Sacral nerve stimulation induces pan-colonic propagating pressure waves and increases defecation frequency in patients with slow-transit constipation

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.

Sacral Neuromodulation Versus Conservative Treatment for Refractory Idiopathic Slow-transit Constipation: The Randomized Clinical No.2-Trial

OBJECTIVE

Assess the effectiveness of sacral neuromodulation (SNM) versus personalized conservative treatment (PCT) in patients with refractory idiopathic slow-transit constipation (STC).

BACKGROUND

Evidence on SNM for idiopathic STC is conflicting and of suboptimal methodological quality.

METHODS

The No.2-Trial was a multicenter, open-label, pragmatic, randomized trial performed in 2 Dutch hospitals. Sixty-seven patients with idiopathic STC, a defecation frequency <3 per week and refractory (ie, unresponsive) to maximal conservative (nonoperative) treatment were included. Exclusion criteria included outlet obstruction, rectal prolapse, and previous colon surgery. Patients were randomized (3:2) to SNM (n=41) or PCT (n=26) with randomization minimization between February 21, 2017 and March 12, 2020. In SNM patients, an implantable pulse generator was implanted after a successful 4-week test stimulation. PCT patients received conservative treatment such as laxatives or retrograde colonic irrigation. The primary outcome was treatment success (defined as average defecation frequency ≥3 per week) after 6 months. Secondary outcomes included constipation severity, fatigue, quality of life, and adverse events. Analysis was according to intention-to-treat.

RESULTS

After 6 months, 22 (53.7%) patients were successfully treated with SNM versus 1 (3.8%) patient with PCT (odds ratio 36.4, 95% CI 3.4-387.5, P =0.003). At 6 months, SNM patients reported lower constipation severity and fatigue scores ( P <0.001) and improved quality of life compared with PCT ( P <0.001). Eight serious adverse events (6 SNM, 2 PCT) and 78 adverse events (68 SNM, 10 PCT) were reported.

CONCLUSIONS

SNM is a promising surgical treatment option in a homogeneous group of adults and adolescents with refractory idiopathic STC. No.2-Trial registered at ClinicalTrials.gov NCT02961582.

Sacral nerve stimulation effect on colonic motility in pediatric patients

BACKGROUND

Sacral nerve stimulation (SNS) is a minimally invasive surgical procedure used to treat refractory constipation in children. While its efficacy in improving symptoms has been studied, its effect on colonic motor function remains unclear. This case series explores SNS's impact on colonic motor function in pediatric patients with idiopathic constipation, using high-resolution colonic manometry (HRCM).

METHODS

Four pediatric patients with chronic idiopathic constipation underwent SNS placement for intractable symptoms and were subsequently evaluated via HRCM. Clinical characteristics, comorbidities, treatment regimens, and outcomes were reviewed. HRCM was conducted during the SNS-off and SNS-on phases. The motility index (MI) was measured during the SNS-off (fasting and postprandial) and SNS-on phases.

RESULTS

Four pediatric patients aged 8 to 21 years met the inclusion criteria. In three patients, SNS-induced high-amplitude propagating contractions (HAPCs) were noted, and in one patient, low-amplitude propagating contractions (LAPCs) were noted. In one patient, propagating contractions were induced only when SNS was turned on. MI changes with SNS-on were variable among different patients with an increase in MI in two patients after turning SNS on and a decrease in the other two compared with baseline. Adverse effects following SNS placement remained minimal across all cases.

CONCLUSION

This case series is the first to report SNS effects on colonic motility evaluated by HRCM in pediatrics. We demonstrate that propagating colonic contractions are promptly induced when SNS is turned on. Although the initial effects of SNS on colonic motility were observable, additional investigation is necessary to comprehend the fundamental mechanisms and long-term effectiveness of SNS in pediatric patients.

Effectiveness, safety and cost-effectiveness of sacral neuromodulation for idiopathic slow-transit constipation: a systematic review

AIM

Sacral neuromodulation (SNM) is a minimally invasive treatment option for functional constipation. Evidence regarding its effectiveness is contradictory, driven by heterogeneous study populations and designs. The aim of this study was to assess the effectiveness, safety and cost-effectiveness of SNM in children and adults with refractory idiopathic slow-transit constipation (STC).

METHOD

OVID Medline, OVID Embase, Cochrane Library, the KSR Evidence Database, the NHS Economic Evaluation Database and the International HTA Database were searched up to 25 May 2023. For effectiveness outcomes, randomized controlled trials (RCTs) were selected. For safety outcomes, all study designs were selected. For cost-effectiveness outcomes, trial- and model-based economic evaluations were selected for review. Study selection, risk of bias and quality assessment, and data extraction were independently performed by two reviewers. For the intervention 'sacral neuromodulation' effectiveness outcomes included defaecation frequency and constipation severity. Safety and cost-effectiveness outcomes were, respectively, adverse events and incremental cost-effectiveness ratios.

RESULTS

Of 1390 records reviewed, 67 studies were selected for full-text screening. For effectiveness, one cross-over and one parallel-group RCT was included, showing contradictory results. Eleven studies on safety were included (four RCTs, three prospective cohort studies and four retrospective cohort studies). Overall infection rates varied between 0% and 22%, whereas reoperation rates varied between 0% and 29%. One trial-based economic evaluation was included, which concluded that SNM was not cost-effective compared with personalized conservative treatment at a time horizon of 6 months. The review findings are limited by the small number of available studies and the heterogeneity in terms of study populations, definitions of refractory idiopathic STC and study designs.

CONCLUSION

Evidence for the (cost-)effectiveness of SNM in children and adults with refractory idiopathic STC is inconclusive. Reoperation rates of up to 29% were reported.

