Clinical esophageal pH recording: a technical review for practice guideline development

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.

Developments in Gastroesophageal Reflux Disease over the Last 40 Years

BACKGROUND

The last 40 years have seen a remarkable change in our understanding of reflux disease.

SUMMARY

These changes encompass disease definition and impact, pathophysiology, diagnostic testing, regulatory oversight of clinical trials, pharmacotherapy, endoscopic, and surgical treatment. We have also seen a number of promising therapies fail.

KEY MESSAGES

The future holds the promise of further advances. Adaptive artificial intelligence will take over diagnostics in manometry and pH impedance testing and patient-driven outcomes may be changed by interactions with artificial intelligence rather than humans. Changes in chip technology will allow higher resolution chips to be carried on smaller devices making extra-esophageal areas where reflux may play a role more accessible to prolonged observation and testing.

Correlation of Probe-Based Confocal Laser Endomicroscopy (pCLE) and Mucosal Integrity Testing (MIT) with Epithelial Barrier Function and Presence of Gastroesophageal Reflux Disease (GERD)

INTRODUCTION

Epithelial barrier function (EBF) disruption is a key mechanism underlying gastroesophageal reflux disease (GERD). Our aim was to assess whether two novel technologies, probe-based confocal laser endomicroscopy (pCLE) and mucosal integrity testing (MIT), could assess EBF.

METHODS

We prospectively enrolled patients undergoing upper endoscopy for refractory GERD or non-GERD conditions. Patients underwent esophagogastroduodenoscopy, pCLE, MIT, esophageal biopsy at 2 cm and 6 cm above the esophagogastric junction, and wireless pH testing. To assess EBF in vitro, biopsies were mounted in a mini-Ussing chamber, 1 ml of fluorescein was instilled on the mucosal side, and concentration of fluorescein on the serosal side was measured at 3 h.

RESULTS

We enrolled 54 subjects (28 GERD, 26 non-GERD based on Lyon consensus criteria). In vivo permeability assessed by pCLE did not differ significantly between GERD vs. non-GERD patients and did not correlate with in vitro permeability. Mean MIT at 2 cm was lower in GERD compared to non-GERD (1914 vs. 3727 ohms). MIT correlated inversely with in vitro permeability at 2 cm and at 6 cm. Using a predictive model that used slope and intercept of MIT at 2 cm and 6 cm, sensitivity and specificity of MIT at identifying GERD was 76% and 72%, respectively.

CONCLUSION

pCLE did not differentiate GERD vs non-GERD and did not correlate with EBF measured in vitro. MIT, on the other hand, may be more promising as it differentiated GERD vs non-GERD and correlated with EBF measured in vitro.

The assessment of patients with non-erosive gastroesophageal reflux disease by using the Bravo® pH monitoring system

Background and aim: Gastroesophageal reflux disease (GERD) is a common disease in the world. GERD is always treated with drugs. The Bravo® wireless pH monitoring system is a good technique. The Bravo® may affect increasing the specificity and sensitivity in the diagnosis of GERD with its 48-hour recording feature. In this study, we aimed to assess the diagnostic performance of the Bravo® pH monitoring system in patients with non-erosive GERD. Materials and Methods: Patients with non-erosive reflux disease (normal endoscopy) whose symptoms persisted after PPI treatment (at least two months) were included in the study. All patients had upper gastrointestinal system endoscopies performed in our clinic between January 2013 and December 2019. All patients had a 48-hour Bravo® wireless pH monitoring record. Results: Twenty-three patients (M: 18 (78.3%; Age: 35.7 ± 11) were included in the study. All patients completed the 2-day recording protocol. During and after the procedure, no patient showed any adverse effects of the Bravo® procedure. We diagnosed GERD in 13 of 23 patients by Bravo® capsule. According to the Bravo® pH-meter recordings; Total time pH < 4 (minute) was 187 ± 190, the total number of refluxes was 90 ± 61, the percentage of time with pH < 4 was 7.1 ± 7.22, the number of long reflux events were 8.1 ± 8, the duration of the longest reflux episode during pH < 4 (minute) was 31 ± 49, the Demeester score was 20.8 ± 19.3 detected. Conclusion: Based on the results of the current study, the Bravo® pH monitoring system is a practical and effective diagnostic technique for non-erosive GERD. Further prospective studies would be useful for comparing the differences between 24-hour and 48-hour pH recording results.

Associations between sleep bruxism and other sleep-related disorders in adults: a systematic review

OBJECTIVE

Systematic reviews on sleep bruxism (SB) as a comorbid condition of other sleep-related disorders are lacking. Such reviews would contribute to the insight of sleep clinicians into the occurrence of SB in patients with other sleep-related disorders, and into the underlying mechanisms of such comorbid associations. This systematic review aimed: 1. to determine the prevalence of SB in adults with other sleep-related disorders; and 2. to determine the associations between SB and other sleep-related disorders, and to explain the underlying mechanisms of these associations.

METHODS

A systematic search on SB and sleep-related disorders was performed in PubMed, Embase, Cochrane Library, and Web of Science to identify eligible studies published until May 15, 2020. Quality assessment was performed using the Risk of Bias Assessment tool for Non-randomized Studies.

RESULTS

Of the 1539 unique retrieved studies, 37 articles were included in this systematic review. The prevalence of SB in adult patients with obstructive sleep apnea, restless leg syndrome, periodic limb movement during sleep, sleep-related gastroesophageal reflux disease, REM behavior disorder (RBD), and sleep-related epilepsy was higher than that in the general population. The specific mechanisms behind these positive associations could not be identified.

