Effect of electrical stimulation of the LES on LES pressure in a canine model

Wirelessly powered deformable electronic stent for noninvasive electrical stimulation of lower esophageal sphincter

Electrical stimulation is a promising method to modulate gastrointestinal disorders. However, conventional stimulators need invasive implantation and removal surgeries associated with risks of infection and secondary injuries. Here, we report a battery-free and deformable electronic esophageal stent for wireless stimulation of the lower esophageal sphincter in a noninvasive fashion. The stent consists of an elastic receiver antenna infilled with liquid metal (eutectic gallium-indium), a superelastic nitinol stent skeleton, and a stretchable pulse generator that jointly enables 150% axial elongation and 50% radial compression for transoral delivery through the narrow esophagus. The compliant stent adaptive to the dynamic environment of the esophagus can wirelessly harvest energy through deep tissue. Continuous electrical stimulations delivered by the stent in vivo using pig models significantly increase the pressure of the lower esophageal sphincter. The electronic stent provides a noninvasive platform for bioelectronic therapies in the gastrointestinal tract without the need for open surgery.

A Comparative Assessment of the Diagnosis of Swallowing Impairment and Gastroesophageal Reflux in Canines and Humans

Swallowing impairment is a highly prevalent and clinically significant problem affecting people and dogs. There are myriad causes of swallowing impairment of which gastroesophageal reflux is the most common in both species. Similarities in anatomy and physiology between humans and canines results in analogous swallowing disorders including cricopharyngeus muscle achalasia, esophageal achalasia, hiatal herniation, and gastroesophageal reflux with secondary esophagitis and esophageal dysmotility. Accordingly, the diagnostic approach to human and canine patients with swallowing impairment is similar. Diagnostic procedures such as swallowing fluoroscopy, high-resolution manometry, pH/impedance monitoring, and endolumenal functional luminal imaging probe can be performed in both species; however, nasofacial conformation, increased esophageal length, and the difficulty of completing several of these procedures in awake dogs are inherent challenges that need to be considered. Human patients can convey their symptoms and respond to verbal cues, whereas veterinarians must rely on clinical histories narrated by pet owners followed by comprehensive physical examination and observation of the animal eating different food consistencies and drinking water. Dogs may also be unwilling to drink or eat in the hospital setting and may be resistant to physical restraint during diagnostic procedures. Despite the species differences and diagnostic challenges, dogs are a natural animal model for many oropharyngeal and esophageal disorders affecting people, which presents a tremendous opportunity for shared learnings. This manuscript reviews the comparative aspects of esophageal anatomy and physiology between humans and canines, summarizes the diagnostic assessment of swallowing impairment in both species, and discusses future considerations for collaborative medicine and translational research.

Anti-reflux mucosectomy for refractory gastroesophageal reflux disease: a systematic review and meta-analysis

Background and study aims  Anti-reflux mucosectomy (ARMS) is an emerging endoscopic treatment for refractory gastroesophageal reflux disease (GERD). We conducted a systematic review and meta-analysis to evaluate the safety and efficacy ARMS in refractory GERD. Methods  A comprehensive search of multiple databases (through March 2020) was performed to identify studies that reported outcomes of ARMS for refractory GERD. Outcomes assessed included technical success, clinical response, and adverse events (AEs). Clinical response was defined as discontinuation (complete) or reduction (partial) of proton pump inhibitors post-ARMS at follow up. Results  A total of 307 patients (mean age 46.9 [8.1] years, 41.5 % females) were included from 10 studies. The technical success and clinical response rates were 97.7 % (95 % confidence interval [CI], 94.6-99.0) and 80.1 % (95 % CI, 61.6-91.0), respectively. The pooled rate of complete and partial clinical response was 65.3 % (95 % CI, 51.4-77.0) and 21.5 % (95 % CI, 14.2-31.2), respectively. The rate of AEs was 17.2 % (95 % CI, 13.1-22.2) with most common AE being dysphagia/esophageal stricture followed by bleeding with rates of 11.4 % and 5.0 %, respectively. GERD health-related quality of life (GERD-HRQL) (mean difference [MD] = 14.9, P  < 0.001), GERD questionnaire (GERD-Q) (MD = 4.85, P  < 0.001) and mean acid exposure time (MD = 2.39, P  = 0.01) decreased significantly post-ARMS as compared to pre-procedure. There was no difference in terms of clinical response and AEs between ARMS and ARMS with banding on subgroup analysis. Conclusions  ARMS is a safe and effective procedure for treatment of refractory GERD with high rates of clinical response, acceptable safety profile and significant improvement in GERD-related quality of life. Prospective studies are needed to validate our findings.

Electrical stimulation therapy of the lower esophageal sphincter in GERD patients—a prospective single-center study

Background

Electrical stimulation therapy (EST) of the lower esophageal sphincter (LES) for gastro esophageal reflux disease (GERD) treatment increases LES pressure through chronic stimulation, with a low risk for gastrointestinal side effects and preservation of hiatal anatomy. The aim of this study was to evaluate the efficacy and safety of this novel technique in a high-output specialized reflux center.

Methods

This is a prospective single-center study including GERD patients indicated for anti-reflux therapy who consented to undergo LES-EST. Patients underwent prospective scheduled follow-up visits including interrogation of the stimulation device, clinical examination, and assessment of health-related quality of life (HRQL).

