in an increasing range of human diseases as well as gastrointestinal disorders. The application of neuromodulation to treat pediatric motility and functional disorders is an exciting recent development. This review aims to briefly discuss the use of neuromodulation for the treatment of pediatric gastroparesis, constipation, and visceral hyperalgesia.

The Relationship Between Cortical Activation in Response to Anorectal Stimuli and Continence Behavior in Freely Behaving Rats Before and After Application of Sacral Nerve Stimulation

BACKGROUND

Changes in anorectal sensation have been reported in patients with fecal incontinence, and there is limited evidence that sacral nerve stimulation can restore normal sensation.

OBJECTIVE

The aims of the present study were to investigate changes in the transmission of sensory anorectal stimuli in a rodent model of fecal incontinence and to study the effects of sacral nerve stimulation on defecation behavior.

DESIGN

An established model of fecal incontinence was utilized for this study.

INTERVENTION

Pudendal nerve stretch and compression were used in 16 adult female Wistar rats and were monitored for 3 weeks: 6 rats received sacral nerve stimulation for 1 week by using an implantable neurostimulator and 10 rats had nonfunctioning "dummy" devices inserted. Five additional rats were sham operated. Anorectal cortical evoked potentials were used as a surrogate marker for anorectal sensory function.

MAIN OUTCOME MEASURES

The primary outcomes measured were fecal incontinence index, evoked potential amplitude, and latency.

RESULTS

Fifty percent of rats showed behavioral signs of fecal incontinence measured by the Fecal Incontinence Index (>0.20), calculated by using the pellet distribution outside the cage's latrine area. Anorectal evoked potential amplitude was reduced in rats with a Fecal Incontinence Index >0.20 (p = 0.019). The amplitude of forepaw evoked potentials recorded as a control was not different between groups. Chronic sacral nerve stimulation using the fully implantable device and custom rodent lead was safe and stable during this chronic prospective study. Incontinent rats (n = 3) that received sacral nerve stimulation showed an improvement of Fecal Incontinence Index and an increase of evoked potential amplitude to anorectal stimulation compared with the dummy implant controls (n = 5).

LIMITATIONS

The main limitation is the small number of animals that received sacral nerve stimulation.

CONCLUSIONS

Chronic sacral nerve stimulation is feasible in rats when miniature telemetric devices are used. Behavioral signs of fecal incontinence were positively correlated with the latency of anorectal evoked potentials. See Video Abstract at http://links.lww.com/DCR/B712.RELACIÓN ENTRE LA ACTIVACIÓN CORTICAL EN RESPUESTA A LOS ESTÍMULOS ANORRECTALES Y EL COMPORTAMIENTO DE CONTINENCIA EN RATAS QUE SE COMPORTAN LIBREMENTE ANTES Y DESPUÉS DE LA APLICACIÓN DE ESTIMULACIÓN DEL NERVIO SACRO.

ANTECEDENTES

Se han informado cambios en la sensación anorrectal en pacientes con incontinencia fecal y hay evidencia limitada de que la estimulación del nervio sacro puede restaurar la sensación normal.

OBJETIVO

Los objetivos del presente estudio fueron investigar los cambios en la transmisión de estímulos anorrectales sensoriales en un modelo de roedor de incontinencia fecal y estudiar los efectos de la estimulación del nervio sacro en la conducta de defecación.

DISEO

Un modelo establecido de incontinencia fecal.

INTERVENCIN

Se utilizó estiramiento y compresión del nervio pudendo en 16 ratas Wistar hembras adultas y se les realizó un seguimiento durante 3 semanas: seis ratas recibieron estimulación del nervio sacro durante 1 semana utilizando un neuroestimulador implantable y diez ratas tuvieron insertados dispositivos "ficticios" no funcionantes. Se operaron simuladamente cinco ratas adicionales. Los potenciales evocados corticales anorrectales se utilizaron como marcador subrogado de la función sensorial anorrectal.

PRINCIPALES MEDIDAS DE RESULTADO

Índice de incontinencia fecal, amplitud de potenciales evocados y latencia.

RESULTADOS

El cincuenta por ciento de las ratas mostró signos de comportamiento de incontinencia fecal medidos por el Índice de incontinencia fecal (> 0.20), calculado utilizando la distribución de heces fuera del área de la letrina de la jaula. La amplitud del potencial evocado anorrectal se redujo en ratas con un índice de incontinencia fecal >0.20 (p = 0.019). La amplitud de los potenciales evocados de la pata delantera registrados como control no fue diferente entre los grupos. La estimulación crónica del nervio sacro utilizando un dispositivo totalmente implantable y un cable de roedor personalizado fue segura y estable durante este estudio prospectivo crónico. Las ratas con incontinencia (N = 3) que recibieron estimulación del nervio sacro mostraron una mejora del índice de incontinencia fecal y un aumento de la amplitud del potencial evocado a la estimulación anorrectal en comparación con los controles de implante ficticio (N = 5).