CONCLUSIONS

SB is more prevalent in patients with the previously mentioned disorders than in the general population. Sleep arousal may be a common factor with which all the identified disorders are associated, except RBD and Parkinson's disease. The associations between SB and these identified sleep-related disorders call for more SB screening in patients with the abovementioned sleep-related disorders.

Value of pH Impedance Monitoring While on Twice-Daily Proton Pump Inhibitor Therapy to Identify Need for Escalation of Reflux Management

BACKGROUND AND AIMS

Acid exposure time (AET) and reflux episode thresholds from the Lyon Consensus may not apply for pH impedance studies performed while on proton pump inhibitor (PPI) therapy. We aimed to determine metrics from "on PPI" pH impedance studies predicting need for escalation of therapy.

METHODS

De-identified pH impedance studies performed while on twice-daily PPI (Diversatek, Boulder, CO) in healthy volunteers (n = 66, median age 37.5 years, 43.9% female), and patients with proven gastroesophageal reflux disease (GERD) (European heartburn-predominant cohort: n = 43, median age 57.0 years, 55.8% female; North American regurgitation-predominant cohort: n = 42, median age 41.6 years, 42.9% female) were analyzed. Median values and interquartile ranges for pH impedance metrics in healthy volunteers were compared with proven GERD patients with and without 50% symptom improvement on validated measures. Receiver operating characteristic (ROC) analyses identified optimal thresholds predicting symptom response.

RESULTS

Both conventional and novel reflux metrics were similar between PPI responders and nonresponders (P ≥ .1 for each) despite differences from healthy volunteers. Combinations of metrics associated with conclusively abnormal reflux burden (AET >4%, >80 reflux episodes) were seen in 32.6% and 40.5% of heartburn and regurgitation-predominant patients, respectively, 57.1% and 82.4% of whom reported nonresponse; and 85% with these metrics improved with invasive GERD management. On ROC analysis, AET threshold of 0.5% modestly predicted nonresponse (sensitivity, 0.62; specificity, 0.51; P = .22), and 40 reflux episodes had better performance characteristics (sensitivity, 0.80; specificity, 0.51; P = .002); 79% with these metrics improved with invasive GERD management.

CONCLUSION

Combinations of abnormal "on PPI" pH impedance metrics are associated with PPI nonresponse in proven GERD patients, and can be targeted for treatment escalation, including surgery, particularly in regurgitation-predominant GERD.

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.

Esophageal pH increments associated with post-reflux swallow-induced peristaltic waves show the occurrence and relevance of esophago-salivary reflex in clinical setting

BACKGROUND

Following acid perfusion, esophageal pH is restored by swallowed bicarbonate-containing saliva secreted in response to a vagal esophago-salivary reflex. At impedance-pH monitoring, the post-reflux swallow-induced peristaltic wave (PSPW) index puts into relationship timely post-reflux swallows with the number of reflux events: Low values typify reflux-related heartburn (RRH) and lack of on-therapy improvement characterizes proton pump inhibitor (PPI) failure. Considerable esophageal pH increments associated with PSPWs could demonstrate the occurrence of esophago-salivary reflex in clinical setting, while its relevance could be shown by lower esophageal pH increments in PPI-refractory RRH.

METHODS

Prospective multicenter study in patients with PPI-refractory or PPI-responsive RRH evaluated with off-PPI impedance-pH monitoring. Increments in pH associated with PSPWs were measured and the mean calculated to obtain the PSPW-associated ∆pH.

KEY RESULTS

The mean PSPW-associated ∆pH in 294 RRH patients was 1.2 ± 0.7 and was lower in 137 PPI-refractory (1.0 ± 0.6) than in 157 PPI-responsive (1.5 ± 0.6) cases (p < 0.0001). Lower PSPW-associated ∆pH was independently related to PPI failure at multivariable logistic regression analysis (OR 0.16, 95% CI 0.09-0.26). At ROC analysis, comparing PPI-refractory to PPI-responsive cases the AUC for PSPW-associated ∆pH was 0.76 (95% CI 0.71-0.82), the best cutoff value being 1.2.

CONCLUSIONS AND INFERENCES

Considerable PSPW-associated pH increments demonstrate the occurrence of esophago-salivary reflex in clinical setting. Lower increments in PPI-refractory RRH cases show the clinical relevance of esophago-salivary reflex, confirming that PSPW represents a defense mechanism against reflux. PSPW-associated ∆pH can efficiently predict PPI response in patients undergoing off-therapy impedance-pH monitoring.

Value of adjunctive evidence from MII-pH monitoring and high-resolution manometry in inconclusive GERD patients with AET 4-6

OBJECTIVES

Gastro-esophageal reflux disease (GERD) is a common disease in gastroenterology outpatients. However, some patients with typical reflux symptoms does not satisfy diagnostic criteria. This study was to explore the value of adjunctive evidence from multichannel intraluminal impedance-pH (MII-pH) monitoring and esophageal high-resolution manometry (HRM) in inconclusive GERD patients with acid exposure time (AET) 4-6%.

METHODS

Endoscopy, MII-pH monitoring and esophageal HRM were retrospectively analyzed from consecutive patients with typical reflux symptoms in a tertiary hospital from 2013 to 2019. Patients were categorized as conclusive or inconclusive GERD according to AET. Adjunctive evidence for GERD diagnosis from Lyon Consensus were collected and analyzed.

