Sustained esophageal contraction: a motor correlate of heartburn symptom

Mixed Esophageal Disease (MED): A New Concept

We define mixed esophageal disease (MED) as a disorder of esophageal structure and/or function that produces variable signs or symptoms, simulating-fully or in part other well-defined esophageal conditions, such as gastroesophageal reflux disease, esophageal motility disorders, or even neoplasia. The central premise of the MED concept is that of an overlap syndrome that incorporates selected clinical, endoscopic, imaging, and functional features that alter the patient's quality of life and affect natural history, prognosis, and management. In this article, we highlight MED scenarios frequently encountered in medico-surgical practices worldwide, posing new diagnostic and therapeutic challenges. These, in turn, emphasize the need for better understanding and management, aiming towards improved outcomes and prognosis. Since MED has variable and sometimes time-evolving clinical phenotypes, it deserves proper recognition, definition, and collaborative, multidisciplinary approach, be it pharmacologic, endoscopic, or surgical, to optimize therapeutic outcomes, while minimizing iatrogenic complications. In this regard, it is best to define MED early in the process, preferably by teams of clinicians with expertise in managing esophageal diseases. MED is complex enough that is increasingly becoming the subject of virtual, multi-disciplinary, multi-institutional meetings.

Pathophysiology of Pediatric Gastroesophageal Reflux Disease: Similarities and Differences With Adults

Gastroesophageal reflux (GOR) is defined as "the passage of gastric contents into the esophagus with or without regurgitation and vomiting" and gastroesophageal reflux disease (GORD) is defined "when GOR leads to troublesome symptoms affecting the daily functioning and/or complications." This definition was first developed in 2006 by the Montreal consensus group (1) and later on adopted by pediatric gastroenterology societies such as ESPGHAN and NASPGHAN in 2009 (2). The definition of gastroesophageal reflux reveals little about its pathophysiology and is focused on symptomatology. In this way, it acts as an umbrella term for the multifactorial causes of the disease and the various phenotypes encountered; from functional heartburn to hypersensitive esophagus and nonerosive reflux disease, to erosive esophagitis and Barrett's esophagus. This article is devoted to the pathophysiology of pediatric GORD in comparison to adult GORD and is divided in 2 parts. In the first part, we will systematically describe the different mechanisms for the generation and clearance of reflux events, while on the second part we will discuss the mechanisms involved in symptoms generation. Finally, we will discuss the similarities and differences between pediatric and adult GORD.

Analysis of Intestinal Movements with Spatiotemporal Maps: Beyond Anatomy and Physiology

Over 150 years ago, methods for quantitative analysis of gastrointestinal motor patterns first appeared. Graphic representations of physiological variables were recorded with the kymograph after the mid-1800s. Changes in force or length of intestinal muscles could be quantified, however most recordings were limited to a single point along the digestive tract.In parallel, photography and cinematography with X-Rays visualised changes in intestinal shape, but were hard to quantify. More recently, the ability to record physiological events at many sites along the gut in combination with computer processing allowed construction of spatiotemporal maps. These included diameter maps (DMaps), constructed from video recordings of intestinal movements and pressure maps (PMaps), constructed using data from high-resolution manometry catheters. Combining different kinds of spatiotemporal maps revealed additional details about gut wall status, including compliance, which relates forces to changes in length. Plotting compliance values along the intestine enabled combined DPMaps to be constructed, which can distinguish active contractions and relaxations from passive changes. From combinations of spatiotemporal maps, it is possible to deduce the role of enteric circuits and pacemaker cells in the generation of complex motor patterns. Development and application of spatiotemporal methods to normal and abnormal motor patterns in animals and humans is ongoing, with further technical improvements arising from their combination with impedance manometry, magnetic resonance imaging, electrophysiology, and ultrasonography.

GASTROESOPHAGEAL REFLUX DISEASE: A PRACTICAL APPROACH

Gastroesophageal reflux disease (GERD) presents typical manifestations such as heartburn and/or regurgitation as well as atypical manifestations such as throat symptoms, laryngitis, hoarseness, chronic cough, asthma, and sleep alterations. There are two phenotypes of the disease: erosive GERD, when erosions are identified by upper digestive endoscopy, and non-erosive GERD, when the esophageal mucosa presents a normal endoscopic aspect. Relevant clinical findings are usually absent in the physical examination, but it should be highlighted that obesity is an important aggravating factor of reflux. The treatment is established based on clinical findings and, according to the clinical situation, on complementary exams such as upper digestive endoscopy. In dubious cases where a precise diagnosis is required, the indicated test is esophageal pHmetry or impedance-pHmetry. Clinical treatment is divided into behavioral/dietary measures and pharmacological measures. Most patients benefit from clinical treatment, but surgical treatment may be indicated in the presence of a larger hiatal hernia and complications of the disease.

The Natural Course of Gastroesophageal Reflux Disease: A Critical Appraisal of the Literature

Interpreting natural course studies have been very difficult due to their retrospective design, lack of standardization, reliability of reported mucosal findings, liberal use of antireflux medications and accuracy of chart documentation. Studies provided a wide range of progression rates of patients from nonerosive reflux disease (NERD) to erosive esophagitis (EE). However, direct progression from NERD to Barrett's esophagus appears to be an uncommon phenomenon. Importantly, progression of NERD patients was commonly reported to low grades of EE, which are currently considered inconclusive of gastroesophageal reflux disease. Reports of progression rates from low grades to high grades EE also vary considerably. Progression of patients with EE, without metaplastic epithelium underneath the inflammation, to Barrett's esophagus is relatively uncommon. Recently, it was also recognized that regression from high grades to low grades EE and from EE to NERD is a common phenomenon affecting up to 25% of the patients from each group.

Extra-Esophageal Presentation of Gastroesophageal Reflux Disease: 2020 Update

Gastroesophageal reflux disease (GERD) is defined by the presence of symptoms induced by the reflux of the stomach contents into the esophagus. Although clinical manifestations of GERD typically involve the esophagus, extra-esophageal manifestations are widespread and less known. In this review, we discuss extra-esophageal manifestations of GERD, focusing on clinical presentations, diagnosis, and treatment. Common extra-esophageal manifestations of GERD include chronic cough, asthma, laryngitis, dental erosions, and gingivitis. Extra-esophageal involvement can be present also when classic GERD symptoms are absent, making the diagnosis more challenging. Although available clinical studies are heterogeneous and frequently of low quality, a trial with proton pump inhibitors can be suggested as a first-line diagnostic strategy in case of suspected extra-esophageal manifestations of GERD.

Pathophysiology, diagnosis, and pharmacological treatment of gastro-esophageal reflux disease

INTRODUCTION

Gastro-esophageal reflux disease (GERD) is a highly prevalent, chronic, relapsing disorder, whose knowledge has increased in last years thanks to the advent of new sophisticated techniques, such as 24-h impedance-pH monitoring and high-resolution manometry, for the study of esophageal functions.

AREAS COVERED

This review provides an overview of our advancements in understanding the complex pathophysiology, improving the diagnosis and defining the modern pharmacological therapeutic approach to GERD.

