Breathing Exercises in Gastroesophageal Reflux Disease: A Systematic Review

The pathogenesis of gastroesophageal reflux disease (GERD) is multifactorial. The severity of abnormal reflux burden corresponds to the dysfunction of the antireflux barrier and inability to clear refluxate. The crural diaphragm is one of the main components of the esophagogastric junction and plays an important role in preventing gastroesophageal reflux. The diaphragm, as a skeletal muscle, is partially under voluntary control and its dysfunction can be improved via breathing exercises. Thus, diaphragmatic breathing training (DBT) has the potential to alleviate symptoms in selected patients with GERD. High-resolution esophageal manometry (HRM) is a useful method for the assessment of antireflux barrier function and can therefore elucidate the mechanisms responsible for gastroesophageal reflux. We hypothesize that HRM can help define patient phenotypes that may benefit most from DBT, and that HRM can even help in the management of respiratory physiotherapy in patients with GERD. This systematic review aimed to evaluate the current data supporting physiotherapeutic practices in the treatment of GERD and to illustrate how HRM may guide treatment strategies focused on respiratory physiotherapy.

Esophageal Dysmotility Is Associated With Disease Severity in Eosinophilic Esophagitis

BACKGROUND & AIMS

An association of eosinophilic esophagitis (EoE) with esophageal dysmotility has been described, however, the related mechanism remains unclear. We aimed to evaluate clinical and physiologic characteristics, including esophageal distensibility, associated with secondary peristalsis in patients with EoE.

METHODS

A total of 199 consecutive adult patients with EoE (age, 18-78 y; 32% female) who completed a 16-cm functional luminal imaging probe (FLIP) during endoscopy were evaluated in a cross-sectional study. FLIP panometry contractile response (CR) patterns were classified as normal CR or borderline CR if antegrade contractions were present, and abnormal CRs included impaired/disordered CR, absent CR, or spastic-reactive CR. The distensibility plateau of the esophageal body and esophagogastric junction distensibility was measured with FLIP.

RESULTS

FLIP CR patterns included 68 (34%) normal CR, 65 (33%) borderline CR, 44 (22%) impaired/disordered CR, 16 (8%) absent CR, and 6 (3%) spastic-reactive CR. Compared with normal CRs, abnormal CRs more frequently had reduced esophageal distensibility (distensibility plateau <17 mm in 56% vs 32%), greater total EoE reference scores (median, 5; interquartile range [IQR], 3-6 vs median, 4; IQR, 3-5) with more severe ring scores, and a greater duration of symptoms (median, 10 y; IQR, 4-23 y vs median, 7 y; IQR, 3-15 y). Mucosal eosinophil density, however, was similar between abnormal CRs and normal CRs (median, 34 eosinophils/high-power field [hpf]; IQR, 14-60 eosinophils/hpf vs median, 25 eosinophils/hpf; IQR, 5-50 eosinophils/hpf).

CONCLUSIONS

Although normal secondary peristalsis was observed frequently in this EoE cohort, abnormal esophageal CRs were related to EoE disease severity, especially features of fibrostenosis. This study evaluating secondary peristalsis in EoE suggests that esophageal wall remodeling, rather than eosinophilic inflammatory intensity, was associated with esophageal dysmotility in EoE.

Correlation between novel 3D high-resolution manometry esophagogastric junction metrics and pH-metry in reflux disease patients

BACKGROUND AND AIMS

We recently developed 2 novel 3D high-resolution manometry (HRM) metrics of esophagogastric junction (EGJ) contractility to differentiate the lower esophageal sphincter (LES) and crural diaphragm (CD) elements of EGJ pressure. This study aimed to compare these metrics to the EGJ-contractile integral (EGJ-CI) and to analyze their correlation with esophageal acid exposure time (AET) on pH-metry.

METHODS

Thirty-one gastro-oesophageal reflux disease (GERD) patients and 20 control subjects underwent 24-hour pH-metry and HRM using a 3D-HRM catheter. EGJ metrics were calculated during 3 consecutive respiratory cycles at rest. The EGJ-CI was calculated using the DCI tool in the ManoView software. 3D LES pressure (3D-LESP) and 3D-DHA, a metric quantifying the CD component of the 3D-HRM pressure topography, were calculated using a MATLAB program. Pearson correlation was used to calculate correlations with AET.

KEY RESULTS

3D-LESP, 3D-DHA, and EGJ-CI were all significantly lower in GERD patients than in control subjects (P < .05) and all were significantly correlated with AET (R = -.48, -.42, -.52, respectively, all P < .01). The 3D-DHA and EGJ-CI also strongly correlated with each other (R = .84, P < .001).

CONCLUSIONS & INFERENCES

Both 3D-EGJ metrics were correlated with AET emphasizing the importance of both LES and CD function as a determinant of EGJ competence. 3D-DHA also strongly correlated with the EGJ-CI suggesting that EGJ-CI is strongly driven by the asymmetrical CD pressure component.

The 2018 ISDE achalasia guidelines

Achalasia is a relatively rare primary motor esophageal disorder, characterized by absence of relaxations of the lower esophageal sphincter and of peristalsis along the esophageal body. As a result, patients typically present with dysphagia, regurgitation and occasionally chest pain, pulmonary complication and malnutrition. New diagnostic methodologies and therapeutic techniques have been recently added to the armamentarium for treating achalasia. With the aim to offer clinicians and patients an up-to-date framework for making informed decisions on the management of this disease, the International Society for Diseases of the Esophagus Guidelines proposed and endorsed the Esophageal Achalasia Guidelines (I-GOAL). The guidelines were prepared according the Appraisal of Guidelines for Research and Evaluation (AGREE-REX) tool, accredited for guideline production by NICE UK. A systematic literature search was performed and the quality of evidence and the strength of recommendations were graded according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE). Given the relative rarity of this disease and the paucity of high-level evidence in the literature, this process was integrated with a three-step process of anonymous voting on each statement (DELPHI). Only statements with an approval rate >80% were accepted in the guidelines. Fifty-one experts from 11 countries and 3 representatives from patient support associations participated to the preparations of the guidelines. These guidelines deal specifically with the following achalasia issues: Diagnostic workup, Definition of the disease, Severity of presentation, Medical treatment, Botulinum Toxin injection, Pneumatic dilatation, POEM, Other endoscopic treatments, Laparoscopic myotomy, Definition of recurrence, Follow up and risk of cancer, Management of end stage achalasia, Treatment options for failure, Achalasia in children, Achalasia secondary to Chagas' disease.

Trajectory assessment is useful when day-to-day esophageal acid exposure varies in prolonged wireless pH monitoring

Acid exposure time commonly varies from day-to-day in prolonged wireless pH monitoring. Thus, diagnosis based on the number of days with abnormal acid burden may be misleading or inconclusive. We hypothesize that assessing longitudinal patterns of acid exposure may be diagnostically useful. Therefore, this study aims to describe acid exposure trajectories and evaluate agreement between identified trajectory patterns and conventional grouping. In this retrospective cohort study, we assessed patients with nonresponse to proton pump inhibitor therapy who underwent wireless pH monitoring (≥72 h) off therapy between August 2010 and September 2016. The primary outcome was esophageal acid exposure time. Subjects were grouped as 0, 1, 2, and 3+ days positive based on number of days with an acid exposure time >5.0%. Latent class group-based mixture model identified distinct longitudinal acid exposure trajectory groups. Of 212 subjects included 44%, 18%, 14%, and 24% had 0, 1, 2, 3+ days positive, respectively. Group-based modeling identified three significantly stable acid exposure trajectories: low (64%), middle (28%), and high (8%). Trajectory grouping and days positive grouping agreed substantially (weighted K 0.69; 95% CI: 0.63-0.76). Trajectory grouping identified 62% of subjects with conventionally inconclusive studies (one or two days positive) into the low trajectory. Agreement between trajectory groups when using three versus four days of monitoring was substantial (K 0.70; CI: 0.61-0.78). In summary, we found that patients with nonresponse to proton pump inhibitors follow three acid exposure trajectories over prolonged pH-monitoring periods: low, middle, and high. Compared to conventional day positive grouping, the trajectory modeling identified the majority of inconclusive days positive into the low trajectory group. Analyzing prolonged wireless pH data according to trajectories may be a complimentary method to conventional grouping, and may increase precision and accuracy in identifying acid burden.