RESULTS

Among 147 patients with typical reflux symptoms, conclusive GERD was found in only 31.97% of patients (N = 47). The remaining 100 patients (68.03%) were inconclusive GERD, of whom 28% (N = 28) had AET 4-6%. These patients suffered similar reflux burden and impaired esophageal movement. Inconclusive GERD patients with AET 4-6% had lots of positive adjunctive evidence from HRM and MII-pH monitoring. In receiver operating characteristic analysis, mean nocturnal baseline impedance (MNBI) and post-reflux swallow-induced peristaltic wave index (PSPWI) had an area under the curve (AUC) of 0.839 (CI: 0.765-0.913, p < 0.001) and 0.897 (CI: 0.841-0.953, p < 0.001), respectively, better than total reflux episode (AUC of 0.55, p = 0.33). When MNBI was combined with PSPWI, the AUC was elevated to 0.910 (CI: 0.857-0.963, p < 0.001).

CONCLUSIONS

Inconclusive GERD patients with AET 4-6% have similar acid burden and esophagus motility dysfunction to GERD patients. MNBI and PSPWI are pivotal adjunctive evidence for diagnosing GERD when AET is borderline.

Normal acid exposure time in esophageal pH monitoring in Asian and Western populations: A systematic review and meta-analysis

BACKGROUND

Esophageal acid exposure time (AET) during 24 h pH monitoring is reproducible and predictive outcomes of treatment for gastroesophageal reflux disease. Several small Asian studies have investigated the normal range of the AET; the range may be different from that in Western populations. We evaluated its normal range in healthy Asian compared to Western subjects.

METHODS

We searched PubMed, Embase, Cochrane Library, and KoreaMed for studies that reported pH monitoring parameters in healthy subjects. Studies that reported the AET values of healthy subjects were eligible for the analyses. The upper limit of normal of the AET was obtained from the 95th percentile of the available raw data or calculated as the mean value +2 standard deviations.

KEY RESULTS

Nineteen Asian and 49 Western studies were assessed. The estimated AET values were analyzed using a bootstrapping technique, weighted according to the sample size. The mean AET was 1.1% and 2.9% in the Asian and Western populations, respectively. The upper limit of the reference range was 3.2% (95% confidence interval [CI], 2.7-3.9%) and 8.2 (95% CI, 6.7-9.9) in the Asian and Western populations, respectively. The normal AET differed between the Asian and Western populations because the CI of the two groups did not overlap.

CONCLUSIONS & INFERENCES

The upper limit of normal of the AET in healthy Asian subjects was 3.2% (95% CI, 2.7-3.9%), which was lower than that of healthy Western subjects.

Postreflux swallow-induced peristaltic wave index from pH-impedance monitoring associates with esophageal body motility and esophageal acid burden

BACKGROUND

Postreflux swallow-induced peristaltic wave (PSPW) on pH-impedance monitoring and contraction vigor on high-resolution manometry (HRM) both assess esophageal peristaltic response. We aimed to evaluate relationships between PSPW and esophageal peristalsis on HRM in the context of reflux disease in this multicenter cohort study.

METHODS

pH-impedance and HRM studies performed on patients with persisting reflux symptoms were reviewed from 6 centers (5 in Europe and 1 in US). Total, upright and supine acid exposure time (AET) were evaluated from pH-impedance studies; PSPW index (PSPWI) and mean nocturnal baseline impedance (MNBI) were calculated using standard methodology. Esophageal body contraction vigor was analyzed using distal contractile integral (DCI), and DCI ratio > 1 between single swallows and multiple rapid swallows (MRS) defined presence of contraction reserve. Student's t test, ANOVA, and linear regression were utilized to investigate relationships between PSPW, contraction vigor, and contraction reserve.

KEY RESULTS

Of 296 patients (52.8 ± 0.8 yr, 63% F), median PSPWI was 0.475. Only 24.0% had intact DCI; the remainder had varying degrees of hypomotility. As hypomotility increased, PSPWI and MNBI decreased significantly, while total AET and reflux episodes had an inverse response (P ≤ .002 for each). MRS data were available in 167 (56.4%), 72.5% had contraction reserve. MRS cohorts with normal PSPWI had significantly lower reflux burden compared to low PSPWI, regardless of presence or absence of contraction reserve (P ≤ .001).

CONCLUSIONS AND INFERENCES

PSPWI correlates with esophageal hypomotility and reflux burden, and complements clinical reflux evaluation. Intact PSPW is more relevant to esophageal reflux clearance than contraction reserve.

The Role of Symptom Association Analysis in Gastroesophageal Reflux Testing

Gastroesophageal reflux disease is characterized by the reflux of gastric contents into the esophagus with an estimated worldwide prevalence of 8%-33%. The current paradigm in gastroesophageal reflux disease diagnosis relies on recognition of symptoms and/or the presence of mucosal disease at the time of esophagogastroduodenoscopy. Recognition of symptoms, however, can arise with challenges, particularly when patients complain of less typical symptoms. Since first reported in 1969 by Spencer et al., the application of prolonged intraesophageal pH monitoring to identify pathologic reflux has evolved considerably. Utility of pH monitoring aims to investigate the degree of acid burden and frequency of reflux episode, and the relationship between symptoms and acid reflux events. This relationship is represented by either the Symptom Index, Symptom Sensitivity Index, Symptom Association Probability, or Ghillebert Probability Estimate. This article reviews symptom-association analysis during esophageal reflux testing, covering the literature on current methods of reflux testing, interpretation of symptom association, and practical issues that can arise during symptom analysis.