EXPERT OPINION

The growing clinical application of impedance-pH testing has allowed us to know the diversity of patients with non-erosive reflux disease (NERD), who nowadays represent about 70% of the whole population with reflux symptoms. We have realized that NERD has to be considered as an umbrella term covering various subgroups with different pathophysiologies. The development of new impedance metrics, in particular mean nocturnal baseline impedance, seems to be promising in the improvement of the diagnostic process of this disease. There are no particularly innovative features in the pharmacological therapy of GERD, unless the interest toward drugs is able to increase the defense properties of esophageal mucosa and/or its protection. These compounds can be of help in combination with proton pump inhibitors in NERD patients with partial response to antisecretory drugs alone.

Mechanism and Pathophysiology of Gastroesophageal Reflux Disease

Gastroesophageal reflux (GER) describes a process in which gastric contents travel retrograde into the esophagus. GER can be either a physiologic phenomenon that occurs in asymptomatic individuals or can potentially cause symptoms. When the latter occurs, this represents GER disease (GERD). The process by which GER transforms into GERD begins at the esophagogastric junction. Impaired clearance of the refluxate also contributes to GERD. Reflux causes degradation of esophageal mucosal defense. The refluxate triggers sensory afferents leading to symptom generation.

Esophageal mucosal innervation in functional heartburn: Closer to healthy asymptomatic subjects than to non-erosive reflux disease patients

BACKGROUND

Mucosal innervation in non-erosive reflux disease (NERD; pathological esophageal acid exposure, normal macroscopic mucosa) is clearly distinct from that of healthy volunteers (HV) and from patients with esophagitis or Barrett's esophagus: The nerves in NERD are situated much closer to the luminal surface of the mucosa. Patients with functional heartburn (FH) have a similar symptom profile to patients with NERD and indistinguishable macroscopic appearances. However, they have physiological acid exposure and no reflux-symptom association. The aim of our study was to delineate the position of esophageal mucosal nerve fibers in patients with FH and compare it with that in NERD and HV.

METHODS

Distal esophageal biopsies from patients with FH were immunohistochemically stained for CGRP. CGRP-positive nerve fibers were identified, and their position relative to the lumen was determined. These results were compared to our previously published cohort of HV and NERD.

RESULTS

Eleven patients were included in the FH group with a mean age of 46 years (range 33-69); 7F:4M. Nine patients had visible nerve fibers. The location of the afferent nerve fibers in the distal esophageal mucosa (median of 22, range 10.4-28) was similar to the HV group (median 25.5) and significantly deeper than the superficial nerves seen in NERD (median 9.5).

CONCLUSIONS

The mucosal innervation pattern in FH is more alike that of healthy individuals than that of NERD, with afferent nerves lying deep in the mucosa, away from the luminal surface. This supports the theory that heartburn in FH has a distinct nociceptive pathophysiology.

Non-cardiac chest pain: a 2018 update

Non-cardiac chest pain (NCCP) is defined as recurring, angina-like, chest pain of non-cardiac origin. Studies have estimated that gastroesophageal reflux disease (GERD) is the most common contributing factor for NCCP. In patients with non-GERD related NCCP, esophageal motility disorders, and functional chest pain of presumed esophageal origin are the main underlying mechanisms for symptoms. Epidemiologic studies show a high prevalence of panic disorder, anxiety and major depression in NCCP patients. The diagnostic esophageal workup starts only after that cardiac and pulmonary diseases have been ruled out. NCCP patients with typical reflux symptoms are more likely to have GERD-related NCCP than those without typical reflux symptoms. High-dose proton pump inhibitor trial (PPI test) can be used to confirm the diagnosis of GERD-related NCCP. Negative upper endoscopy is quite common. For patients unresponsive to antireflux treatment and with negative endoscopy, impedance-pH monitoring should be done. Treatment of patients with non-GERD-related NCCP has focused on esophageal (hypercontractile or spastic) motility disorders and esophageal visceral hypersensitivity. In the first case, several trials using calcium channel blockers, nitrates, anticholinergics, or botulinum toxin injection and recent trials with endoscopic myotomy have been conducted. In case of visceral hypersensitivity, studies found that the amelioration, when compared to placebo, was significant with venlafaxine, sertraline, and imipramine. In this context, also cognitive behavioral therapy has been proposed.

Sustained esophageal longitudinal smooth muscle contraction may not be a cause of noncardiac chest pain

BACKGROUND

The etiology of noncardiac chest pain (NCCP) is poorly understood. Some evidence suggests that it may be related to sustained esophageal contractions (SECs) of longitudinal smooth muscle. This study attempts to evaluate whether SECs play a role in symptom production in NCCP patients.

METHODS

This was a prospective double-blind study comparing NCCP patients to healthy controls. Subjects underwent high-resolution esophageal manometry followed by infusions of normal saline and 0.1N hydrochloric acid into the esophagus. Pain intensity was recorded during each minute of the infusion using a visual analog scale between 0 and 10. Two blinded investigators measured the esophageal length at the end of the saline and acid infusion periods as well as the point at which esophageal shortening began using the computer based manometry software.

KEY RESULTS

Seventeen NCCP patients and 16 controls completed the study. 64% of study subjects demonstrated esophageal shortening in response to acid infusion with mean shortening of 0.4 ± 0.54 cm. The mean decrease in esophageal length with acid was similar between the groups (1.9% ± 2.6% for NCCP patients vs 1.7% ± 2.4% for controls, P = .82). There was no correlation between pain onset and esophageal shortening.

CONCLUSIONS AND INFERENCES

NCCP patients did not appear to have an exaggerated esophageal shortening response to intraluminal acid. As well, there was poor temporal correlation between esophageal shortening and symptoms. Thus, acid-induced SECs may not play a significant role in pain production in NCCP patients.

Esophageal shortening after rapid drink test during esophageal high-resolution manometry: A relevant finding?

Background

Esophageal shortening (ES) might be observed during high-resolution manometry (HRM), in particular after the rapid drink test (RDT). We aimed to assess its diagnostic value in patients referred for HRM.

Methods

HRM of patients without previous esophagogastric surgery or endoscopic treatment was retrospectively reviewed using the Chicago Classification v3.0. ES and pan-esophageal pressurization were analyzed during the RDT (200-ml free drinking in a sitting position).

Results

A total of 2141 cases (1291 females, mean age 54 years) were reviewed. During the RDT, ES occurred in 4% and pan-esophageal pressurization in 14% of patients. ES was almost exclusively encountered in patients with impaired esophagogastric junction relaxation or major disorders of peristalsis. Among 31 patients with ES and no definite diagnosis of achalasia, 19 had follow-up and 13 (68%) changed diagnostic category: two adenocarcinoma of the cardia, and 11 cases of atypical achalasia. The positive predictive value of ES for a significant esophageal disorder was 95%.

Conclusion

ES is rarely observed during the RDT. When present, it is associated with major motility disorders, especially achalasia. When the diagnostic criteria for achalasia are not fulfilled, further complementary examinations should be performed to rule out incomplete forms of achalasia or an infiltrative process of the cardia.