Classification of esophageal motor findings in gastro-esophageal reflux disease: Conclusions from an international consensus group

BACKGROUND

High-resolution manometry (HRM) has resulted in new revelations regarding the pathophysiology of gastro-esophageal reflux disease (GERD). The impact of new HRM motor paradigms on reflux burden needs further definition, leading to a modern approach to motor testing in GERD.

METHODS

Focused literature searches were conducted, evaluating pathophysiology of GERD with emphasis on HRM. The results were discussed with an international group of experts to develop a consensus on the role of HRM in GERD. A proposed classification system for esophageal motor abnormalities associated with GERD was generated.

KEY RESULTS

Physiologic gastro-esophageal reflux is inherent in all humans, resulting from transient lower esophageal sphincter (LES) relaxations that allow venting of gastric air in the form of a belch. In pathological gastro-esophageal reflux, transient LES relaxations are accompanied by reflux of gastric contents. Structural disruption of the esophagogastric junction (EGJ) barrier, and incomplete clearance of the refluxate can contribute to abnormally high esophageal reflux burden that defines GERD. Esophageal HRM localizes the LES for pH and pH-impedance probe placement, and assesses esophageal body peristaltic performance prior to invasive antireflux therapies and antireflux surgery. Furthermore, HRM can assess EGJ and esophageal body mechanisms contributing to reflux, and exclude conditions that mimic GERD.

CONCLUSIONS & INFERENCES

Structural and motor EGJ and esophageal processes contribute to the pathophysiology of GERD. A classification scheme is proposed incorporating EGJ and esophageal motor findings, and contraction reserve on provocative tests during HRM.

Ambulatory reflux monitoring for diagnosis of gastro-esophageal reflux disease: Update of the Porto consensus and recommendations from an international consensus group

BACKGROUND

An international group of experts evaluated and revised recommendations for ambulatory reflux monitoring for the diagnosis of gastro-esophageal reflux disease (GERD).

METHODS

Literature search was focused on indications and technical recommendations for GERD testing and phenotypes definitions. Statements were proposed and discussed during several structured meetings.

KEY RESULTS

Reflux testing should be performed after cessation of acid suppressive medication in patients with a low likelihood of GERD. In this setting, testing can be either catheter-based or wireless pH-monitoring or pH-impedance monitoring. In patients with a high probability of GERD (esophagitis grade C and D, histology proven Barrett's mucosa >1 cm, peptic stricture, previous positive pH monitoring) and persistent symptoms, pH-impedance monitoring should be performed on treatment. Recommendations are provided for data acquisition and analysis. Esophageal acid exposure is considered as pathological if acid exposure time (AET) is greater than 6% on pH testing. Number of reflux episodes and baseline impedance are exploratory metrics that may complement AET. Positive symptom reflux association is defined as symptom index (SI) >50% or symptom association probability (SAP) >95%. A positive symptom-reflux association in the absence of pathological AET defines hypersensitivity to reflux.

CONCLUSIONS AND INFERENCES

The consensus group determined that grade C or D esophagitis, peptic stricture, histology proven Barrett's mucosa >1 cm, and esophageal acid exposure greater >6% are sufficient to define pathological GERD. Further testing should be considered when none of these criteria are fulfilled.

A review of medical therapy for proton pump inhibitor nonresponsive gastroesophageal reflux disease

Up to 40% of patients report persistent gastroesophageal reflux disease (GERD) symptoms despite proton pump inhibitor (PPI) therapy. This review outlines the evidence for medical therapy for PPI nonresponsive GERD. A literature search for GERD therapies from 2005 to 2015 in PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews identified 2928 unique citations. Of those, 40 unique articles specific to the impact of PPI metabolizer genotype on PPI response and the use adjunctive medical therapies were identified. Thirteen articles reported impacts on CYP genotypes on PPI metabolism demonstrating lower endoscopic healing rates in extensive metabolizers; however, outcomes across genotypes were more uniform with more CYP independent PPIs rabeprazole and esomeprazole. Twenty-seven publications on 11 adjunctive medications showed mixed results for adjunctive therapies including nocturnal histamine-2 receptor antagonists, promotility agents, transient lower esophageal sphincter relaxation inhibitors, and mucosal protective agents. Utilizing PPI metabolizer genotype or switching to a CYP2C19 independent PPI is a simple and conservative measure that may be useful in the setting of incomplete acid suppression. The use of adjunctive medications can be considered particularly when the physiologic mechanism for PPI nonresponse is suspected. Future studies using adjunctive medications with improved study design and patient enrollment are needed to better delineate medical management options before proceeding to antireflux interventions.

High-resolution impedance manometry parameters enhance the esophageal motility evaluation in non-obstructive dysphagia patients without a major Chicago Classification motility disorder

BACKGROUND

High-resolution impedance manometry (HRIM) allows evaluation of esophageal bolus retention, flow, and pressurization. We aimed to perform a collaborative analysis of HRIM metrics to evaluate patients with non-obstructive dysphagia.

METHODS

Fourteen asymptomatic controls (58% female; ages 20-50) and 41 patients (63% female; ages 24-82), 18 evaluated for dysphagia and 23 for reflux (non-dysphagia patients), with esophageal motility diagnoses of normal motility or ineffective esophageal motility, were evaluated with HRIM and a global dysphagia symptom score (Brief Esophageal Dysphagia Questionnaire). HRIM was analyzed to assess Chicago Classification metrics, automated pressure-flow metrics, the esophageal impedance integral (EII) ratio, and the bolus flow time (BFT).

KEY RESULTS

Significant symptom-metric correlations were detected only with basal EGJ pressure, EII ratio, and BFT. The EII ratio, BFT, and impedance ratio differed between controls and dysphagia patients, while the EII ratio in the upright position was the only measure that differentiated dysphagia from non-dysphagia patients.

CONCLUSIONS & INFERENCES

The EII ratio and BFT appear to offer an improved diagnostic evaluation in patients with non-obstructive dysphagia without a major esophageal motility disorder. Bolus retention as measured with the EII ratio appears to carry the strongest association with dysphagia, and thus may aid in the characterization of symptomatic patients with otherwise normal manometry.

Validation of criteria for the definition of transient lower esophageal sphincter relaxations using high-resolution manometry

BACKGROUND

Criteria for transient lower esophageal sphincter relaxations (TLESRs) are well-defined for Dentsleeve manometry. As high-resolution manometry (HRM) is now the gold standard to assess esophageal motility, our aim was to propose a consensus definition of TLESRs using HRM.

METHODS

Postprandial esophageal HRM combined with impedance was performed in 10 patients with gastroesophageal reflux disease. Transient lower esophageal sphincter relaxations identification was performed by 17 experts using a Delphi process. Four investigators then characterized TLESR candidates that achieved 100% agreement (TLESR events) and those that achieved less than 25% agreement (non-events) after the third round. Logistic regression and decision tree analysis were used to define optimal diagnostic criteria.

KEY RESULTS

All diagnostic criteria were more frequently encountered in the 57 TLESR events than in the 52 non-events. Crural diaphragm (CD) inhibition and LES relaxation duration >10 seconds had the highest predictive value to identify TLESR. Based on decision tree analysis, reflux on impedance, esophageal shortening, common cavity, upper esophageal sphincter relaxation without swallow and secondary peristalsis were alternate diagnostic criteria.

CONCLUSION & INFERENCES

Using HRM, TLESR might be defined as LES relaxation occurring in absence of swallowing, lasting more than 10 seconds and associated with CD inhibition.

