Association between baseline impedance values and response proton pump inhibitors in patients with heartburn

Topical Protection of Esophageal Mucosa as a New Treatment of GERD

Among the various factors implicated in the pathogenesis of gastroesophageal reflux disease (GERD), visceral hypersensitivity and mucosal resistance have been recently re-evaluated in relation to the increasing phenomenon of proton pump inhibitor failure, particularly in patients with nonerosive reflux disease (NERD). Intensive research has allowed us to understand that noxious substances contained in the refluxate are able to interact with esophageal epithelium and to induce the elicitation of symptoms. The frequent evidence of microscopic esophagitis able to increase the permeability of the mucosa, the proximity of sensory afferent nerve fibers to the esophageal lumen favoring the higher sensitivity to noxious substances and the possible activation of inflammatory pathways interacting with sensory nerve endings are pathophysiological alterations confirming that mucosal resistance is impaired in GERD patients. Accordingly, the reinforcement of protective mechanisms of esophageal mucosa by topical therapies has become a novel treatment target. Alginate, the combination of hyaluronic acid+chondroitin sulphate and Poliprotect have been shown to adhere to esophageal mucosa and to have good protective properties. Several placebo-controlled clinical trials have shown that these compounds, given alone or as add-on therapy for short periods, enable to relieve symptoms and to improve the quality of life in NERD patients. Further studies are needed to confirm the above results and to find new mucosal protectants in order to improve the management of NERD patients.

Mean Nocturnal Baseline Impedance May Be Greater Than 2500 Ohms in Chinese Patients With GERD

BACKGROUND

According to the Lyon Consensus 2.0, mean nocturnal baseline impedance (MNBI) greater than 2500 Ω is considered evidence against gastroesophageal reflux disease (GERD). However, we have observed that a subset of GERD patients presents with MNBI exceeding 2500 Ω.

AIMS

To investigate MNBI characteristics in Chinese GERD patients, identify clinical features of those with normal MNBI, and examine factors influencing MNBI values.

METHODS

We retrospectively investigated 259 patients with typical reflux symptoms. Demographics, symptoms, proton pump inhibitor (PPI) response, esophageal motility parameters were compared between patients with different AET levels and MNBI levels.

RESULTS

Among the cohort, 38.2% had AET 4%-6%, and 37.5% had AET > 6%. Notably, 95.2% of patients with AET < 4%, 49.5% with AET 4%-6%, and 17.6% with AET > 6% had MNBI > 2500 Ω. Independent risk factors for MNBI > 2500 Ω included the number and duration of supine acid reflux and lower esophageal sphincter (LES) resting pressure. In GERD patients with heartburn, patients with MNBI ≤ 2500 Ω had higher PPI response than MNBI > 2500 Ω (81.1% vs. 55.6%, p = 0.009).

CONCLUSIONS

Approximately one-third of Chinese GERD patients have an MNBI > 2500 Ω. The thresholds of MNBI for supporting or ruling out GERD in the Chinese population should be adjusted. MNBI values are independently predicted by the severity of supine acid reflux and the LES resting pressure. GERD patients with mild supine acid reflux may still exhibit normal MNBI levels. Patients with lower MNBI values tend to show better responses to PPI therapy.

Transoral Incisionless Fundoplication Leads to Esophageal Mucosa Healing in Responder Patients Followed up to 2 Years, as Documented by Esophageal Mean Nocturnal Baseline Impedance

Background/Aims

Decrease of esophageal mean nocturnal baseline impedance reflects loss of mucosal integrity. It can predict response to anti-reflux therapy. Mean nocturnal baseline impedance after transoral incisionless fundoplication for gastroesophageal reflux disease has never been assessed. The aim of the study is to investigate mean nocturnal baseline impedance and conventional pathophysiological parameters following transoral incisionless fundoplication.

Methods

Patients prospectively treated by transoral incisionless fundoplication in a single center were retrospectively reviewed regarding 1- and 2-year 24-hour pH-metry and multichannel intraluminal impedance with calculation of mean nocturnal baseline impedance, gastroesophageal reflux disease-health related quality of life and reflux symptom index scores.

Results

Thirty-eight and 17/38 patients with 1- and 2-year 24-hour pH-multichannel intraluminal impedance assessment and mean nocturnal baseline impedance's calculation after transoral incisionless fundoplication, respectively, were identified. Mean nocturnal baseline impedance significantly increased up to 2-year follow-up (P = 0.033), along with significant decrease in % of acid exposure time (P = 0.003), gastroesophageal reflux disease-health related quality of life score (P < 0.001), and reflux symptom index (P = 0.008), compared with baseline. The longest orthostatic reflux decreased too, approaching statistical significance (P = 0.054). These significant changes occurred in patients experiencing ≥ 50% reduction of symptom questionnaires' scores ("responders"). Conversely, mean nocturnal baseline impedance worsened and no significant changes of 24-hour pH-multichannel intraluminal impedance metrics were observed in "non-responder" patients (symptom questionnaires' scores decrease < 50%).ConclusionIn patients who responded a significant improvement of mean nocturnal baseline impedance and % acid exposure time was observed up to 2-year follow-up, suggesting that transoral incisionless fundoplication achieves an effective esophageal mucosa healing besides symptom improvement.

Utility of mean nocturnal baseline impedance and post-reflux swallow-induced peristaltic wave index in clinical pH-impedance reflux study

BACKGROUND AND AIMS

Analysis of mean nocturnal baseline impedance (MNBI) and post-reflux swallow-induced peristaltic wave index (PSPWi) have been proposed to increase the diagnostic yield of pH-impedance studies in reflux disease. However, routine use of these indices in clinical studies is yet to be established, particularly with PSPWi, which requires laborious manual analysis. Our study aimed to assess the utility of MNBI and PSPWi and their potential for future incorporation into clinical practice.

METHODS

pH-impedance recordings from consecutive patients referred to the Motility Laboratory at Royal Adelaide Hospital for evaluation of gastro-oesophageal reflux disease (GORD) were prospectively collected and manually analysed. Baseline demographic characteristics, symptoms, acid exposure time (AET), number of reflux episodes, and MNBI and PSPWi were collected.

RESULTS

Eighty-nine patients were included in the study (age 50 ± 17 years, 35 males). MNBI and PSPWi inversely correlated with AET (R = -0.678, P < 0.0001 and R = -0.460, P < 0.0001 respectively) and with reflux episodes (R = -0.391, P = 0.0002 and R = -0.305, P = 0.0037 respectively). In patients with a negative pH study, but with typical reflux symptoms, 4/30 (13%) had pathologic MNBI and PSPWi. There was a positive correlation between MNBI and PSPWi values (R = 0.525, P < 0.0001). Performing analysis of PSPWi was substantially more laborious than MNBI.

CONCLUSION

MNBI and PSPWi are both useful adjuncts in the diagnosis of reflux disease, although in our cohort MNBI showed stronger correlation with AET with less time to analyse. The role of these indices remains to be further explored, particularly in patients with inconclusive AET and in those with positive compared to negative symptom association.

Automated software-derived supine baseline impedance is highly correlated with manual nocturnal baseline impedance for the diagnosis of GERD

BACKGROUND

Mean nocturnal baseline impedance (MNBI) can improve diagnostic accuracy for gastroesophageal reflux disease (GERD), but must be manually calculated and is not routinely reported. We aimed to determine how automated software-derived mean supine baseline impedance (MSBI), a potential novel GERD metric, is related to MNBI.

METHODS

Consecutively obtained pH-impedance studies were assessed. Manually extracted MNBI was compared to MSBI using paired t-test and Spearman's correlations.

KEY RESULTS

The correlation between MNBI and MSBI was very high (ρ = 0.966, p < 0.01).

CONCLUSIONS & INFERENCES

The ease of acquisition and correlation with MNBI warrant the routine clinical use and reporting of MSBI with pH-impedance studies.

The Revised Reflux Symptom Index (R-RSI): Development, Internal and External Validation Study

INTRODUCTION

This study proposes a revised version of the Reflux Symptom Index (R-RSI), a seventeen-item questionnaire that was revised to increase the suspicion of laryngopharyngeal reflux disease (LPRD).

METHODS

Internal validation involved 213 participants, comprising 160 subjects without a previous LPRD diagnosis and 53 subjects with a self-reported previous diagnosis of LPRD with or without gastroesophageal reflux disease (GERD). Test-retest reliability and internal consistency were calculated. For the external validation, 56 patients (independent from the previous cohort) were enrolled to explore the R-RSI screening properties and determine a cutoff using 24-h MII-pH as the gold standard.