Results

Within a 4-year period, 37 LES-EST implantations were performed. The majority of patients were male (54.1%), mean BMI was 25.8 (SD 4.4), and mean age was 54.0 (SD 15.8). The median GERD HRQL composite score was 41 (IQR 21–49). Median total % of pH <4 was 10.1 (IQR 4.4–17.3). Six (16.2%) individuals underwent explantation of the entire system (IPG and leads) due to technical defect (n = 4) or failure of therapy (n = 2). HRQL score improved from 41 (IQR 21–49) to 8.50 (IQR 4.25–20.5, p < 0.001) and 9 (23.7%) patients were on at least occasional PPI treatment.

Conclusion

Due to the low rate of GI side effects and its minimal invasive character preserving the hiatal anatomy, this novel technique might find its place in anti-reflux surgery. However, the considerably high rate of device dysfunction needs further investigation.

Promotion of Regular Oesophageal Motility to Prevent Regurgitation and Enhance Nutrition Intake in Long-Stay ICU Patients. A Multicenter, Phase II, Sham-Controlled, Randomized Trial: The PROPEL Study

OBJECTIVES

To evaluate the effect of esophageal stimulation on nutritional adequacy in critically ill patients at risk for enteral feeding intolerance.

DESIGN

A multicenter randomized sham-controlled clinical trial.

SETTING

Twelve ICUs in Canada.

PATIENTS

We included mechanically ventilated ICU patients who were given moderate-to-high doses of opioids and expected to remain alive and ventilated for an additional 48 hours and who were receiving enteral nutrition or expected to start imminently.

INTERVENTIONS

Patients were randomly assigned 1:1 to esophageal stimulation via an esophageal stimulating catheter (E-Motion Tube; E-Motion Medical, Tel Aviv, Israel) or sham treatment. All patients were fed via these catheters using a standardized feeding protocol.

MEASUREMENTS AND MAIN RESULTS

The co-primary outcomes were proportion of caloric and protein prescription received enterally over the initial 7 days following randomization. Among 159 patients randomized, the modified intention-to-treat analysis included 155 patients: 73 patients in the active treatment group and 82 in the sham treatment group. Over the 7-day study period, the percent of prescribed caloric intake (± SE) received by the enteral route was 64% ± 2 in the active group and 65% ± 2 in sham patients for calories (difference, -1; 95% CI, -8 to 6; p = 0.74). For protein, it was 57% ± 3 in the active group and 60% ± 3 in the sham group (difference, -3; 95% CI, -10 to 3; p = 0.30). Compared to the sham group, there were more serious adverse events reported in the active treatment group (13 vs 6; p = 0.053). Clinically important arrhythmias were detected by Holter monitoring in 36 out of 70 (51%) in the active group versus 22 out of 76 (29%) in the sham group (p = 0.006).

CONCLUSIONS

Esophageal stimulation via a special feeding catheter did not improve nutritional adequacy and was associated with increase risk of harm in critically ill patients.

Novel Therapies for Gastroesophageal Reflux Disease: Beyond Proton Pump Inhibitors

PURPOSE OF REVIEW

Despite the many areas of unmet needs in gastroesophageal reflux disease (GERD), proton pump inhibitors (PPIs) remain the cornerstone of medical therapy. However, since their introduction, the therapeutic limitations of PPIs in GERD management have been increasingly recognized.

RECENT FINDINGS

In this review we discuss the new medical, endoscopic, and surgical therapeutic modalities that have been developed over the last decade. They include the potassium-competitive acid blockers (P-CABs) which provide a rapid onset, prolonged, and profound acid suppression, mucosal protectants which promote the physiological protective barrier of the esophageal mucosa, new prokinetics and neuromodulators. There are growing numbers of novel therapeutic endoscopic techniques that are under investigation or were recently introduced into the market, further expanding our therapeutic armamentarium for GERD. The development of diverse therapeutic modalities for GERD, despite the availability of PPIs, suggests that there are many areas of unmet need in GERD that will continue and drive future exploration for novel therapies.

Wirelessly Powered Endoscopically Implantable Devices into the Submucosa as the Possible Treatment of Gastroesophageal Reflux Disease

Gastroesophageal reflux disease (GERD) is a rather common disease with a prevalence reaching up to 10 or 20% in the western world. The most specific symptoms which point to the diagnosis of GERD are feelings of heartburn and the regurgitation of acidic stomach contents into the esophagus. However, a certain number of patients do not respond to standard therapy, and in these cases, it is necessary to resort to other treatment methods, such as laparoscopic fundoplication or electrostimulation of the lower esophageal sphincter. The aim of our work was to design and manufacture a miniature, battery-less stimulator to provide electric stimulation of the lower esophageal sphincter, which could be implanted deep into the submucosa of the distal esophagus. The main goal was to provide a battery-less system as opposed to traditional battery neurostimulators to reduce the size and weight of the device. An electronic prototype of a wirelessly powered implantable device was developed. We used animal models for the experiments. The device is designed to treat GERD via electrical stimulation of the muscularis propria. It is implanted into the submucosal pocket by the lower esophageal sphincter with an endoscope. This method of implantation is superior to esophageal stimulators used today because of very low invasiveness of the surgery. Bipolar neurostimulation via two gold-plated leads is provided. The device does not have any source of energy; it is powered wirelessly which reduces the risk of potential battery leakage and reduces the overall dimensions.