LIMITACIONES

La principal limitación es el pequeño número de animales que recibieron estimulación del nervio sacro.

CONCLUSIONES

La estimulación crónica del nervio sacro es factible en ratas cuando se utilizan dispositivos telemétricos en miniatura. Los signos conductuales de incontinencia fecal se correlacionaron positivamente con la latencia de los potenciales evocados anorrectales. Consulte Video Resumen en http://links.lww.com/DCR/B712. (Traducción-Dr. Jorge Silva Velazco).

Cholinergic immunomodulation in inflammatory bowel diseases

Inflammatory bowel diseases (IBD) are chronic intestinal disorders characterized by dysregulated immune responses to resident microbiota in genetically susceptible hosts. The activation of the cholinergic system has been proposed for the treatment of IBD patients according to its potential anti-inflammatory effect in vivo. The α-7-nicotinic-acetylcholine receptor (α7nAChR) is involved in the inhibition of inflammatory processes, modulating the production of cytokines, suppressing dendritic cells and macrophage activity, leading to the suppression of T cells. In this review, we address the most recent studies and clinical trials concerning cholinergic signaling and its therapeutic potential for inflammatory bowel diseases.

The Role of Traditional Acupuncture in Low Anterior Resection Syndrome Treatment: A Pilot Study

BACKGROUND

There is limited evidence on the efficacy of acupuncture in bowel dysfunction treatment.

OBJECTIVE

The aim of this pilot study was to investigate the potential value of acupuncture in the treatment of low anterior resection syndrome.

DESIGN

This was an open-design pilot study.

SETTINGS

This was a single-center study.

PATIENTS

Nine (5 female) patients with major low anterior resection syndrome were included.

INTERVENTIONS

All patients underwent acupuncture by a trained specialist once a week for 10 weeks.

MAIN OUTCOME MEASURES

Bowel function was assessed by using the low anterior resection syndrome score and the Memorial Sloan-Kettering Cancer Center bowel function instrument before the procedure, just after finishing the course of acupuncture, and 6 months after the treatment.

RESULTS

The average age was 56.44 (50-65; SD ±5.4). Median age was 56 years. At the end of the procedure, all patients reported significant improvement in low anterior resection syndrome symptoms: the average low anterior resection syndrome score before acupuncture was 39 (±2.7), after acupuncture it was 30.3 (±10.6), and 6 months after acupuncture it was 7.22 (±10.244; p < 0.000). The average Memorial Sloan-Kettering Cancer Center bowel function instrument score before acupuncture was 55.33 (±11.55), after the procedure it was 60 (±14.97), and 6 months later it was 70.22 (±12.2; p < 0.000).

LIMITATIONS

The small sample size and the fact that this is a single-center nonblinded study are limitations of this work.

CONCLUSIONS

Acupuncture may be effective in low anterior resection syndrome treatment and needs further evaluation. The procedure is safe and feasible. See Video Abstract at http://links.lww.com/DCR/B700.

REGISTRATION

ClinicalTrials.gov: NCT03916549.

EL PAPEL DE LA ACUPUNTURA TRADICIONAL EN EL TRATAMIENTO DEL SNDROME DE RESECCIN ANTERIOR BAJA UN ESTUDIO PILOTO

ANTECEDENTES:Existe evidencia limitada sobre la eficacia de la acupuntura para el tratamiento de la disfunción intestinal.OBJETIVO:El objetivo de este estudio piloto fue investigar el valor potencial de la acupuntura en el tratamiento del síndrome de resección anterior baja.DISEÑO:Este fue un estudio piloto de diseño abiertoAJUSTES:Este fue un estudio en un solo centroPACIENTES:Fueron incluidos nueve pacientes con síndrome de resección anterior baja (muy sintomáticos), cinco de ellos eran mujeresINTERVENCIONES:Todos los pacientes fueron tratados con acupuntura, una vez a la semana durante diez semanas por un especialista capacitado.PRINCIPALES MEDIDAS DE RESULTADO:La función intestinal fue evaluada, antes del procedimiento, justo al finalizar el ciclo de acupuntura y a los seis meses, utilizando la puntuación (score) para el síndrome de resección anterior baja y el instrumento de función intestinal del Memorial Sloan-Kettering Cancer Center.RESULTADOS:La edad media fue 56,44 (50 - 65) (DE ± 5,4). Edad mediana 56 años. Al final del procedimiento, todos los pacientes manifestaron una mejoría significativa de los síntomas del síndrome de resección anterior baja: La puntuación promedio del síndrome de resección anterior baja antes de la acupuntura fue 39 (± 2,7), después de - 30,3 (± 10,6) y 6 meses después de 7,22 (± 10,244) (p <0,000). El puntaje promedio del instrumento de función intestinal del Memorial Sloan-Kettering Cancer Center antes de la acupuntura fue 55.33 (± 11.55), después del procedimiento 60 (± 14.97) y 6 meses después 70.22 (± 12.2) (p <0,000).LIMITACIONES:Tamaño de muestra pequeño, estudio no cegado en un solo centro.CONCLUSIONES:La acupuntura puede ser eficaz en el tratamiento del síndrome de resección anterior baja, pero es necesario continuar evaluando su utilidad. El procedimiento es seguro y factible. Consulte Video Resumen en http://links.lww.com/DCR/B700.