Weak acids induce PGE2 production in human oesophageal cells: novel mechanisms underlying GERD symptoms

The role of weak acids with pH values in the range of 4–7 has been implicated in the symptoms of gastroesophageal reflux disease (GERD). Prostaglandin E₂ (PGE₂) is associated with heartburn symptom in GERD patients; however, the precise productive mechanisms remain unclear. In this study, we revealed that exposure to weak acids increases PGE₂ production with a peak at pH 4–5, slightly in human normal oesophageal cells (Het-1A), and robustly in oesophageal squamous carcinoma cells (KYSE-270). Release of PGE₂ from the oesophageal mucosa was augmented by weak acid treatment in rat. Chenodeoxycholic acid (CDCA), a bile acid, upregulated cyclooxygenase-2 (COX-2) expression in Het-1A and KYSE-270 and induced PGE₂ production in KYSE-270 cells. Weak acid-induced PGE₂ production was significantly inhibited by cytosolic phospholipase A2 (cPLA2), ERK, and transient receptor potential cation channel subfamily V member 4 (TRPV4), a pH-sensing ion channel, inhibitors. Hangeshashinto, a potent inhibitor of COX-2, strongly decreased weak acid- and CDCA-induced PGE₂ levels in KYSE-270. These results indicated that weak acids induce PGE₂ production via TRPV4/ERK/cPLA2 in oesophageal epithelial cells, suggesting a role in GERD symptoms like heartburn. Interventions targeting pH values up to 5 may be necessary for the treatment of GERD.

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.

Clinical utility of salivary pepsin measurement in patients with proton pump inhibitor-refractory gastroesophageal reflux disease symptoms: a prospective comparative study

BACKGROUND

Salivary pepsin measurement has been reported to be useful for diagnosing gastroesophageal reflux disease (GERD). This study aimed to clarify the usefulness of salivary pepsin measurement in patients with proton pump inhibitor (PPI)-refractory GERD symptoms without erosive esophagitis.

METHODS

One hundred and two patients were included. Over seven days after terminating PPI treatment, all patients underwent a 24-h pH-impedance test and salivary pepsin measurement. In patients whose main symptoms included laryngopharyngeal symptoms, a hypopharyngeal multichannel intraluminal impedance (HMII) test was performed, whereas in other patients, a conventional combined multichannel intraluminal impedance-pH (MII-pH) test was performed. In the HMII tests, patients were divided into abnormal proximal exposure (APE) and non-APE groups. Salivary pepsin concentrations were compared according to acid exposure time (AET) values and were also compared between the APE and non-APE groups.

RESULTS

The median salivary pepsin concentration in patients with AET > 6% was significantly higher than that in patients with AET ≤ 6% (345.0 [170.0-469.3] ng/mL vs. 120.0 [97.0-290.1] ng/mL, p < 0.01). The sensitivity, specificity, positive predictive value, and negative predictive value of a positive test (> 109 ng/mL) to diagnose patients with AET > 6% were 75.0%, 51.3%, 32.1%, and 86.9%, respectively. There was no significant difference between concentrations in the APE group and concentrations in the non-APE group.

CONCLUSIONS

In patients with PPI-refractory nonerosive reflux disease, salivary pepsin measurement may help diagnose patients who have conclusive evidence of reflux, whereas it is not adequate for identifying patients with APE.

No Barrett's-No Cancer: A Proposed New Paradigm for Prevention of Esophageal Adenocarcinoma

Esophageal adenocarcinoma is inflammation-associated cancer with a recognizable preneoplastic stage, Barrett's. Barrett's describes the metaplastic transformation of esophageal squamous mucosa into columnar epithelium that typically results secondary to mucosal damage caused by acidic gastroduodenal reflux. Continued acid reflux may then result in mucosal inflammation which results in progressive inflammation-induced genetic instability that may eventuate in esophageal adenocarcinoma. Barrett's is the only recognized precursor lesion to esophageal carcinoma. Barrett's mucosa is unique among preneoplastic lesions; ablation therapy results in restitution of a squamous epithelium reducing or eliminating accumulated genetic instabilities and resetting the biological clock progressing toward invasive cancer. However, recurrence of Barrett's after ablation is common. We propose that both Barrett's and recurrence of Barrett's after ablation can be prevented and discuss how current approaches to therapy for gastroesophageal reflux disease, for Barrett's screening, chemoprevention, and ablation therapy all might be reconsidered. We propose (1) improved approaches to Barrett's prevention, (2) universal Barrett's screening by linking Barrett's screening to colon cancer screening, (3) ablation of all Barrett's mucosa along with (4) acid-suppressive-antireflux therapy tailored to prevent development of Barrett's or the recurrence of Barrett's after ablation therapy. We propose that ultimately, treatment decisions for gastroesophageal reflux disease and prevention of Barrett's and esophageal carcinoma should be based on assessing and maintaining esophageal mucosal integrity. This will require development and verification of specific measurements that reliably correlate with prevention of Barrett's. We outline the new research and technical advances needed to cost-effectively achieve these goals.