Management of Gastroesophageal Reflux Disease

Management of gastroesophageal reflux disease (GERD) commonly starts with an empiric trial of proton pump inhibitor (PPI) therapy and complementary lifestyle measures, for patients without alarm symptoms. Optimization of therapy (improving compliance and timing of PPI doses), or increasing PPI dosage to twice daily in select circumstances, can reduce persistent symptoms. Patients with continued symptoms can be evaluated with endoscopy and tests of esophageal physiology, to better determine their disease phenotype and optimize treatment. Laparoscopic fundoplication, magnetic sphincter augmentation, and endoscopic therapies can benefit patients with well-characterized GERD. Patients with functional diseases that overlap with or mimic GERD can also be treated with neuromodulators (primarily antidepressants), or psychological interventions (psychotherapy, hypnotherapy, cognitive and behavioral therapy). Future approaches to treatment of GERD include potassium-competitive acid blockers, reflux-reducing agents, bile acid binders, injection of inert substances into the esophagogastric junction, and electrical stimulation of the lower esophageal sphincter.

Esophagogastric anastomosis in rats: Improved healing by BPC 157 and L-arginine, aggravated by L-NAME

AIM

To cure typically life-threatening esophagogastric anastomosis in rats, lacking anastomosis healing and sphincter function rescue, in particular.

METHODS

Because we assume esophagogastric fistulas represent a particular NO-system disability, we attempt to identify the benefits of anti-ulcer stable gastric pentadecapeptide BPC 157, which was in trials for ulcerative colitis and currently for multiple sclerosis, in rats with esophagocutaneous fistulas. Previously, BPC 157 therapies have promoted the healing of intestinal anastomosis and fistulas, and esophagitis and gastric lesions, along with rescued sphincter function. Additionally, BPC 157 particularly interacts with the NO-system. In the 4 d after esophagogastric anastomosis creation, rats received medication (/kg intraperitoneally once daily: BPC 157 (10 μg, 10 ng), L-NAME (5 mg), or L-arginine (100 mg) alone and/or combined or BPC 157 (10 μg, 10 ng) in drinking water). For rats underwent esophagogastric anastomosis, daily assessment included progressive stomach damage (sum of the longest diameters, mm), esophagitis (scored 0-5), weak anastomosis (mL H₂O before leak), low pressure in esophagus at anastomosis and in the pyloric sphincter (cm H₂O), progressive weight loss (g) and mortality. Immediate effect assessed blood vessels disappearance (scored 0-5) at the stomach surface immediately after anastomosis creation.

RESULTS

BPC 157 (all regimens) fully counteracted the perilous disease course from the very beginning (i.e., with the BPC 157 bath, blood vessels remained present at the gastric surface after anastomosis creation) and eliminated mortality. Additionally, BPC 157 treatment in combination with L-NAME nullified any effect of L-NAME that otherwise intensified the regular course. Consistently, with worsening (with L-NAME administration) and amelioration (with L-arginine), either L-arginine amelioration prevails (attenuated esophageal and gastric lesions) or they counteract each other (L-NAME + L-arginine); with the addition of BPC 157 (L-NAME + L-arginine + BPC 157), there was a marked beneficial effect. BPC 157 treatment for esophagogastric anastomosis, along with NOS-blocker L-NAME and/or NOS substrate L-arginine, demonstrated an innate NO-system disability (as observed with L-arginine effectiveness). BPC 157 distinctively affected corresponding events: worsening (obtained with L-NAME administration that was counteracted); or amelioration (L-arginine + BPC 157-rats correspond to BPC 157-rats).

CONCLUSION

Innate NO-system disability for esophagogastric anastomoses, including L-NAME-worsening, suggests that these effects could be corrected by L-arginine and almost completely eliminated by BPC 157 therapy.

Some Non-FDA Approved Uses for Neuromodulation in Treating Autonomic Nervous System Disorders: A Discussion of the Preliminary Support

INTRODUCTION

Neuromodulation, including cavernous nerve stimulation, gastric electrical stimulation, deep brain stimulation, and vagus nerve stimulation, has been used with success in treating several functional disease conditions. The FDA has approved the use of neuromodulation for a few indications. We discuss in our review article the evidence of using neuromodulation for treating some important disorders involving the autonomic nervous system that are not currently FDA approved.

METHODS

This was a review article that included a systematic online web search for human clinical studies testing the efficacy of neuromodulation in treating erectile dysfunction, gastroparesis, gastroesophageal reflux disease, obesity, asthma, and heart failure. Our review includes all feasibility studies, nonrandomized clinical trials, and randomized controlled trials.

RESULTS

Our systematic literature search found 3, 4, 5, 4, 1, and 4 clinical studies relating to erectile dysfunction, gastroparesis, gastroesophageal reflux disease, obesity, asthma, and heart failure, respectively.

CONCLUSION

This review article shows preliminary support based on clinical studies that neuromodulation can be of benefit for patients with important autonomic nervous system disease conditions that are not currently approved by the FDA. All of these investigational uses are encouraging; further studies are necessary and warranted for all indications discussed in this review before achieving FDA approval.

Effect of electrical stimulation of the lower esophageal sphincter in gastroesophageal reflux disease patients refractory to proton pump inhibitors

AIM: To evaluate the efficacy of lower esophageal sphincter (LES)-electrical stimulation therapy (EST) in a subgroup of patients that reported only partial response to proton pump inhibitors (PPIs) therapy, compared to a group of patient with complete response.