Anxiety can significantly explain bolus perception in the context of hypotensive esophageal motility: Results of a large multicenter study in asymptomatic individuals

BACKGROUND

Previous studies have not been able to correlate manometry findings with bolus perception. The aim of this study was to evaluate correlation of different variables, including traditional manometric variables (at diagnostic and extreme thresholds), esophageal shortening, bolus transit, automated impedance manometry (AIM) metrics and mood with bolus passage perception in a large cohort of asymptomatic individuals.

METHODS

High resolution manometry (HRM) was performed in healthy individuals from nine centers. Perception was evaluated using a 5-point Likert scale. Anxiety was evaluated using Hospitalized Anxiety and Depression scale (HAD). Subgroup analysis was also performed classifying studies into normal, hypotensive, vigorous, and obstructive patterns.

KEY RESULTS

One hundred fifteen studies were analyzed (69 using HRM and 46 using high resolution impedance manometry (HRIM); 3.5% swallows in 9.6% of volunteers were perceived. There was no correlation of any of the traditional HRM variables, esophageal shortening, AIM metrics nor bolus transit with perception scores. There was no HRM variable showing difference in perception when comparing normal vs extreme values (percentile 1 or 99). Anxiety but not depression was correlated with perception. Among hypotensive pattern, anxiety was a strong predictor of variance in perception (R² up to .70).

CONCLUSION AND INFERENCES

Bolus perception is less common than abnormal motility among healthy individuals. Neither esophageal motor function nor bolus dynamics evaluated with several techniques seems to explain differences in bolus perception. Different mechanisms seem to be relevant in different manometric patterns. Anxiety is a significant predictor of bolus perception in the context of hypotensive motility.

The Role of Esophageal Hypersensitivity in Functional Heartburn

Functional heartburn (FH) is defined as a functional esophageal disorder characterized by symptoms of chronic heartburn with no apparent correlation to acid or nonacid reflux. In addition, its symptoms persist despite the lack of organic abnormalities or inflammation, esophageal motility disorders, or metabolic disorders. Although conditions presenting with esophageal symptoms without endoscopic abnormalities were previously categorized as nonerosive reflux disease, such conditions are now classified into 3 categories under Rome IV criteria: nonerosive reflux disease, reflux hypersensitivity, and FH. Although many aspects of FH remain unclear, its onset mechanism is considered to be strongly associated with peripheral or central sensitization, given the fact that its symptoms seem to be unrelated to gastroesophageal reflux. In addition, the cause of such hypersensitivity is an interesting topic in itself, and psychological factors, such as stress followed by increasing esophageal permeability are gaining attention as factors that can potentially influence this condition. There is a great unmet clinical need for therapeutic drugs that can be used to treat FH, and the development of novel drugs, diagnostic tests and biomarkers is eagerly awaited.

Exploration of the Esophageal Mucosal Barrier in Non-Erosive Reflux Disease

In the absence of visible mucosal damage, it is hypothesized that the esophageal mucosal barrier is functionally impaired in patients with non-erosive reflux disease (NERD). The aim of the present study was to perform an exploratory analysis of the mucosal barrier in NERD compared to erosive esophagitis (EE) and controls. A second aim was to explore TRPV1 gene transcription in relation to the mucosal barrier function and heartburn symptoms. In this prospective study, 10 NERD patients, 11 patients with active erosive esophagitis and 10 healthy volunteers were included. Biopsies from non-eroded mucosa were obtained for (1) ex vivo analyses (Ussing chamber) of transepithelial electrical resistance (TEER) and permeability (2) gene transcription of tight-junction proteins and transient receptor potential vanilloid subfamily member 1 (TRPV1). No differences in TEER or permeability were found between NERD and healthy volunteers, whereas TEER was lower in patients with erosive esophagitis. TRPV1 gene transcription was not significantly different between EE, NERD and controls. Conclusions: esophageal mucosal barrier function and TRPV1 transcription is not significantly altered in NERD patients. Future research is needed to explore other potential mechanisms that may account for the high symptom burden in these patients.

Chicago Classification of Esophageal Motility Disorders: Applications and Limits in Adults and Pediatric Patients with Esophageal Symptoms

The Chicago classification (CC) is most valued for its systematic approach to esophageal disorders and great impact in unifying practice for esophageal manometric studies. In view of the ever-growing wealth of knowledge and experience gained by the expanding use of high-resolution manometry (HRM) in various clinical scenarios, the CC is regularly updated. Its clinical impact and ability to predict clinical outcome, both in adults and pediatrics, will be further promoted by recognizing its current limitations, incorporating new metrics in its diagnostic algorithms and adjusting the HRM protocols based on the clinical question posed. Herein, we discuss the current limitations of the CC and highlight some areas of improvement for the future.

Regulation and dysregulation of esophageal peristalsis by the integrated function of circular and longitudinal muscle layers in health and disease

Muscularis propria throughout the entire gastrointestinal tract including the esophagus is comprised of circular and longitudinal muscle layers. Based on the studies conducted in the colon and the small intestine, for more than a century, it has been debated whether the two muscle layers contract synchronously or reciprocally during the ascending contraction and descending relaxation of the peristaltic reflex. Recent studies in the esophagus and colon prove that the two muscle layers indeed contract and relax together in almost perfect synchrony during ascending contraction and descending relaxation of the peristaltic reflex, respectively. Studies in patients with various types of esophageal motor disorders reveal temporal disassociation between the circular and longitudinal muscle layers. We suggest that the discoordination between the two muscle layers plays a role in the genesis of esophageal symptoms, i.e., dysphagia and esophageal pain. Certain pathologies may selectively target one and not the other muscle layer, e.g., in eosinophilic esophagitis there is a selective dysfunction of the longitudinal muscle layer. In achalasia esophagus, swallows are accompanied by the strong contraction of the longitudinal muscle without circular muscle contraction. The possibility that the discoordination between two muscle layers plays a role in the genesis of esophageal symptoms, i.e., dysphagia and esophageal pain are discussed. The purpose of this review is to summarize the regulation and dysregulation of peristalsis by the coordinated and discoordinated function of circular and longitudinal muscle layers in health and diseased states.

Low esophageal mucosal blood flow in patients with nutcracker esophagus

Nutcracker esophagus (NE) is characterized by high-amplitude peristaltic esophageal contractions, and these patients often present with symptoms of "angina-like" or noncardiac chest pain. Tissue ischemia is a known cause of visceral pain, and the goal of our present study was to determine whether esophageal wall blood perfusion (EWBP) is reduced in patients with NE. Fourteen normal subjects (mean age 51 yr, 11 men) and 12 patients (mean age 53 yr, 9 men) with NE and noncardiac chest pain were investigated. The EWBP was measured continuously using a custom-designed laser Doppler probe tethered to a Bravo capsule, which anchored it to the esophageal wall. The baseline EWBP in normal subjects was 651 ± 27 perfusion units. In patients with NE, the baseline EWBP was significantly lower than in the normal subjects (451 ± 32 perfusion units). The EWBP decreased after injection of edrophonium (which increases muscle contractions) and increased following sublingual nitroglycerin administration (which relaxes muscle) in normal subjects, as well as in NE patients. Spontaneous pain events during the recording period were often associated with drops in the EWBP. We propose that low EWBP leads to hypoxia of the esophageal tissue, which may be a mechanism of esophageal pain in patients with NE.