Lower oesophageal sphincter identification for gastro-oesophageal reflux monitoring: The step-up method revisited with use of basal impedance

Background

Oesophageal manometry is the gold standard for accurate positioning of multichannel intraluminal impedance pH (MII-pH) monitoring. The pH step-up method is not as accurate as oesophageal manometry and needs patients to be off proton pump inhibitor (PPI) therapy.

Objective

This study aimed to evaluate the feasibility of the impedance step-up method for lower oesophageal sphincter (LOS) localisation.

Methods

A total of 100 patients who underwent 24-hour MII-pH monitoring were enrolled. High-resolution manometry (HRM) was performed before MII-pH monitoring in order to locate the LOS by a different operator. The impedance step-up was defined as an increase of ≥50% with respect to gastric baseline. Lin's concordance correlation coefficient (ρ_c ) with 95% Bland-Altman limits of agreement (LOA) and Spearman's rho correlation coefficient were used when appropriate.

Results

The median impedance step-up was on average 0.8 cm caudal to the manometric upper border of the LOS. Agreement between two step-up impedance performances and inter-observer agreement were excellent (ρ_c  = 0.98 and 0.95), although the LOA ranges were wide (-2.4 to 4.0 cm). Impedance step-up performances were similar between patients off and on PPI.

Conclusions

We have described an alternative new method for pH impedance probe positioning using impedance step-up. Although less accurate than HRM in locating the LOS, it has excellent intra- and inter-observer agreement.

Role of Matrix Metalloproteinases 7 in the Pathogenesis of Laryngopharyngeal Reflux: Decreased E-cadherin in Acid exposed Primary Human Pharyngeal Epithelial Cells

Cleavage of E-cadherin and the resultant weakness in the cell-cell links in the laryngeal epithelium lining is induced by exposure to acidic contents of the refluxate. Herein, we aimed to evaluate the role of matrix metalloproteinases (MMPs) in inducing E-cadherin level changes following acid exposure to the human pharyngeal mucosal cells. E-cadherin levels were inversely correlated with the duration of acid exposure. Treatment with actinonin, a broad MMP inhibitor, inhibited this change. Immunocytochemical staining and transepithelial permeability test revealed that the cell surface staining of E-cadherin decreased and transepithelial permeability increased after acid exposure, which was significantly inhibited by the MMP inhibitor. Among the various MMPs analyzed, the mRNA for MMP-7 in the cellular component was upregulated, and the secretion and enzymatic activity of MMP-7 in the culture media increased with the acid treatment. Consequently, MMP-7 plays a significant role in the degradation of E-cadherin after exposure to a relatively weak acidic condition that would be similar to the physiologic condition that occurs in Laryngopharyngeal reflux disease patients.

Advances in the Diagnosis of GERD Using the Esophageal pH Monitoring, Gastro-Esophageal Impedance-pH Monitoring, And Pitfalls

PH monitoring is not capable of detecting all types of reflux, especially when the amount of acid is very low or not at all in the refluxate. Multichannel intraluminal impedance-pH monitoring (MII-pH) is used as a new method to assess bolus transport. The types of reflexes including acid, weak acid and weak alkaline MII-pH is capable of distinguishing more reflux episodes based upon use of physical and chemical parameters of the refluxate, leads to a diagnosis of normal acid reflux from abnormal nonacidic reflux. 24-h oesophagal pH monitoring can be effectively used to assess the potential relationship between symptoms and refluxes. MII-pH is capable of distinguishing more reflux episodes based upon use of physical and chemical parameters of the refluxate, leads to a diagnosis of normal acid reflux from abnormal nonacidic reflux. It can be used to confirm gastro-oesophagal reflux episodes, where has a sensitivity and specificity for diagnosing GERD in comparison with endoscopy or pH-metry.

Chronic Cough Is Associated With Long Breaks in Esophageal Peristaltic Integrity on High-resolution Manometry

Background/Aims

Breaks in the peristaltic contour on esophageal high-resolution manometry (HRM) may be associated with bolus retention in the esophagus. We evaluated the relationship between peristaltic breaks and esophageal symptoms, reflux exposure, and symptom outcomes in a prospective patient cohort.

Methods

Two hundred and eighteen patients (53.2 ± 0.9 years, 68.3% female) undergoing both pH-impedance testing and HRM over a 5–year period were prospectively evaluated. Demographics, symptom presentation, acid exposure time, symptom association probability, and symptom burden scores were collected. Outcomes were assessed on follow-up using changes in symptom scores. Presence of long breaks (≥ 5 cm) on HRM was assessed by a blinded author. Relationships between breaks, reflux parameters, presenting symptoms, and outcomes were assessed.

Results

Patients with long breaks were more likely to have cough as a presenting symptom than those without (43.4% vs 28.6%, P = 0.024); statistical differences were not demonstrated with other symptoms (P ≥ 0.3). Numbers of swallows with long breaks were higher in patients with cough compared to those without (2.4 ± 0.3 vs 1.6 ± 0.2, P = 0.021); differences were not found with other symptoms (P ≥ 0.4). Long breaks were not associated with age, gender, race, reflux burden, symptom association, or changes in symptom metrics (P ≥ 0.1 for all comparisons). Among patients with cough, the presence of long breaks predicted suboptimal symptom improvement with antireflux therapy (P = 0.018); this difference did not hold true for other symptoms (P ≥ 0.2).

Conclusions

Long breaks in esophageal peristaltic integrity are associated with cough. The presence of long breaks is associated with suboptimal benefit from antireflux therapy.