Feasibility and acceptability of esophageal-directed hypnotherapy for functional heartburn

Functional heartburn (FH) is a benign but burdensome condition characterized by painful, burning epigastric sensations in the absence of acid reflux or symptom-reflux correlation. Esophageal hypersensitivity and its psychological counterpart, esophageal hypervigilance (EHv) drive symptom experience. Hypnotherapy (HYP) is an established and preferred intervention for refractory symptoms in functional gastrointestinal disorders (FGIDs) and could be applied to FH. The objective of this study was to determine the feasibility, acceptability, and clinical utility of 7 weekly sessions of esophageal-directed HYP (EHYP) on heartburn symptoms, quality of life, and EHv. Similar to other work in FGIDs and regardless of hypnotizability, there were consistent and significant changes in heartburn symptoms, visceral anxiety, and quality of life and a trend for improvement in catastrophizing. We would recommend EHYP in FH patients who are either non-responsive to medications or who would prefer a lifestyle intervention.

Vigor of peristalsis during multiple rapid swallows is inversely correlated with acid exposure time in patients with NERD

BACKGROUND

Multiple rapid swallowing (MRS) during high-resolution manometry (HRM) is increasingly utilized as provocative test to assess esophageal peristaltic reserve. The aim of this study was to evaluate the correlation between MRS response and impedance and pH (MII-pH) parameters in endoscopy negative heartburn (ENH) patients.

METHODS

We enrolled consecutive ENH patients, who underwent HRM and MII-pH study, with a selected MII-pH profile: abnormal MII-pH (pH+/MII+); normal MII-pH (pH-/MII-). HRM was performed with 10 wet swallows (WS) and one MRS. Mean distal contractile integral (DCI) during WS and MRS were calculated. MII-pH parameters including acid exposure time (AET), reflux events, baseline impedance levels (BI) and the efficacy of chemical clearance evaluated with the postreflux swallow-induced peristaltic wave (PSPW) index were measured.

KEY RESULTS

We analyzed 103 patients: 49 MII+/pH+ (27 male), and 54 MII-/pH- (19 male). Mean age was similar between the two groups. As expected, mean AET and number of refluxes were higher in pH+/MII+ (p < 0.05). HRM was normal in all selected patients. Mean DCI-WS was similar between two groups (p = n.s.). Mean DCI-MRS- was higher in MII-/pH- vs MII+/pH+ (p < 0.05). The increase in DCI-MRS was inversely correlated with AET (-0.699; p < 0.001) and directly correlated with BI values (0.631; p < 0.001) and PSPW index (0.626; p < 0.001).

CONCLUSIONS & INFERENCES

Following MRS, patients with abnormal impedance-pH test showed suboptimal contraction response as compared with those with normal impedance-pH test. Moreover, MRS response was inversely correlated with AET and directly correlated with BI values and PSPW index.

Utilizing functional lumen imaging probe topography to evaluate esophageal contractility during volumetric distention: a pilot study

BACKGROUND

The functional lumen imaging probe (FLIP) measures luminal cross-sectional area and pressure during volumetric distension. By applying novel customized software to produce FLIP topography plots, organized esophageal contractility can be visualized and analyzed. We aimed to describe the stimulus thresholds and contractile characteristics for distension-induced esophageal body contractility using FLIP topography in normal controls.

METHODS

Ten healthy controls were evaluated during endoscopy with FLIP. During stepwise bag distension, simultaneous intra-bag pressure and luminal diameter measurements were obtained and exported to a MatLab program to generate FLIP topography plots. The distension volume, intra-bag pressure, and maximum esophageal body diameters were measured for the onset and cessation of repetitive antegrade contractions (RACs). Contraction duration, interval, magnitude, and velocity were measured at 8 and 3-cm proximal to the esophagogastric junction.

KEY RESULTS

Eight of ten subjects demonstrated RACs at a median onset volume of 29 mL (IQR: 25-38.8), median intra-bag pressure of 10.7 mmHg (IQR: 8.6-15.9), and median maximum esophageal body diameter of 18.5 mm (IQR: 17.5-19.6). Cessation of RACs occurred prior to completion of the distension protocol in three of the eight subjects exhibiting RACs. Values of the RAC-associated contractile metrics were also generated to characterize these events.

CONCLUSIONS & INFERENCES

Distension-induced esophageal contractions can be assessed utilizing FLIP topography. RACs are a common finding in asymptomatic controls in response to volume distention and have similar characteristics to secondary peristalsis and repetitive rapid swallows.

The Pathogenesis and Management of Achalasia: Current Status and Future Directions

Achalasia is an esophageal motility disorder that is commonly misdiagnosed initially as gastroesophageal reflux disease. Patients with achalasia often complain of dysphagia with solids and liquids but may focus on regurgitation as the primary symptom, leading to initial misdiagnosis. Diagnostic tests for achalasia include esophageal motility testing, esophagogastroduodenoscopy and barium swallow. These tests play a complimentary role in establishing the diagnosis of suspected achalasia. High-resolution manometry has now identified three subtypes of achalasia, with therapeutic implications. Pneumatic dilation and surgical myotomy are the only definitive treatment options for patients with achalasia who can undergo surgery. Botulinum toxin injection into the lower esophageal sphincter should be reserved for those who cannot undergo definitive therapy. Close follow-up is paramount because many patients will have a recurrence of symptoms and require repeat treatment.

Role of a health psychologist in the management of functional esophageal complaints

Upper gastrointestinal complaints are common among patients in a gastrointestinal clinic. Outside of typical gastroesophageal reflux disease symptoms that are treated with medication, the symptom presentations of esophageal patients, particularly those with functional conditions, are often difficult to treat and account for high health-care utilization. This manuscript describes the role of a health psychologist in the treatment of esophageal disorders using behavioral medicine interventions. Observations over the course of a 1-year period indicate that the sample presents with a relatively low level of psychological distress but reports negative effects of their symptoms on health-related quality of life. Five case examples of commonly treated disorders (globus, non-cardiac chest pain, functional dysphagia, rumination syndrome, supragastric belching) are described to highlight how behavioral treatment can improve patients' symptoms, decrease health-care utilization, and improve overall quality of life in a timely and relatively simple manner. Successful treatment outcomes are associated with a collaborative working alliance between patient, health psychologist, and gastroenterologist. Results indicate the benefit of referring appropriate esophageal patients to a health psychologist with specialization in gastroenterology.

Inter-observer agreement for diagnostic classification of esophageal motility disorders defined in high-resolution manometry

High-resolution esophageal manometry (HRM) is a recent development used in the evaluation of esophageal function. Our aim was to assess the inter-observer agreement for diagnosis of esophageal motility disorders using this technology. Practitioners registered on the HRM Working Group website were invited to review and classify (i) 147 individual water swallows and (ii) 40 diagnostic studies comprising 10 swallows using a drop-down menu that followed the Chicago Classification system. Data were presented using a standardized format with pressure contours without a summary of HRM metrics. The sequence of swallows was fixed for each user but randomized between users to avoid sequence bias. Participants were blinded to other entries. (i) Individual swallows were assessed by 18 practitioners (13 institutions). Consensus agreement (≤ 2/18 dissenters) was present for most cases of normal peristalsis and achalasia but not for cases of peristaltic dysmotility. (ii) Diagnostic studies were assessed by 36 practitioners (28 institutions). Overall inter-observer agreement was 'moderate' (kappa 0.51) being 'substantial' (kappa > 0.7) for achalasia type I/II and no lower than 'fair-moderate' (kappa >0.34) for any diagnosis. Overall agreement was somewhat higher among those that had performed >400 studies (n = 9; kappa 0.55) and 'substantial' among experts involved in development of the Chicago Classification system (n = 4; kappa 0.66). This prospective, randomized, and blinded study reports an acceptable level of inter-observer agreement for HRM diagnoses across the full spectrum of esophageal motility disorders for a large group of clinicians working in a range of medical institutions. Suboptimal agreement for diagnosis of peristaltic motility disorders highlights contribution of objective HRM metrics.