Pathophysiology of gastroesophageal reflux disease: new understanding in a new era

BACKGROUND

The prevalence of gastroesophageal reflux disease (GERD) has increased in the last decades and it is now one of the most common chronic diseases. Throughout time our insight in the pathophysiology of GERD has been characterized by remarkable back and forth swings, often prompted by new investigational techniques. Even today, the pathophysiology of GERD is not fully understood but it is now recognized to be a multifactorial disease. Among the factors that have been shown to be involved in the provocation or increase of reflux, are sliding hiatus hernia, low lower esophageal sphincter pressure, transient lower esophageal sphincter relaxation, the acid pocket, obesity, increased distensibility of the esophagogastric junction, prolonged esophageal clearance, and delayed gastric emptying. Moreover, multiple mechanisms influence the perception of GERD symptoms, such as the acidity of the refluxate, its proximal extent, the presence of gas in the refluxate, duodenogastroesophageal reflux, longitudinal muscle contraction, mucosal integrity, and peripheral and central sensitization. Understanding the pathophysiology of GERD is important for future targets for therapy as proton pump inhibitor-refractory GERD symptoms remain a common problem.

PURPOSE

In this review we provide an overview of the mechanisms leading to reflux and the factors influencing perception, in the light of historical developments. It is clear that further research remains necessary despite the recent advances in the understanding of the pathophysiology of GERD.

Esophageal function testing: beyond manometry and impedance

Manometry and impedance provide only surrogate information regarding longitudinal wall function and are focused on contractile amplitude and lumen content. Ultrasound imaging provides a unique perspective of esophageal function by providing important information regarding longitudinal muscle contraction. Laser Doppler assessment of perfusion may be an important complementary tool to assess abnormal wall blood perfusion as a possible mechanism of pain.

Treatment of esophageal (noncardiac) chest pain: an expert review

BACKGROUND & AIMS

Chest pain is a common and frightening symptom. Once cardiac disease has been excluded, an esophageal source is most likely. Pathophysiologically, gastroesophageal reflux disease, esophageal dysmotility, esophageal hypersensitivity, and anxiety disorders have been implicated. However, treatment remains a challenge. Here we examined the efficacy and safety of various commonly used modalities for treatment of esophageal (noncardiac) chest pain (ECP) and provided evidence-based recommendations.

METHODS

We reviewed the English language literature for drug trials evaluating treatment of ECP in PubMed, Cochrane, and MEDLINE databases from 1968-2012. Standard forms were used to abstract data regarding study design, duration, outcome measures and adverse events, and study quality.

RESULTS

Thirty-five studies comprising various treatments were included and grouped under 5 broad categories. Patient inclusion criteria were extremely variable, and studies were generally small with methodological concerns. There was good evidence to support the use of omeprazole and fair evidence for lansoprazole, rabeprazole, theophylline, sertraline, trazodone, venlafaxine, imipramine, and cognitive behavioral therapy. There was poor evidence for nifedipine, diltiazem, paroxetine, biofeedback therapy, ranitidine, nitrates, botulinum toxin, esophageal myotomy, and hypnotherapy.

CONCLUSIONS

Ideally, treatment of ECP should be aimed at correcting the underlying mechanism(s) and relieving symptoms. Proton pump inhibitors, antidepressants, theophylline, and cognitive behavioral therapy appear to be useful for the treatment of ECP. However, there is urgent and unmet need for effective treatments and for rigorous, randomized controlled trials.

Longitudinal muscle of the esophagus: its role in esophageal health and disease

PURPOSE OF REVIEW

The muscularis propria of the esophagus is organized into circular and longitudinal muscle layers. The function of the longitudinal muscle and its role in bolus propulsion are not clear. The goal of this review is to summarize what is known of the role of the longitudinal muscle in health, as well as in sensory and motor disorders of the esophagus.

RECENT FINDINGS

Simultaneous manometry and ultrasound imaging reveal that, during peristalsis, the two muscle layers of the esophagus contract in perfect synchrony. On the contrary, during transient lower esophageal sphincter (LES) relaxation, longitudinal muscle contracts independent of the circular muscle. Recent studies have provided novel insights into the role of the longitudinal muscle in LES relaxation and descending relaxation of the esophagus. In certain diseases (e.g. some motility disorders of the esophagus), there is discoordination between the two muscle layers, which likely plays an important role in the genesis of dysphagia and delayed esophageal emptying. There is close temporal correlation between prolonged contractions of the longitudinal muscles of the esophagus and esophageal 'angina-like' pain. Novel techniques to record longitudinal muscle contraction are reviewed.

SUMMARY

Longitudinal muscles of the esophagus play a key role in the physiology and pathophysiology of esophageal sensory and motor function. Neuro-pharmacologic controls of circular and longitudinal muscle are different, which provides an opportunity for the development of novel pharmacological therapies in the treatment of esophageal sensory and motor disorders.

How reflux causes symptoms: reflux perception in gastroesophageal reflux disease

In gastroesophageal reflux disease (GERD) symptoms arise due to reflux of gastric content into the oesophagus. However, the relation between magnitude and onset of reflux and symptom generation in GERD patients is far from simple; gastroesophageal reflux occurs several times a day in everyone and the majority of reflux episodes remains asymptomatic. This review aims to address the question how reflux causes symptoms, focussing on factors leading to enhanced reflux perception. We will highlight esophageal sensitivity variance between subtypes of GERD, which is influenced by peripheral sensitization of primary afferents, central sensitization of spinal dorsal horn neurons, impaired mucosal barrier function and genetic factors. We will also discuss the contribution of specific refluxate characteristics to reflux perception, including acidity, and the role of bile, pepsin and gas and proximal extent. Further understanding of reflux perception might improve GERD treatment, especially in current partial responders to therapy.

NERD: an umbrella term including heterogeneous subpopulations

Nonerosive reflux disease (NERD) represents the more common phenotypic presentation of GERD and comprises patients who have typical symptoms without any mucosal breaks at endoscopy. However, these patients are markedly heterogeneous from a pathophysiological point of view and should be correctly classified by means of 24 h impedance-pH testing, which enables detection of both acidic and weakly acidic reflux and correlation with symptoms. This technique is able to identify two subsets of NERD (that is, patients with an excess of acid or with a hypersensitive oesophagus to both acid and weakly acidic reflux) and patients with functional heartburn (who do not have any kind of reflux underlying their symptoms and must be excluded from the realm of GERD). The mechanisms of symptom generation are not clear in patients with NERD, but the presence of microscopic oesophagitis, including the dilation of intercellular spaces, seems to have a relevant role. Patients with NERD in whom acid is the main pathogenetic factor respond successfully to PPI therapy, while those with hypersensitive oesophagus to weakly acidic reflux need to be treated with reflux inhibitors or surgery, although the experience in this field is very scant. Patients with functional heartburn should undergo therapy with pain modulators, but large placebo-controlled trials are necessary.