Diagnostic and therapeutic approach to children with chronic refractory constipation: Consensus report by the SIGENP motility working group

Constipation is a common problem in children, accounting for about 3% of all primary care visits and up to 25% of referrals to paediatric gastroenterologists. Although polyethylene glycol often proves effective, most children require prolonged treatment and about 50% of them have at least one relapse within the first 5 years after initial recovery. When conventional treatment fails, children are considered to have refractory constipation. Children with refractory constipation deserve specialist management and guidance. Over the last decades, there has been a remarkable increase in our knowledge of normal and abnormal colonic and anorectal motility in children, and a number of different techniques to measure transit and motility have been developed. The present review analyses the possible diagnostic investigations for children with refractory constipation, focusing on their actual indications and their utility in clinical practice. Moreover, we have also analytically reviewed medical and surgical therapeutic options, which should be considered in selected patients in order to achieve the best clinical outcome.

Childhood constipation: Current status, challenges, and future perspectives

Constipation in children is a major health issue around the world, with a global prevalence of 9.5%. They present to clinicians with a myriad of clinical signs. The Rome IV symptom-based criteria are used to diagnose functional constipation. Functional constipation is also a huge financial burden for healthcare system and has a detrimental impact on health-related quality of life of children. There are various risk factors identified globally, including centrally connected factors such as child abuse, emotional and behavioral issues, and psychological stress. Constipation is also precipitated by a low-fiber diet, physical inactivity, and an altered intestinal microbiome. The main pathophysiological mechanism is stool withholding, while altered rectal function, anal sphincter, pelvic floor, and colonic dysfunction also play important roles. Clinical evaluation is critical in making a diagnosis, and most investigations are only required in refractory patients. In the treatment of childhood constipation, both nonpharmacological (education and de-mystification, dietary changes, toilet training, behavioral interventions, biofeedback, and pelvic floor physiotherapy), and pharmacological (osmotic and stimulant laxatives and novel drugs like prucalopride and lubiprostone) interventions are used. For children with refractory constipation, transanal irrigation, botulinum toxin, neuromodulation, and surgical treatments are reserved. While frequent use of probiotics is still in the experimental stage, healthy dietary habits, living a healthy lifestyle and limiting exposure to stressful events, are all beneficial preventive measures.

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.

Bioelectronic medicine for the autonomic nervous system: clinical applications and perspectives

Bioelectronic medicine (BM) is an emerging new approach for developing novel neuromodulation therapies for pathologies that have been previously treated with pharmacological approaches. In this review, we will focus on the neuromodulation of autonomic nervous system (ANS) activity with implantable devices, a field of BM that has already demonstrated the ability to treat a variety of conditions, from inflammation to metabolic and cognitive disorders. Recent discoveries about immune responses to ANS stimulation are the laying foundation for a new field holding great potential for medical advancement and therapies and involving an increasing number of research groups around the world, with funding from international public agencies and private investors. Here, we summarize the current achievements and future perspectives for clinical applications of neural decoding and stimulation of the ANS. First, we present the main clinical results achieved so far by different BM approaches and discuss the challenges encountered in fully exploiting the potential of neuromodulatory strategies. Then, we present current preclinical studies aimed at overcoming the present limitations by looking for optimal anatomical targets, developing novel neural interface technology, and conceiving more efficient signal processing strategies. Finally, we explore the prospects for translating these advancements into clinical practice.

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.

Progress in research of sacral nerve stimulation

Sacral nerve stimulation (SNS) is well-known as a minimally invasive treatment. Originally, it was mainly used to treat urinary system diseases such as urge urinary incontinence. Gradually, it is used to treat digestive system diseases such as fecal incontinence and chronic constipation. SNS is a method in which electrical pulse signals are sent out through pulse generators to stimulate the sacral nerve directly or indirectly, thus modulating the nerve reflex of the bladder, urethra, anus, colon, and rectum and improving abnormal nerve regulation to achieve the therapeutic effect. The regulation of the sacral nerve is often carried out by inserting electrodes into the sacral spinal canal S_2-4 (mostly S₃), and the symptoms are improved by complex regulation of spinal reflex and supraspinal reflex. However, the exact mechanism is still unclear. Many studies have shown that SNS plays a key role in the treatment of many diseases of the urinary system and digestive system. This paper reviews the progress in the research of SNS.

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.

The effect of colonic tissue electrical stimulation and celiac branch of the abdominal vagus nerve neuromodulation on colonic motility in anesthetized pigs

BACKGROUND

Knowledge on optimal electrical stimulation (ES) modalities and region-specific functional effects of colonic neuromodulation is lacking. We aimed to map the regional colonic motility in response to ES of (a) the colonic tissue and (b) celiac branch of the abdominal vagus nerve (CBVN) in an anesthetized porcine model.

METHODS

In male Yucatan pigs, direct ES (10 Hz, 2 ms, 15 mA) of proximal (pC), transverse (tC), or distal (dC) colon was done using planar flexible multi-electrode array panels and CBVN ES (2 Hz, 0.3-4 ms, 5 mA) using pulse train (PT), continuous (10 min), or square-wave (SW) modalities, with or without afferent nerve block (200 Hz, 0.1 ms, 2 mA). The regional luminal manometric changes were quantified as area under the curve of contractions (AUC) and luminal pressure maps generated. Contractions frequency power spectral analysis was performed. Contraction propagation was assessed using video animation of motility changes.