Mucosal Impedance: a New Approach to Diagnosing Gastroesophageal Reflux Disease and Eosinophilic Esophagitis

PURPOSE OF REVIEW

In this review, we discuss current diagnostic testing modalities for both gastroesophageal reflux disease (GERD) and eosinophilic esophagitis (EoE) and then introduce mucosal impedance (MI), a novel technology that measures epithelial integrity in real time during endoscopy. We describe the advantages and disadvantages of MI as compared with traditional diagnostic testing.

RECENT FINDINGS

We review studies that demonstrate that GERD and EoE have distinct MI patterns, and that physicians can accurately diagnose and distinguish the two during endoscopy with minimal time added to the procedure. We also review studies showing that MI has the capability to assess treatment response in both GERD and EoE and that it can be used to diagnose GERD in patients with extraesophageal reflux symptoms. Mucosal impedance testing is a major advancement in the diagnosis of GERD and EoE. Future studies are planned to assess whether MI can be used as a treatment endpoint in EoE and whether it can be used to predict response to anti-reflux surgery.

Esophagogastric junction and esophageal body contraction metrics on high-resolution manometry predict esophageal acid burden

BACKGROUND

Distal contractile integral (DCI) and esophagogastric junction contractile integral (EGJ-CI) are high-resolution manometry (HRM) software metrics assessing esophageal motor function in gastroesophageal reflux disease (GERD).

METHODS

Patients undergoing HRM and ambulatory pH monitoring off antisecretory therapy prospectively completed symptom questionnaires assessing symptom burden and a global symptom score (GSS) at baseline and after GERD therapy. DCI<450 mm Hg/cm/s in ≥5 swallows diagnosed ineffective esophageal motility (IEM); proportions of failed (DCI<100 mm Hg/cm/s) and weak (DCI 100-450 mm Hg/cm/s) sequences were separately assessed. EGJ-CI assessed vigor of the EGJ barrier. Univariate and multivariate analyses addressed performance of esophageal body and EGJ metrics in predicting abnormal esophageal reflux burden, and symptom outcome from antireflux therapy.

KEY RESULTS

Of 188 patients (55.2 ± 0.9 year, 64% F), 42.6% had low EGJ-CI, and 25.0% had IEM. While low EGJ-CI was associated with abnormal reflux burden (P = 0.003), IEM alone was not (P = 0.2). Increasing proportions of failed swallows predicted abnormal AET better than the current IEM definition. Combined low EGJ-CI and IEM segregated abnormal total and supine acid burden compared to patients with normal EGJ-CI and no IEM (P ≤ 0.007 for each comparison). Medical therapy and surgical antireflux therapy were similarly effective in improving symptom burden; surgery resulted in better outcomes with low EGJ-CI (P ≤ 0.04), especially with intact esophageal body motor function (P = 0.02).

CONCLUSIONS & INFERENCES

While abnormal EGJ and esophageal body metrics are collectively associated with elevated esophageal reflux burden, increasing proportions of failed swallows are better predictors of reflux burden and outcome compared to the current IEM definition.

Symptom association probability does not reliably distinguish functional heartburn from reflux hypersensitivity

BACKGROUND

Symptom association probability (SAP) is thought to distinguish reflux hypersensitivity from functional disorders. A diagnosis of hypersensitive oesophagus (SAP-positive) indicates that gastro-oesophageal reflux disease (GERD) is the cause of continued symptoms.

AIM

To conduct an analysis of pH and symptom criteria that lead to a diagnosis of SAP-positivity METHODS: We calculated SAP for 205 patients with GERD symptoms refractory to proton pump inhibitor (PPI) therapy who underwent endoscopy with wireless pH monitoring from 2007 to 2014. Patients were divided into three groups: pH-negative with no oesophagitis (n = 45), pH-positive with no oesophagitis (n = 130), and patients with oesophagitis (n = 30). We constructed a 2 × 2 table of symptom and reflux event association and quantified the number of 2-minute intervals for each of the 2 × 2 variables that distinguished SAP-positive from SAP-negative. In a separate cohort of 58 patients who had undergone anti-reflux surgery, we evaluated the effects of pre-surgery SAP.

RESULTS

The difference in symptom association parameters that led to a diagnosis of an SAP-positive was small (2.98% in oesophagitis-positive; 1.56% in oesophagitis-negative/pH-positive; 0.48% in oesophagitis-negative/pH-negative). In the pH-negative/oesophagitis-negative group, a difference of 0.48% led to a diagnosis of hypersensitivity. There was significant variability in SAP values between day 1 and day 2 of pH testing in all groups, with the greatest in the oesophagitis-positive group, despite objective evidence for reflux (27% in oesophagitis-positive, 19% pH-positive/oesophagitis-negative, and 7% in pH-negative/oesophagitis-negative). Pre-surgery SAP was not associated with response to anti-reflux surgery.

CONCLUSION

In PPI-refractory GERD, SAP cannot accurately distinguish reflux hypersensitivity from functional oesophageal symptoms.