METHODS: Bipolar stitch electrodes were laparoscopically placed in the LES and connected to an implantable pulse generator (EndoStim BV, the Hague, the Netherlands), placed subcutaneously in the anterior abdominal wall. Stimulation at 20 Hz, 215 μsec, 3-8 mAmp in 30 min sessions was delivered starting on day 1 post-implant. Patients were evaluated using gastroesophageal reflux disease (GERD)-HRQL, symptom diaries; esophageal pH and esophageal manometry before and up to 24 mo after therapy and results were compared between partial and complete responders.

RESULTS: Twenty-three patients with GERD on LES-EST were enrolled and received continuous per-protocol stimulation through 12 mo and 21 patients completed 24 mo of therapy. Of the 23 patients, 16 (8 male, mean age 52.1 ± 12 years) had incomplete response to PPIs prior to LES-EST, while 7 patients (5 male, mean age 52.7 ± 4.7) had complete response to PPIs. In the sub-group with incomplete response to PPIs, median (IQR) composite GERD-HRQL score improved significantly from 9.5 (9.0-10.0) at baseline on-PPI and 24.0 (20.8-26.3) at baseline off-PPI to 2.5 (0.0-4.0) at 12-mo and 0.0 (0.0-2.5) at 24-mo follow-up (P < 0.05 compared to on-and off-PPI at baseline). Median (IQR) % 24-h esophageal pH < 4.0 at baseline in this sub-group improved significantly from 9.8% (7.8-11.5) at baseline to 3.0% (1.9-6.3) at 12 mo (P < 0.001) and 4.6% (2.0-5.8) at 24 mo follow-up (P < 0.01). At their 24-mo follow-up, 9/11 patients in this sub-group were completely free of PPI use. These results were comparable to the sub-group that reported complete response to PPI therapy at baseline. No unanticipated implantation or stimulation-related adverse events, or any untoward sensation due to stimulation were reported in either group and LES-EST was safely tolerated by both groups.

CONCLUSION: LES-EST is safe and effective in controlling symptoms and esophageal acid exposure in GERD patients with incomplete response to PPIs. These results were comparable to those observed PPI responders.

Electrical stimulation for gastroesophageal reflux disease: current state of the art

Patients with gastroesophageal reflux disease (GERD) who are not satisfied with acid suppression therapy can benefit primarily from fundoplication, a surgical intervention. Fundoplication has been the standard surgical procedure for GERD. It is effective but is associated with adverse effects, resulting in a declining number of interventions, creating a need for alternative interventions that are effective, yet have a better adverse effect profile. One such alternative involves the application of electrical stimulation to the lower esophageal sphincter. A number of animal studies showed that such stimulation can increase resting lower esophageal sphincter pressure. An acute human study confirmed this effect, and was followed by two open-label studies, with a follow-up of up to 3 years. Results thus far show that the therapy is associated with a significant improvement in symptoms, a significant reduction in esophageal acid exposure, and a very good safety profile. This review will describe the evolution of electrical stimulation therapy for GERD, as well as the safety and efficacy of this intervention.

Electrical stimulation therapy of the lower oesophageal sphincter for refractory gastro-oesophageal reflux disease - interim results of an international multicentre trial

BACKGROUND

A previous single-centre study showed that lower oesophageal sphincter electrical stimulation therapy (LES-EST) in gastro-oesophageal reflux disease (GERD) patients improves reflux symptoms and decreases oesophageal acid exposure.

AIM

To evaluate safety and efficacy of LES-EST in GERD patients with incomplete response to proton pump inhibitors (PPIs) in a prospective, international, multicentre, open-label study.

METHODS

GERD patients, partially responsive to PPIs, received LES-EST. GERD health-related quality of life (GERD-HRQL), daily symptom diaries, quality of life scores, oesophageal acid exposure, and LES resting and residual pressure were measured before and after initiation of LES-EST. Stimulation sessions were optimised based on residual symptoms and oesophageal acid exposure.

RESULTS

Forty-four patients were enrolled and 6-month data from 41 patients are available. Hiatal repair was performed in 16 patients. One device-related, one procedure-related and one unrelated severe adverse event were reported. GERD-HRQL improved from 31.0 (IQR 26.2-36.8) off-PPI and 16.5 (IQR 9.0-22.8) on-PPI to 4 (IQR 1-8) at 3-month and 5 (IQR 3-9) at 6-month follow-up (P < 0.0001 vs. on- and off-PPI). Oesophageal acid exposure (pH < 4.0) improved from 10.0% (IQR 7.5-12.9) to 3.8% (IQR 1.9-12.3) at 3 months (P = 0.0027) and 4.4% (IQR 2.2-7.2) at 6 months (P < 0.0001).

CONCLUSIONS

These interim results show an acceptable safety record of LES-EST to date, combined with good short-term efficacy in GERD patients who are partially responsive to PPI therapy. A remarkable reduction in regurgitation symptoms, without the risk of intervention-requiring dysphagia may prove to be an advantage compared with other anti-reflux procedures. ClinicalTrials.gov Identifier: NCT01574339.