Endoscopic ultrasound as an adjunctive evaluation in patients with esophageal motor disorders subtyped by high-resolution manometry

BACKGROUND

Esophageal motor disorders are a heterogeneous group of conditions identified by esophageal manometry that lead to esophageal dysfunction. The aim of this study was to assess the clinical utility of endoscopic ultrasound (EUS) in the further evaluation of patients with esophageal motor disorders categorized using the updated Chicago Classification.

METHODS

We performed a retrospective, single center study of 62 patients with esophageal motor disorders categorized according to the Chicago Classification. All patients underwent standard radial endosonography to assess for extra-esophageal findings or alternative explanations for esophageal outflow obstruction. Secondary outcomes included esophageal wall thickness among the different patient subsets within the Chicago Classification.

KEY RESULTS

EUS identified 9/62 (15%) clinically relevant findings that altered patient management and explained the etiology of esophageal outflow obstruction. We further identified substantial variability in esophageal wall thickness in a proportion of patients including some with a significantly thickened non-muscular layer.

CONCLUSIONS & INFERENCES

EUS findings are clinically relevant in a significant number of patients with motor disorders and can alter clinical management. Variability in esophageal wall thickness of the muscularis propria and non-muscular layers identified by EUS may also explain the observed variability in response to standard therapies for achalasia.

Evaluation of esophageal motor function in clinical practice

Esophageal motor function is highly coordinated between central and enteric nervous systems and the esophageal musculature, which consists of proximal skeletal and distal smooth muscle in three functional regions, the upper and lower esophageal sphincters, and the esophageal body. While upper endoscopy is useful in evaluating for structural disorders of the esophagus, barium esophagography, radionuclide transit studies, and esophageal intraluminal impedance evaluate esophageal transit and partially assess motor function. However, esophageal manometry is the test of choice for the evaluation of esophageal motor function. In recent years, high-resolution manometry (HRM) has streamlined the process of acquisition and display of esophageal pressure data, while uncovering hitherto unrecognized esophageal physiologic mechanisms and pathophysiologic patterns. New algorithms have been devised for analysis and reporting of esophageal pressure topography from HRM. The clinical value of HRM extends to the pediatric population, and complements preoperative evaluation prior to foregut surgery. Provocative maneuvers during HRM may add to the assessment of esophageal motor function. The addition of impedance to HRM provides bolus transit data, but impact on clinical management remains unclear. Emerging techniques such as 3-D HRM and impedance planimetry show promise in the assessment of esophageal sphincter function and esophageal biomechanics.

Utilization of wireless pH monitoring technologies: a summary of the proceedings from the esophageal diagnostic working group

Gastroesophageal reflux disease (GERD) can be difficult to diagnose - symptoms alone are often not enough, and thus, objective testing is often required. GERD is a manifestation of pathologic levels of reflux into the esophagus of acidic, nonacidic, and/or bilious gastric content. However, in our current evidence-based knowledge approach, we only have reasonable outcome data in regards to acid reflux, as this particular type of refluxate predictably causes symptoms and mucosal damage, which improves with medical or surgical therapy. While there are data suggesting that nonacid reflux may be responsible for ongoing symptoms despite acid suppression in some patients, outcome data about this issue are limited. Therefore, this working group believes that it is essential to confirm the presence of acid reflux in patients with 'refractory' GERD symptoms or extraesophageal symptoms thought to be caused by gastroesophageal reflux before an escalation of antireflux therapy is considered. If patients do not have pathologic acid reflux off antisecretory therapy, they are unlikely to have clinically significant nonacid or bile reflux. Patients who do not have pathologic acid gastroesophageal reflux parameters on ambulatory pH monitoring then: (i) could attempt to discontinue antisecretory medications like proton pump inhibitors and H2-receptor antagonists (which are expensive and which carry risks - i.e. C. diff, etc.); (ii) may undergo further evaluation for other causes of their esophageal symptoms (e.g. functional heartburn or chest pain, eosinophilic esophagitis, gastroparesis, achalasia, other esophageal motor disorders); and (iii) can be referred to an ear, nose, and throat/pulmonary/allergy physician for assessment of non-GERD causes of their extraesophageal symptoms.

The Kagoshima consensus on esophageal achalasia

Esophageal achalasia is a primary esophageal motility disorder characterized by lack of peristalsis and a lower esophageal sphincter that fails to relax appropriately in response to swallowing. This article summarizes the most salient issues in the diagnosis and management of achalasia as discussed in a symposium that took place in Kagoshima, Japan, in September 2010 under the auspices of the International Society for Diseases of the Esophagus.

Automated calculation of the distal contractile integral in esophageal pressure topography with a region-growing algorithm

BACKGROUND

The distal contractile integral (DCI) is an index of contractile vigor in high-resolution esophageal pressure topography (EPT) calculated as the product of amplitude, duration, and span of the distal esophageal contraction. The aim of this study was to develop an automated algorithm calculating DCI.

METHODS

The DCI was calculated conventionally using ManoView™ (Given Imaging, Los Angeles, CA, USA) software in EPT studies from 72 controls and 20 patients and compared to the calculation using a MATLAB™ (Version 7.9.0, R2009b; The MathWorks Inc., Natick, MA, USA) 'region-growing' algorithm. This algorithm first established the spatial limits of the distal contraction (the proximal pressure trough to either the distal pressure trough or to the superior margin of the lower esophageal sphincter at rest). Pixel-by-pixel horizontal line segments were then analyzed within this span starting at the pressure maximum and extending outward from that point. The limits of 'region-growing' were defined either by the spatial DCI limits or by encountering a pressure <20 mmHg. The DCI was then calculated as the total units of mmHg s cm greater than 20 mmHg within this domain.

KEY RESULTS

Excellent correlation existed between the two methods (r = 0.98, P < 0.001). The DCI values obtained with the conventional calculation were slightly but significantly greater than with the region-growing algorithm. Differences were attributed to the inclusion of vascular pressures in the conventional calculation or to differences in localization of the distal limit of the DCI.

CONCLUSIONS & INFERENCES

The proposed region-growing algorithm provides an automated method to calculate DCI that limits inclusion of vascular pressure artifacts and minimizes the need for user input in data analysis.

Esophageal symptoms questionnaire for the assessment of dysphagia, globus, and reflux symptoms: initial development and validation

Esophageal symptoms often co-occur. A validated self-report measure encompassing multiple esophageal symptoms is necessary to determine their frequency and severity both independently and in association with each other. Such a questionnaire could streamline the diagnostic process and guide patient management. We aimed to develop an integrative measure that provides a clinical 'snapshot' of common esophageal symptoms. Internal reliability and content validity of a 38-item self-report Esophageal Symptoms Questionnaire (ESQ), measuring the frequency and severity of typical esophageal symptoms using Likert-rating scales were assessed in 211 patients presenting to gastroenterology and ENT outpatient tertiary care clinics. Reproducibility, concurrent and predictive validity were evaluated using the reduced-item ESQ. The 38-item ESQ had high internal reliability. Principal component analyses and item reduction methods identified three components, to which 30 of 38 items contributed significantly, providing 59% of total variance. The test-retest correlations were moderate-to-strong for 24 of 30 new items (r(s) ≥ 0.44, P < 0.05). The resultant subscales measuring dysphagia (ESQ-D), globus (ESQ-G), and reflux (ESQ-R) compared well against concurrent physician's 'working' diagnosis (odds ratio 1.04-1.09). The receiver operating characteristics were adequate-to-good for ESQ-D (area under the curve [AUC]= 0.87) and ESQ-G (AUC = 0.74), but poor for ESQ-R (AUC = 0.61) although it matched the content of the validated Reflux Disease Questionnaire. The brief 30-item ESQ shows good internal reliability and content validity as a summary of the extent of dysphagia, globus and reflux symptoms. As a tool measuring more than one esophageal symptom, ESQ could guide patient management by indicating which of the coexisting symptoms needs to be addressed first.