Longitudinal muscle dysfunction in achalasia esophagus and its relevance

Muscularis propria of the esophagus is organized into circular and longitudinal muscle layers. Goal of this review is to summarize the role of longitudinal muscle in physiology and pathophysiology of esophageal sensory and motor function. Simultaneous manometry and ultrasound imaging that measure circular and longitudinal muscle contraction respectively reveal that during peristalsis 2 layers of the esophagus contract in perfect synchrony. On the other hand, during transient relaxation of the lower esophageal sphincter (LES), longitudinal muscle contracts independently of circular muscle. Recent studies provide novel insights, i.e., longitudinal muscle contraction of the esophagus induces LES relaxation and possibly descending relaxation of the esophagus. In achalasia esophagus and other motility disorders there is discoordination between the 2 muscle layers. Longitudinal muscle contraction patterns are different in the recently described three types of achalasia identified by high-resolution manometry. Robust contraction of the longitudinal muscle in type II achalasia causes pan-esophageal pressurization and is the mechanism of whatever little esophageal emptying that take place in the absence of peristalsis and impaired LES relaxation. It may be that preserved longitudinal muscle contraction is also the reason for superior outcome to medical/surgical therapy in type II achalasia esophagus. Prolonged contractions of longitudinal muscles of the esophagus is a possible mechanism of heartburn and "angina like" pain seen in esophageal motility disorders and possibly achalasia esophagus. Novel techniques to record longitudinal muscle contraction are on the horizon. Neuro-pharmacologic control of circular and longitudinal muscles is different, which provides an important opportunity for the development of novel pharmacological therapies to treat sensory and motor disorders of the esophagus.

Measuring movement and location of the gastroesophageal junction: research and clinical implications

Understanding the physiology of gastroesophageal junction (GEJ) is important as failure of its function is associated with reflux disease, hiatus hernia, and cancer. In recent years, there have been impressive developments in high resolution technologies allowing measurement of luminal pressure, pH, and impedance. One obvious deficiency is the lack of technique to monitor the movement and location of the GEJ over a prolonged period of time. Proximal movement of the GEJ during peristalsis and transient lower esophageal sphincter relaxations (TLESRs) is due to shortening of the longitudinal muscle of the esophagus. Techniques for measuring shortening include fluoroscopic imaging of mucosal clip, high-frequency intraluminal ultrasound, and high resolution manometry, but these techniques have limitations. Short segment reflux is recently found to be more common than traditional reflux and may account for the high prevalence of intestinal metaplasia and cancer seen at GEJ. While high resolution pHmetry is available, there is no technique that can reliably and continuously measure the position of the squamocolumnar junction. A new technique is recently reported allowing a precise and continuous measurement of the GEJ based on the principle of Hall effect. Reported studies have validated its accuracy both on the bench and against the gold standard, fluoroscopy. It has been used alongside high resolution manometry in studying the behavior of the GEJ during TLESRs and swallows. While there are challenges associated with this new technique, there are promising ongoing developments. There is exciting time ahead in research and clinical applications for this new technique.

Effect of acid swallowing on esophageal contraction in patients with heartburn related to hypersensitivity

BACKGROUND AND AIM

There are heterogeneous subgroups among those with heartburn, and data on these individuals are relatively scant. We aimed to evaluate the effect of acid challenge on the segmental contractions of esophageal smooth muscle in endoscopy-negative patients with normal esophageal acid exposure.

METHODS

High-resolution esophageal manometry (HRM) was performed on 30 endoscopy-negative patients with heartburn accompanied by normal esophageal acid exposure using 10 water swallows followed by 10 acidic pomegranate juice swallows. Patients were classified into functional heartburn (FH) and hypersensitive esophagus (HE) groups based on the results of 24-hr impedance pH testing. HRM topographic plots were analyzed and maximal wave amplitude and pressure volumes were measured for proximal and distal smooth muscle segments.

RESULTS

The pressure volume of the distal smooth muscle segment in the HE group measured during acidic swallows was higher than during water swallows (2224.1 ± 68.2 mmHg/cm per s versus 2105.6 ± 66.4 mmHg/cm per s, P = 0.027). A prominent shift in the pressure volume to the distal smooth muscle segment was observed in the HE group compared with the FH group (segmental ratio: 2.72 ± 0.08 versus 2.39 ± 0.07, P = 0.005). Manometric measurements during acidic swallows revealed that this shift was augmented in the HE group. The optimal ratio of pomegranate juice swallowing for discrimination of FH from HE was 2.82, with a sensitivity of 88.9% and a specificity of 100%.

CONCLUSIONS

Hypercontractile response of distal smooth muscle segment to acid swallowing was more prominent in the HE group than the FH group.

How to differentiate non-erosive reflux disease from functional heartburn

Heartburn is a common symptom in gastroesophageal reflux disease. Endoscopic examination can differentiate between reflux esophagitis and non-erosive reflux disease (NERD), but not between NERD and functional heartburn. With the development of new techniques, more NERD patients could be identified among those previously diagnosed with functional heartburn. Most patients with NERD, however, could be identified based on their clinical characteristics and response to proton pump inhibitors and/or integrated anti-gastroesophageal reflux therapy.

High-resolution Manometry: Esophageal Disorders Not Addressed by the "Chicago Classification"

The development of the high-resolution esophageal manometry (HRM) and the Chicago classification have improved the diagnosis and management of esophageal motility disorders. However, some conditions have yet to be addressed by this classification. This review describes findings in HRM which are not included in the current Chicago classification based on the experience in our center. This includes the analysis of the upper esophageal sphincter, proximal esophagus, longitudinal muscle contraction, disorders related to gastroesophageal reflux disease and respiratory symptoms. The utility of provocative tests and the use of HRM in the evaluation of rumination syndrome and post-surgical patients will also be discussed. We believe that characterization of the manometric findings in these areas will eventually lead to incorporation of new criteria into the existing classification.

Esophageal motility disorders (distal esophageal spasm, nutcracker esophagus, and hypertensive lower esophageal sphincter): modern management

The group of hypercontractile esophageal motility disorders includes distal esophageal spasm (DES), nutcracker esophagus (NE), and hypertensive lower esophageal sphincter (LES). The clinical relevance of these abnormalities identified during esophageal manometry is debated, and their management can be challenging. Hypercontractile esophageal motility abnormalities are defined through specific manometric criteria. Current pathophysiologic concepts for these abnormalities include defects in the nitronergic neural pathways and imbalances between the cholinergic and nitronergic pathway. Proposed treatments for NE, DES, and hypertensive LES include proton-pump inhibitors, nitrates, calcium channel blockers, phosphodiasterase inhibitors, and tricyclic antidepressants or serotonin reuptake inhibitors. Small case series reported benefits after botulinum toxin injections, dilatations, and myotomies. The optional management of esophageal spasm, NE, and hypertensive LES is still debated. Treatment recommendations are based on controlled studies with small numbers of patients or on case series. Medical treatment, including acid suppression, smooth muscle relaxants, and visceral analgesics, should be tried first. In nonresponding patients, botulinum toxin injections or balloon dilatations can be tried. Pneumatic dilatations or myotomies should be regarded as last-option treatments for nonresponding patients.