Novel surgical options for gastroesophageal reflux disease

There are limited options to patients with gastroesophageal reflux disease (GERD) who are not satisfied with acid suppression therapy. Fundoplication, the standard surgical procedure for GERD, is effective but is associated with adverse side effects and has thus been performed less frequently, creating a need for alternative surgical interventions that are effective, yet less invasive and reversible. Lately, two such interventions were developed: the magnetic sphincter augmentation and electrical stimulation of the lower esophageal sphincter. Human studies describing safety and efficacy over a follow-up period of a number of years have been published, documenting efficacy and safety of these interventions. Future studies should clarify the role of these procedures in the spectrum of GERD therapy.

Recent advances in treatment of gastroesophageal reflux disease by acupuncture

The purpose of this paper is to summarize the effect and mechanism of three kinds of common acupuncture methods for gastroesophageal reflux disease (GERD), and to analyze their advantages and disadvantages. Currently, there have been no uniform standards for the selection of acupuncture points and acupuncture frequency, which often depends on the experience. By using different evaluation methods, such as 24 h esophageal pH monitoring, high resolution manometry, and the quality of life and symptom scores, we found that treatment of GERD by acupuncture can improve patients' symptoms and quality of life.

Two-year results of intermittent electrical stimulation of the lower esophageal sphincter treatment of gastroesophageal reflux disease

BACKGROUND

Lower esophageal sphincter (LES) electrical stimulation therapy (EST) has been shown to improve outcome in gastroesophageal reflux disease (GERD) patients at 1 year. The aim of this open-label extension trial (NCT01578642) was to study the 2-year safety and efficacy of LES-EST in GERD patients.

METHODS

GERD patients responsive partially to proton pump inhibitors (PPI) with off-PPI GERD health-related quality of life (HRQL) of ≥20, 24-hour esophageal pH ≤4.0 for >5% of the time, hiatal hernia ≤3 cm, and esophagitis LA grade C or lower participated in this trial. Bipolar stitch electrodes and a pulse generator (EndoStim BV, The Hague, The Netherlands) were implanted laparoscopically. LES-EST at 20 Hz, 215 μs, 3-8 mAmp was delivered over 30-minute sessions, 6-12 sessions per day, starting on day 1 after implantation. Patients were evaluated using GERD-HRQL, symptom diaries, Short Form-12, and esophageal pH testing at regular intervals. Stimulation sessions were optimized based on residual symptoms and esophageal pH at follow-up.

RESULTS

Twenty-five patients (mean age [SD] = 52 [12] years; 14 men) were implanted successfully; 23 patients participated in the 2-year extension trial, and 21 completed their 2-year evaluation. At 2 years, there was improvement in their median GERD-HRQL on LES-EST compared with both their on-PPI (9 vs 0; P = .001) and off-PPI (23.5 vs. 0; P < .001) baseline scores. Median 24-hour distal esophageal acid exposure improved from 10% at baseline to 4% (per-protocol analysis; P < .001) at 2 years with 71% demonstrating either normalization or a ≥50% decrease in their distal esophageal acid exposure. All except 5 patients (16/21) reported complete cessation of PPI use; only 2 patients were using a PPI regularly (≥50% of days). There was significant improvement in sleep quality and daily symptoms of heartburn and regurgitation on LES-EST. At baseline, 92% of the subjects (22/24) reported that they were "unsatisfied" with their condition off-PPI and 71% (17/24) on-PPI compared with 0% (0/21) "unsatisfied" at the 24-month visits on LES-EST. There were no device- or therapy-related serious adverse events and no untoward sensation or dysphagia reported with LES-EST.

CONCLUSION

LES-EST is safe and effective for treating patients with GERD over a period of 2 years. LES-EST resulted in a significant and sustained improvement in GERD symptoms, and esophageal acid exposure and eliminated PPI use in majority of patients (16 of 21). Further, LES-EST was not associated with any gastrointestinal side effects or adverse events.

Neuromodulation of perineally transposed antropylorus with pudendal nerve anastomosis following total anorectal reconstruction in humans

BACKGROUND

We have reported perineal antropyloric segment transposition with its pudendal innervation as a replacement for anal sphincter. Our aim herein was to neuromodulate this segment by electrical stimulation.

METHODS

Eight patients with a permanent colostomy underwent perineal antropyloric segment transposition followed by neural anastomosis of its anterior vagus branch to pudendal nerve branch in the perineum. Perineal antropyloric graft was assessed for its functional integrity and electrophysiological effects. Nerve stimulation was done by surface stimulation technique, using a customized stimulation protocol for smooth muscle. Antral pressures were recorded on voluntary attempts and on nerve stimulation with simultaneous concentric needle electromyography of the perineal antropylorus.

KEY RESULTS

The antral segment showed slow spontaneous contractions (2-3/min) on digital examination, endoscopy, and electrophysiology. Stimulated antropyloric electromyography showed a latency of 2-5 s with a differential rise in amplitude (mean range 58.57-998.75 μV) according to the frequency of stimulation (range 10-150 Hz). An average latency of 10 s in relation to rise in the antral pressure was observed on pudendal nerve stimulation. Triggering of the intrinsic rhythm was observed in patients where it was initially absent. Voluntary attempts at contraction also showed a rise in perineally transposed antral pressure.

CONCLUSIONS & INFERENCES

Spontaneous rhythm, its generation after electrical stimulation, and response to voluntary contraction demonstrates the viability and functional reinnervation of the perineally transposed antropyloric segment. Rise in pressure on electrical stimulation shows evidence for its neuromodulation.