KEY RESULTS

Direct colon ES caused visible local circular (pC, tC) or longitudinal (dC) muscle contractions and increased luminal pressure AUC in pC, tC, and dC (143.0 ± 40.7%, 135.8 ± 59.7%, and 142.0 ± 62%, respectively). The colon displayed prominent phasic pressure frequencies ranging from 1 to 12 cpm. Direct pC and tC ES increased the dominant contraction frequency band (1-6 cpm) power locally. Pulse train CBVN ES (2 Hz, 4 ms, 5 mA) triggered pancolonic contractions, reduced by concurrent afferent block. Colon contractions propagated both orally and aborally in short distances.

CONCLUSION AND INFERENCES

In anesthetized pigs, the dominant contraction frequency band is 1-6 cpm. Direct colonic ES causes primarily local contractions. The CBVN ES-induced pancolonic contractions involve central neural network.

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.

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.

Mechanisms, Evaluation, and Management of Chronic Constipation

With a worldwide prevalence of 15%, chronic constipation is one of the most frequent gastrointestinal diagnoses made in ambulatory medicine clinics, and is a common source cause for referrals to gastroenterologists and colorectal surgeons in the United States. Symptoms vary among patients; straining, incomplete evacuation, and a sense of anorectal blockage are just as important as decreased stool frequency. Chronic constipation is either a primary disorder (such as normal transit, slow transit, or defecatory disorders) or a secondary one (due to medications or, in rare cases, anatomic alterations). Colonic sensorimotor disturbances and pelvic floor dysfunction (such as defecatory disorders) are the most widely recognized pathogenic mechanisms. Guided by efficacy and cost, management of constipation should begin with dietary fiber supplementation and stimulant and/or osmotic laxatives, as appropriate, followed, if necessary, by intestinal secretagogues and/or prokinetic agents. Peripherally acting μ-opiate antagonists are another option for opioid-induced constipation. Anorectal tests to evaluate for defecatory disorders should be performed in patients who do not respond to over-the-counter agents. Colonic transit, followed if necessary with assessment of colonic motility with manometry and/or a barostat, can identify colonic dysmotility. Defecatory disorders often respond to biofeedback therapy. For specific patients, slow-transit constipation may necessitate a colectomy. No studies have compared inexpensive laxatives with newer drugs with different mechanisms. We review the mechanisms, evaluation, and management of chronic constipation. We discuss the importance of meticulous analyses of patient history and physical examination, advantages and disadvantages of diagnostic testing, guidance for individualized treatment, and management of medically refractory patients.

Heterogeneous outcome reporting in adult slow-transit constipation studies: Systematic review towards a core outcome set

BACKGROUND AND AIM

Standardizing evaluative outcomes and their assessment facilitates comparisons between clinical studies and provides a basis for comparing direct effects of different treatment options. The aim of this study was to systematically review types of outcomes and measurement instruments used in studies regarding treatment options for slow-transit constipation (STC) in adults.

METHODS

In this systematic review of the literature, we searched MEDLINE, Embase, and PsycINFO from inception through February 2018, for papers assessing any STC treatment in adult patients. Outcomes were systematically extracted and categorized in domains using the conceptual framework of the Outcome Measures in Rheumatology filter 2.0. Outcome reporting was stratified by decade of publication, intervention, and study type.

RESULTS

Forty-seven studies were included in this systematic review. Fifty-nine different types of outcomes were identified. The outcomes were structured in three core areas and 18 domains. The most commonly reported domains were defecation functions (94%), gastrointestinal transit (53%), and health-care service use (51%). The most frequently reported outcomes were defecation frequency (83%), health-related quality of life (43%), and adverse events and complications (43%). In 62% of the studies, no primary outcome was defined, whereas in two studies, more than one primary outcomes were selected. A wide diversity of measurement instruments was used to assess the reported outcomes.

CONCLUSION

Outcomes reported in studies on STC in adults are heterogeneous. A lack of standardization complicates comparisons between studies. Developing a core outcome set for STC in adults could contribute to standardization of outcome reporting in (future) studies.

A Pilot Study of Non-invasive Sacral Nerve Stimulation in Treatment of Constipation in Childhood and Adolescence

Background/Aims: Constipation shows both, a high prevalence and a significant impact. However, it is often perceived as minor and treatment choices are limited. The neuromodulation approach is a valuable option to be considered. This study assesses the use of non-invasive sacral nerve stimulation to reduce constipation in children. Methods: Between February 2013 and May 2015, pediatric patients with chronic constipation were treated with this non-invasive neuromodulation procedure, adapted from classical sacral nerve stimulation. A stimulation device attached to adhesive electrodes on the lower abdomen and back generated an electrical field with a stable frequency of 15 Hz via variable stimulation intensity (1-10 V). The effect of therapy was evaluated in routine check-ups and by specialized questionnaires. Results: The study assessed non-invasive sacral nerve stimulation in 17 patients (9 boys, 8 girls, mean age 6.5 years). They underwent stimulation with 6-9 V for a mean of 11 h per day (range 0.5-24 h) over a mean of 12.7 weeks. Improvement of constipation was achieved in more than half of the patients (12/17) and sustained in almost half of these patients (5/12). Complications were minor (skin irritation, electrode dislocation). Conclusions: Non-invasive sacral nerve stimulation appears to be effective in achieving improvement in pediatric patients with chronic constipation. As an additional external neuromodulation concept, this stimulation may represent a relevant addition to currently available therapeutic options. Further studies are needed to confirm these results.