RESULTS

R-RSI test-retest reliability was high, both for the total score (ICC: 0.970) and for each item (ranging from 0.876 to 0.980). Cronbach's alpha was 0.910, indicating excellent internal consistency of the questionnaire. Participants with a previous self-reported diagnosis scored significantly higher (mean 24.94 ± 7.4; median 26, IQR 20-29) than those without a previous diagnosis (mean 4.66 ± 5.3; median 4, IQR 1-6) (p value <0.0001). Participants with both previous LPRD and GERD diagnoses had higher scores (27.20 ± 7.8) compared to those with only LPRD (21.77 ± 5.5) (p value = 0.003). Using 24-h MII-pH diagnosis as a gold standard, the optimal R-RSI cutoff point was determined to be 18, with a sensitivity of 84.5% and a specificity of 81.8%, positive predictive value of 95%, and negative predictive value of 60%.

CONCLUSIONS

Our results suggest that the R-RSI may be useful to suspect LPRD, with or without GERD. The R-RSI is a self-administered patient-reported outcome questionnaire that demonstrates excellent reliability and high screening properties. Employing a cutoff of ≥18 in the R-RSI can assist in diagnosing and monitoring LPRD.

Latin American consensus on diagnosis of gastroesophageal reflux disease

BACKGROUND

Diagnosing gastroesophageal reflux disease (GERD) can be challenging given varying symptom presentations, and complex multifactorial pathophysiology. The gold standard for GERD diagnosis is esophageal acid exposure time (AET) measured by pH-metry. A variety of additional diagnostic tools are available. The goal of this consensus was to assess the individual merits of GERD diagnostic tools based on current evidence, and provide consensus recommendations following discussion and voting by experts.

METHODS

This consensus was developed by 15 experts from nine countries, based on a systematic search of the literature, using GRADE (grading of recommendations, assessment, development and evaluation) methodology to assess the quality and strength of the evidence, and provide recommendations regarding the diagnostic utility of different GERD diagnosis tools, using AET as the reference standard.

KEY RESULTS

A proton pump inhibitor (PPI) trial is appropriate for patients with heartburn and no alarm symptoms, but nor for patients with regurgitation, chest pain, or extraesophageal presentations. Severe erosive esophagitis and abnormal reflux monitoring off PPI are clearly indicative of GERD. Esophagram, esophageal biopsies, laryngoscopy, and pharyngeal pH monitoring are not recommended to diagnose GERD. Patients with PPI-refractory symptoms and normal endoscopy require reflux monitoring by pH or pH-impedance to confirm or exclude GERD, and identify treatment failure mechanisms. GERD confounders need to be considered in some patients, pH-impedance can identify supragrastric belching, impedance-manometry can diagnose rumination.

CONCLUSIONS

Erosive esophagitis on endoscopy and abnormal pH or pH-impedance monitoring are the most appropriate methods to establish a diagnosis of GERD. Other tools may add useful complementary information.

Effect of Body Weight and Obesity on Esophageal Function

The incidence of obesity in the population is gradually increasing. Obesity can cause a variety of complications in the digestive system such as gastroesophageal reflux disease, and impacts the integrity of the esophageal mucosal barrier and esophageal motility. However, not many studies have focused on the effect of varying degrees of obesity on the esophagus. A total of 611 participants were included in this study. We divided them into three groups according to their body mass index (BMI): the normal weight group, the overweight group, and the obesity group. We performed a retrospective comparison between groups based on indicators from high resolution esophageal manometry (HREM) and 24-hour pH impedance monitoring, and did a correlation analysis on multiple indicators such as esophageal mucosal barrier, esophageal motility, and acid reflux. The mean nocturnal baseline impedance (MNBI) in the overweight and obesity groups was lower than that in the normal group. The MNBI of the subjects in Z5-Z6 channels in the overweight group was significantly lower than that in the normal group. With respect to Z3-Z6 channels, MNBI values in the obesity group were significantly lower than those in the normal group. 'The acid exposure time (AET), the DeMeester scores (DMS) and 24-hour total reflux episodes was significantly higher in the obesity group than those in the normal and overweight groups. The upper esophageal sphincter (UES) residual pressure, and intrabolus pressure (IBP) in the overweight and obesity groups were significantly higher than those in the normal group. In addition, lower esophageal sphincter (LES) resting pressure, and esophagogastric junction contractile integral (EGJ-CI) in the obesity group were significantly higher than those in the normal group. We found that increase in body weight affected the integrity of esophageal mucosa, and different degrees of increase associated with different degrees and different aspects of changes in esophageal motility.

Proximal esophageal impedance baseline increases the yield of impedance-pH monitoring for GERD diagnosis and is associated with heartburn response to PPI

BACKGROUND

Impairment of esophageal mucosal integrity as assessed by low mean nocturnal baseline impedance (MNBI) measured in the distal esophagus increases the diagnostic yield of impedance-pH in patients with inconclusive GERD diagnosis as defined by Lyon criteria.

AIM

To assess the diagnostic yield of MNBI measurement in the proximal esophagus, and its relationship with PPI response.

METHODS

Expert review of off-therapy impedance-pH tracings from consecutive patients with heartburn, 80 responders and 80 non-responders to label-dose PPI. Data were compared to those from 36 healthy controls using ROC analysis. Multivariate analysis was performed to measure the strength of association of MNBI with PPI response.

RESULTS

A threshold value of 2665 Ω was defined for proximal MNBI by ROC analysis, affording 91.7% sensitivity and 86.5% specificity. Proximal and distal MNBI were significantly lower in non-responder cases as compared to responders. Adding proximal MNBI positivity to pathologic (>6%) acid exposure time (AET) and positive symptom-reflux association, the proportion of patients with abnormal impedance-pH findings increased from 74/160 (46%) to 106/160 (66.3%) (p = 0.0016). Among the 12 patients with pathologic proximal MNBI as the only positive impedance-pH finding, 9 cases (75%) were PPI responders. According to multivariate analysis, AET and pathological distal and proximal MNBI were significantly associated with PPI response, the strongest association observed for proximal MNBI.

CONCLUSIONS

Impedance baseline assessment in the proximal esophagus may increase the diagnostic yield of impedance-pH monitoring. Heartburn response to PPI is directly related to ultrastructural mucosal damage in the distal and in the proximal esophagus as well.

Encouraging appropriate use of proton pump inhibitors: existing initiatives and proposals for the future

INTRODUCTION

Proton pump inhibitors (PPIs) have revolutionized the management of acid-related disorders, representing today the mainstay treatment of these conditions. However, despite their large range of indications and usefulness, the remarkable expansion of their use in the last two decades cannot be explained by the increasing prevalence of acid-related diseases only. An inappropriate prescription for clinical conditions in which the pathogenetic role of acid has not been documented has been described, with the natural consequence of increasing the costs and the potential risk of iatrogenic harm due to adverse events and complications recently emerged.

AREAS COVERED

In this review, we summarize current indications of PPIs administration, potential adverse events associated with their chronic utilization, and misuse of PPIs. Moreover, we describe existing and possible initiatives for improving the use of PPIs, and some proposals for the future.

EXPERT OPINION

PPI deprescribing is the preferred and most effective approach to reduce the use of PPIs, rather than adopting sharp discontinuation, probably due to fewer withdrawal symptoms. Nonetheless, large knowledge gaps still exist in clinical practice regarding the optimal approach of PPI deprescribing in various clinical scenarios. Further prospective well-designed international studies are eagerly warranted to improve our perspectives on controlling global PPI inappropriate use.

Prospective validation of reflux monitoring by impedance-pH in predicting PPI response in typical GERD

BACKGROUND

The Lyon Consensus proposed a hierarchical approach to GERD diagnosis based on conventional and new impedance-pH metrics, namely acid exposure time (AET), number of reflux episodes, post-reflux swallow-induced peristaltic wave (PSPW) index, and mean nocturnal baseline impedance (MNBI).

AIMS

To define the value of conventional and new impedance-pH parameters as predictors of response to label-dose PPI in typical GERD.

METHODS

Consecutive adult patients with typical esophageal symptoms were prospectively studied with impedance-pH monitoring and treated with 8-week label-dose PPI. At the end of the PPI course, symptoms response was assessed.

RESULTS

Among 255 patients who entered the study, 168 (65.9%) reported symptom remission. At ROC analysis, both MNBI and PSPW index were significantly associated to PPI responsiveness with AUC of 0.783 and 0.801, respectively. Cut-off values of 1747Ω for MNBI and 50% for PSPW index were identified as discriminators between response and non-response to label-dose PPI. At multivariate analysis, MNBI, PSPW index, and AET >6% were efficient predictors of PPI responses (OR 3, 5.4 and 2.3, respectively). Number of reflux episodes did not predict PPI response.

CONCLUSIONS

The novel MII-pH variables together with pathological are highly predictive of response of the typical GERD syndrome to label-dose PPI.