Interstitial cells of Cajal and human colon motility in health and disease

Our understanding of human colonic motility, and autonomic reflexes that generate motor patterns, has increased markedly through high-resolution manometry. Details of the motor patterns are emerging related to frequency and propagation characteristics that allow linkage to interstitial cells of Cajal (ICC) networks. In studies on colonic motor dysfunction requiring surgery, ICC are almost always abnormal or significantly reduced. However, there are still gaps in our knowledge about the role of ICC in the control of colonic motility and there is little understanding of a mechanistic link between ICC abnormalities and colonic motor dysfunction. This review will outline the various ICC networks in the human colon and their proven and likely associations with the enteric and extrinsic autonomic nervous systems. Based on our extensive knowledge of the role of ICC in the control of gastrointestinal motility of animal models and the human stomach and small intestine, we propose how ICC networks are underlying the motor patterns of the human colon. The role of ICC will be reviewed in the autonomic neural reflexes that evoke essential motor patterns for transit and defecation. Mechanisms underlying ICC injury, maintenance, and repair will be discussed. Hypotheses are formulated as to how ICC dysfunction can lead to motor abnormalities in slow transit constipation, chronic idiopathic pseudo-obstruction, Hirschsprung's disease, fecal incontinence, diverticular disease, and inflammatory conditions. Recent studies on ICC repair after injury hold promise for future therapies.

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.

Effects of Translumbosacral Neuromodulation Therapy on Gut and Brain Interactions and Anorectal Neuropathy in Fecal Incontinence: A Randomized Study

OBJECTIVES

Translumbosacral neuromodulation therapy (TNT) improves symptoms of fecal incontinence (FI), but its mechanism of action is unknown. We tested the hypothesis that TNT at one or more frequency will significantly improve underlying pathophysiology of FI through modulation of ascending and/or descending signaling pathways in the gut and brain axis and anorectal sensorimotor function.

MATERIALS AND METHODS

We assessed afferent anorectal-cortical evoked potentials (CEP) following electrical stimulation of anorectum, efferent cortico-anorectal and lumbo-anorectal and sacro-anorectal motor evoked potentials (MEP) after transcranial and lumbosacral magnetic stimulations, and anorectal manometry before and after six weekly TNT sessions in FI subjects, randomized to 1, 5, or 15 Hz repetitive magnetic stimulations. Neurophysiology, anorectal sensorimotor function, and symptoms were compared to examine mechanistic effects. Co-primary measures were ano-cortical CEPs, cortico-anal MEPs, and lumbosacral-anal MEPs. Baseline and post-treatment data were compared with Wilcoxon signed-rank test and changes between the three frequencies with one-way ANOVA.

RESULTS

Thirty-three FI patients participated. After TNT, the afferent anal CEP latencies significantly decreased in the 1 Hz group compared to baseline (p = 0.0029) and 5 Hz or 15 Hz groups (p = 0.032). Cortico-anal MEPs were unchanged in all three groups. Bilateral lumbo-anal and sacro-anal MEP latencies significantly decreased with 1 Hz, lumbo-anal with 15 Hz, and sacro-anal with 5 Hz compared to baseline but without group differences. The 1 Hz group showed significant increase in anal squeeze sphincter pressure (p < 0.005) and maximum tolerable volume (p < 0.019) and demonstrated higher FI responder rate (p < 0.04) compared to the other two groups. The MEP responders were significantly correlated with FI responders (p = 0.006) in 1 Hz group.

CONCLUSIONS

TNT significantly improves afferent ano-cortical signaling, efferent lumbo-anal and sacro-anal neuropathy and anorectal sensorimotor function. These neurobiologic effects were most prominent with 1 Hz frequency. TNT improves FI by modifying the underlying pathophysiology possibly through neuromodulation.