Sacral nerve stimulation with appropriate parameters improves constipation in rats by enhancing colon motility mediated via the autonomic-cholinergic mechanisms

Although sacral nerve stimulation (SNS) has been applied for treating constipation, its parameters were adopted from SNS for fecal incontinence, its effects are limited, and mechanisms are largely unknown. We investigated the effects and mechanism of SNS with appropriate parameters on constipation in rats treated with loperamide. First, using rectal compliance as an outcome measure, an experiment was performed to derive effective SNS parameters. Then, a 7-day SNS was performed in rats with constipation induced by loperamide. Autonomic functions were assessed by spectral analysis of heart rate variability (HRV) derived from an electrocardiogram. Serum levels of pancreatic polypeptide (PP), norepinephrine (NE), and acetylcholine (ACh) in colon were assessed. 1) Acute SNS at 5 Hz, 100 µs was found effective in enhancing rectal compliance and accelerating distal colon transit (P < 0.05 vs. sham SNS). 2) The 7-day SNS normalized loperamide-induced constipation, assessed by the number, weight, and water content of fecal pellets, and accelerated the distal colon transit (29.4 ± 3.7 min with sham SNS vs. 16.4 ± 5.3 min with SNS but not gastric emptying or intestinal transit. 3) SNS significantly increased vagal activity (P = 0.035) and decreased sympathetic activity (P = 0.012), assessed by spectral analysis of HRV as well as by the serum PP. 4) SNS increased ACh in the colon tissue; atropine blocked the accelerative effect of SNS on distal colon transit. We concluded that SNS with appropriate parameters improves constipation induced by loperamide by accelerating distal colon motility, mediated via the autonomic-cholinergic function.NEW & NOTEWORTHY Although sacral nerve stimulation (SNS) has been applied for treating constipation, its parameters were adopted from SNS for fecal incontinence, effects are limited, and mechanisms are largely unknown. This paper shows that SNS with appropriate parameters improves constipation induced by loperamide by accelerating distal colon motility mediated via the autonomic-cholinergic function.

Use of Bioelectronics in the Gastrointestinal Tract

Gastrointestinal (GI) motility disorders are major contributing factors to functional GI diseases that account for >40% of patients seen in gastroenterology clinics and affect >20% of the general population. The autonomic and enteric nervous systems and the muscles within the luminal GI tract have key roles in motility. In health, this complex integrated system works seamlessly to transport liquid, solid, and gas through the GI tract. However, major and minor motility disorders occur when these systems fail. Common functional GI motility disorders include dysphagia, gastroesophageal reflux disease, functional dyspepsia, gastroparesis, chronic intestinal pseudo-obstruction, postoperative ileus, irritable bowel syndrome, functional diarrhea, functional constipation, and fecal incontinence. Although still in its infancy, bioelectronic therapy in the GI tract holds great promise through the targeted stimulation of nerves and muscles.

Transabdominal Functional Magnetic Stimulation for the Treatment of Constipation in Brain-Injured Patients: A Randomized Controlled Trial

Objective

To investigate the effects of the transabdominal functional magnetic stimulation (A-FMS) for constipation in stroke or brain-injured patients.

Methods

Twenty-four brain-injured patients (11 males and 13 females; median age, 65 years; 22 cases of stroke and 2 cases of traumatic brain injury) with constipation, who were admitted to the rehabilitation department, were enrolled and randomly divided into magnetic stimulation (MS) group and sham stimulation (Sham) group. Several parameters related with constipation such as total and segmental colon transit time (CTT), defecation frequency, and Bristol Stool Scale (BSS) before and after 2 weeks of A-FMS (5 times per week, total 10 times of A-FMS) were evaluated. The Korean version of the Modified Barthel Index (K-MBI) was also evaluated.

Results

A significant decrease in segmental CTT in the left colon (-8.2±3.9 vs. 4.1±2.5 hours; p<0.05 by paired sample t-test) and a significant increase in the frequency of defecation (1.5±0.2 vs 0.7±0.3; p<0.05 by paired sample t-test) were observed in the MS group compared with the Sham group. Stool hardness became significantly softer in the MS group compared with the Sham group (2.3–3.5 in the MS and 2.6–3.1 in the Sham; p<0.05 by chi-square test) as evaluated by BSS. No difference in the K-MBI was observed between the two groups.

Conclusion

The present study suggests that A-FMS can be an additional therapeutic tool for managing constipation in brain-injured patients with abnormal bowel movement, defecation frequency, and stool hardness.

Long-term outcome of intractable constipation treated by sacral neuromodulation: a comparison between children and adults

AIM

Sacral neuromodulation (SNM) is a minimally invasive therapy for functional constipation (FC) and is most often used to treat adults. Recent studies suggest that SNM may also beneficial in children. However, comparative data regarding preferred age of SNM for FC are lacking. Therefore, long-term results of SNM for FC were compared between children and adults.

METHOD

All patients treated with SNM for FC between 2004 and 2015 were evaluated. Outcomes of children (age 10-18 years) were compared with those for adults (≥ 18 years). The primary end-point was a defaecation frequency of three or more times per week, which is consistent with the ROME-III criteria. Secondary outcomes were quality of life (QoL; SF-36) and the Cleveland Clinic Constipation Score.

RESULTS

One hundred and eighty patients (45 children, 135 adults) were eligible for SNM. The mean age was 15.8 (children) and 41.4 years (adults). One hundred and twenty-six patients received permanent SNM (38 children, 88 adults). Mean follow-up was 47 months in both groups. Defaecation frequency increased in both groups after SNM compared with baseline. Defaecation frequency in adults was higher than in children. The increased defaecation frequency was maintained during the entire follow-up period in both groups. QoL of children was impaired compared with the Dutch population with regard to bodily pain, general health and vitality. Adults had worse QoL with regard to physical functioning, bodily pain, general health, vitality and social functioning compared with the Dutch population. QoL of children did not differ from adults.