Critical appraisal of Rome IV criteria: hypersensitive esophagus does belong to gastroesophageal reflux disease spectrum

The Rome IV Committee introduced a major change in the classification of functional gastrointestinal disorders, proposing a more restrictive definition of gastroesophageal reflux disease (GERD). It was suggested that hypersensitive esophagus (HE) may sit more firmly within the functional realm. It was suggested that GERD diagnosis should be based upon abnormal acid exposure time (AET) only, implying no advantage of impedance-pH over pH monitoring. Symptom association probability (SAP), symptom index (SI) and heartburn relief with proton pump inhibitor (PPI) therapy were regarded as unreliable, whereas a lack of response to PPI was considered as evidence of functional heartburn. These assumptions are contradicted by numerous studies showing the clinical relevance of weakly acidic refluxes and the diagnostic utility of SAP, SI and new impedance parameters, namely the post-reflux swallow-induced peristaltic wave (PSPW) index and the mean nocturnal baseline impedance (MNBI). The PSPW index and MNBI provide significant diagnostic advantage, particularly in patients with normal AET who can be classified as HE when both parameters are abnormal, even though SAP and SI are negative. Visceral pain modulators are recommended by the Rome IV Committee despite scanty evidence of efficacy, but a positive outcome with medical or surgical anti-reflux treatment has been reported by several studies of HE patients. Therefore, we believe that patients with endoscopy-negative heartburn should be investigated by means of impedance-pH monitoring with analysis of PSPW index and MNBI: such an approach provides accurate identification of HE cases, who remain, in our opinion, within the realm of GERD and should be treated accordingly.

Genetic risk factors for perception of symptoms in GERD: an observational cohort study

BACKGROUND

Genetic polymorphisms in G-protein beta-3 subunit (GNβ3) and beta-2 adrenergic receptor (ADRB2) are associated with pain and gut hypersensitivity, which can overlap with gastroesophageal reflux disease (GERD).

AIM

To evaluate relationships between single nucleotide polymorphisms (SNPs) within GNβ3 and ADRB2 systems, and reflux symptom burden, GERD phenotypes from ambulatory reflux monitoring, and quality of life.

METHODS

Symptomatic adults undergoing ambulatory reflux testing were recruited and phenotyped based on acid burden and symptom reflux association; major oesophageal motor disorders and prior foregut surgery were exclusions. A comparison asymptomatic control cohort was also identified. Subjects and controls completed questionnaires assessing symptom burden on visual analog scales, short-form health survey-36 (SF-36), and Beck Anxiety and Depression Inventories (BAI and BDI). Genotyping was performed from saliva samples; 6 SNPs selected from each of the two genes of interest were compared.

RESULTS

Saliva from 151 study subjects (55.3 ± 1.2 years, 63.6% F) and 60 control subjects (50.9 ± 2.2 years, 66.7%) had sufficient genetic material for genotyping. Study subjects had higher symptom burden, worse total and physical health, and higher anxiety scores compared to controls (P ≤ .002). Tested SNPs within ADRB2 were similar between study subjects and controls (P > .09). Study subjects with recessive alleles in 3 GNβ3 SNPs (Rs2301339, Rs5443, and Rs5446) had worse symptom severity (P = .011), worse mental health (P = .03), and higher depression scores (P = .005) despite no associations with GERD phenotypes or reflux metrics.

CONCLUSIONS

Genetic variation within GNβ3 predicts oesophageal symptom burden and affect, but not oesophageal acid burden or symptom association with reflux episodes.

A New Algorithm to Reduce the Incidence of Gastroesophageal Reflux Symptoms after Laparoscopic Sleeve Gastrectomy

BACKGROUND

Laparoscopic sleeve gastrectomy (LSG) is one of the most prefered treatment option for morbid obesity. However, the effects of LSG on gastroesophageal reflux disease (GERD) are controversial. Asymptomatic GERD and hiatal hernia (HH) is common in obese patients. Therefore, it is important to identify the high risk patients prior to surgery. This study aims to evaluate efficacy of cruroplasty for HH during LSG in morbidly obese patients using ambulatory pH monitoring (APM) results, and to investigate the patients' selection criteria for this procedure.

METHODS

This retrospective study includes outcomes of 59 patients who underwent LSG and HH repair according to our patient selection algorithm. Outcomes included preoperative GERD Health-Related Quality of Life (GERD-HRQL) questionnaire, APM results, percentage of postoperative excess weight loss, and total weight loss.

RESULTS

For a total of 402 patients, APM was applied in 70 patients who had a positive score of GERD-HRQL, and 59 patients underwent LSG and concomitant HH repair who had a DeMeester score of 14.7% or above. There was no statistically significant difference in weight loss at 6 and 12-month follow-up. Two patients (3.3%) had symptoms of GERD at 12 months postoperatively, and only one (1.6%) patient required treatment of proton pump inhibitor for reflux. In the total cohort, 11 (2.7%) patients also evolved de novo GERD symptoms.

CONCLUSIONS

This study confirm that careful attention to patient selection and surgical technique can reduce the symptoms of GERD at short-term. Routine bilateral crus exploration could be a major risk factor of postoperative GERD.

Postreflux swallow-induced peristaltic wave index and nocturnal baseline impedance can link PPI-responsive heartburn to reflux better than acid exposure time

BACKGROUND

Acid exposure time (AET) is considered the most useful parameter to predict response of reflux-related heartburn to medical or surgical treatment. However, recent studies showed high rates of heartburn response to proton pump inhibitor (PPI) therapy in patients with normal AET. We aimed to compare the efficacy of postreflux swallow-induced peristaltic wave (PSPW) index and mean nocturnal baseline impedance (MNBI) with AET in linking PPI-responsive heartburn to reflux.