Nonmedical therapeutic strategies for nonerosive reflux disease

There has been a marked decline over the last several years in drug development for gastroesophageal reflux disease and specifically for nonerosive reflux disease (NERD), despite there being many areas of unmet need. In contrast, we have seen a proliferation, during the same period of time, in development of novel, nonmedical therapeutic strategies for NERD using cutting-edge technology. Presently, compliance and lifestyle modifications are readily available noninvasive therapeutic interventions for NERD. Other nonmedical therapies include, the Stretta procedure, transoral incisionless fundoplication, and the magnetic sphincter augmentation device (LINX). Antireflux surgery, in experienced hands, has been repeatedly shown to be efficacious in resolving NERD-related symptoms. Psychological therapeutic interventions and alternative medicine techniques, such as acupuncture, continue to show promise, especially in NERD patients who failed antireflux treatment.

Electrical stimulation therapy for gastroesophageal reflux disease

Electrical stimulation therapy (EST) of the lower esophageal sphincter is a relatively new technique for the treatment of gastroesophageal reflux disease (GERD) that may address the need of GERD patients, unsatisfied with acid suppressive medication and concerned with the potential risks of surgical fundoplication. In this paper we review available data about EST for GERD, including the development of the technique, implant procedure, safety and results from open-label trials. Two short-term temporary stimulation and long-term open-label human trials each were initiated to investigate the safety and efficacy of EST for the treatment of GERD and currently up to 2 years follow-up results are available. The results of EST are promising as the open-label studies have shown that EST is a safe technique with a significant improvement in both subjective outcomes of symptoms and objective outcomes of esophageal acid exposure in patients with GERD. However, long-term data from larger number of patients and a sham-controlled trial are required before EST can be conclusively advised as a viable treatment option for GERD patients.

Long-term results of electrical stimulation of the lower esophageal sphincter for treatment of proximal GERD

INTRODUCTION

Electrical stimulation of the lower esophageal sphincter (LES) in gastroesophageal reflux disease (GERD) patients, using EndoStim(®) LES stimulation system (EndoStim BV, the Hague, Netherlands), enhances LES pressure, decrease distal esophageal acid exposure, improves symptoms, and eliminates the need in many patients for daily GERD medications.

AIM

To evaluate, in a post hoc analysis, the effect of LES stimulation on proximal esophageal acid exposure in a subgroup of patients with abnormal proximal esophageal acid exposure.

METHODS

Nineteen patients (median age 54 years; IQR 47-64; men-10) with GERD partially responsive to proton pump inhibitors (PPI), hiatal hernia ≤ 3 cm, esophagitis ≤ LA grade C underwent laparoscopic implantation of the LES stimulator. LES stimulation at 20 Hz, 215 μs, 5-8 m Amp sessions was delivered in 6-12, 30 min sessions each day. Esophageal pH at baseline and after 12-months of LES stimulation was measured 5 and 23 cm above the manometric upper border of LES.

RESULTS

Total, upright and supine values of median (IQR) proximal esophageal pH at baseline were 0.4 (0.1-1.4), 0.6 (0.2-2.3), and 0 (0.0-0.2) %, respectively, and at 12 months on LES-EST were 0 (0-0) % (p = 0.001 total and upright; p = 0.043 supine comparisons). 24-hour distal esophageal acid exposure improved from 10.2 (7.6-11.7) to 3.4 (1.6-7.0) % (p = 0.001). Seven (37%) patients had abnormal (>1.1%) 24-hour proximal acid exposure at baseline; all normalized at 12 months (p = 0.008). In these 7 patients, total, upright, and supine median proximal acid exposure values at baseline were 1.7 (1.3-4.1), 2.9 (1.9-3.7), and 0.3 (0-4.9) %, respectively, and after 12 months of LES-EST were 0 (0-0.0), 0 (0-0.1), and 0 (0-0) % (p = 0.018 total and upright; p = 0.043 supine comparisons). Distal esophageal pH for this group improved from 9.3 (7.8-17.2) at baseline to 3.2 (1.1-3.7) % at 12-months (p = 0.043). There were no GI side effects such as dysphagia, gas-bloat or diarrhea or device or procedure related serious adverse events with LES-EST. There was also a significant improvement in their GERD-HRQL scores.

CONCLUSION

LES-EST is associated with normalization of proximal esophageal pH in patients with GERD and may be useful in treating those with proximal GERD. The LES-EST is safe without typical side effects associated with traditional antireflux surgery.

Effect of electrical stimulation of the lower esophageal sphincter using endoscopically implanted temporary stimulation leads in patients with reflux disease

BACKGROUND

Electrical stimulation therapy (EST) has been shown to increase lower esophageal sphincter (LES) pressure in animals; however, data on the effect of EST on LES pressure in patients with gastroesophageal reflux disease (GERD) are lacking.

OBJECTIVE

The aim of our study was to investigate the effect of EST on LES pressure and esophageal function in patients with GERD.