CONCLUSION

Sacral neuromodulation (SNM) should be considered in children (< 18 years) with FC. However, the indication of SNM for FC remains debatable considering the limited improvements and high costs.

Sacral neuromodulation versus personalized conservative treatment in patients with idiopathic slow-transit constipation: study protocol of the No.2-trial, a multicenter open-label randomized controlled trial and cost-effectiveness analysis

PURPOSE

The evidence regarding the (cost-)effectiveness of sacral neuromodulation (SNM) in patients with therapy-resistant idiopathic slow-transit constipation is of suboptimal quality. The Dutch Ministry of Health, Welfare and Sports has granted conditional reimbursement for SNM treatment. The objective is to assess the effectiveness, cost-effectiveness, and budget impact of SNM compared to personalized conservative treatment (PCT) in patients with idiopathic slow-transit constipation refractory to conservative treatment.

METHODS

This study is an open-label, multicenter randomized controlled trial. Patients aged 14 to 80 with slow-transit constipation, a defecation frequency (DF) < 3 per week and meeting at least one other Rome-IV criterion, are eligible. Patients with obstructed outlet, irritable bowel syndrome, bowel pathology, or rectal prolapse are excluded. Patients are randomized to SNM or PCT. The primary outcome is success at 6 months (DF ≥ 3 a week), requiring a sample size of 64 (α = 0.05, β = 0.80, 30% difference in success). Secondary outcomes are straining, sense of incomplete evacuation, constipation severity, fatigue, constipation specific and generic quality of life, and costs at 6 months. Long-term costs and effectiveness will be estimated by a decision analytic model. The time frame is 57 months, starting October 2016. SNM treatment costs are funded by the Dutch conditional reimbursement program, research costs by Medtronic.

CONCLUSIONS

The results of this trial will be used to make a final decision regarding reimbursement of SNM from the Dutch Health Care Package in this patient group.

TRIAL REGISTRATION

This trial is registered at clinicaltrials.gov , identifier NCT02961582, on 12 October 2016.

Surgery for constipation: systematic review and practice recommendations: Results V: Sacral Nerve Stimulation

AIM

To assess the outcomes of sacral nerve stimulation in adults with chronic constipation.

METHOD

Standardised methods and reporting of benefits and harms were used for all CapaCiTY reviews that closely adhered to PRISMA 2016 guidance. Main conclusions were presented as summary evidence statements with a summative Oxford Centre for Evidence-Based Medicine (2009) level.

RESULTS

Seven articles were identified, providing data on outcomes in 375 patients. Length of procedures and length of stay was not reported. Data on harms were inconsistently reported and heterogeneous, making estimates of harm tentative and imprecise. Morbidity rates ranged between 13 and 34%, with overall device removal rate between 8 and 23%. Although inconsistently reported, pooled treatment success was typically 57-87% for patients receiving permanent implants, although there was significant variation between studies. Patient selection was inconsistently documented. No conclusions could be drawn regarding particular phenotypes that responded favourably or unfavourably to sacral nerve stimulation.

CONCLUSION

Evidence supporting sacral nerve stimulation is derived from poor quality studies. Three methodologically robust trials are have reported since this review and all have all urged greater caution.

Electrical therapies for gastrointestinal motility disorders

Gastrointestinal (GI) motility disorders are common in clinical settings, including esophageal motility disorders, gastroesophageal reflux disease, functional dyspepsia, gastroparesis, chronic intestinal pseudo-obstruction, post-operative ileus, irritable bowel syndrome, diarrhea and constipation. While a number of drugs have been developed for treating GI motility disorders, few are currently available. Emerging electrical stimulation methods may provide new treatment options for these GI motility disorders. Areas covered: This review gives an overview of electrical therapies that have been, and are being developed for GI motility disorders, including gastroesophageal reflux, functional dyspepsia, gastroparesis, intestinal motility disorders and constipation. Various methods of gastrointestinal electrical stimulation are introduced. A few methods of nerve stimulation have also been described, including spinal cord stimulation and sacral nerve stimulation. Potentials of electrical therapies for obesity are also discussed. PubMed was searched using keywords and their combinations: electrical stimulation, spinal cord stimulation, sacral nerve stimulation, gastrointestinal motility and functional gastrointestinal diseases. Expert commentary: Electrical stimulation is an area of great interest and has potential for treating GI motility disorders. However, further development in technologies (devices suitable for GI stimulation) and extensive clinical research are needed to advance the field and bring electrical therapies to bedside.

Sacral nerve stimulation allows for decreased antegrade continence enema use in children with severe constipation

BACKGROUND

Sacral nerve stimulation (SNS) can be beneficial for children with constipation, but no studies have focused on children with constipation severe enough to require antegrade continence enemas (ACEs). Our objective was to evaluate the efficacy of SNS in children with constipation treated with ACE.

METHODS

Using a prospective patient registry, we identified patients <21years old who were receiving ACE prior to SNS placement. We compared ACE/laxative usage, PedsQL Gastrointestinal Symptom Scale (GSS), Fecal Incontinence Quality of Life Scale (FIQL), Fecal Incontinence Severity Index (FISI), and Vancouver Dysfunctional Elimination Syndrome Score (DES) at baseline and progressive follow-up time intervals.

RESULTS

Twenty-two patients (55% male, median 12years) were included. Median ACE frequency decreased from 7 per week at baseline to 1 per week at 12months (p<0.0001). Ten children (45%) had their cecostomy/appendicostomy closed. Laxative use, GSS, FIQL, and DES did not change. FISI improved over the first 12months with statistical significance reached only at 6months (p=0.02). Six (27%) children experienced complications after SNS that required further surgery.