Novel Diagnostic Techniques in the Evaluation of Gastroesophageal Reflux Disease (GERD)

In our present clinical paradigm, patient symptoms and presentation in the setting of traditional findings from endoscopy (erosive esophagitis, Barrett's esophagus, reflux-mediated stenosis), esophageal high-resolution manometry, and/or ambulatory reflux monitoring (distal esophageal acid exposure time, numbers of reflux events, reflux-symptom association) guide the care of patients with suspected GERD. However, novel metrics and techniques acquired from or performed at endoscopy, manometry, or pH-impedance monitoring, beyond conventional evaluation, are of great interest to the gastroenterology community given the frequent (and sometimes challenging) presentation of suspected GERD. These novel and evolving diagnostic approaches have the potential to enhance the evaluation of these patients and optimize their management. In this invited review, we discuss the present evidence and potential clinical utility of selected GERD metrics and techniques of interest at endoscopy (dilated intercellular spaces, mucosal impedance), manometry (contractile integral, impedance analysis, straight leg raise, multiple rapid swallow maneuvers), and reflux monitoring (mean nocturnal baseline impedance, post-reflux swallow-induced peristaltic wave indices), and how these tools may be most optimally adopted and utilized for clinical care (Fig. 1).

Application of Artificial Intelligence in Measuring Novel pH-Impedance Metrics for Optimal Diagnosis of GERD

Novel metrics extracted from pH-impedance monitoring can augment the diagnosis of gastroesophageal reflux disease (GERD). Artificial intelligence (AI) is being widely used to improve the diagnostic capabilities of various diseases. In this review, we update the current literature regarding applications of artificial intelligence in measuring novel pH-impedance metrics. AI demonstrates high performance in the measurement of impedance metrics, including numbers of reflux episodes and post-reflux swallow-induced peristaltic wave index and, furthermore, extracts baseline impedance from the entire pH-impedance study. AI is expected to play a reliable role in facilitating measuring novel impedance metrics in patients with GERD in the near future.

Mean nocturnal baseline impedance: Influencing factors and diagnostic value in gastroesophageal reflux disease

BACKGROUND

At present, there are few studies related to mean nocturnal baseline impedance (MNBI), esophageal dynamic reflux monitoring, high-resolution esophageal manometry (HRM) parameter indexes, and its diagnostic value in gastroesophageal reflux disease (GERD).

OBJECTIVE

To analyze the factors influencing MNBI and examine the diagnostic value of MNBI in GERD.

METHODS

A retrospective analysis on 434 patients with typical reflux symptoms who underwent gastroscopy, 24-hour multichannel intraluminal impedance and pH monitoring (MII/pH) and HRM. They were divided into the conclusive evidence group (103 cases), borderline evidence group (229 cases), and exclusion evidence group (102 cases) according to the level of diagnostic evidence of GERD based on the Lyon Consensus. We analyzed the differences in MNBI, esophagitis grade, MII/pH and HRM index among the groups; the correlation between MNBI and the above indexes and its influence on MNBI; and to evaluate the diagnostic value of MNBI in GERD.

RESULTS

There were significant differences in MNBI, Acid Exposure Time (AET) 4%, DeMeester score, and total reflux episodes among the three groups (P< 0.001). EGJ contractile integral (EGJ-CI) of the conclusive evidence group and the borderline evidence group was significantly lower than that in the exclusion evidence group (P< 0.001). MNBI was significantly and negatively correlated with age, BMI, AET 4%, DeMeester score, total reflux episodes, EGJ classification, esophageal motility abnormalities, and esophagitis grade (all P< 0.05), and significantly and positively correlated with EGJ-CI (P< 0.001). Age, BMI, AET 4%, EGJ classification, EGJ-CI, and esophagitis grade had significant effects on MNBI (P< 0.05); MNBI was used to diagnose GERD with a diagnostic cutoff of 2061 Ω, and AUC was 0.792 (sensitivity 74.9%, specificity 67.4%); MNBI was used to diagnose exclusion evidence group with a diagnostic cutoff of 2432 Ω, AUC was 0.774 (sensitivity 67.6%, specificity 72%).

CONCLUSION

AET, EGJ-CI, and esophagitis grade are the most important influence factors of MNBI. MNBI has good diagnostic value in identifying conclusive GERD.

GERD-related chronic cough: Possible mechanism, diagnosis and treatment

GERD, or gastroesophageal reflux disease, is a prevalent medical condition that affects millions of individuals throughout the world. Chronic cough is often caused by GERD, and chronic cough caused by GER is defined as GERD-related chronic cough (GERC). It is still unclear what the underlying molecular mechanism behind GERC is. Reflux theory, reflex theory, airway allergies, and the novel mechanism of esophageal motility disorders are all assumed to be linked to GERC. Multichannel intraluminal impedance combined with pH monitoring remains the gold standard for the diagnosis of GERC, but is not well tolerated by patients due to its invasive nature. Recent discoveries of new impedance markers and new techniques (mucosal impedance testing, salivary pepsin, real-time MRI and narrow band imaging) show promises in the diagnosis of GERD, but the role in GERC needs further investigation. Advances in pharmacological treatment include potassium-competitive acid blockers and neuromodulators (such as Baclofen and Gabapentin), prokinetics and herbal medicines, as well as non-pharmacological treatments (such as lifestyle changes and respiratory exercises). More options have been provided for the treatment of GERC other than acid suppression therapy and anti-reflux surgery. In this review, we attempt to review recent advances in GERC mechanism, diagnosis, and subsequent treatment options, so as to provide guidance for management of GERC.

Trends in gastroesophageal reflux disease research: A bibliometric and visualized study

Background

Gastroesophageal reflux disease (GERD), a disorder resulting from the retrograde flow of gastric contents into the esophagus, affects an estimated 10-30% of the Western population, which is characterized by multifactorial pathogenesis. Over the past few decades, there have been many aspects of uncertainty regarding GERD leading to an ongoing interest in the field as reflected by a large number of publications, whose heterogeneity and variable quality may present a challenge for researchers to measure their scientific impact, identify scientific collaborations, and to grasp actively researched themes in the GERD field. Accordingly, we aim to evaluate the knowledge structure, evolution of research themes, and emerging topics of GERD research between 2012 and 2022 with the help of bibliometric approaches.

Methods

The literature focusing on GERD from 2012 to 2022 was retrieved from the Science Citation Index Expanded of the Web of Science Core Collection. The overall publication performance, the most prolific countries or regions, authors, journals and resources-, knowledge- and intellectual-networking, as well as the co-citation analysis of references and keywords, were analyzed through Microsoft Office Excel 2019, CiteSpace, and VOSviewer.

Results

A total of 8,964 publications were included in the study. The USA published the most articles (3,204, 35.74%). Mayo Clin ranked first in the number of articles published (201, 2.24%). EDOARDO SAVARINO was the most productive author (86, 0.96%). The most productive journal in this field was SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES (304, 3.39%). AMERICAN JOURNAL OF GASTROENTEROLOGY had the most co-citations (4,953, 3.30%). Keywords with the ongoing strong citation bursts were transoral incision less fundoplication, eosinophilic esophagitis, baseline impedance, and functional heartburn.

Conclusion

For the first time, we obtained deep insights into GERD research through bibliometric analysis. Findings in this study will be helpful for scholars seeking to understand essential information in this field and identify research frontiers.

Mean nocturnal baseline impedance, a novel metric of multichannel intraluminal impedance-pH monitoring in diagnosing gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is a common disease with increasing prevalence worldwide. However, the diagnosis of GERD is challenging because there are no definite gold standard criteria. Recently, a novel impedance parameter, namely mean nocturnal baseline impedance (MNBI), has been proposed, which reflects the burden of longitudinal reflux and the integrity of esophageal mucosa. MNBI has shown an immense promise for increasing the diagnostic rate of multichannel intraluminal impedance-pH (MII-pH) monitoring and predicting the response to proton pump inhibitor (PPI) or anti-reflux intervention in patients with reflux symptoms. The present paper reviews the association between baseline impedance and esophageal mucosal integrity, the acquisition of MNBI in 24-h MII-pH monitoring, the clinical utilization of MNBI in improving the diagnosis rate of GERD in patients with typical reflux symptoms, predicting the response to PPI or anti-reflux treatment in these patients, the utilization of MNBI in diagnosing patients with atypical symptoms or extra-esophageal symptoms, and the correlation between reflux burden and MNBI. MNBI should be routinely assessed using MII-pH monitoring.

Recent insights on functional heartburn and reflux hypersensitivity

PURPOSE OF REVIEW

Rome IV experts have proposed that gastroesophageal reflux disease (GERD) should be diagnosed only in patients with abnormal esophageal acid exposure, and that reflux hypersensitivity (RH) and functional heartburn (FH) both should be considered functional conditions separate from GERD. Although past and recent evidence support that FH can be completely distinguished from GERD, the concept that RH is not GERD is highly questionable. This review attempts to provide current data on these issues.

RECENT FINDINGS

Many recent investigations have provided new data on the different pathophysiological features characterizing RH and FH. Major differences have emerged from analyses of impedance-pH monitoring studies using the novel impedance metrics of baseline impedance (an index of mucosal integrity) and the rate of postreflux swallow-induced peristaltic waves (a reflection of the integrity of esophageal chemical clearance).