3D-high resolution manometry of the esophagogastric junction

BACKGROUND

The esophagogastric junction (EGJ) is a complex structure that challenges accurate manometric recording. This study aimed to define EGJ pressure morphology relative to the squamocolumnar junction (SCJ) during respiration with 3D-high resolution manometry (3D-HRM).

METHODS

A 7.5-cm long 3D-HRM array with 96 independent solid-state pressure sensors (axial spacing 0.75 cm, radial spacing 45°) was used to record EGJ pressure in 15 normal subjects. Concurrent videofluoroscopy was used to localize the SCJ marked with an endoclip. Ex vivo experiments were done on the effect of bending the probe to match that seen fluoroscopically.

KEY RESULTS

3D-high resolution manometry EGJ pressure recordings were dominated by an asymmetric pressure peak superimposed on the lower esophageal sphincter (LES) attributable to the crural diaphragm (CD). Median peak CD pressure at expiration and inspiration (51 and 119 mmHg, respectively) was much greater in 3D-HRM than evident in HRM with circumferential pressure averaging. Esophagogastric junction length, defined as the zone of circumferential pressure exceeding that of adjacent esophagus or stomach was also substantially shorter (2.4 cm) than evident in conventional HRM. No consistent circumferential EGJ pressure was evident distal to the SCJ in 3D-HRM recordings and ex vivo experiments suggested that the intra-gastric pressure peak seen contralateral to the CD related to bending the assembly rather than the sphincter per se.

CONCLUSIONS & INFERENCES

3D-high resolution manometry demonstrated a profoundly asymmetric and vigorous CD component to EGJ pressure superimposed on the LES. Esophagogastric junction length was shorter than evident with conventional HRM and the distal margin of the EGJ sphincteric zone closely correlated with the SCJ.

Use of a continuing medical education course to improve fellows' knowledge and skills in esophageal disorders

Advanced esophageal endoscopic procedures such as stricture dilation, hemostasis tools, and stent placement as well as high-resolution manometry (HRM) interpretation are necessary skills for gastroenterology fellows to obtain during their training. Becoming proficient in these skills may be challenging in light of higher complication rates compared with diagnostic procedures and infrequent opportunities to practice these skills. Our aim was to determine if intensive training during a continuing medical education (CME) course boosts the knowledge and skills of gastroenterology fellows in esophageal diagnostic test interpretation and performance of therapeutic procedures. This was a pretest-posttest design without a control group of a simulation-based, educational intervention in esophageal stricture balloon dilation and HRM interpretation. The participants were 24 gastroenterology fellows from 21 accredited US training programs. This was an intensive CME course held in Las Vegas, Nevada from August 7 to August 9, 2009. The research procedure had two phases. First, the subjects were measured at baseline (pretest) for their knowledge and procedural skill. Second, the fellows received 6 hours of education sessions featuring didactic content, instruction in HRM indications and interpretation, and deliberate practice using an esophageal stricture dilation model. After the intervention, all of the fellows were retested (posttest). A 17-item checklist was developed for the esophageal balloon dilation procedure using relevant sources, expert opinion, and rigorous step-by-step procedures. Nineteen representative HRM swallow studies were obtained from Northwestern's motility lab and formed the pretest and posttest in HRM interpretation. Mean scores on the dilation checklist improved 81% from 39.4% (standard deviation [SD]= 33.4%) at pretest to 71.3% (SD = 29.5%) after simulation training (P < 0.001). HRM mean examination scores increased from 27.2% (SD = 16.4%) to 46.5% (SD = 15.8%), representing a 71% improvement (P < 0.001). Pearson's correlations indicated there was no correlation between pretest performance, medical knowledge measured by United States Medical Licensing Examination examinations, prior clinical experience, or procedural self-confidence and posttest performance of esophageal dilation or HRM interpretation. The education program was rated highly. This study demonstrated that a CME course significantly enhanced the technical skills and knowledge of gastroenterology fellows in esophageal balloon dilation and HRM interpretation. CME courses such as this may be a valuable adjunct to standard fellowship training in gastroenterology.

An alginate-antacid formulation (Gaviscon Double Action Liquid) can eliminate or displace the postprandial 'acid pocket' in symptomatic GERD patients

BACKGROUND

Recently, an 'acid pocket' has been described in the proximal stomach, particularly evident postprandially in GERD patients, when heartburn is common. By creating a low density gel 'raft' that floats on top of gastric contents, alginate-antacid formulations may neutralise the 'acid pocket'.

AIM

To assess the ability of a commercial high-concentration alginate-antacid formulation to neutralize and/or displace the acid pocket in GERD patients.

METHODS

The 'acid pocket' was studied in ten symptomatic GERD patients. Measurements were made using concurrent stepwise pH pull-throughs, high resolution manometry and fluoroscopy in a semi-recumbent posture. Each subject was studied in three conditions: fasted, 20 min after consuming a high-fat meal and 20 min later after a 20 mL oral dose of an alginate-antacid formulation (Gaviscon Double Action Liquid, Reckitt Benckiser Healthcare, Hull, UK). The relative position of pH transition points (pH >4) to the EGJ high-pressure zone was analysed.

RESULTS

Most patients (8/10) exhibited an acidified segment extending from the proximal stomach into the EGJ when fasted that persisted postprandially. Gaviscon neutralised the acidified segment in six of the eight subjects shifting the pH transition point significantly away from the EGJ. The length and pressure of the EGJ high-pressure zone were minimally affected.

CONCLUSIONS

Gaviscon can eliminate or displace the 'acid pocket' in GERD patients. Considering that EGJ length was unchanged throughout, this effect was likely attributable to the alginate 'raft' displacing gastric contents away from the EGJ. These findings suggest the alginate-antacid formulation to be an appropriately targeted postprandial GERD therapy.

Manometric features of eosinophilic esophagitis in esophageal pressure topography

BACKGROUND

Although most of the patients with eosinophilic esophagitis (EoE) have mucosal and structural changes that could potentially explain their symptoms, it is unclear whether EoE is associated with abnormal esophageal motor function. The aims of this study were to evaluate the esophageal pressure topography (EPT) findings in EoE and to compare them with controls and patients with gastro-esophageal disease (GERD).

METHODS

Esophageal pressure topography studies in 48 EoE patients, 48 GERD patients, and 50 controls were compared. The esophageal contractile pattern was described for ten 5-mL swallows for each subject and each swallow was secondarily characterized based on the bolus pressurization pattern: absent, pan-esophageal pressurization, or compartmentalized distal pressurization.

KEY RESULTS

Thirty-seven percent of EoE patients were classified as having abnormal esophageal motility. The most frequent diagnoses were of weak peristalsis and frequent failed peristalsis. Although motility disorders were more frequent in EoE patients than in controls, the prevalence and type were similar to those observed in GERD patients (P=0.61, chi-square test). Pan-esophageal pressurization was present in 17% of EoE and 2% of GERD patients while compartmentalized pressurization was present in 19% of EoE and 10% of GERD patients. These patterns were not seen in control subjects.

CONCLUSIONS & INFERENCES

The prevalence of abnormal esophageal motility in EoE was approximately 37% and was similar in frequency and type to motor patterns observed in GERD. Eosinophilic esophagitis patients were more likely to have abnormal bolus pressurization patterns during swallowing and we hypothesize that this may be a manifestation of reduced esophageal compliance.