CONCLUSIONS

In children with severe constipation dependent on ACE, SNS led to a steady decrease in ACE usage with nearly half of patients receiving cecostomy/appendicostomy closure within 2years.

LEVEL OF EVIDENCE

IV.

Use of Sacral Nerve Stimulation for the Treatment of Overlapping Constipation and Fecal Incontinence

Patient: Female, 51

Final Diagnosis: Fecal incontinence

Symptoms: Constipation • fecal incontinence

Medication: —

Clinical Procedure: Sacral nerve stimulator

Specialty: Gastroenterology and Hepatology

Bilateral Posterior Tibial Nerve Stimulation in the Treatment of Rectal Evacuation Disorder: A Preliminary Report

BACKGROUND

Posterior tibial nerve stimulation influences both motor and sensory pathways, as well as the central nervous system. Stimulation of posterior tibial nerve roots (L4 to S3) could improve stool evacuation through S3 and/or S2 stimulation.

OBJECTIVE

This study aimed to assess the efficiency of bilateral posterior tibial nerve stimulation in the treatment of rectal evacuation disorder without anatomic obstruction.

DESIGN

This was a prospective case series studying the treatment of patients with obstructed defecation by posterior tibial nerve stimulation.

SETTING

The study was conducted at a tertiary referral academic medical center.

PATIENTS

Patients with rectal evacuation disorder without anatomic obstruction who were failing maximal conservative treatments were included.

INTERVENTION

Thirty minutes of bilateral transcutaneous posterior tibial nerve stimulation was applied 3 times weekly for each patient for 6 consecutive weeks.

MAIN OUTCOME MEASURES

The primary end point was the change in the modified obstructed defecation score. Secondary end points were changes in rectal sensitivity volumes (urge to defecate volume and maximal tolerable volume) and quality of life using the Patient Assessment of Constipation-Quality of Life questionnaire.

RESULTS

Thirty-six patients (25 women) completed the trial. The mean age of patients was 57.2 years (SD = 14.4 y). No adverse events were reported. Symptomatic successful outcome was reported in 17 patients (47%) and modified obstructed defecation score decreased over 6 weeks (mean decrease = 10 points (95% CI, 8.7-11.3 points); p < 0.0001). Patients with successful outcome (responders) had relatively lower preoperative modified obstructed defecation score compared with patients with unsuccessful outcome (nonresponders). In the successful group, there were significant improvement after 6 weeks in both Patient Assessment of Constipation-Quality of Life score (mean improvement = 43.0 points (95% CI, 35.2-50.7 points); p < 0.0001) and rectal sensitivity (significant reductions in urge to defecate volume (from 258.1 ± 21.2 to 239.6 ± 15.3; p < 0.0001) and maximal tolerable volume (from 304.5 ± 24.8 to 286.8 ± 19.7; p < 0.0001)). No significant change in Patient Assessment of Constipation-Quality of Life or rectal sensitivity was observed in the nonresponders.

LIMITATIONS

The study was designed just to proof the concept, but small sample size is a limitation. Another limitation is the short duration of study of only 6 weeks.

CONCLUSIONS

Current data showed that bilateral transcutaneous posterior tibial nerve stimulation can improve symptoms in a considerable percentage of patients with obstructed defecation without anatomic obstruction. The procedure is more effective in patients with a less-modified obstructed defecation score. Additional studies are needed to discover the predictive factors for success.

Increased yield pressure in the anal canal during sacral nerve stimulation: a pilot study with the functional lumen imaging probe

BACKGROUND

Sacral nerve stimulation (SNS) is a well-established treatment for fecal incontinence but its mode of action remains obscure. Anal sphincter function is usually evaluated with manometry but resistance to distension may be a more appropriate parameter than luminal pressure. The functional lumen imaging probe allows detailed description of distension properties of the anal canal. Our objective in this study was to characterize the impact of SNS on distension properties of the anal canal in patients with idiopathic fecal incontinence.

METHODS

We studied 10 women (median age 64 [44-79] years) with idiopathic fecal incontinence at baseline and during SNS. The luminal geometry of the anal canal was examined with the FLIP at rest and during squeeze and the distensibility of the anal canal was investigated during filling of the bag.

KEY RESULTS

All patients were successfully treated with SNS and the mean Wexner Incontinence Score was reduced from 14.9 ± 4 to 7.1 ± 4.8 (P<.001). The pressure required to open the narrowest point of the anal canal during distension (yield pressure) increased from 14.5 ± 12.2 mmHg at baseline to 20.5 ± 13.3 mmHg during SNS (P<.01). The pressure-strain elastic modulus increased non-significantly from 2.2 ± 0.5 to 2.9 ± 1.6 kPa, indicating increased stiffness of the anal canal.

CONCLUSION AND INFERENCES

The yield pressure and the resistance to distension increased in response to SNS for idiopathic fecal incontinence. This will inevitably increase the resistance to flow through the anal canal, which may contribute to the benefits of sacral nerve stimulation.

Three-year follow-up of sacral nerve stimulation for patients with diarrhoea-predominant and mixed irritable bowel syndrome

AIM

Our unit has recently shown that sacral nerve stimulation (SNS) has a significantly positive short-term effect on selected patients with diarrhoea-predominant or mixed irritable bowel syndrome (IBS). The aim of the present prospective study was to evaluate the medium-term efficacy of SNS for IBS to establish whether SNS could have a future role in the treatment of IBS.