SUMMARY

The better ability to interpret impedance-pH tracings together with earlier data on the different prevalence of microscopic esophagitis in RH and FH patients, and recent studies documenting poor therapeutic efficacy of pain modulators and good results of antireflux surgery for RH support recategorization of RH within the GERD world. Further research is needed to correctly phenotype patients who have heartburn without mucosal breaks, and to guide their effective management.

Application of Lyon Consensus criteria for GORD diagnosis: evaluation of conventional and new impedance-pH parameters

OBJECTIVE

To validate Lyon Consensus criteria for diagnosing gastro-oesophageal reflux disease (GORD) by reflux monitoring.

DESIGN

Manual review of impedance-pH tracings from patients with proton pump inhibitor (PPI)-dependent heartburn, evaluated off PPI. Acid exposure time (AET) thresholds defined by the Lyon Consensus and impedance parameters were investigated, namely, total refluxes (TRs), postreflux swallow-induced peristaltic wave (PSPW) index and mean nocturnal baseline impedance (MNBI).

RESULTS

The study included 488 patients, 178 (36%) with normal (<4%) AET, 89 (18%) with inconclusive (4%-6%) AET and 221 (45%) with abnormal (>6%) AET, alongside with 70 healthy controls. At receiver operating characteristic analysis, area under curve was 0.89, 0.95 and 0.89 for TRs, PSPW index and MNBI, respectively, and threshold values were 40, 50% and 2000 Ω; the 4% physiological AET threshold defined by the Lyon Consensus showed 100% specificity but 63% sensitivity. The thresholds defined for impedance parameters were validated against AET by means of ordered logistic regression, being in concordance with the 4% AET threshold (OR 2.5 for TRs, 18.9 for PSPW index and 5.7 for MNBI). TRs positivity and concordant PSPW index/MNBI positivity were found in 80%-90% of patients in the abnormal AET group, in 73%-74% of cases in the inconclusive AET group and in 28%-40% of cases in the group with normal AET.

CONCLUSIONS

Our results show the overall validity of the Lyon Consensus approach to GORD diagnosis. Adding evaluation of impedance parameters, namely, TRs, PSPW index and MNBI to AET appraisal, substantially improves the diagnostic yield of reflux monitoring.

Complex Gastroesophageal Reflux Disease

Gastroesophageal reflux disease (GERD) is the most prevalent gastrointestinal disorder posing diagnostic and therapeutic challenges. Diagnosis should be objectively defined with endoscopy and pH testing, while novel metrics may augment diagnosis for inconclusive GERD cases, including the postreflux swallow-induced peristaltic wave index and esophageal mucosal impedance. Conditions that overlap with or mimic GERD should be considered such as achalasia, rumination, and eosinophilic esophagitis. Genetic testing for proton pump inhibitor metabolism is an option for precision therapy in complex persistent GERD. Proton pump inhibitor refractory GERD may require medical, surgical, or endoscopic therapies. The presence of GERD should be objectively evaluated in achalasia patients treated with peroral endoscopic myotomy, and further studies are needed to determine timing of this evaluation. Patients with scleroderma are at a high risk for GERD owing to abnormal esophageal motility and should be managed with aggressive medical therapy and lifestyle changes given the high prevalence of esophagitis and Barrett's esophagus in this population. Further studies are needed to understand the complex mechanisms of GERD in idiopathic pulmonary fibrosis and lung transplantation.

Novel Advanced Impedance Metrics on Impedance-pH Testing Predict Lung Function Decline in Idiopathic Pulmonary Fibrosis

INTRODUCTION

Gastroesophageal reflux has been associated with idiopathic pulmonary fibrosis (IPF). Mean nocturnal baseline impedance (MNBI) is a marker of esophageal mucosal integrity, whereas postreflux swallow-induced peristaltic wave (PSPW) index reflects esophageal chemical clearance. Both metrics offer novel ways to assess reflux burden on multichannel intraluminal impedance-pH testing (MII-pH), but their role in extraesophageal reflux remains unclear. We aimed to evaluate the relationship between these novel metrics and lung function decline in patients with IPF.

METHODS

Adults with IPF undergoing prelung transplant MII-pH were enrolled. All patients completed pulmonary function testing (PFT) at the time of MII-pH and at the 1-year follow-up. MNBI was calculated by averaging baseline impedance at three 10-minute intervals (1 AM/2 AM/3 AM). PSPW index was the proportion of all reflux episodes, followed by a peristaltic swallow within 30 seconds. Univariate (Student t-test/Pearson correlation) and multivariable (general linear regression) analyses were performed.

RESULTS

One hundred twenty-five subjects (mean age = 61.7 years, 62% men) were included. Forced expiratory volume in one second and forced vital capacity declined more significantly over 12 months in subjects with lower distal MNBI, proximal MNBI, and PSPW index (all P < 0.05). On multivariable analyses adjusting for age, sex, proton pump inhibitor use, and baseline lung function, distal MNBI (β = -10.86, P = 0.024; β = -8.03, P = 0.045), proximal MNBI (β = -13.5, P = 0.0068; β = -9.80, P = 0.025), and PSPW index (β = -18.1, P = 0.010; β = -12.55, P = 0.050) remained predictive of greater forced expiratory volume in one second and forced vital capacity decline.

DISCUSSION

Low distal MNBI, proximal MNBI, and PSPW index independently predicted more severe lung function decline over 1 year in patients with IPF. These impedance metrics may have prognostic value and support a role for reflux in IPF pathogenesis.

Nonachalasic esophageal motor disorders, from diagnosis to therapy

INTRODUCTION

Investigations conducted using conventional manometry and, recently, using high-resolution manometry (HRM), allowed us to explore the field of esophageal motility and understand the potential link between motor features and gastroesophageal reflux disease (GERD) pathogenesis. The management of patients with nonachalasic esophageal motor disorders is often challenging, due to the clinical heterogeneous presentation and the multifactorial nature of the mechanisms underlying symptoms.

AREAS COVERED

Several studies, carried out using HRM, have better interpreted the esophageal motor function in patients with esophagogastric junction outflow obstruction (EGJOO), distal esophageal spasm (DES), hypertensive esophagus, and hypomotility disorders. Moreover, HRM studies have shown a direct correlation between reduced esophageal motility, disruption of the esophagogastric junction, and gastroesophageal reflux burden.

EXPERT OPINION

Pathogenesis, clinical presentation, diagnosis, and treatment of nonachalasic esophageal motor disorders still represent a challenging area, requiring future evaluation by multicenter outcome studies carried out in a large cohort of patients and asymptomatic subjects. However, we believe that an accurate clinical, endoscopic, and HRM evaluation is, nowadays, helpful in addressing patients with nonachalasic esophageal motor disorders to optimal treatment options.

Refractory Gastroesophageal Reflux Disease: A Management Update

Gastroesophageal reflux disease (GERD) is one of the most frequent gastrointestinal disorders. Proton pump inhibitors (PPIs) are effective in healing lesions and improving symptoms in most cases, although up to 40% of GERD patients do not respond adequately to PPI therapy. Refractory GERD (rGERD) is one of the most challenging problems, given its impact on the quality of life and consumption of health care resources. The definition of rGERD is a controversial topic as it has not been unequivocally established. Indeed, some patients unresponsive to PPIs who experience symptoms potentially related to GERD may not have GERD; in this case the definition could be replaced with “reflux-like PPI-refractory symptoms.” Patients with persistent reflux-like symptoms should undergo a diagnostic workup aimed at finding objective evidence of GERD through endoscopic and pH-impedance investigations. The management strategies regarding rGERD, apart from a careful check of patient's compliance with PPIs, a possible change in the timing of their administration and the choice of a PPI with a different metabolic pathway, include other pharmacologic treatments. These include histamine-2 receptor antagonists (H2RAs), alginates, antacids and mucosal protective agents, potassium competitive acid blockers (PCABs), prokinetics, gamma aminobutyric acid-B (GABA-B) receptor agonists and metabotropic glutamate receptor-5 (mGluR5) antagonists, and pain modulators. If there is no benefit from medical therapy, but there is objective evidence of GERD, invasive antireflux options should be evaluated after having carefully explained the risks and benefits to the patient. The most widely performed invasive antireflux option remains laparoscopic antireflux surgery (LARS), even if other, less invasive, interventions have been suggested in the last few decades, including endoscopic transoral incisionless fundoplication (TIF), magnetic sphincter augmentation (LINX) or radiofrequency therapy (Stretta). Due to the different mechanisms underlying rGERD, the most effective strategy can vary, and it should be tailored to each patient. The aim of this paper is to review the different management options available to successfully deal with rGERD.

Patients With Definite and Inconclusive Evidence of Reflux According to Lyon Consensus Display Similar Motility and Esophagogastric Junction Characteristics

BACKGROUND/AIMS

The role of esophageal high-resolution manometry (HRM) within Lyon consensus phenotypes, especially patients with inconclusive gastroesophageal reflux disease (GERD) evidence, has not been fully investigated. In this multicenter, observational study we aim to compare HRM parameters in patients with GERD stratified according to the Lyon consensus.