Do patients with globus sensation respond to hypnotically assisted relaxation therapy? A case series report

Globus sensation is a bothersome and difficult symptom to treat. The aims of this study were to evaluate the acceptability and utility of hypnotically-assisted relaxation (HAR) in decreasing the perception of globus sensation and the effect of HAR on interdeglutitive upper esophageal sphincter (UES) pressure. Sixteen subjects with persistent globus sensation unresponsive to therapy for reflux disease and with normal esophageal/laryngeal imaging studies were invited to participate in a 7-session clinical protocol. Before and after HAR, subjects completed standard questionnaires including the esophageal symptoms questionnaire. High-resolution manometric assessment of respiratory augmentation and average resting UES pressure were assessed before and after HAR. Ten of the 16 subjects agreed to participate in the protocol. All participants were women with median age 51.5 (range 30-72 years). The participants found HAR acceptable and completed the entire 7-session trial. Globus symptom severity varied widely pre-treatment (median=52.5, range 16-72), and 9 of 10 subjects reported a reduction in globus symptomatology following treatment (median=14.0, range 3-19; P=.007). Only 1 subject exhibited abnormal respiratory augmentation of UES pressure (>27 mm Hg) prior to treatment and was normal following treatment (9.9 mm Hg). Resting UES pressure was normal in all subjects (<118 mm Hg). Group respiratory augmentation and average resting UES pressure were unaffected by HAR (P=.48, .89). This case series suggests that HAR can provide a substantial improvement in globus sensation irrespective of cause. UES function was unaffected. We suggest that HAR therapy is an acceptable and useful intervention for patients with globus sensation.

The contractile deceleration point: an important physiologic landmark on oesophageal pressure topography

BACKGROUND

This study aimed to correlate oesophageal bolus transit with features of oesophageal pressure topography (OPT) plots and establish OPT metrics for accurately measuring peristaltic velocity.

METHODS

About 18 subjects underwent concurrent OPT and fluoroscopy studies. The deglutitive Contractile Front Velocity (CFV) in OPT plots was subdivided into an initial fast phase (CFV(fast)) and subsequent slow phase (CFV(slow)) separated by a user-defined deceleration point (CDP). Fluoroscopy studies were analyzed for the transition from the initial rapidly propagated luminal closure associated with peristalsis to slow bolus clearance characteristic of phrenic ampullary emptying and to identify the pressure sensors at the closure front and at the hiatus. Oesophageal pressure topography measures were correlated with fluoroscopic milestones of bolus transit. Oesophageal pressure topography studies from another 68 volunteers were utilized to develop normative ranges for CFV(fast) and CFV(slow).

KEY RESULTS

A distinct change in velocity could be determined in all 36 barium swallows with the fast and slow contractile segments having a median velocity of 4.2 cm s(-1) and 1.0 cm s(-1), respectively. The CDP noted on OPT correlated closely with formation of the phrenic ampulla making CFV(fast) (mean 5.1 cm s(-1)) correspond closely to peristaltic propagation and CFV(slow) (mean 1.7 cm s(-1)) to ampullary emptying.

CONCLUSIONS & INFERENCES

The deceleration point in the CFV on OPT plots accurately demarcated the early region in which the CFV reflects peristaltic velocity (CFV(fast)) from the later region where it reflects the progression of ampullary emptying (CFV(slow)). These distinctions should help objectify definitions of disordered peristalsis, especially spasm, and improve understanding of impaired bolus transit across the oesophagogastric junction.

Transient lower oesophageal sphincter relaxation in achalasia: everything but LOS relaxation

In conducting clinical high-resolution oesophageal pressure topography (HROPT) studies we observed that after subjects sat upright between series of supine and upright test swallows, they frequently had a transient lower oesophageal sphincter relaxation (TLOSR). When achalasia patients were studied in the same protocol, they exhibited a similar HROPT event leading to the hypothesis that achalasics had incomplete TLOSRs. We reviewed clinical HROPT studies of 94 consecutive non-achalasics and 25 achalasics. Studies were analyzed for a TLOSR-like event during the study and, when observed, that TLOSR-like event was characterized for the degree and duration of distal oesophageal shortening, the degree of LOS relaxation, associated crural diaphragm (CD) inhibition, oesophageal pressurization and upper oesophageal sphincter (UOS) relaxation. About 64/94 (68%) non-achalasics and 15/24 (63%) of achalasics had a pressure topography event after the posture change characterized by a prolonged period of distal oesophageal shortening and/or LOS relaxation. Events among the non-achalasics and achalasics were similar in terms of magnitude and duration of shortening and all were associated with CD inhibition. Similar proportions had associated non-deglutitive UOS relaxations. The only consistent differences were the absence of associated LOS relaxation and the absence of HROPT evidence of reflux among the achalasics leading us to conclude that their events were incomplete TLOSRs. Achalasic patients exhibit a selective defect in the TLOSR response suggesting preservation of all sensory, central and efferent aspects of the requisite neural substrate with the notable exception of LOS relaxation, a function of inhibitory (nitrergic) myenteric plexus neurons.

High-resolution manometry in clinical practice: utilizing pressure topography to classify oesophageal motility abnormalities

High-resolution manometry capable of pressure monitoring from the pharynx to the stomach together with pressure topography plotting represents an unquestionable evolution in oesophageal manometry. However, with this advanced technology come challenges and one of those is devising the optimal scheme to apply high-resolution oesophageal pressure topography (HROPT) to the clinical evaluation of patients. The first iteration of the Chicago classification was based on a systematic analysis of motility patterns in 75 control subjects and 400 consecutive patients. This review summarizes the analysis process as it has evolved. Individual swallows are analysed in a stepwise fashion for the morphology of the oesophagogastric junction (OGJ), the extent of OGJ relaxation, the propagation velocity of peristalsis, the vigour of the peristaltic contraction, and abnormalities of intrabolus pressure utilizing metrics that have now been customized to HROPT. These results are then synthesized into a comprehensive diagnosis that, although based on conventional manometry criteria, is also customized to HROPT measures. The resultant classification objectifies the identification of three unique subtypes of achalasia. Additionally, it provides enhanced detail in the description of distal oesophageal spasm, nutcracker oesophagus subtypes, and OGJ obstruction. It is our expectation that modification of this classification scheme will continue to occur and this should further clarify the utility of pressure topography plotting in assessing oesophageal motility disorders.

Oesophageal peristaltic transition zone defects: real but few and far between

This study analysed the association between oesophageal transition zone (TZ) defects [characterized by a delay and/or spatial gap between the terminus of the proximal oesophageal (striated muscle) contraction and the initiation of the distal oesophageal (smooth muscle) contraction] and dysphagia in a large patient cohort. Four hundred consecutive patients (178 with dysphagia) and 75 controls were studied with 36-channel high-resolution manometry (HRM). The resultant pressure topography plots were first analysed for impaired oesophagogastric junction (OGJ) relaxation, distal segment contractile abnormalities, and proximal contractile abnormalities using normal values from the 75 controls. If these aspects of oesophageal motility were deemed normal, the TZ was characterized by length and duration between the proximal and distal contractions using a 20 mmHg isobaric contour to establish the segment boundaries. Patients were then classified according to whether or not they exhibited TZ defects (spatial separation or delay) and the occurrence of unexplained dysphagia. Of the 400 patients, 267 were suitable for TZ analysis and of these 55 had a spatial or temporal TZ measurement exceeding the 95th percentile of the controls (2 cm, 1 s). Exactly 34.6% of the patients (n = 19) with spatial and/or temporal TZ defects had unexplained dysphagia, which was significantly more than seen with normal TZ dimensions (19.8%). Although far less common than distal peristaltic or OGJ abnormailites, TZ defects may be related to dysphagia in a minority of patients (<4% in this series) and should be considered a distinct oesophageal motility disorder.

Timely confirmation of gastro-esophageal reflux disease via pH monitoring: estimating budget impact on managed care organizations

BACKGROUND

Current guidelines recommend the use of pH monitoring to confirm the diagnosis of acid reflux in patients with a normal endoscopy. This analysis evaluated the financial impact of pH monitoring with the wireless pH capsule on a managed care organization (MCO) in the United States.

METHODS

A decision model was constructed to project total 1-year costs to manage GERD symptoms with and without the adoption of wireless pH capsules in a hypothetical MCO with 10 000 eligible adult enrollees, of whom 600 presented with GERD-like symptoms. Costs of GERD diagnosis, treatment, and symptom management for those in whom a GERD diagnosis was ruled out by pH monitoring were assessed. The incremental per-member-per-month (PMPM) and per-treated-member-per-month (PTMPM) costs were the primary outcomes. Data sources included literature, expert input, and standardized fee schedules.