Esophageal wall blood perfusion during contraction and transient lower esophageal sphincter relaxation in humans

We recently reported that esophageal contraction reduces esophageal wall perfusion in an animal study. Our aim was to determine esophageal wall blood perfusion (EWBP) during esophageal contraction and transient lower esophageal sphincter relaxations (TLESRs) in humans. We studied 12 healthy volunteers. A custom-designed laser Doppler probe was anchored to the esophageal wall, 4-6 cm above the LES, by use of the Bravo pH system so that the laser light beam stay directed toward the esophageal mucosa. A high-resolution manometry equipped with impedance electrodes recorded esophageal pressures and reflux events. Synchronized pressure, impedance, pH, and EWBP recordings were obtained during dry and wet swallows and following a meal. Stable recordings of laser Doppler EWBP were only recorded when the laser Doppler probe was firmly anchored to the esophageal wall. Esophageal contractions induced by dry and wet swallows resulted in 46 ± 9% and 60 ± 10% reduction in the EWBP, respectively (compared to baseline). Reduction in EWBP was directly related to the amplitude (curvilinear fit) and duration of esophageal contraction. Atropine reduced the esophageal contraction amplitude and decreased the EWBP reduction associated with esophageal contraction. TLESRs were also associated with reduction in the EWBP, albeit of smaller amplitude (29 ± 3%) but longer duration (19 ± 2 s) compared with swallow-induced esophageal contractions. We report 1) an innovative technique to record EWBP for extended time periods in humans and 2) contraction of circular and longitudinal muscle during peristalsis and selective longitudinal muscle contraction during TLESR causes reduction in the EWBP; 3) using our innovative technique, future studies may determine whether esophageal wall ischemia is the cause of esophageal pain/heartburn.

Functional aspects of distal oesophageal spasm: the role of onset velocity and contraction amplitude on bolus transit

BACKGROUND

Distal oesophageal spasm is a rare and under-investigated motility abnormality. Recent studies indicate effective bolus transit in varying percentages of distal oesophageal spasm patients.

AIM

Explore functional aspects including contraction onset velocity and contraction amplitude cut-off values for simultaneous contractions to predict complete bolus transit.

METHODS

We re-examined data from 107 impedance-manometry recordings with a diagnosis of distal oesophageal spasm. Receiver operating characteristic analysis was conducted, regarding effects of onset velocity on bolus transit taking into account distal oesophageal amplitude and correcting for intra-individual repeated measures.

RESULTS

Mean area under the receiver operating characteristic curve for saline and viscous swallows were 0.84±0.05 and 0.84±0.04, respectively. Velocity criteria of >30 cm/s when distal oesophageal amplitude>100 mmHg and 8 cm/s when distal oesophageal amplitude<100 mmHg for saline and 32cm/s when distal oesophageal amplitude>100 mmHg and >7 cm/s when distal oesophageal amplitude<100 mmHg for viscous had a sensitivity of 75% and specificity of 80% to identify complete bolus transit. Using these criteria, final diagnosis changed in 44.9% of patients. Abnormal bolus transit was observed in 50.9% of newly diagnosed distal oesophageal spasm patients versus 7.5% of patients classified as normal. Distal oesophageal spasm patients with distal oesophageal amplitude>100 mmHg suffered twice as often from chest pain than those with distal oesophageal amplitude<100 mmHg.

CONCLUSION

The proposed velocity cut-offs for diagnosing distal oesophageal spasm improve the ability to identify patients with spasm and abnormal bolus transit.

Segmental changes in smooth muscle contraction as a predictive factor of the response to high-dose proton pump inhibitor treatment in patients with functional chest pain

BACKGROUND AND AIMS

High-dose proton pump inhibitor (PPI) treatment leads to relatively little symptomatic improvement in patients with functional chest pain (FCP). This study was to evaluate the use of smooth muscle segmental changes in esophageal contraction as measured by topographical plots of high resolution manometry (HRM) as predictive factors of the response to high-dose PPI treatment in FCP patients.

METHODS

Thirty patients diagnosed with FCP were treated with rabeprazole 20 mg twice daily for 2 weeks and classified as positive and negative responders based on symptom intensity score. HRM topographical plots were analyzed for segment lengths, maximal wave amplitudes, and pressure volumes of the proximal and distal smooth muscle segments.

RESULTS

A positive response was observed in 23.3% of the patients. While the pressure volume of the proximal segment was significantly higher in the positive responders than the negative responders (900.4 ± 91.5 mm Hg/cm per s vs. 780.5 ± 133.3 mm Hg/cm per s, P = 0.017), the pressure volume of the distal segment was significantly lower in the positive responders (1914.0 ± 159.8 mm Hg/cm per s vs. 2140.5 ± 276.2 mm Hg/cm per s, P = 0.014). A prominent shifting in pressure volume to the distal segment was observed in the negative responders compared with the positive responders (segmental ratio of pressure volume (SRPV): 2.9 ± 0.5 vs. 2.1 ± 0.1, P < 0.001), and 2.39 was found to be the SRPV that best differentiated positive and negative responders.

CONCLUSIONS

A low SRPV was associated with a positive response to high-dose PPI treatment in patients with FCP.

A study on the efficacy of rebamipide for patients with proton pump inhibitor-refractory non-erosive reflux disease

BACKGROUND AND AIM

Reflux symptoms in patients with non-erosive reflux disease (NERD) cannot be easily controlled by treatment with proton pump inhibitors (PPI). The anti-inflammatory function of rebamipide may be effective for protecting the esophageal mucosa. This prospective randomized multicenter placebo-controlled study was performed to clarify the efficacy of rebamipide for NERD patients whose reflux symptoms were refractory to PPI treatment.

METHODS

One hundred forty-nine patients were enrolled on the basis of a QUEST score of over 6 and absence of endoscopically proven esophageal mucosal breaks. All the patients were initially administered 15 mg of lansoprazole for 4 weeks, and the symptoms were then assessed using QUEST and GSRS. PPI-refractory patients were randomly assigned to administration of rebamipide or placebo t.i.d. for 4 weeks.

RESULTS

Three of the 149 patients were lost to follow-up, and 60 among the remaining 146 patients were found to be PPI-refractory. Among these PPI-refractory patients, 31 were randomly assigned to a rebamipide group and 29 to a placebo group. At the end of drug administration, the QUEST and GSRS scores did not differ between the rebamipide and placebo groups, although a significantly higher proportion of patients in the rebamipide group showed amelioration of abdominal pain and diarrhea.

CONCLUSION

Administration of rebamipide cannot effectively control reflux symptoms in NERD patients whose symptoms are refractory to PPI therapy.

Current and future techniques in the evaluation of dysphagia

Dysphagia is common in the general population, and is generally due to either mechanical obstruction or dysmotility. Patient demographics and symptom evaluation are often useful in determining the likely cause, and guide subsequent investigation and management. Oropharyngeal dysphagia is usually caused by neurological conditions where treatment options are limited. Conversely, many of the esophageal causes of dysphagia are amenable to therapy. Gastroscopy is often the first test of choice, given its diagnostic and therapeutic potential, especially when mechanical causes are concerned. Esophageal motor function can be assessed by a variety of techniques, ranging from radiology such as barium swallow, to dedicated motility tests such as manometry and impedance monitoring. The choice of test relies on the clinical indication and the results should be interpreted in conjunction with the patients' symptoms. High-resolution manometry with topography is now the new benchmark for motility studies. Several new techniques for motility testing have also become available, such as esophageal ultrasound and functional lumen imaging probe, but are currently limited to the research setting.