METHOD

Patients with IBS who had previously been implanted with a permanent neurostimulator as part of a randomized, controlled, crossover study, were assessed for medium-term follow-up. The primary end-point was change in the IBS-specific symptom score (Gastrointestinal Symptom Rating Scale-Irritable Bowel Syndrome version questionnaire) from baseline to 3-year follow-up. The secondary end-point was a change in the IBS-specific quality of life score (Irritable Bowel Syndrome-Impact Scale questionnaire) from baseline to 3-year follow-up.

RESULTS

Of 26 patients, 20 were eligible for 3-year follow-up. The median IBS-specific symptom score was significantly lower at 3-year follow-up (30, range 13-71) than at baseline (62, 45-80) (P = 0.0001). The effect was observed in all symptom clusters within the score. Also, the median IBS-specific quality of life score was significantly improved at 3-year follow-up (52, 26-169) compared with baseline (135, 82-180, P = 0.0002). The effect was observed in all domains of the score. As per the protocol, 75% of patients were judged therapeutic successes. Seventy per cent of patients had a more than 50% reduction in daily IBS symptoms.

CONCLUSION

At medium-term follow-up, SNS continues to be an effective treatment for highly selected patients with diarrhoea-predominant or mixed IBS.

Electroneurostimulation for the management of bladder bowel dysfunction in childhood

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

Functional Disorders: Slow-Transit Constipation

Constipation is a very common complaint, with slow-transit constipation (STC) accounting for a significant proportion of cases. Old age, female gender, psychiatric illness, and history of sexual abuse are all associated with STC. The exact cause of STC remains elusive; however, multiple immune and cellular changes have been demonstrated. Diagnosis requires evidence of slowed colonic transit which may be achieved via numerous modalities. While a variety of medical therapies exist, these are often met with limited success and a minority of patients ultimately require operative intervention. When evaluating a patient with STC, it is important to determine the presence of concomitant obstructed defecation or other forms of enteric dysmotility, as this may affect treatment decisions. Although a variety of surgical procedures have been reported, subtotal colectomy with ileorectal anastomosis is the most commonly performed and well-studied procedure, with the best track record of success.

Bilateral transcutaneous tibial nerve stimulation for chronic constipation

AIM

Chronic constipation is difficult to treat when symptoms are intractable. Colonic propulsion may be altered by distal neuromodulation but this is conventionally delivered percutaneously. Transcutaneous tibial nerve stimulation is noninvasive and cheap: this study aimed to assess its efficacy in chronic constipation.

METHOD

Eighteen patients (median age 46 years, 12 female) with chronic constipation were recruited consecutively. Conservative and behavioural therapy had failed to improve symptoms in all 18. Thirty minutes of daily bilateral transcutaneous tibial nerve stimulation was administered by each patient at home for 6 weeks. The primary outcome measure was a change in the Patient Assessment of Constipation Quality of Life (PAC-QoL) score. Change in Patient Assessment of Constipation Symptoms (PAC-SYM), weekly bowel frequency and visual analogue scale (VAS) score were also measured.

RESULTS

Fifteen patients (12 female) completed the trial. The PAC-QoL score improved significantly with treatment [pretreatment, median 2.95, interquartile range (IQR) 1.18; posttreatment, median 2.50, IQR 0.70; P = 0.047]. There was no change in PAC-SYM score (pretreatment, median 2.36, IQR 1.59; posttreatment, median 2.08, IQR 0.92; P = 0.53). Weekly stool frequency improved as did VAS score, but these did not reach statistical significance (P = 0.229 and 0.161). The PAC-QoL and PAC-SYM scores both improved in four (26%) patients. Two patients reported complete cure. There were no adverse events reported.

CONCLUSION

Bilateral transcutaneous tibial nerve stimulation appears to be effective in a quarter of patients with chronic constipation. Carefully selected patients with less severe disease may benefit more. This requires further study.

Sacral nerve stimulation for faecal incontinence and constipation in adults

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Transcutaneous Electrical Nerve Stimulation Increases Rectal Activity in Children

OBJECTIVES

Neurostimulation is increasingly used in treating bladder and bowel dysfunction, but its effect on rectal motility is obscure. The aim of the study was to evaluate the acute effect of transcutaneous electrical nerve stimulation (TENS) on rectal motility in children with overactive bladder (OAB).

METHODS

In this double-blind placebo-controlled study in 20 children with OAB (mean age 8.6 ± 1.8 years; 7 girls), 48-hour urodynamic monitoring including rectal manometry was performed. After 24-hours of baseline investigation without stimulation the children were randomised to either active TENS (n = 10) or placebo (n = 10). Surface electrodes were placed over the sacral bone. The exterior of active and placebo stimulators was identical. Starting in the morning, the children received either continuous TENS stimulation or placebo until bedtime. Rectal contractions were de&filig;ned as pressure runs exceeding 5 cm H2O and lasting ≥3 minutes.

RESULTS

At baseline there was no significant difference in proportion of time with rectal contractions in the 2 groups (TENS group median 31% [range 12%-66%] vs placebo group median 31% [range 10%-66%]; P = 0.75); however, on the day of stimulation there was more time with rectal contractions in the group receiving TENS (median 51% [range 25%-78%]) compared with placebo (median 32% [range 4%-68%]; P = 0.02). Also, there was an increase in time with rectal contractions in the TENS group (P = 0.007) but not in the placebo group (P = 0.39). The night after the TENS was disabled, rectal activity in both groups returned to baseline level.

CONCLUSIONS

TENS acutely increases time with rectal contractions in children undergoing urodynamic investigation. The effect disappears when the stimulator is turned off.

Results after sacral nerve stimulation for chronic constipation

BACKGROUND

Sacral nerve stimulation is an established treatment for fecal incontinence and initial reports describe successful results also in subjects with chronic constipation.