METHODS

Clinical and endoscopic data, HRM and multichannel intraluminal impedance-pH (MII-pH) studies performed off proton pump inhibitor therapy in patients with esophageal GERD symptoms were reviewed. Lyon consensus criteria identified pathological GERD, reflux hypersensitivity, functional heartburn, and inconclusive GERD. Patients, with inconclusive GERD were further subdivided into 2 groups based on total reflux numbers (≤ 80 or > 80 reflux episodes) during the MII-pH recording time.

RESULTS

A total of 264 patients formed the study cohort. Pathological GERD and inconclusive GERD patients were associated with higher numbers of reflux episodes, lower mean nocturnal baseline impedance (MNBI) values, and a higher proportion of patients with pathologic MNBI compared to functional heartburn (P < 0.05 for each comparison). On multivariate analysis, pathological GERD and inconclusive GERD patients, both with ≤ 80 or > 80 reflux episodes, were significantly associated with pathologic esophagogastric junction contractile integral values and with presence of hiatus hernia (type 2/3 esophagogastric junction). Patients with inconclusive GERD and > 80 reflux episodes were significantly associated with fragmented peristalsis and ineffective esophageal motility whilst inconclusive GERD with ≤ 80 reflux episodes were significantly associated with fragmented peristalsis.

CONCLUSION

Esophageal motor parameters on HRM are similar between pathologic and inconclusive GERD according to the Lyon consensus.

How a modified Nissen procedure works: a mechanistic study using intraoperative esophageal high-resolution manometry

OBJECTIVE

We aimed at demonstrating how a modified Nissen procedure works by analyzing intraoperatively the variations of the low esophageal sphincter pressure values using high resolution manometry.

METHODS

This study included 15 patients with documented gastroesophageal reflux disease who underwent a laparoscopic modified Nissen procedure. Data regarding the changes in the pressure values were recorded at each step of the procedures using high resolution manometry and after the progressive insufflation of air in the stomach. Categorical data were compared between the preoperative and postoperative periods using Fisher's test, and continuous data were compared using Mann-Whitney U non-parametric test. Preoperative versus postoperative variations in continuous data were assessed using Wilcoxon's non-parametric test for paired data.

RESULTS

Intraoperative manometric data showed a rise of basal LES pressure until the creation of the wrap. An evident increase of pressure values was recorded after gastric air insufflation, as consequence of the increase of intragastric pressure. No intraoperative and postoperative complications were observed. All patients experienced a significant reduction in terms of intensity and frequency of gastroesophageal reflux symptoms and no patients complained of dysphagia.

CONCLUSIONS

Intraoperative high resolution manometry was feasible in all patients and demonstrated that the modified Nissen procedure works by increasing the LES pressure in response to gastric distension, without impeding the progression of the bolus into the stomach.

Guidance on performance and reporting of high-resolution oesophageal manometry and ambulatory pH monitoring in Singapore

INTRODUCTION

We aimed to provide a practical and evidence-based guide on the indications, performance and reporting of high-resolution oesophageal manometry (HRM) and ambulatory pH monitoring (PHM) in adult patients in Singapore.

METHODS

The guideline committee comprised local gastroenterologists from public and private sectors with particular expertise in aspects of HRM and PHM, and it was tasked to produce evidence-based statements on the indications, performance and reporting of these tests. Each committee member performed literature searches to retrieve relevant articles within the context of domains to which they were assigned.

RESULTS

Twelve recommendation statements were created and summarised.

CONCLUSION

Standardising key aspects of HRM and PHM is imperative to ensure the delivery of high-quality care. We reported the development of recommendations for the performance and interpretation of HRM and ambulatory reflux monitoring in Singapore.

Untangling Nonerosive Reflux Disease From Functional Heartburn

Heartburn is a common symptom in clinical practice, but as many as 70% of patients have normal findings from upper endoscopy. Most of these patients have nonerosive reflux disease (NERD) or functional esophageal disorders. NERD is the most common phenotype of gastroesophageal reflux disease, and functional heartburn is the most common cause for refractory heartburn. In patients with NERD, symptoms arise from gastroesophageal reflux and esophageal hypersensitivity, whereas in patients with functional heartburn, symptoms result from esophageal hypersensitivity. A diagnosis of NERD requires endoscopy and reflux testing, whereas a diagnosis of functional heartburn also requires esophageal manometry. NERD is treated most commonly with medical, endoscopic, and surgical antireflux approaches, whereas functional heartburn as well as NERD can be treated with neuromodulators, psychological intervention, and complementary medicine options.

Gastroesophageal Reflux Disease Diagnosis by New Consensus in Clinical Practice: The Additional Value of Mean Basal Impedance

BACKGROUND

Recently, Lyon consensus and ROME IV were published as there was a need to create a more objective evaluation for gastroesophageal reflux disease (GERD) in order to better predict treatment outcomes. However, with classical pH-impedance measures, some patients would still have diagnostic uncertainty, and new metrics, such as mean nocturnal basal impedance (MNBI), have emerged to corroborate with GERD diagnosis. The aim of the present study was to describe the prevalence of GERD, functional heartburn (FH), reflux hypersensitivity (RH), and undetermined diagnosis using current consensuses and to evaluate if MNBI could be considered a supportive measure for the diagnosis of GERD.

METHODS

Patients who underwent pH-multichannel intraluminal impedance (MII-pH) for suspected GERD between 2013 and 2018 were included. Subjects with previous diagnosis of GERD (e.g., esophagitis grade C or D according to Los Angeles classification, Barrett's esophagus, or peptic stricture), atypical symptoms, major esophageal motor disorder, eosinophilic esophagitis, or under proton pump inhibitor were excluded from the analysis.

RESULTS

We included 75 patients. The prevalence of GERD, FH, RH and undetermined diagnosis was 44%, 14.7%, 12%, and 29.3%, respectively. MNBI was lower in patients with GERD (GERD: 1,307.5 ± 817.9 Ω vs. FH: 3,039.6 ± 1,040.8 Ω, RH: 2,617.1 ± 1,342.2 Ω, undetermined: 2,351.9 ± 1,018.2, p < 0.001), although it was similar between patients with FH and RH (p = 0.44) or between undetermined diagnosis and FH/RH (p = 0.15). More patients with a GERD diagnosis had a MNBI under 2,292 Ω (GERD: 93.9% vs. non-GERD: 31.7%, p < 0.001).

CONCLUSION

In our study, using MII-pH criteria, less than half of the patients had a GERD diagnosis. MNBI showed additional value as another metric for the diagnosis of GERD.

Sex-Based Differences in pH Parameters and Esophageal Impedance of Patients With Gastroesophageal Reflux Disease

Background/Aims: The incidence of reflux esophagitis (RE) has a striking predominance in males. Conversely, non-erosive reflux disease (NERD) is more common in females. This imbalance of gastroesophageal reflux disease (GERD) implies sex-related differences in its pathogenesis. However, limited studies have analyzed the sex-based differences in pH parameters and esophageal impedance of GERD patients.

Methods: This study evaluated sex-based pathogenesis differences by comparing reflux episodes, mean nocturnal baseline impedance (MNBI) values, and post-reflux swallow-induced peristaltic wave (PSPW) index values of males with GERD and females with GERD using 24-h multichannel intraluminal impedance and pH monitoring.

Results: We analyzed 181 patients (102 males and 79 females) with GERD. Reflux symptom index (RSI) scores were higher in females than that in males (P < 0.05). Males had significantly longer acid exposure times, higher DeMeester scores, and more acid reflux episodes than females (P < 0.05). Females had more instances of weakly acidic reflux than males (P < 0.01). The PSPW index values of males and females were similar (P > 0.05). Compared with females, males had lower MNBI values for the mid and distal esophagus (P < 0.05). However, with increasing age, the MNBI values of females decreased more rapidly than those of males. MNBI values of elderly patients of both sexes older than 60 years were similar.

Conclusions: Acid reflux is more likely to occur in males; however, females tend to have more instances of weakly acid reflux. The integrity of the esophageal mucosa is more fragile in males than in females; however, the esophageal mucosal barrier attenuates more rapidly with increasing age in females than in males.