Esophageal hypertensive peristaltic disorders

BACKGROUND

Esophageal motility abnormalities include a series of manometric findings that differ to a significant degree from findings in normal, asymptomatic volunteers.

METHODS

Current review summarizes conventional and high-resolution esophageal manometry criteria used to define and characterize esophageal hypertensive motility abnormalities.

KEY RESULTS

In the conventional esophageal manometry classification scheme hypertensive esophageal motility abnormalities include nutcracker esophagus (average distal contraction amplitude >180 mmHg), hypertensive lower esophageal sphincter (average resting LES pressure >45 mmHg) and poorly relaxing lower esophageal sphincter (average LES residual pressure >8 mmHg). The new, high resolution esophageal manometry scheme includes in the group of hypertensive peristaltic disorders hypertensive peristalsis ("nutcracker esophagus": mean DCI >5000 mmHg*sec*cm) and hypercontractile esophagus ("jackhammer esophagus": at least one contraction with DCI > 8,000 mmHg*sec*cm) and defines a separate group for disorders with impaired esophageal-gastric junction relaxation (mean integrated residual (LES) pressure >15 mmHg).

CONCLUSIONS & INFERENCES

Hypertensive motility disorders represent a heterogeneous condition subdivided into hypercontractile esophagus and hypertensive peristalsis. Further studies are required to determine the clinical relevance of this new classification.

Rikkunshito improves symptoms in PPI-refractory GERD patients: a prospective, randomized, multicenter trial in Japan

BACKGROUND

To seek a promising therapeutic regimen for proton pump inhibitor (PPI)-refractory patients with gastroesophageal reflux disease (GERD) after the standard PPI treatment, we compared the efficacies of rikkunshito (a Japanese traditional medication) combined with rabeprazole (RPZ) and a double dose of RPZ in a prospective randomized multicenter trial in Japanese PPI-refractory GERD patients.

METHODS

One hundred and four patients with GERD symptoms remaining after 4-week treatment with RPZ (10 mg/day) were randomly assigned to 4 weeks of either combination therapy [rikkunshito (7.5 g/day) with a standard dose of RPZ (10 mg/day)] or a double dose of RPZ (20 mg/day). The primary endpoint was the improvement rate, calculated based on the frequency scale for the symptoms of GERD (FSSG) before and after treatment. Subgroup analysis was also performed with respect to each subject's background factors such as reflux esophagitis (RE)/non-erosive GERD (NERD), age, gender, and body mass index (BMI).

RESULTS

Four-week treatment with rikkunshito combined with RPZ significantly decreased the FSSG score from 17.6 ± 6.5 to 12.0 ± 6.9, similar to the decrease seen on treatment with a double dose of RPZ. Regarding the therapeutic improvement rate, there were also significant effects in both groups. However, in the subgroup analysis based on RE/NERD, the improvement rate of male NERD patients in the rikkunshito group was significantly greater than that of such patients in the other group (P < 0.05). In the rikkunshito group, the treatment was more effective in NERD patients with a low BMI than in those with a high BMI (P < 0.05).

CONCLUSION

Rikkunshito combined with standard-dose RPZ therapy may be a useful new strategy for PPI-refractory GERD patients.

Future directions in esophageal motility and function - new technology and methodology

BACKGROUND

Symptom based diagnosis is not reliable in patients with swallowing problems, heartburn, and other dyspeptic complaints. The aim of investigation is to provide clinically relevant measurements of gastrointestinal structure and function that explain the cause of symptoms, identify pathology, and guide effective management. Current practice rarely meets these ideals.

PURPOSE

This review considers recent advances in technology such as high-resolution manometry (HRM) with esophageal pressure topography (EPT), HRM with impedance, high frequency ultrasound, and endoscopic functional luminal impedance planimetry (Endo-FLIP) that provide new opportunities to identify the pathophysiologic basis of esophageal symptoms and disease. As experience with these new devices increases researchers are developing new methodologies that maximize their utility in clinical practice. For example, application of HRM to assess motility and function during and after a test meal can identify the causes of swallowing problems, reflux and other postprandial symptoms and intra-operative application of Endo-FLIP may help surgeons perform antireflux surgery. These examples illustrate the potential of physiologic measurement to direct rational and effective clinical management for individual patients.

Ambulatory high-resolution manometry, lower esophageal sphincter lift and transient lower esophageal sphincter relaxation

BACKGROUND

Lower esophageal sphincter (LES) lift seen on high-resolution manometry (HRM) is a possible surrogate marker of the longitudinal muscle contraction of the esophagus. Recent studies suggest that longitudinal muscle contraction of the esophagus induces LES relaxation.

AIM

Our goal was to determine: (i) the feasibility of prolonged ambulatory HRM and (ii) to detect LES lift with LES relaxation using ambulatory HRM color isobaric contour plots.

METHODS

In vitro validation studies were performed to determine the accuracy of HRM technique in detecting axial movement of the LES. Eight healthy normal volunteers were studied using a custom designed HRM catheter and a 16 channel data recorder, in the ambulatory setting of subject's home environment. Color HRM plots were analyzed to determine the LES lift during swallow-induced LES relaxation as well as during complete and incomplete transient LES relaxations (TLESR).

KEY RESULTS

Satisfactory recordings were obtained for 16 h in all subjects. LES lift was small (2 mm) in association with swallow-induced LES relaxation. LES lift could not be measured during complete TLESR as the LES is not identified on the HRM color isobaric contour plot once it is fully relaxed. On the other hand, LES lift, mean 8.4 ± 0.6 mm, range: 4-18 mm was seen with incomplete TLESRs (n = 80).

CONCLUSIONS & INFERENCES

Our study demonstrates the feasibility of prolonged ambulatory HRM recordings. Similar to a complete TLESR, longitudinal muscle contraction of the distal esophagus occurs during incomplete TLESRs, which can be detected by the HRM. Using prolonged ambulatory HRM, future studies may investigate the temporal correlation between abnormal longitudinal muscle contraction and esophageal symptoms.

Mechanisms of reflux perception in gastroesophageal reflux disease: a review

Patients with reflux symptoms often do not have excessive esophageal acid exposure, and patients with severe gastroesophageal reflux often do not have reflux symptoms. Understanding why different types of reflux induce symptoms in different patients is vital for addressing therapeutic gaps in the treatment of gastroesophageal reflux disease (GERD). Here we review studies providing insight into how gastroesophageal reflux is perceived, with a focus on comparing reflux characteristics and esophageal sensitivity among subgroups of patients with GERD. The available studies indicate that patients with nonerosive reflux disease have fewer acid reflux episodes and thus less esophageal acid exposure than patients with reflux esophagitis but perceive less intense stimuli because of greater esophageal sensitivity. Reflux characteristics other than acidity, such as the presence of bile, pepsin, liquid, or gas in reflux, and the proximal extent or volume of reflux, may also contribute to symptom perception. Factors contributing to greater esophageal sensitivity may include impaired mucosal barrier function, peripherally mediated esophageal sensitivity (enhanced esophageal receptor signaling), and centrally mediated esophageal sensitivity (physiological stressors, sensitization of spinal sensory neurons). Further insight into mechanisms of reflux perception may require a shift toward studies aimed at understanding predisposing cellular, molecular, and genetic factors.