Percutaneous tibial nerve stimulation in patients with severe low anterior resection syndrome: randomized clinical trial

BACKGROUND

Treatment of low anterior resection syndrome (LARS) is challenging. Percutaneous tibial nerve stimulation (PTNS) can improve select bowel disorders. An RCT was conducted to assess the efficacy of PTNS compared with sham stimulation in patients with severe LARS.

METHOD

This was a multicentre, double-blind RCT. Patients with major LARS score were allocated to receive PTNS or sham therapy (needle placement simulation without nerve stimulation). The study included 16 sessions of 30 min once a week for 12 consecutive weeks, followed by four additional sessions once a fortnight for the following 4 weeks. The primary endpoint was efficacy of PTNS defined by the LARS score 12 months after treatment. Secondary endpoints included faecal incontinence, quality of life (QoL), and sexual function.

RESULTS

Between September 2016 and July 2018, 46 eligible patients were assigned randomly in a 1 : 1 ratio to PTNS or sham therapy. Baseline characteristics were similar. LARS scores were reduced in both groups, but only patients who received PTNS maintained the effect in the long term (mean(s.d.) score 36.4(3.9) at baseline versus 30.7(11.5) at 12 months; P = 0.018; effect size -5.4, 95 per cent c.i. -9.8 to -1.0), with a mean reduction of 15.7 per cent at 12-month follow-up. The faecal incontinence score was improved after 12 months in the PTNS group (mean(s.d.) score 15.4(5.2) at baseline versus 12.5(6.4) at 12 months; P = 0.018). No major changes in QoL and sexual function were observed in either group. There was no therapy-associated morbidity. Three patients discontinued the study, but none owing to study-related issues.

CONCLUSION

PTNS has positive effects in some patients with major LARS, especially in those with faecal incontinence. Registration number: NCT02517853 (http://www.clinicaltrials.gov).

The role of neuromodulation in chronic functional constipation: a systematic review

BACKGROUND

Chronic functional constipation is a highly prevalent disorder in which, when conservative measures fail to relieve symptoms, surgical interventions are sometimes indicated. In recent years, neuromodulation for the treatment of functional constipation has gained interest but its role and effectiveness are still unclear. The purpose of this review is to provide a systematic overview on the current literature on the different modalities of neurostimulation and their effect on chronic functional constipation in adults as reported in the literature.

METHODS

A search in the literature for articles concerning the effect of different types of neuromodulation on constipation was performed in PubMed using extensive search terms for the different modalities of neuromodulation. Studies and trials were checked for eligibility. For all types of neuromodulation together, 27 articles were included.

RESULTS

17 studies were included on SNM (sacral nerve modulation). Although multiple studies show positive results on the effect of SNM in constipation, double-blind crossover RCT's (randomised controlled trials) showed no significant effect. 3 studies were included for tSNS (transcutaneous sacral nerve stimulation), 2 for PTNS (percutaneous tibial nerve stimulation) and 2 for TTNS (transcutaneous tibial nerve stimulation). Studies and trials on these modalities of neuromodulation reported ambiguous results on statistical significance of the effect. For transcutaneous IFC (interferential current therapy) 2 studies were included, which both reported a statistically significant effect on all outcomes.

CONCLUSION

The beneficial effect of neuromodulation in chronic functional constipation remains questionable. However, neuro-modulation might be worth considering in patients refractory to treatment before turning to more invasive measures. Future research should shed more light on the effects of neuromodulation in constipation.

Chronic constipation in adults: Contemporary perspectives and clinical challenges. 2: Conservative, behavioural, medical and surgical treatment

BACKGROUND

Chronic constipation is a prevalent disorder that affects quality of life of patients and consumes resources in healthcare systems worldwide. In clinical practice, it is still considered a challenge as clinicians frequently are unsure as to which treatments to use and when. Over a decade ago, a Neurogastroenterology and Motility journal supplement devoted to the investigation and management of constipation was published (Neurogastroenterol Motil 2009;21(Suppl 2):1). In October 2018, the 3rd London Masterclass, entitled "Contemporary management of constipation" was held. The faculty members of this symposium were invited to write two reviews to present a collective synthesis of talks presented and discussions held during this meeting. The first review addresses epidemiology, diagnosis, clinical associations, pathophysiology, and investigation.

PURPOSE

The present is the second of these reviews, providing contemporary perspectives and clinical challenges regarding behavioral, conservative, medical, and surgical treatments for patients presenting with constipation. It includes a management algorithm to guide clinical practice.