The importance of functional diagnostics in determining the cause of antisecretary therapy inefficiency in a patient with heartburn: clinical observation

One of the main symptoms of gastroesophageal reflux disease is heartburn, for the relief of which proton pump inhibitors are traditionally prescribed. However, there are frequent cases of heartburn, refractory to antisecretory therapy, when there is no complete relief of the symptom or only a partial clinical effect. The reason for an unsatisfactory response may be the functional genesis of heartburn. The purpose of the presented clinical observation is to demonstrate the heterogeneity of patients with heartburn, the role of functional research methods in the differential diagnosis of various conditions that accompany this symptom. A 42-year-old patient was admitted for an additional clinical examination with complaints of heartburn refractory to antisecretory therapy, which included high-resolution esophageal manometry, 24-hours pH-impedance. The manometric assessment of the structure and function of the lower esophageal sphincter, as well as the contractility of the thoracic esophagus, revealed no violations. The data of 24-hours pH-impedance demonstrated the absence of pathological reflux and the association of active symptoms with refluxes, which determined the functional nature of heartburn and explained the ineffectiveness of treatment with proton pump inhibitors. Heartburn can be functional in  nature and significantly reduce the  quality of  life of  patients. Functional heartburn requires different management tactics from gastroesophageal reflux disease, which is based on an adequate differential diagnosis, including functional research methods such as high-resolution esophageal manometry and 24-hours pH-impedance measurement, which allow to exclude other conditions accompanied by similar symptoms. 

ESNM/ANMS consensus paper: Diagnosis and management of refractory gastro-esophageal reflux disease

Up to 40% of patients with symptoms suspicious of gastroesophageal reflux disease (GERD) do not respond completely to proton pump inhibitor (PPI) therapy. The term "refractory GERD" has been used loosely in the literature. A distinction should be made between refractory symptoms (ie, symptoms may or may not be GERD-related), refractory GERD symptoms (ie, persisting symptoms in patients with proven GERD, regardless of relationship to ongoing reflux), and refractory GERD (ie, objective evidence of GERD despite adequate medical management). The present ESNM/ANMS consensus paper proposes use the term "refractory GERD symptoms" only in patients with persisting symptoms and previously proven GERD by either endoscopy or esophageal pH monitoring. Even in this context, symptoms may or may not be reflux related. Objective evaluation, including endoscopy and esophageal physiologic testing, is requisite to provide insights into mechanisms of symptom generation and evidence of true refractory GERD. Some patients may have true ongoing refractory acid or weakly acidic reflux despite PPIs, while others have no evidence of ongoing reflux, and yet others have functional esophageal disorders (overlapping with proven GERD confirmed off therapy). In this context, attention should also be paid to supragastric belching and rumination syndrome, which may be important contributors to refractory symptoms.

Advances in the diagnosis of GERD

Gastroesophageal reflux disease (GERD) is considered one of the most frequent chronic gastrointestinal diseases globally with high costs due to treatment and investigations.First line therapy is with proton pump inhibitors, those who do not respond to initial treatment usually require further investigations such as upper gastrointestinal endoscopy or ambulatory 24-hours esophageal pH monitoring. The total time of exposure to acid and the DeMeester score represent the most useful parameters associated with conventional pH-metry, because they can identify gastroesophageal reflux disease.Although pH-metry is considered the gold standard for the evaluation of gastroesophageal reflux disease, new impedance-based parameters have been introduced in recent years with the role of increasing the accuracy of diagnosing gastroesophageal reflux disease and characterizing the type of reflux. The development of multichannel intraluminal pH-impedance has improved the ability to detect and quantify gastroesophageal reflux. New parameters such as post-reflux swallowing peristaltic wave (PSPW) index and the mean nocturnal basal impedance (MNBI) have recently been introduced to assess GERD phenotypes more accurately. This review evaluates current GERD diagnotic tools while also taking a brief look at newer diagnostic parameters like PSPW and MNBI.

Esophageal contractile segment impedance from high-resolution impedance manometry correlates with mean nocturnal baseline impedance and acid exposure time from 24-hour pH-impedance monitoring

Esophageal baseline impedance (BI) acquired during esophageal contraction (contractile segment impedance [CSI]) is proposed to improve BI accuracy in gastroesophageal reflux disease (GERD). We evaluated associations between CSI and conventional and novel GERD metrics. We analyzed high-resolution impedance manometry (HRIM) and ambulatory pH-impedance studies from 51 patients (58.6 ± 1.5 years; 26% F) with GERD symptoms studied off antisecretory therapy. Patients with achalasia or absent contractility were excluded. CSI (averaged across 10 swallows) and BI-HRIM (from the resting landmark phase) were acquired from the distal impedance sensors (distal sensor and 5 cm above the lower esophageal sphincter). Acid exposure time (AET) and mean nocturnal baseline impedance (MNBI) were calculated. Associations between CSI, BI-HRIM, MNBI, and AET were evaluated using correlation (Pearson) and receiver operating characteristic (ROC) analysis. Presenting symptoms included heartburn (67%), regurgitation (12%), cough (12%), and chest pain (10%). CSI-distal and CSI-5 each correlated with BI-HRIM, AET, and distal MNBI. Associations with AET were numerically stronger for CSI-distal (r = -0.46) and BI-HRIM-distal (r = -0.44) than CSI-5 (r = -0.33), BI-HRIM-5 (r = -0.28), or distal MNBI (r < -0.36). When compared to AET <4%, patients with AET >6% had significantly lower CSI-distal and BI-HRIM-distal values but not CSI-5, BI-HRIM-5, or MNBI. ROC areas under the curve for AET >6% were numerically higher for CSI-distal (0.81) than BI-HRIM-distal (0.77), distal MNBI (0.68-0.75), CSI-5 (0.68), or BI-HRIM-5 (0.68). CSI from HRIM studies inversely correlates with pathologic AET and has potential to augment the evaluation of GERD.

Bile reflux in patients with nerd is associated with more severe heartburn and lower values of mean nocturnal baseline impedance and chemical clearance

BACKGROUND

Mean nocturnal baseline impedance (MNBI) and postreflux swallow-induced peristaltic wave (PSPW) index are novel impedance-based markers of reflux, but the effect of bile reflux on these metrics is unknown. The aim of this study was to evaluate bile reflux, MNBI, and PSPW index in patients with endoscopy-negative GERD partially responsive to PPI therapy.

METHODS

All patients underwent off-PPI endoscopy, esophageal manometry, multichannel intraluminal impedance pH (MII-pH), and bile reflux monitoring. Abnormal esophageal acid exposure time (AET) was required for inclusion. Symptom intensity (using 10-cm visual analog scales), and conventional and novel MII-pH metrics were compared between patients with and without abnormal bile reflux.

KEY RESULTS

We evaluated 42 NERD patients (29 males, mean age: 53.4 ± 13. years), mean AET 6.1 ± 2%, of which 21 had abnormal bile reflux (Group A, 10.2 ± 4.9%), and 21 had normal bile reflux (Group B, 0.4 ± 0.1%, P < .05 compared with Group A). Heartburn reporting on PPI was higher in Group A (7.2 ± 2.1 vs 5.8 ± 0.9; P = .002), but AET, number of reflux events (acidic and weakly acidic), did not differ between the two groups. However, both PSPW index and MNBI were lower in Group A (P < .001). A strong inverse linear correlation was found between bile reflux and both MNBI (Pearson's test; R = -0.714; P < .001) and PSPW index (R = -0.722; P < .001).

CONCLUSIONS AND INFERENCES

Compared to acid reflux alone, the presence of bile in an acidic esophageal environment is associated with more severe heartburn, lesser relief from PPI therapy, higher impairment of esophageal mucosal integrity and less effective chemical clearance.

Esophageal reflux hypersensitivity: Non-GERD or still GERD?

The most recent iteration of the classifications for functional esophageal disorders, Rome IV, proposed relevant modifications of the previous definitions for Rome III. They specifically considered increased esophageal acid exposure as the marker of gastroesophageal reflux disease (GERD), including the remaining part of non-erosive reflux disease patients with normal acid in the group with functional alterations, considering both reflux hypersensitivity and functional heartburn. However, recent pathophysiological and therapeutic data suggest the need for a return to including reflux hypersensitivity in the GERD spectrum. Indeed, physiologic alterations in esophageal mucosal integrity and chemical clearance, the presence of microscopic esophagitis, and strict symptom-reflux association support the concept that reflux hypersensitivity pertains to GERD. Surgical anti-reflux therapy has resulted in positive outcomes, even in the long term, in patients with reflux hypersensitivity and not in those with functional heartburn. Moreover, clinical trials using neuromodulators have been scarce and provided conflicting results. As a result, the real progress of the Rome IV classifications is in dispute. This article aims to summarize the most recent knowledge of non-erosive reflux disease and reflux hypersensitivity to discuss the utility of Rome IV criteria in the identification and management of functional esophageal disorders.