Effect of esophageal contraction on esophageal wall blood perfusion

Myocardial blood flow occurs during the diastolic phase of the cardiac cycle, because myocardial contraction during the systolic phase impedes myocardial perfusion. Using laser Doppler perfusion technique, we studied the effect of esophageal contraction on the esophageal wall perfusion. Studies were conducted in rats. A laser Doppler probe was anchored to the esophageal wall, and wall perfusion was studied under various experimental conditions. Increase and decrease in the systemic blood pressure induced by different pharmacological agents was associated with the increase and decrease in the esophageal wall perfusion, respectively. Esophageal contractions induced by electrical stimulation of the vagus nerve and electrical stimulation of the muscle directly resulted in a reduction in the esophageal wall perfusion, in a dose-dependent fashion. Esophageal wall perfusion could be monitored by placing the Doppler probe on the esophageal mucosa or on the outside of the esophageal wall. Esophageal contraction impedes entry of blood into the esophageal wall. Future studies may investigate if ischemia of the esophageal wall induced by sustained esophageal contractions/esophageal spasm is the cause of esophageal pain symptoms in humans.

Rikkunshito improves symptoms in PPI-refractory GERD patients: a prospective, randomized, multicenter trial in Japan

BACKGROUND

To seek a promising therapeutic regimen for proton pump inhibitor (PPI)-refractory patients with gastroesophageal reflux disease (GERD) after the standard PPI treatment, we compared the efficacies of rikkunshito (a Japanese traditional medication) combined with rabeprazole (RPZ) and a double dose of RPZ in a prospective randomized multicenter trial in Japanese PPI-refractory GERD patients.

METHODS

One hundred and four patients with GERD symptoms remaining after 4-week treatment with RPZ (10 mg/day) were randomly assigned to 4 weeks of either combination therapy [rikkunshito (7.5 g/day) with a standard dose of RPZ (10 mg/day)] or a double dose of RPZ (20 mg/day). The primary endpoint was the improvement rate, calculated based on the frequency scale for the symptoms of GERD (FSSG) before and after treatment. Subgroup analysis was also performed with respect to each subject's background factors such as reflux esophagitis (RE)/non-erosive GERD (NERD), age, gender, and body mass index (BMI).

RESULTS

Four-week treatment with rikkunshito combined with RPZ significantly decreased the FSSG score from 17.6 ± 6.5 to 12.0 ± 6.9, similar to the decrease seen on treatment with a double dose of RPZ. Regarding the therapeutic improvement rate, there were also significant effects in both groups. However, in the subgroup analysis based on RE/NERD, the improvement rate of male NERD patients in the rikkunshito group was significantly greater than that of such patients in the other group (P < 0.05). In the rikkunshito group, the treatment was more effective in NERD patients with a low BMI than in those with a high BMI (P < 0.05).

CONCLUSION

Rikkunshito combined with standard-dose RPZ therapy may be a useful new strategy for PPI-refractory GERD patients.

Lansoprazole-induced improvement of esophageal submucosal injury

The proton pumpvinhibitor, lansoprazole, is reported to have acid secretion inhibiting effect as well as anti-inflammatory effects such as inhibition of cytokine secretion from inflammatory cells. Clinically, excellent efficacy of lansoprazole is reported for not only gastric ulcer but also gastroesophageal reflux disease (GERD). Since GERD is categorized endoscopically into erosive esophagitis and non-erosive reflux disease, it is important to make accurate assessment of any improvement in the inflammatory process when using endoscopic ultrasonography (EUS) capable of visualizing the submucosal structure. We report here our experience in assessing the effect of treatment with lansoprazole on esophageal wall structure using EUS in patients with GERD. At baseline (before treatment), EUS showed abnormalities in the mucosa, submucosa and muscularis propria caused by inflammation, thickening of the entire esophageal wall and changes in the contractile properties of esophageal smooth muscles reflecting the effects of inflammation on the entire wall of the lower esophagus in reflux esophagitis regardless of whether it is erosive or endoscopically-negative. Treatment with lansoprazole resulted in normalization of esophageal wall structure and improvement of motility, suggesting that lansoprazole improves not only mucosal inflammation but also submucosal inflammation in GERD.

Noncardiac chest pain: epidemiology, natural course and pathogenesis

Noncardiac chest pain is defined as recurrent chest pain that is indistinguishable from ischemic heart pain after a reasonable workup has excluded a cardiac cause. Noncardiac chest pain is a prevalent disorder resulting in high healthcare utilization and significant work absenteeism. However, despite its chronic nature, noncardiac chest pain has no impact on patients' mortality. The main underlying mechanisms include gastroesophageal reflux, esophageal dysmotility and esophageal hypersensitivity. Gastroesophageal reflux disease is likely the most common cause of noncardiac chest pain. Esophageal dysmotility affects only the minority of noncardiac chest pain patients. Esophageal hypersensitivity may be present in non-GERD-related noncardiac chest pain patients regardless if esophageal dysmotility is present or absent. Psychological co-morbidities such as panic disorder, anxiety, and depression are also common in noncardiac chest pain patients and often modulate patients' perception of disease severity.

Randomised clinical trial: efficacy of the addition of a prokinetic, mosapride citrate, to omeprazole in the treatment of patients with non-erosive reflux disease - a double-blind, placebo-controlled study

BACKGROUND

Proton pump inhibitors (PPIs) are less effective in non-erosive reflux disease (NERD) patients than in reflux oesophagitis patients. Whether the addition of prokinetics to PPIs improves NERD patients' symptoms remains unknown.

AIM

To evaluate the efficacy of mosapride in NERD patients when used with PPI.

METHODS

A total of 200 NERD patients were randomised to one of two arms: omeprazole (10 mg once daily) plus mosapride citrate (5 mg three times a day) (treatment arm) and omeprazole plus placebo (placebo arm). The primary endpoint was the rate of responders [visual analogue scale (VAS) was zero or <1 cm] after 4 weeks of treatment. The secondary endpoints were changes in the VAS score and the safety profile.

RESULTS

There was no significant difference between the rates of responders in both arms in intent-to-treat (ITT) and per-protocol (PP) analysis. The change in the VAS score in treatment arm was significantly better than placebo arm in PP analysis (-4.0 ± 0.2 and -3.3 ± 0.2, mean ± S.E.M.) (N.S. in ITT analysis). The rate of adverse events was similar in both groups.

CONCLUSION

The addition of mosapride to omeprazole was not more effective than omeprazole alone.

The hypersensitive esophagus: pathophysiology, evaluation, and treatment options

Visceral hypersensitivity plays a key role in the pathogenesis of esophageal functional disorders such as functional heartburn and chest pain of presumed esophageal origin (noncardiac chest pain). About 80% of patients with unexplained noncardiac chest pain exhibit lower esophageal sensory thresholds when compared to controls during esophageal sensory testing (ie, esophageal barostat, impedance planimetry). Such information has led to prescription of peripherally and/or centrally acting therapies for the management of these patients. This review summarizes and highlights recent and significant findings regarding the pathophysiology, evaluation, and treatment of the hypersensitive esophagus, a central factor in functional esophageal disorders.