Assessment and management of low anterior resection syndrome after sphincter preserving surgery for rectal cancer

Many patients develop a variety of bowel dysfunction after sphincter preserving surgeries (SPS) for rectal cancer. The bowel dysfunction usually manifests in the form of low anterior resection syndrome (LARS), which has a negative impact on the patients’ quality of life. This study reviewed the LARS after SPS, its mechanism, risk factors, diagnosis, prevention, and treatment based on previously published studies. Adequate history taking, physical examination of the patients, using validated questionnaires and other diagnostic tools are important for assessment of LARS severity. Treatment of LARS should be tailored to each patient. Multimodal therapy is usually needed for patients with major LARS with acceptable results. The treatment includes conservative management in the form of medical, pelvic floor rehabilitation and transanal irrigation and invasive procedures including neuromodulation. If this treatment failed, fecal diversion may be needed. In conclusion, Initial meticulous dissection with preservation of nerves and creation of a neorectal reservoir during anastomosis and proper Kegel exercise of the anal sphincter can minimize the occurrence of LARS. Pre-treatment counseling is an essential step for patients who have risk factors for developing LARS.

Electroacupuncture vs Prucalopride for Severe Chronic Constipation: A Multicenter, Randomized, Controlled, Noninferiority Trial

INTRODUCTION

This multicenter, randomized, noninferiority trial compared electroacupuncture with prucalopride for the treatment of severe chronic constipation (SCC).

METHODS

Participants with SCC (≤ 2 mean weekly complete spontaneous bowel movements [CSBMs]) were randomly assigned to receive either 28-session electroacupuncture over 8 weeks with follow-up without treatment over 24 weeks or prucalopride (2 mg/d before breakfast) over 32 weeks. The primary outcome was the proportion of participants with ≥3 mean weekly CSBMs over weeks 3-8, based on the modified intention-to-treat population, with -10% as the noninferior margin.

RESULTS

Five hundred sixty participants were randomized, 280 in each group. Electroacupuncture was noninferior to prucalopride for the primary outcome (36.2% vs 37.8%, with a difference of -1.6% [95% confidence interval, -8% to 4.7%], P < 0.001 for noninferiority); almost the same results were found in the per-protocol population. The proportions of overall CSBM responders through weeks 1-8 were similar in the electroacupuncture and prucalopride groups (24.91% vs 25.54%, with a difference of -0.63% [95% confidence interval, -7.86% to 6.60%, P = 0.864]). Except during the first 2-week treatment, no between-group differences were found in outcomes of excessive straining, stool consistency, and quality of life. Adverse events occurred in 49 (17.69%) participants in the electroacupuncture group and 123 (44.24%) in the prucalopride group. One non-treatment-related serious adverse event was recorded in the electroacupuncture group.

DISCUSSION

Electroacupuncture was noninferior to prucalopride in relieving SCC with a good safety profile. The effects of 8-week electroacupuncture could sustain for 24 weeks after treatment. Electroacupuncture is a promising noninferior alternative for SCC (see Visual Abstract, http://links.lww.com/AJG/B776).

[Low anterior resection syndrome-Causes and treatment approaches]

BACKGROUND

With improvement of the oncological prognosis and more sphincter-preserving procedures for rectal cancer of the lower third, the functional sequelae of anterior rectal resection become more and more predominant and are summarized under the term low anterior resection syndrome (LARS).

MATERIAL AND METHODS

In this narrative review the causes, associated factors, prevalence, diagnostics and treatment strategies are presented based on an evaluation of the international literature.

RESULTS

The central role of the rectum in the physiology of defecation and continence explains the frequency of symptoms following anterior rectal resection. In an unselected patient population a major LARS is to be expected in approximately 40% and a minor LARS in approximately 20%. The most important factor is the length of the remaining rectal stump. The diagnosis of LARS is made clinically and can be quantified by scores, especially by the LARS score. Treatment options range from patient counselling to stoma construction and a symptom-related, stepwise approach is generally accepted.

CONCLUSION

While the evidence for the causes, the quantification and determination of associated factors of LARS is good, the treatment options are based either on experience or on only few studies.

Effects of temporary sacral nerve stimulation on gastrointestinal motility and function in patients with chronic refractory slow-transit constipation

BACKGROUND

The efficacy of sacral nerve stimulation (SNS) on patients with chronic refractory slow-transit constipation is controversial and its mechanism of action on gastrointestinal motility and transit is not fully understood. The aim of this study was to document the effects of temporary SNS on the gastrointestinal and biliary tract motility and on gastrointestinal transit in patients with refractory slow-transit constipation.

METHODS

This was a prospective interventional study. Patients with slow-transit chronic constipation, unresponsive to any conservative treatment, were enrolled between January 2013 and December 2018. Patients' quality of life [patient assessment of constipation quality of life (PAC-QOL) questionnaire], constipation scores (Cleveland Clinic Constipation Score) colonic transit time (CTT), orocecal transit time (OCTT), gastric and gallbladder kinetics, together with the assessment of the autonomic nerve function were evaluated before and during temporary SNS.