METHODS

Patients with a diagnosis of GERD responsive to proton pump inhibitors (PPIs), increased esophageal acid on 24-h pH monitoring off GERD medications, basal LES pressure >5 mmHg, hernia <2 cm and esophagitis <LA grade B were included. A temporary pacemaker lead was placed endoscopically in the LES by creating a 3 cm submucosal tunnel, secured to the esophagus using endoscopic clips along the body of the lead and exteriorized nasally. EST was delivered 6-12 h post-implant per protocol using (i) short-pulse 200 μs, 20 Hz, and (ii) intermediate-pulse 3 ms, 20 Hz, each for 20 min at varying amplitudes. High-resolution manometry was performed pre-, during and post-EST. Symptoms of heartburn, chest or abdominal pain and dysphagia pre-, during and post-stimulation and 7 days post-procedure were recorded. Continuous cardiac monitoring was performed during and after the EST to evaluate any effect of EST on cardiac rhythm.

RESULTS

Six male patients (mean age 34.6 years) underwent successful endoscopic lead implantation; the first patient had premature lead dislodgement and did not undergo EST. The remaining five patients underwent successful EST. All patients had a significant increase in LES pressure with all sessions of EST. There was no effect on swallow-induced LES relaxation, And there were no EST-related adverse symptoms or any cardiac rhythm abnormalities.

CONCLUSIONS

In patients with GERD, short-term EST delivered using electrodes endoscopically implanted in the LES results in a significant increase in LES pressure without affecting patients' swallow function or causing any adverse symptoms or cardiac rhythm disturbances. EST may offer a novel therapy to patients with GERD.

Emerging therapeutic options in GERD

Gastroesophageal reflux disease (GERD) is a prevalent problem resulting in a high level of healthcare consultation and expenditure in the Western World. Although standard medical therapy (in the form of proton pump inhibitor drugs) is effective in the majority of cases, there remains a significant proportion who are refractory to treatment. In addition, surgical therapy (in the form of laparoscopic fundoplication) is not always effective, and in some can be associated with significant side-effects, particularly gas-bloat, flatulence and dysphagia. As such there remains an unmet need in GERD to develop new therapies for refractory cases, and to develop alternatives to fundoplication with fewer side-effects. This article discusses the current state of pharmacological and non-pharmacological emerging therapies for GERD.

Electrical stimulation therapy of the lower esophageal sphincter is successful in treating GERD: final results of open-label prospective trial

BACKGROUND

Electrical stimulation of the lower esophageal sphincter (LES) improves LES pressure without interfering with LES relaxation. The aim of this open-label pilot trial was to evaluate the safety and efficacy of long-term LES stimulation using a permanently implanted LES stimulator in patients with gastroesophageal reflux disease (GERD).

METHODS

GERD patients who were at least partially responsive to proton pump inhibitors (PPI) with abnormal esophageal pH, hiatal hernia ≤ 3 cm, and esophagitis ≤ LA grade C were included. Bipolar stitch electrodes were placed in the LES and an IPG was placed in a subcutaneous pocket. Electrical stimulation was delivered at 20 Hz, 215 μs, 3-8 mA in 30 min sessions. The number and timing of sessions was tailored to each patient's GERD profile. Patients were evaluated using GERD-HRQL, daily symptom and medication diaries, SF-12, esophageal pH, and high-resolution manometry.

RESULTS

24 patients (mean age = 53 years, SD = 12 years; 14 men) were implanted; 23 completed their 6-month evaluation. Median GERD-HRQL scores at 6 months was 2.0 (IQR = 0-5.5) and was significantly better than both baseline on-PPI [9.0 (range = 6.0-10.0); p < 0.001] and off-PPI [23 (21-25); p < 0.001] GERD-HRQL. Median% 24-h esophageal pH < 4.0 at baseline was 10.1 and improved to 5.1 at 6 months (p < 0.001). At their 6-month follow-up, 91 % (21/23) of the patients were off PPI and had significantly better median GERD-HRQL on LES stimulation compared to their on-PPI GERD-HRQL at baseline (9.0 vs. 2.0; p < 0.001). There were no unanticipated implantation- or stimulation-related adverse events or untoward sensation due to stimulation. There were no reports of treatment-related dysphagia, and manometric swallow was also unaffected.

CONCLUSIONS

Electrical stimulation of the LES is safe and effective for treating GERD. There is a significant and sustained improvement in GERD symptoms, esophageal pH, and reduction in PPI usage without any side effects with the therapy. Furthermore, the therapy can be optimized to address an individual patient's disease.

Electrical stimulation therapy of the lower esophageal sphincter is successful in treating GERD: final results of open-label prospective trial

BACKGROUND

Electrical stimulation of the lower esophageal sphincter (LES) improves LES pressure without interfering with LES relaxation. The aim of this open-label pilot trial was to evaluate the safety and efficacy of long-term LES stimulation using a permanently implanted LES stimulator in patients with gastroesophageal reflux disease (GERD).

METHODS

GERD patients who were at least partially responsive to proton pump inhibitors (PPI) with abnormal esophageal pH, hiatal hernia ≤ 3 cm, and esophagitis ≤ LA grade C were included. Bipolar stitch electrodes were placed in the LES and an IPG was placed in a subcutaneous pocket. Electrical stimulation was delivered at 20 Hz, 215 μs, 3-8 mA in 30 min sessions. The number and timing of sessions was tailored to each patient's GERD profile. Patients were evaluated using GERD-HRQL, daily symptom and medication diaries, SF-12, esophageal pH, and high-resolution manometry.