RESULTS

An increase of 10 percentage points in the use of pH monitoring with wireless pH capsules yielded incremental PMPM and PTMPM costs of $0.029 and $0.481, respectively. The costs of proton pump inhibitor (PPI) therapy to the plan dropped to $236,363 from $238,086, while increases were observed in pH monitoring (from $16 739 to $21 973) and non-GERD therapy costs (from $1392 to $1740). The results were sensitive to the percentage of patients requiring repeat endoscopy before wireless pH monitoring and the cost of PPIs.

CONCLUSIONS

Timely and increased use of pH monitoring as recommended in published guidelines leads to less unnecessary use of PPIs with a modest budgetary impact on health plans.

The Bravo pH capsule system

Limitations of existing pH recording methodology have been the impetus for the emergence of new technologies focused on improving ambulatory pH monitoring. The Bravo pH capsule system (Bravo, Medtronic, Shoreview, MN) is one of the recent advances that utilize a wireless system to improve patient compliance and extend the period of monitoring. These changes could potentially improve diagnostic accuracy along with patient acceptance. Given this fact, the following review will evaluate the potential benefits that wireless pH monitoring may have over conventional catheter based pH monitoring based on the available data. In addition, we will also focus on the technical aspects related to its safety, tolerability and diagnostic accuracy.

Does the Bravo pH capsule affect esophageal motor function?

The aim of this study was to determine whether attachment of the Bravo pH monitoring capsule alters esophageal motility. Twenty normal subjects were studied with 36-channel high-resolution manometry before and after Bravo capsule placement. Subjects performed 10 5-mL water-swallows in both upright and supine positions and two 5-mL barium-swallows under fluoroscopy synchronized with manometry recordings. There was no significant change in basal esophagogastric junction (EGJ) pressure, EGJ relaxation pressure or peristaltic function before and after Bravo placement in either position. However, a 2-cm focus of augmented peristalsis was found corresponding to the position of the Bravo capsule. Ten subjects were aware of the capsule (7 had a mild foreign body sensation, 1 had mild discomfort, and 2 had chest pain altering daily activity or diet) while nine subjects were unaware of the capsule. Subjects who were aware of the capsule's presence exhibited a greater augmentation of peristalsis than those who were not (P < 0.05). Neither EGJ function nor peristaltic performance were significantly altered by the presence of a Bravo capsule. However, capsule presence was associated with a locus of augmented peristalsis and this phenomenon was most evident in subjects who perceived the presence of the Bravo capsule.

Upper sphincter function during transient lower oesophageal sphincter relaxation (tLOSR); it is mainly about microburps

Transient lower oesophageal sphincter relaxations (tLOSRs) are both a dominant mechanism of reflux and an element of the belch reflex. This study aimed to analyse the interplay between reflux and upper oesophageal sphincter (UOS) activity during meal-induced tLOSRs. Fifteen normal subjects were studied with a solid-state high-resolution manometry assembly positioned to record from the hypopharynx to the stomach and a catheter pH electrode 5 cm above the LOS. Subjects ate a 1000-calorie high-fat meal and were monitored for 120 min in a sitting posture. The relationship among tLOSRs, common cavities, pressure changes within the oesophagus and UOS contractile activity were analysed. A total of 218 tLOSRs occurred among the 15 subjects. The majority (79%) were coupled with UOS relaxation and 84% (145/173) of these occurred in association with a common cavity. Upper oesophageal sphincter relaxation was usually preceded by a pressure change in the oesophagus; however, some relaxations (16%) occurred without a discernable increase in pressure or before the pressure increase began. Acid reflux did not appear to play a role in determining UOS response to tLOSRs. The majority of post-prandial tLOSRs were associated with brief periods of UOS relaxation, likely permissive of gas venting (microburps). Intraoesophageal pressure changes likely modulate this UOS response; however, an anticipatory characteristic was evident in some subjects. Whether or not GORD patients with extra-oesophageal symptoms exhibit an exaggeration of the UOS relaxation response during reflux is yet to be determined.

Comparison of esophageal acid exposure at 1 cm and 6 cm above the squamocolumnar junction using the Bravo pH monitoring system

The aim of this study was to assess the quantitative differences of acid exposure at 1 cm and 6 cm above the squamocolumnar junction (SCJ) using two radiotelemetry pH capsules affixed to the esophageal mucosa. Ten normal subjects and 10 endoscopy-negative gastroesophageal reflux disease (GERD) patients without hiatus hernia (ages 20-54, 12 male) were studied for a 24-h period using the Bravo pH monitoring system. pH capsules were placed 1 cm and 6 cm above the SCJ. Interpretable data for at least 14 h was obtained in 18 of the 20 subjects (9 normal, 9 GERD). Two failures occurred secondary to early capsule dislodgement. Median esophageal acid exposure was significantly increased at 1 cm above the SCJ compared to 6 cm above the SCJ during the total, upright and postprandial time periods in both normal and GERD subjects. During a 2 h postprandial period the esophageal acid exposure was 8-fold greater in GERD subjects and 5-fold greater in normal subjects 1 cm above the SCJ compared to 6 cm above the SCJ. Confident measurement of esophageal acid exposure at a fixed position 1 cm above the SCJ is feasible with the Bravo system. Acid exposure was significantly higher 1 cm above the SCJ compared to 6 cm above the SCJ in both GERD patients and controls. These findings suggest that measurement of acid exposure 1 cm above the SCJ may improve accuracy of pH monitoring by detecting acid reflux events confined to the distal esophagus.

Slimline vs. glass pH electrodes: what degree of accuracy should we expect?

BACKGROUND

Ambulatory pH monitoring is considered the gold standard for measuring oesophageal acid exposure, however, data comparing antimony and glass electrodes are limited.

AIM

To compare the accuracy of the Slimline antimony pH monitoring system and a conventional glass electrode catheter pH monitoring system during ambulatory conditions.

METHODS

Eighteen subjects (13 males, 23-45 years) underwent simultaneous pH monitoring using the Slimline antimony pH electrode and MIC M3 glass pH electrode pH monitoring systems for 12 h. Acid exposure was analysed and compared by manual extraction of the data onto an excel spreadsheet.

RESULTS

There was no statistical difference in the median per cent time the pH was <4 recorded by the two systems (Slimline, 3%, Glass MIC M3, 2%, P = 0.77) and the correlation was excellent (r = 0.84). The difference in recorded reflux events was also not significantly different between the two systems, with the absolute difference being 23 events (s.d., 26). Point-by-point discrepancy was 28% (s.d., 18%), however, the agreement in terms of reflex events was excellent (Kappa value, 0.89, s.d., 0.09).

CONCLUSION

Despite substantial point-by-point disagreement, the antimony Slimline pH catheter compares favourably to the Glass MIC M3 pH catheter in terms of measuring standard pH parameters.

Review article: oesophageal pH monitoring--technologies, interpretation and correlation with clinical outcomes

Using a simple 'test' to diagnose gastro-oesophageal reflux disease is difficult because accurately measuring gastric refluxate and correlating reflux events with symptom episodes is complex. This paper reviews the safety, tolerability and diagnostic accuracy of Bravo (Medtronic, Shoreview, MN, USA), ambulatory oesophageal pH monitoring technology. Catheter-based pH electrodes inhibit patients' normal activity, and can yield erroneous results because of placement or subsequent migration of the probe or errors in the thermal compensation algorithm that is requisite for antimony pH electrodes. Bravo pH studies reliably discriminated oesophagitis patients from controls, but are less discriminatory in endoscopy-negative gastro-oesophageal reflux disease patients. The Bravo system can be accurately placed using endoscopic landmarks and pH studies demonstrated more accurate in vivo pH recording than with a catheter-based system. The Bravo system detected fewer reflux events of short duration compared with a catheter-based system. Studies examining the correlation between reflux events and symptoms have not yet been conducted using the Bravo system. In conclusion, the Bravo system offers a more user-friendly ambulatory pH monitoring technique that more accurately records pH compared with a catheter-based system. More research is needed to determine whether the detection of reflux events with Bravo will provide a good correlation with symptom episodes.