RESULTS

14 patients (12 females, median age 38 years, range 24-42 years) had temporary SNS. The Cleveland Clinic Constipation Score did not change compared to baseline (23 ± 3 vs 21.4; p = 070). The PAC-QOL did not improve significantly during the stimulation period. Gallbladder/stomach motility (half-emptying time) did not change significantly before and after SNS. OCTT was delayed at baseline, as compared to standard internal normal values, and did not change during SNS. CTT did not improve significantly, although in two patients it decreased substantially from 97 to 53 h, and from 100 to 65 h.

CONCLUSIONS

Temporary SNS did not have any effect on upper/lower gastrointestinal motility and transit in patients with severe constipation.

Current Position of Sacral Neuromodulation in Treatment of Fecal Incontinence

Fecal incontinence (FI) is defined as uncontrolled passage of feces or gas for at least 1-month duration in an individual who previously had control. FI is a common and debilitating condition affecting many individuals. Continence depends on complex relationships between anal sphincters, rectal curvatures, rectoanal sensation, rectal compliance, stool consistency, and neurologic function. Factors, such as pregnancy, chronic diarrhea, diabetes mellitus, previous anorectal surgery, urinary incontinence, smoking, obesity, limited physical activity, white race, and neurologic disease, are known to be the risk factors for FI. Conservative/medical management including biofeedback are recognized as the first-line treatment of the FI. Those who are suitable for surgical intervention and who have failed conservative management, sacral nerve stimulation (SNS) has emerged as the treatment of choice in many patients. The surgical technique involves placement of a tined lead with four electrodes through the S3 sacral foramen. The lead is attached to a battery, which acts as a pulse generator, and is placed under the patient's skin in the lower lumbar region. The use of SNS in the treatment of FI has increased over the years and the beneficial effects of this treatment have been substantiated by multiple studies. This review describes SNS as a modality of treatment for FI and its position in the current medical diaspora in patients with FI.

Effects of sEA on Slow Transit Constipation through the Microbiota-Gut-Brain Axis in Rats

To investigate the effect of sacral electroacupuncture (sEA) on the microbiota-gut-brain axis in the treatment of slow transit constipation, this study established a drug-induced model of slow transit constipation in rats and carried out sEA at the Baliao acupoints (BL31-BL34). On the 14th day of the therapeutic period (24 h fecal pellets), the aquaporin 3 (AQP3), 5-hydroxytryptamine (5-HT), and substance P (SP) transcripts from the distal colon and hypothalamus were analyzed. 16S rDNA has been widely used to analyze the diversity of the microbial communities. Therefore, in the present study, changes in the intestinal microbiota were analyzed by 16S rDNA gene sequencing. The results showed that sEA significantly increased the number of fecal pellets and the water content in the feces and reduced the reabsorption of intestinal water in 24 h. sEA also upregulated the level of SP mRNA expression in the distal colon and the hypothalamus, but downregulated the level of 5-HT mRNA expression in the distal colon. Moreover, sEA improved the Bacteroidetes to Firmicutes (B/F) ratio, which is beneficial to the general structure of the intestinal microflora. Our findings suggested that the microbiota-gut-brain axis constitutes a crucial pathological basis in the development of slow transit constipation. sEA improved the slow transit constipation by regulating the balance of the microbiota-gut-brain axis.

Constipation and Fecal Incontinence in the Elderly

PURPOSE OF REVIEW

To review the epidemiology, pathogenesis, clinical features, and management of primary constipation and fecal incontinence in the elderly.

RECENT FINDINGS

Among elderly people, 6.5%, 1.7%, and 1.1% have functional constipation, constipation-predominant IBS, and opioid-induced constipation. In elderly people, the number of colonic enteric neurons and smooth muscle functions is preserved; decreased cholinergic function with unopposed nitrergic relaxation may explain colonic motor dysfunction. Less physical activity or dietary fiber intake and postmenopausal hormonal therapy are risk factors for fecal incontinence in elderly people. Two thirds of patients with fecal incontinence respond to biofeedback therapy. Used in combination, loperamide and biofeedback therapy are more effective than placebo, education, and biofeedback therapy. Vaginal or anal insert devices are another option. In the elderly, constipation and fecal incontinence are common and often distressing symptoms that can often be managed by addressing bowel disturbances. Selected diagnostic tests, prescription medications, and, infrequently, surgical options should be considered when necessary.

Comparison of antegrade continence enema treatment and sacral nerve stimulation for children with severe functional constipation and fecal incontinence

BACKGROUND

To compare antegrade continence enema (ACE) treatment and sacral nerve stimulation (SNS) in children with intractable functional constipation (FC) and fecal incontinence (FI).