The Role of Salivary Pepsin in the Diagnosis of Gastroesophageal Reflux Disease (GERD) Evaluated Using High-Resolution Manometry and 24-Hour Multichannel Intraluminal Impedance-pH Monitoring

BACKGROUND The Lyon Consensus classification confirms or rules out gastroesophageal reflux disease (GERD). The refractory symptoms of patients with GERD taking proton pump inhibitors (PPIs) are challenging in clinical practice. Salivary pepsin concentration was proposed as a diagnostic biomarker for GERD. We aimed to determine the diagnostic value of salivary pepsin concentration for patients with conclusive GERD, based on the Lyon classification, and the correlation of salivary pepsin concentration with parameters of high-resolution manometry and 24-h multichannel intraluminal impedance-pH in patients with PPI-refractory symptoms. MATERIAL AND METHODS Saliva samples obtained from 130 patients who were suspicious for GERD and had PPI-refractory symptoms were used for pepsin determination using the enzyme-linked immunosorbent assay. All patients underwent upper gastrointestinal endoscopy, high-resolution manometry, 24-h multichannel intraluminal impedance, and pH recording and were classified as conclusive GERD, inconclusive GERD, and evidence against GERD groups according to Lyon classification. RESULTS Salivary pepsin concentration was 8.2 ng/mL (3.8-17.8 ng/mL), 4.0 ng/mL (2.3-6.1 ng/mL), and 2.4 ng/mL (2.2-3.1 ng/mL) in conclusive GERD, inconclusive GERD, and evidence against GERD groups, respectively (P<0.001), and had a negative correlation with distal mean nocturnal baseline impedance and positive correlations with acid exposure time, total number of reflux events, and esophagogastric junction type. The area under the ROC curve of salivary pepsin for conclusive GERD was 0.76 (0.68-0.84), with a sensitivity of 76.36% and a specificity of 63.41% for conclusive GERD diagnosis at a cut-off value of 4.21 ng/mL. CONCLUSIONS Salivary pepsin test had moderate diagnostic value for conclusive GERD by Lyon classification in patients with PPI-refractory symptoms.

The esophageal mucosal barrier in health and disease: mucosal pathophysiology and protective mechanisms

Diseases of the esophagus, such as gastroesophageal reflux (GER), can result in changes to mucosal integrity, neurological function, and the microbiome. Although poorly understood, both age and GER can lead to changes to the enteric nervous system. In addition, the esophagus has a distinct microbiome that can be altered in GER. Mucosal integrity is also at risk due to persistent damage from acid. Diagnostic tools, such as ambulatory pH/impedance testing and esophageal mucosal impedance, can assess short-term and longitudinal GER burden, which can also assess the risk for mucosal compromise. The quality of the mucosal barrier is determined by its intercellular spaces, tight junctions, and tight junction proteins, which are represented by claudins, occludins, and adhesion molecules. Fortunately, there are protective factors for mucosal integrity that are secreted by the esophageal submucosal mucous glands and within saliva that are augmented by mastication. These protective factors have potential as therapeutic targets for GER. In this article, we aim to review diagnostic tools used to predict mucosal integrity, aging, and microbiome changes to the esophagus and esophageal mucosal defense mechanisms.

Normal values and regional differences in oesophageal impedance-pH metrics: a consensus analysis of impedance-pH studies from around the world

OBJECTIVE

Limitations of existing impedance-pH thresholds include small sample size of normative studies, inclusion of artefactual pH drops and incorrect identification of impedance reflux events. We aimed to obtain new impedance-pH thresholds from expert consensus analysis of tracings from a large number of healthy subjects.

DESIGN

Of 541 studies performed worldwide using two different systems (Diversatek, USA, and Laborie, Netherlands), 150 tracings with oesophageal diagnoses, behavioural disorders and study-related artefacts were excluded. The remainder studies were subject to two reviewer consensus analysis, in-person or through video conference, consisting of editing meals and pH drops, identification of impedance reflux and postreflux swallow-induced peristaltic wave (PSPW) using strict pre-established criteria and measurement of distal mean nocturnal baseline impedance (MNBI).

RESULTS

Consensus analysis was performed in 391 tracings (age 32.7 years, range 18-71, 54.2% female). Normative thresholds were significantly different between Diversatek and Laborie (total acid exposure time: 2.8% and 5%; reflux episodes: 55 and 78; MNBI at 3 cm: 1400 and 1500 ohms, at 5 cm: 1400 and 1800 ohms). Males had higher acid exposure, more reflux episodes and lower MNBI. Significant regional differences were identified, including higher PSPW scores in Western countries, and higher MNBI in Asia using Diversatek, and higher acid exposure in the Netherlands, higher MNBI in Asia and South Africa, and lower MNBI in Turkey using Laborie.

CONCLUSION

Normal impedance-pH monitoring thresholds have regional and system-related differences. Clinical interpretation needs to use normal thresholds valid for the system used and world region, following careful editing of the tracings.

Understanding the relationship between esophageal motor disorders and reflux disease

INTRODUCTION

The management of gastro-esophageal reflux disease (GERD) patients is often complex as the clinical presentation is heterogeneous and the mechanisms underlying symptoms are multifactorial. In the past decades, investigations conducted with conventional manometry and, above all, the more accurate high resolution manometry (HRM), helped us in exploring the field of esophageal motility and in understanding the link between motor features and GERD pathogenesis.

AREAS COVERED

Several studies carried out with conventional manometry and HRM have confirmed a relevant role of esophageal motor function in GERD pathogenesis. In particular, HRM studies have shown a direct correlation between impaired esophageal body motility, disruption of the esophagogastric junction and reflux burden. These findings impact the clinical and therapeutical management of GERD patients. Moreover, HRM findings might be helpful in evaluating patients with proton pump inhibitor (PPI) resistance and inconclusive evidences of GERD.

EXPERT OPINION

The relationship between esophageal motility and GERD pathogenesis needs to be further evaluated by multicenter outcome studies involving a large number of GERD patients and healthy controls. However, other more promising areas could be progressed.

The Usefulness of Esophageal Baseline Impedance Levels for the Diagnosis of Nonerosive Reflux Disease and the Proper Time for Measurement in Endoscopy-negative Korean Patients With Esophageal or Supraesophageal Symptoms

Background/Aims

Low baseline impedance levels (BILs) have been suggested to be evidence of GERD. The aim of this study is to investigate the usefulness of esophageal BILs for the diagnosis of nonerosive reflux disease (NERD) and the proper time for measurement in endoscopy-negative Korean patients with esophageal or supraesophageal symptoms.

Methods

Endoscopy-negative patients with esophageal or supraesophageal symptoms who underwent esophageal multichannel intraluminal impedance-pH monitoring were included. BILs were measured in the proximal and distal esophagus around 10 minutes before meals, 10 minutes and 30 minutes after meals, 30 minutes before the start of nighttime sleep, and 30 minutes and 60 minutes after the start of nighttime sleep.

Results

A total of 104 patients were included in the study. Distal and proximal esophageal BILs were decreased after meal ingestion. The BILs of the distal esophagus were significantly lower at all time points in the NERD group, but not in the reflux hypersensitivity (RH) group, compared with the functional group. The area under the receiver operating characteristic curve for the diagnosis of NERD was significant at all time points, but that for the diagnosis of RH was not. The cut-off value of 2375 Ω or 2125 Ω measured around 30 minutes before or 60 minutes after the start of nighttime sleep, respectively, were appropriate for the diagnosis of NERD.

Conclusion

The BILs of the distal esophagus measured at time points before or after the start of nighttime sleep appear to be useful for the diagnosis of NERD, but not for the diagnosis of RH, in endoscopy-negative Korean patients with esophageal or supraesophageal symptoms.

Esophageal Baseline Impedance From High-resolution Impedance Manometry Correlates With Mean Nocturnal Baseline Impedance From pH-impedance Monitoring

Background/Aims

Esophageal baseline impedance (BI) can be extracted from pH-impedance tracings as mean nocturnal baseline impedance (MNBI), and from high-resolution impedance manometry (HRIM), but it is unknown if values are similar between acquisition methods across HRIM manufacturers. We aim to assess correlations between MNBI and BI from HRIM (BI-HRIM) from 2 HRIM manufacturers in the setting of physiologic acid exposure time (AET).

Methods

HRIM and pH-impedance monitoring demonstrating physiologic AET (< 4%) off proton pump inhibitors were required. BI-HRIM was extracted as the average from 5 cm and 10 cm above the lower esophageal sphincter. Distal BI-HRIM (DBI-HRIM) was also extracted from the most distal channel (Medtronic studies). MNBI was extracted from 6 channels. Concordance between BI-HRIM across manufacturers with MNBI was analyzed.

Results

Thirty-six patients met the inclusion criteria (59.6 ± 1.7 years; 22% female; body mass index 30.5 ± 0.7; AET 1.6 ± 0.2%). Although MNBI was similar at all channels (P ≥ 0.18), Diversatek BI-HRIM was lower than Medtronic BI-HRIM (P = 0.003). Overall, BI-HRIM correlated with MNBI at corresponding recording sites, 7 cm and 9 cm (P < 0.05), but not at other sites (P ≥ 0.19). Pearson’s correlations > 0.5 were seen at MNBI at 7 cm for both systems, and at 9 cm for Medtronic. DBI-HRIM correlated with MNBI at 3 cm and 5 cm (P < 0.03), but not at other locations (P > 0.1).