Acid reflux event detection using the Bravo wireless versus the Slimline catheter pH systems: why are the numbers so different?

OBJECTIVE

This study analysed the relative accuracy of the Bravo wireless and the Slimline catheter-Mark III Digitrapper pH systems in the detection of acid reflux events.

METHODS

Twenty five asymptomatic subjects were studied. A Bravo capsule was placed 6 cm above the squamocolumnar junction (SCJ), marked by an endoclip, and a Slimline pH catheter was placed 5 cm above the manometrically localised lower oesophageal sphincter. The distance between the SCJ and each pH electrode was measured fluoroscopically. An in vivo pH reference was established using swallows of orange juice (pH 3.88). Concurrent pH data from the two systems were analysed in Excel spreadsheets.

RESULTS

Significantly more acid reflux events were reported by the Digitrapper system than the Bravo system (117.0 v 41.8). This was not explained by electrode position as there was no difference in median distance between the SCJ and either pH electrode (7.25 cm v 7.08 cm). The dominant source of discrepancy between systems was inaccuracy in electrode calibration and, after adjustment using the in vivo orange juice pH measurement, the discrepancy improved by 40%. However, discrepancy still existed and was most pronounced with short reflux events (1-15 s for the catheter, 1-17 s for the Bravo) associated with minimal intraoesophageal acidity and poor concordance between systems.

CONCLUSION

Substantially more reflux events were reported by the Digitrapper system compared with the Bravo system; 40% of excess events were attributable to a flawed software scheme for electrode thermal calibration while most of the remainder were brief events with poor reproducibility between systems.

Measuring EGJ opening patterns using high resolution intraluminal impedance

The aim of this study was to adapt impedance methodology to study esophagogastric junction (EGJ) sphincter opening and compare opening patterns of the EGJ during deglutitive LES relaxation (dLESR) and transient LES relaxation (tLESR). We studied eight healthy subjects with a novel 12-lumen combined impedance/manometry catheter, the main element of which was a 6 cm sleeve sensor with six side hole sensors and six impedance rings spaced at 1 cm increments along its length. Subjects underwent an air infusion protocol after standard assessment and data tracings and isocontour plots were analysed to assess opening characteristics of the EGJ during dLESRs and tLESRs. Our results revealed that during dLESR the opening pattern was top to bottom, occurred in 0-2.7 s and in 29 of 35 (83%) cases the leading edge of the bolus was liquid. Opening during tLESR began between -7.8 and +8.6 s relative to the onset of nadir LES relaxation. The opening pattern during tLESR was bottom to top, occurred in 0-7.7 s, and in 22 of 29 (76%) the leading edge was liquid. These results support that impedance monitoring can be adapted to identify sphincter opening, to distinguish sphincter opening from sphincter relaxation, and to determine luminal contents during the opening period.

Diagnostic approach to gastro-oesophageal reflux disease

It is neither practical nor necessary to embark on a diagnostic evaluation of every patient with classic symptoms of gastroesophageal reflux disease (GERD). In most cases a well-taken history is usually sufficient to confirm the diagnosis of GERD and begin therapy. However, some patients may present with atypical symptoms; and many with classic symptoms are refractory to standard medical therapy. In these cases one must rely on diagnostic studies to confirm that abnormal acid reflux is present and potentially responsible for the symptoms in question. Modern technology has given us many different modalities to quantify esophageal acid exposure and determine whether symptoms are correlated to reflux events. Unfortunately, these studies are not perfect and the work-up of refractory patients typically requires more than one test. The goal of the following review will be to summarize the currently available techniques for diagnosis of GERD and also discuss the possible impact of new techniques, such as intraluminal impedance monitoring and wireless ambulatory pH monitoring.

The effect of glucagon-induced gastric relaxation on TLOSR frequency

This study aimed to determine the effect of glucagon-induced gastric relaxation on the frequency of transient lower oesophageal sphincter relaxations (TLOSRs). Eight normal subjects (four male, age 18-52 y) were studied after a 6-h fast using a combined manometric barostat assembly. The recording was divided into two 1-h sessions: (1) a baseline period with the barostat set at minimal distending pressure (MDP) + 2 mmHg and (2) a period with continuous glucagon or placebo infusion with barostat set at MDP + 2 mmHg. Patients were studied on two different days and randomly received glucagon (4.8 microg kg(-1) bolus followed by 9.6 microg kg(-1) h(-1) infusion) on 1 day and placebo (saline) on another. Lower oesophageal sphincter (LOS) pressure, frequency of TLOSRs, and barostat bag volumes were determined for both placebo and glucagon infusion. Glucagon induced significant fundal relaxation compared with placebo (P < 0.05) and significantly decreased baseline LEOS pressure (P < 0.05). The frequency of TLOSRs was not altered by glucagon infusion compared with placebo. Despite causing substantial proximal stomach relaxation, glucagon did not increase TLOSR frequency. This suggests that the relevant gastric mechanoreceptors responsible for triggering TLOSRs do not respond to passive elongation.

Distinct patterns of oesophageal shortening during primary peristalsis, secondary peristalsis and transient lower oesophageal sphincter relaxation

This study characterized oesophageal shortening during secondary peristalsis and transient lower oesophageal sphincter relaxation (TLOSR) in an attempt to determine its contribution to the opening mechanism. Eight healthy subjects (four males, 26 +/- 1 years) had metal clips affixed at 0, +3, and +8 cm relative to the squamocolumnar junction (SCJ), defining two distal oesophageal segments. Axial clip movement was assessed with concurrent videofluoroscopy and manometry during primary peristalsis, secondary peristalsis and TLOSR. Clip-defined oesophageal segment length change was measured at 0.5-s intervals. The magnitude of the most distal segment shortening was least with TLOSR, greatest with primary peristalsis and intermediate with secondary peristalsis. Conversely, maximal overall oesophageal shortening during TLOSR, evidenced by SCJ movement, was similar to that during primary peristalsis. In 3/12 TLOSRs, the moment of LOS opening and gas reflux was optimally imaged; SCJ excursion was 0.3 +/- 0.1 cm prior to LOS opening and 1.4 +/- 0.7 cm immediately after gas reflux. The segmental pattern of oesophageal shortening was distinct during primary peristalsis, secondary peristalsis and TLOSR. During TLOSR, significant elevation of the SCJ occurred only after LOS opening, suggesting that this was a consequence of oesophageal distension induced by gas reflux rather than a component of the opening mechanism.

Smoking and gastro-oesophageal reflux disease

The role of smoking in the pathogenesis of gastrooesophageal reflux disease has been controversial since the early 1970s when Stanciu reported the two to be 92% epidemiologically associated (a study subsequently challenged by inconsistencies in the observational data). Mechanistically, reflux disease is caused by excessive oesophageal acid exposure, which is potentially attributable to excessive reflux events and/or prolonged acid clearance. Currently, the best available pH monitoring data confirm that smoking increases oesophageal acid exposure. Smoking reduces lower oesophageal sphincter (LOS) pressure and predisposes to strain-induced reflux. Consistent with this, smoking has been shown to cause an increased number of reflux events that are not attributable to increased transient LOS relaxations, but rather are associated with deep inspiration and coughing. Once reflux occurs, acid is cleared from the oesophagus by a two-step process consisting of oesophageal peristalsis followed by neutralization of the residual acid by swallowed saliva. Smoking prolongs acid clearance by decreasing salivation. The effects of smoking on LOS tone and acid clearance are most likely mainly due to nicotine but are incompletely understood. Transdermal nicotine has similar effects to smoking on LOS pressure and salivation. Thus, although perhaps not a dominant risk factor, smoking and nicotine impact on pathophysiological variables of gastro-oesophageal reflux disease. In itself, smoking cessation is unlikely to cure severe gastrooesophageal reflux disease, but, along with appropriate pharmacological therapy, it may be beneficial.