METHODS

We performed a retrospective review of children 6-18 years old with FC and FI treated with either ACE or SNS at our institution. We recorded symptoms at baseline, 6 months, 12 months, 24 months, and their most recent visit after starting treatment. We compared improvement in FI, bowel movement (BM) frequency, abdominal pain, laxative use, and complications. Patients were contacted to evaluate perceived benefit using the Glasgow Children's Benefit Inventory.

KEY RESULTS

We included 23 patients treated with ACE (52% female, median age 10 years) and 19 patients treated with SNS (74% female, median age 10 years). Improvement in FI was greater with SNS than ACE at 12 months (92.9% vs 57.1%, P = .03) and 24 months (100% vs 57.1%, P = .02). Improvement in BM frequency was greater with ACE, and children were more likely to discontinue laxatives at all follow-up time points (all P < .05). Improvement in abdominal pain was greater with ACE at the most recent visit (P < .05). Rate of complications requiring surgery was similar between groups (26.3% vs 21.7%). Benefit was reported in 83.3% and 100% of ACE and SNS groups, respectively (NS).

CONCLUSIONS AND INFERENCES

Although both ACE and SNS can lead to durable improvement in children with FC and FI, SNS appears more effective for FI and ACE more effective in improving BM frequency and abdominal pain and in discontinuation of laxatives.

Potential of Electrical Neuromodulation for Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a common chronic inflammatory disease of the digestive tract that is often debilitating. It affects patients' quality of life and imposes a financial burden. Despite advances in treatment with medications such as biologics, a large proportion of patients do not respond to medical therapy or develop adverse events. Therefore, alternative treatment options such as electrical neuromodulation are currently being investigated. Electrical neuromodulation, also called bioelectronic medicine, is emerging as a potential new treatment for IBD. Over the past decade, advancements have been made in electrical neuromodulation. A number of electrical neuromodulation methods, such as vagus nerve stimulation, sacral nerve stimulation, and tibial nerve stimulation, have been tested to treat IBD. A series of animal and clinical trials have been performed to evaluate efficacy with promising results. Although the exact underlying mechanisms of action for electrical neuromodulation remain to be explored, this modality is promising. Further randomized controlled trials and basic experiments are needed to investigate efficacy and clarify intrinsic mechanisms.

Treatment for refractory overactive bladder: a systematic review and meta-analysis of sacral neuromodulation and onabotulinumtoxinA

INTRODUCTION AND HYPOTHESIS

This systematic review and meta-analysis aim to evaluate the outcomes between SNM and BTX in the treatment of refractory OAB.

METHODS

PubMed, Embase, and CENTRAL were comprehensively searched from their inception to December 2019. Randomized and nonrandomized controlled trials evaluating OAB patients who underwent SNM and BTX were included. Data extraction and quality assessment were conducted by two independent reviewers. The outcomes, side effects, and cost-effectiveness values of both procedures were compared in meta-analysis.

RESULTS

This review involved six articles (2629 patients). Specifically, three articles were based on the same trial, and the other studies were retrospective cohort studies. No significant difference was found in successful treatment between BTX and SNM at 6 months after procedures [risk ratio (RR) = 0.93, 95% confidence interval (CI) 0.63-1.39]. BTX exhibited a significantly higher total adverse event rate than SNM through 6 months (RR = 1.55, 95% CI 1.28-1.88). Patients suffered more urinary tract infection (UTI) risk under BTX injection at the early stage (RR = 1.58, 95% CI 1.10-2.25); however, the difference in UTI events was not significant between the two groups (RR = 1.13, 95% CI 1.10-2.25) during the period of 7-12 months postoperatively. Obviously, the short-term cost (1-2 years) of BTX was significantly lower than that of the SNM procedure.

CONCLUSIONS

Both treatments were effective; however, because of the high complication rate of BTX, it may not be a better way to treat refractory OAB than SNM, although BTX is more cost-effective for short-term treatment at present.

Sacral Nerve Modulation Has No Effect on the Postprandial Response in Irritable Bowel Syndrome

Purpose

Irritable bowel syndrome is a common gastrointestinal disorder with a global prevalence of approximately 11%. Onset or worsening of symptoms following digestion is one of the characteristics of the condition. The present study aimed at evaluating the postprandial sensory and motor response before and after treatment with sacral nerve modulation.

Patients and Methods

Twenty-one irritable bowel syndrome patients, 12 diarrhea-predominant and 9 mixed, were eligible for a 6-week sacral nerve modulation test period. Patients were investigated with multimodal impedance planimetry including a standardized meal at baseline and at the end of 2 weeks of suprasensory stimulation embedded in the 6-week sacral nerve modulation period.