RESULTS

24 patients (mean age = 53 years, SD = 12 years; 14 men) were implanted; 23 completed their 6-month evaluation. Median GERD-HRQL scores at 6 months was 2.0 (IQR = 0-5.5) and was significantly better than both baseline on-PPI [9.0 (range = 6.0-10.0); p < 0.001] and off-PPI [23 (21-25); p < 0.001] GERD-HRQL. Median% 24-h esophageal pH < 4.0 at baseline was 10.1 and improved to 5.1 at 6 months (p < 0.001). At their 6-month follow-up, 91 % (21/23) of the patients were off PPI and had significantly better median GERD-HRQL on LES stimulation compared to their on-PPI GERD-HRQL at baseline (9.0 vs. 2.0; p < 0.001). There were no unanticipated implantation- or stimulation-related adverse events or untoward sensation due to stimulation. There were no reports of treatment-related dysphagia, and manometric swallow was also unaffected.

CONCLUSIONS

Electrical stimulation of the LES is safe and effective for treating GERD. There is a significant and sustained improvement in GERD symptoms, esophageal pH, and reduction in PPI usage without any side effects with the therapy. Furthermore, the therapy can be optimized to address an individual patient's disease.

Short-term electrical stimulation of the lower esophageal sphincter increases sphincter pressure in patients with gastroesophageal reflux disease

BACKGROUND

Electrical stimulation (ES) of the lower esophageal sphincter (LES) increases resting LES pressure (LESP) in animal models. Our aims were to evaluate the safety of such stimulation in humans, and test the hypothesis that ES increases resting LESP in patients with gastroesophageal reflux disease (GERD).

METHODS

A total of 10 subjects (nine female patients, mean age 52.6 years), with symptoms of GERD responsive to PPIs, low resting LES pressure, and abnormal 24-h intraesophageal pH test were enrolled. Those with hiatal hernia >2 cm and/or esophagitis >Los Angeles Grade B were excluded. Bipolar stitch electrodes were placed longitudinally in the LES during an elective laparoscopic cholecystectomy, secured by a clip and exteriorized through the abdominal wall. Following recovery, an external pulse generator delivered two types of stimulation for periods of 30 min: (i) low energy stimulation; pulse width of 200 μs, frequency of 20 Hz and current of 5-15 mA (current was increased up to 15 mA if LESP was less than 15 mmHg), and (ii) high energy stimulation; pulse width of 375 ms, frequency of 6 cpm, and current 5 mA. Resting LESP, amplitude of esophageal contractions and residual LESP in response to swallows were assessed before and after stimulation. Symptoms of chest pain, abdominal pain, and dysphagia were recorded before, during, and after stimulation and 7-days after stimulation. Continuous cardiac monitoring was performed during and after stimulation.

KEY RESULTS

All patients were successfully implanted nine subjects received high frequency, low energy, and four subjects received low frequency, high energy stimulation. Both types of stimulation significantly increased resting LESP: from 8.6 mmHg (95% CI 4.1-13.1) to 16.6 mmHg (95% CI 10.8-19.2), P < 0.001 with low energy stimulation and from 9.2 mmHg (95% CI 2.0-16.3) to 16.5 mmHg (95% CI 2.7-30.1), P = 0.03 with high energy stimulation. Neither type of stimulation affected the amplitude of esophageal peristalsis or residual LESP. No subject complained of dysphagia. One subject had retrosternal discomfort with stimulation at 15 mA that was not experienced with stimulation at 13 mA. There were no adverse events or any cardiac rhythm abnormalities with either type of stimulation.

CONCLUSIONS & INFERENCES

Short-term stimulation of the LES in patients with GERD significantly increases resting LESP without affecting esophageal peristalsis or LES relaxation. Electrical stimulation of the LES may offer a novel therapy for patients with GERD.

In vitro effect of pantoprazole on lower esophageal sphincter tone in rats

AIM: To investigate the in vitro effects of pantoprazole on rat lower esophageal sphincter (LES) tone.

METHODS: Rats weighing 250-300 g, provided by the Yeditepe University Experimental Research Center (YÜDETAM), were used throughout the study. They were anesthetized before decapitation. LES tissues whose mucosal lining were removed were placed in a standard 30-mL organ bath with a modified Krebs solution and continuously aerated with 95% oxygen-5% carbon dioxide gas mixture and kept at room temperature. The tissues were allowed to stabilize for 60 min. Subsequently, the contractile response to 10^-6 mol/L carbachol was obtained. Different concentrations of freshly prepared pantoprazole were added directly to the tissue bath to generate cumulative concentrations of 5 × 10^-6 mol/L, 5 × 10^-5 mol/L, and 1.5 × 10^-4 mol/L. Activities were recorded on an online computer via a 4-channel transducer data acquisition system using the software BSL PRO v 3.7, which also analyzed the data.

RESULTS: Pantoprazole at 5 × 10^-6 mol/L caused a small, but statistically insignificant, relaxation in the carbachol-contracted LES (2.23% vs 3.95%). The 5 × 10^-5 mol/L concentration, however, caused a significant relaxation of 10.47% compared with the control. 1.5 × 10^-4 mol/L concentration of pantoprazol caused a 19.89% relaxation in the carbachol contracted LES (P < 0.001).

CONCLUSION: This is the first study to demonstrate that pantoprazole has a relaxing effect in isolated LESs. These results might have significant clinical implications for the subset of patients using proton pump inhibitors who do not receive full symptomatic alleviation from gastroesophageal reflux disease.