METHODS

Consecutive patients with slow transit or outlet obstruction type constipation were offered external stimulation through a test electrode inserted in a sacral foramen during a 3-week period. The symptomatic evaluation was based on the number of bowel movements and a validated obstructed defecation score (ODS). A permanent implant was performed provided an overall 50% decrease in symptoms was observed.

KEY RESULTS

In total, 44 patients with chronic constipation were treated with a 3-week test stimulation. Fifteen experienced a 50% reduction of symptoms and received a permanent implant. Four of the 15 with permanent implants were explanted during the course of the study. Five subjects (11% of original group) reported sustained symptom relief at final follow-up after a mean of 24 months (range 4-81). Mean ODS score did not change during the treatment. Patients with predominantly slow transit constipation or outlet obstruction did not differ concerning success rate.

CONCLUSIONS & INFERENCES

Sacral nerve stimulation has limited efficacy in unselected patients with chronic constipation and cannot be recommended for treatment on routine basis.

Treatment efficacy of sacral nerve stimulation in slow transit constipation: a two-phase, double-blind randomized controlled crossover study

OBJECTIVES

Sacral nerve stimulation (SNS) is a potential treatment for constipation refractory to standard therapies. However, there have been no randomized controlled studies examining its efficacy. In patients with slow transit constipation, we evaluated the efficacy of suprasensory and subsensory SNS compared with sham, in a prospective, 18-week randomized, double-blind, placebo-controlled, two-phase crossover study. The primary outcome measure was the proportion of patients who, on more than 2 days/week for at least 2 of 3 weeks, reported a bowel movement associated with a feeling of complete evacuation.

METHODS

After 3 weeks of temporary peripheral nerve evaluation (PNE), all patients had permanent implantation and were randomized to subsensory/sham (3 weeks each) and then re-randomized to suprasensory/sham (3 weeks each) with a 2-week washout period between each arm. Daily stool dairies were kept, and quality of life (QoL; SF36) was measured at the end of each arm.

RESULTS

Between November 2006 and March 2012, 234 constipated patients were assessed, of whom 59 were willing and deemed eligible to participate (4 male; median age 42 years). Of the 59 patients, 16 (28%) responded to PNE. Fifty-five patients went on to permanent SNS implantation. The proportion of patients satisfying the primary outcome measure did not differ between suprasensory (30%) and sham (21%) stimulations, nor between subsensory (25%) and sham (25%) stimulations. There were no significant changes in QoL scores.

CONCLUSIONS

In patients with refractory slow transit constipation, SNS did not improve the frequency of complete bowel movements over the 3-week active period.

Long-term results following sacral nerve stimulation for chronic constipation

AIM

The long-term outcome of sacral nerve stimulation (SNS) for chronic functional constipation was assessed.

METHOD

Patients who received a definitive SNS implant for chronic functional constipation only (according to the Rome III criteria) and were followed up for at least 3 years were included in this study. Slow transit constipation (STC) was distinguished from obstructed defaecation (OD) and mixed/undetermined constipation (MU). Constipation features, Cleveland Clinic Constipation score (CCCS) and SF-36 questionnaire data were collected; physiological tests were performed.

RESULTS

Forty-two out of 61 patients suitable for SNS received a definitive implant (14 for STC, 15 for OD, 13 for MU). Following SNS device implantation (mean follow-up 51 ± 15 months), the baseline CCCS (17 ± 6) dropped to 9 ± 6 (P < 0.001) and 47% of patients had an improvement in the CCCS of more than 50%. Such improvement was more significant in patients with OD. Anal pressures did not change, while threshold and urgency rectal sensation significantly decreased, in particular in patients with OD. All aspects of patients' health status (SF-36) improved significantly following SNS; this was more marked in patients with OD.

CONCLUSION

Data from this study suggest that the clinical efficacy of SNS can be prolonged in constipated patients, but in both the preliminary diagnostic assessment and pathophysiological interpretation every effort should be made to select patients for SNS. Although SNS showed efficacy in a low percentage of patients with STC, patients with OD were more responsive.

Colonic motor abnormalities in slow transit constipation defined by high resolution, fibre-optic manometry

BACKGROUND

Slow transit constipation (STC) is associated with colonic motor abnormalities. The underlying cause(s) of the abnormalities remain poorly defined. In health, utilizing high resolution fiber-optic manometry, we have described a distal colonic propagating motor pattern with a slow wave frequency of 2-6 cycles per minute (cpm). A high calorie meal caused a rapid and significant increase in this activity, suggesting the intrinsic slow wave activity could be mediated by extrinsic neural input. Utilizing the same protocol our aim was to characterize colonic meal response STC patients.

METHODS

A fiber-optic manometry catheter (72 sensors at 1 cm intervals) was colonoscopically placed with the tip clipped at the ascending or transverse colon, in 14 patients with scintigraphically confirmed STC. Manometric recordings were taken, for 2 h pre and post a 700 kCal meal. Data were compared to 12 healthy adults.

KEY RESULTS

Prior to and/or after the meal the cyclic propagating motor pattern was identified in 13 of 14 patients. However, the meal, did not increase the cyclic motor pattern (preprandial 7.4 ± 7.6 vs postprandial 8.3 ± 4.5 per/2 h), this is in contrast to the dramatic increase observed in health (8.3 ± 13.3 vs 59.1 ± 89.0 per/2 h; p < 0.001).

CONCLUSIONS & INFERENCES

In patients with STC a meal fails to induce the normal increase in the distal colonic cyclic propagating motor patterns. We propose that these data may indicate that the normal extrinsic parasympathetic inputs to the colon are attenuated in these patients.