Results

There was no statistical significant difference in the sensory response to heat or cold before and after sacral nerve modulation, p>0.05. At baseline, wall tension increased after the meal (mean 124.79 [range 82.5 to 237.3] mmHg.mm before the meal, mean 207.76 [range, 143.5 to 429] mmHg.mm after the meal), p=0.048 indicating a postprandial response. During sacral nerve modulation, the postprandial increase in wall tension did not reach statistical significance (mean 86.79 [range 28.8 to 204.5] mmHg.mm before the meal, mean 159.71 [range 71.3 to 270.8] mmHg.mm after the meal), p=0.277. However, there was no statistically significant difference between the postprandial wall tension at baseline and during sacral nerve modulation, p=0.489. Likewise, we found no difference between pressure or stretch ratio at baseline and during sacral nerve modulation, p>0.05.

Conclusion

Sacral nerve modulation does not exert its positive treatments effects in diarrhea-predominant and mixed irritable bowel syndrome through a modulation of the postprandial response.

Transcutaneous Neuromodulation at ST36 (Zusanli) is More Effective than Transcutaneous Tibial Nerve Stimulation in Treating Constipation

BACKGROUND AND GOALS

Combined transcutaneous neuromodulation (TN) at acupoint ST36 (Zusanli) and TN at the posterior tibial nerve (PTN) has been reported effective in treating functional constipation. This study was designed to compare the effectiveness of TN between these 2 points.

MATERIALS AND METHODS

Eighteen functional constipation patients (M/F: 9/9) were recruited to participate in a cross-over study with a 2-week TN at ST36 and a 2-week TN at PTN. A bowel movement diary, and the questionnaires of Patient Assessment of Constipation Symptom (PAC-SYM) and Constipation Quality of Life (PAC-QoL) were completed; anorectal manometry and spectral analysis of heart rate variability for assessing the autonomic function were performed.

RESULTS

(1) Both TN at ST36 and TN at PTN improved constipation-related symptoms (PAC-SYM scores on pre-TN vs. post-TN: 1.4±0.1 vs. 0.6±0.1 for ST36, 1.4±0.1 vs. 0.9±0.1 for PTN, both P≤0.001). (2) TN at ST36, but not TN at PTN, increased the number of weekly spontaneous bowel movements (0.9±0.2 pre-TN vs. 3.5±0.7 post-TN, P<0.001) and decreased the total PAC-QoL score. TN at ST36 was more potent than TN at PTN in improving the PAC-SYM score (decrement 0.8±0.1 vs. 0.5±0.1, P<0.05). (3) TN at ST36 rather than TN at PTN resulted in a reduction in sensation thresholds, including rectal distention for urge (134.1±14.3 mL pre-TN vs. 85.6±6.5 mL post-TN, P<0.01) and maximum tolerance (P<0.05). (4) Both TN at ST36 and TN at PTN significantly increased vagal activity and decreased sympathetic activity (P<0.05).

CONCLUSIONS

TN at ST36 is more potent than TN at PTN in treating constipation and improving constipation-related symptoms and rectal sensation.

A novel method of sacral nerve stimulation for colonic inflammation

BACKGROUND

Vagal nerve stimulation has been reported to treat inflammation with promising results. The aims of our study were to optimize sacral nerve stimulation (SNS) methodologies for colonic inflammation in a rodent model of colitis and to investigate autonomic and cytokine mechanisms.

METHODS

Three major efforts were made in optimizing SNS: (a) to determine the best stimulation duration: SNS-0.5h daily, SNS-1h daily, and SNS-3h daily with the parameters set at 5 Hz, 10 seconds on, 90 seconds off; (b) to determine the best stimulation position: bilateral, bipolar, and unipolar stimulation; (c) to determine the best stimulation parameters: our 5 Hz intermittent stimulation vs 14 Hz-210 μs continuous stimulation. Inflammatory responses were assessed by the disease activity index (DAI), histological analyses, and the myeloperoxidase (MPO) activity. Levels of inflammatory cytokines, norepinephrine (NE), and pancreatic polypeptide (PP) in both plasma and colon tissues were assessed.

KEY RESULTS

Both SNS-1h and SNS-3h significantly ameliorated intestinal inflammation; SNS-1h was superior to SNS-3h. Bipolar but not bilateral or unipolar stimulation improved the inflammation in colitis. SNS with 5 Hz intermittent stimulation but not the 14 Hz continuous SNS was better for treating colitis in rats. SNS with the optimized stimulation parameters increased vagal activity and decreased sympathetic activity. CONCLUSION & INFERENCES: Bipolar stimulation for 1 hour daily using intermittent 5 Hz parameters is most effective in improving colonic inflammation in TNBS-treated rats by inhibiting pro-inflammatory cytokines and increasing anti-inflammatory cytokines via the modulation of the autonomic function.