Conclusions

While numeric differences exist between manufacturers, BI-HRIM correlates with MNBI from corresponding channels in patients with physiologic AET. Comparison with AET elevation is needed to determine correlations between pathologic MNBI with BI-HRIM across manufacturers. The optimal HRIM channels from which BI values should be extracted also warrants further study.

Gastroesophageal reflux disease in pediatric esophageal atresia: Assessment of clinical symptoms and pH-impedance data

BACKGROUND

Esophageal atresia (EA) is the most common congenital anomaly of the gastrointestinal tract. Gastroesophageal reflux disease (GERD) is a frequent and lifelong problem in these patients. GERD can be asymptomatic and the incidence of esophageal gastric and intestinal metaplasia (Barrett’s esophagus) is increased in adults with EA compared with the general population. Timely and accurate diagnosis of GERD is important to reduce long-term problems and this may be achieved by pH-impedance testing.

AIM

To assess symptoms and pH-impedance data in children after EA, in order to identify their specific features of GERD.

METHODS

This study was conducted from November 2017 to February 2020 and involved 37 children who had undergone EA via open surgical repair (51.35% boys, 48.65% girls; age range: 1-14 years, median: 4.99 years). GERD diagnosis was made based on multichannel intraluminal impedance/pH study and two groups were established: EA without GERD, n = 17; EA with GERD, n = 20. A control group was established with 66 children with proven GERD (68.18% boys, 31.82% girls; median age: 7.21 years), composed of a nonerosive reflux disease (referred to as NERD) group (n = 41) and a reflux esophagitis group (n = 25). Upper gastrointestinal endoscopy with a mucosal esophageal biopsy was performed on all patients.

RESULTS

The most frequently observed symptom in EA patients with GERD and without GERD was cough (70% and 76.5% respectively). The number of patients with positive symptom association probability in the EA groups was significantly larger in the EA without GERD group (P = 0.03). In the control reflux esophagitis group, prevalence of gastrointestinal symptoms was significantly higher than in the NERD group (P = 0.017). For both EA groups, there was strong correlation with index of proximal events (IPE) and total proximal events (EA with GERD: 0.96, P < 0.001; EA without GERD: 0.97, P < 0.001) but level of IPE was significantly lower than in GERD patients without any surgical treatment (P < 0.001). Data on distal mean nocturnal baseline impedance were significantly different between the EA with GERD group (P < 0.001) and the two control groups but not between EA without GERD and the two control groups.

CONCLUSION

Mean nocturnal baseline impedance may have diagnostic value for GERD in EA children after open surgical repair. IPE might be an additional parameter of pH-impedance monitoring.

A SIGE-SINGEM-AIGO technical review on the clinical use of esophageal reflux monitoring

Patients with esophageal symptoms potentially associated with gastroesophageal reflux disease such as heartburn, regurgitation, chest pain, or cough represent one of the most frequent reasons for referral to gastroenterological evaluation. The utility of esophageal reflux monitoring in clinical practice is: (1) to accurately define reflux burden, (2) to segregate patients according to reflux monitoring results as true GERD, reflux hypersensitivity and functional heartburn, and (3) to establish a treatment plan. With this in mind, in the last decade, investigations and technical advances, with the introduction of impedance-pH monitoring and wireless pH capsule, have enhanced our understanding and management of GERD. The following recommendations were discussed and approved after a comprehensive review of the medical literature pertaining to reflux testing techniques and their recent application. This review created under the auspices of the Società Italiana di Gastroenterologia ed Endoscopia Digestiva (SIGE), Società Italiana di Neuro-Gastro-Enterologia e Motilità (SINGEM) and Associazione Italiana Gastroenterologi ed Endoscopisti Digestivi Ospedalieri (AIGO) is intended to help clinicians in applying reflux studies in the most fruitful manner within the context of their patients with esophageal symptoms.

ACG Clinical Guidelines: Clinical Use of Esophageal Physiologic Testing

Esophageal symptoms are common and may indicate the presence of gastroesophageal reflux disease (GERD), structural processes, motor dysfunction, behavioral conditions, or functional disorders. Esophageal physiologic tests are often performed when initial endoscopic evaluation is unrevealing, especially when symptoms persist despite empiric management. Commonly used esophageal physiologic tests include esophageal manometry, ambulatory reflux monitoring, and barium esophagram. Functional lumen imaging probe (FLIP) has recently been approved for the evaluation of esophageal pressure and dimensions using volumetric distension of a catheter-mounted balloon and as an adjunctive test for the evaluation of symptoms suggestive of motor dysfunction. Targeted utilization of esophageal physiologic tests can lead to definitive diagnosis of esophageal disorders but can also help rule out organic disorders while making a diagnosis of functional esophageal disorders. Esophageal physiologic tests can evaluate obstructive symptoms (dysphagia and regurgitation), typical and atypical GERD symptoms, and behavioral symptoms (belching and rumination). Certain parameters from esophageal physiologic tests can help guide the management of GERD and predict outcomes. In this ACG clinical guideline, we used the Grading of Recommendations Assessment, Development and Evaluation process to describe performance characteristics and clinical value of esophageal physiologic tests and provide recommendations for their utilization in routine clinical practice.

Reflux Hypersensitivity: How to Approach Diagnosis and Management

PURPOSE OF REVIEW

This paper aims to review the definition and diagnostic criteria for reflux hypersensitivity and comment on the present and future management of this condition.

RECENT FINDINGS

In 2016, the Rome IV criteria redefined reflux hypersensitivity as characterized by typical reflux symptoms, absence of endoscopic mucosal disease, absence of pathologic gastroesophageal reflux, and positive symptom correlation between reflux and heartburn episodes. Though uncertain, TPRV1 receptors have been implicated in the pathophysiology of reflux hypersensitivity. Recent studies have shown neuromodulators like SSRIs, SNRIs, and TCAs may be the future of managing this condition. With the release of the Rome IV criteria and availability of continuous pH monitoring, the diagnosis of reflux hypersensitivity has become more streamlined. Though there is no definitive therapy for reflux hypersensitivity, several anti-secretory agents and neuromodulators have shown some efficacy in therapeutic trials. The lack of large-scale, randomized controlled trials, however, reinforces the need for further research into the pharmacotherapy of reflux hypersensitivity.

Esophageal physiology-an overview of esophageal disorders from a pathophysiological point of view

The esophagus serves the principal purpose of transporting food from the pharynx into the stomach. A complex interplay between nerves and muscle fibers ensures that swallowing takes place as a finely coordinated event. Esophageal function can be tested by a variety of methods, endoscopy, manometry, and reflux monitoring being some of the most important. Regarding pathophysiology, motor disorders, such as achalasia, often cause dysphagia and/or chest pain. Functional esophageal disorders are a heterogeneous group with hypersensitivity as a dominant pathophysiological factor. Gastroesophageal reflux disease often causes symptoms, such as heartburn and regurgitation, and a spectrum of disease, ranging from minimal mucosal damage visible only in the microscope to esophageal ulcers and strictures in the most severe cases. Eosinophilic esophagitis is an immune-mediated condition that can result in significant dysphagia and associated luminal narrowing. In the following, we will provide an overview of the most common esophageal disorders from a combined pathophysiological and clinical view.

The Lyon Consensus: Does It Differ From the Previous Ones?

Gastroesophageal reflux disease (GERD) is a complex disorder with heterogeneous symptoms and a multifaceted pathogenetic basis, which prevent a simple diagnostic algorithm or any categorical classification. Clinical history, questionnaires and response to proton pump inhibitor (PPI) therapy are insufficient tools to make a conclusive diagnosis of GERD and further investigations are frequently required. The Lyon Consensus goes beyond the previous classifications and defines endoscopic and functional parameters able to establish the presence of GERD. Evidences for reflux include high-grade erosive esophagitis, Barrett’s esophagus, and peptic strictures at endoscopy as well as esophageal acid exposure time > 6% on pH-metry or combined pH-impedance monitoring. Even if a normal endoscopy does not exclude GERD, its combination with distal acid exposure time < 4% on off-PPI pH-impedance monitoring provides sufficient evidence refuting this diagnosis. Reflux-symptom association on pH-monitoring provides supportive evidence for reflux-triggered symptoms and may predict a better treatment outcome, when present. Also recommendations to perform pH-impedance “on” or “off” PPI are well depicted. When endoscopy and pH-metry or combined pH-impedance monitoring are inconclusive, adjunctive evidence from biopsy findings (eg, microscopic esophagitis), high-resolution manometry (ie, ineffective esophagogastric barrier and esophageal body hypomotility), and novel impedance metrics, such as mean nocturnal baseline impedance and post-reflux swallow-induced peristaltic wave index, can contribute to better identify patients with GERD. Definition of individual patient phenotype, based on the level of refluxate exposure, mechanism of reflux, efficacy of clearance, underlying anatomy of the esophagogastric junction, and clinical presentation, will lead to manage GERD patients with a tailored approach chosen among different types of therapy.