METHODS

Off-therapy impedance-pH tracings from 425 patients, 317 with PPI-responsive and 108 with PPI-refractory heartburn were blindly re-analyzed. Demographic and endoscopic characteristics, conventional impedance-pH variables, PSPW index, and MNBI were assessed with multivariate logistic regression to identify factors independently associated with PPI responsiveness. Prediction models were developed to assess the strength of reflux linkage with factors independently associated with PPI responsiveness by calculating the area under the curve (AUC) at receiver-operating-characteristic (ROC) analysis.

KEY RESULTS

At multivariate logistic regression analysis, AET, MNBI, and PSPW index were the only factors independently associated with PPI responsiveness, abnormal values found in 60%, 76%, and 92% of PPI-responsive cases (P<.017). At ROC analysis, PSPW index (AUC:.794, P=.002) and MNBI (AUC: 0.742, P=.003), both separately and combined (AUC: 0.811, P<.001) linked reflux with PPI-responsiveness better than AET (AUC: 0.687).

CONCLUSIONS & INFERENCES

AET, PSPW index, and MNBI are independently associated with PPI-responsive heartburn. PSPW index and MNBI can link PPI-responsive heartburn to reflux better than AET and should become part of the standard analysis of impedance-pH tracings.

Expert consensus document: Advances in the physiological assessment and diagnosis of GERD

GERD is a common condition worldwide. Key mechanisms of disease include abnormal oesophagogastric junction structure and function, and impaired oesophageal clearance. A therapeutic trial of acid-suppressive PPI therapy is often the initial management, with endoscopy performed in the setting of alarm symptoms and to exclude other conditions. If symptoms persist and endoscopy does not reveal evidence of GERD, oesophageal function tests are performed, including oesophageal manometry and ambulatory reflux monitoring. However, reflux episodes can be physiological, and some findings on endoscopy and manometry can be encountered in asymptomatic individuals without GERD symptoms. The diagnosis of GERD on the basis of functional oesophageal testing has been previously reported, but no updated expert recommendations on indications and the interpretation of oesophageal function testing in GERD has been made since the Porto consensus over a decade ago. In this Consensus Statement, we aim to describe modern oesophageal physiological tests and their analysis with an emphasis on establishing indications and consensus on interpretation parameters of oesophageal function testing for the evaluation of GERD in clinical practice. This document reflects the collective conclusions of the international GERD working group, incorporating existing data with expert consensus opinion.

Relationship Between Salivary Pepsin Concentration and Esophageal Mucosal Integrity in Patients With Gastroesophageal Reflux Disease

Background/Aims

Increased salivary pepsin could indicate an increase in gastro-esophageal reflux, however, previous studies failed to demonstrate a correlation between salivary pepsin concentrations and 24-hour esophageal acid exposure. This study aims to detect the salivary pepsin and to evaluate the relationship between salivary pepsin concentrations and intercellular spaces (IS) in different gastroesophageal reflux disease phenotypes in patients.

Methods

A total of 45 patients and 11 healthy volunteers were included in this study. All subjects underwent upper gastrointestinal endoscopy, 24-hour ambulatory multichannel impedance-pH (MII-pH) monitoring, and salivary sampling at 3-time points during the 24-hour MII-pH monitoring. IS were measured by transmission electron microscopy, and salivary pepsin concentrations were determined by enzyme-linked immunosorbent assay.

Results

The IS measurements were greater in the esophagitis (EE), non-erosive reflux disease (NERD), and hypersensitive esophagus (HO) groups than in the functional heartburn (FH) and healthy volunteer groups, and significant differences were indicated. Patients with NERD and HO had higher average pepsin concentrations compared with FH patients. A weak correlation was determined between IS and salivary pepsin among patients with NERD (r = 0.669, P = 0.035).

Conclusions

We confirmed the presence of a higher level of salivary pepsin in patients with NERD than in patients with FH. Salivary pepsin concentrations correlated with severity of mucosal integrity impairment in the NERD group. We suggest that in patients with NERD, low levels of salivary pepsin can help identify patients with FH, in addition the higher the pepsin concentration, the more likely the severity of dilated IS.

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.

Tobacco smoking, alcohol consumption and gastro-oesophageal reflux disease

Gastro-oesophageal reflux disease (GORD) develops when reflux of gastric content causes troublesome symptoms or complications. The main symptoms are heartburn and acid regurgitation and complications include oesophagitis, strictures, Barrett's oesophagus and oesophageal adenocarcinoma. In addition to hereditary influence, GORD is associated with lifestyle factors, mainly obesity. Tobacco smoking is regarded as an aetiological factor of GORD, while alcohol consumption is considered a triggering factor of reflux episodes and not a causal factor. Yet, both tobacco smoking and alcohol consumption can reduce the lower oesophageal sphincter pressure, facilitating reflux. In addition, tobacco smoking reduces the production of saliva rich in bicarbonate, which is important for buffering and clearance of acid in the oesophagus. Alcohol also has a direct noxious effect on the oesophageal mucosa, which predisposes to acidic injury. Tobacco smoking cessation reduces the risk of GORD symptoms and avoidance of alcohol is encouraged in individuals where alcohol consumption triggers reflux.

Long-term wireless pH monitoring of the distal esophagus: prolonging the test beyond 48 hours is unnecessary and may be misleading

Wireless pH monitoring of the esophagus has been widely used to detect GERD for more than a decade. It is generally well tolerated and accepted by patients, but it is still unclear whether prolonging a recording beyond the usual 48 hours can improve the test's diagnostic value. The aim of this study is to examine the diagnostic yield of 96-hour pH monitoring vis-à-vis 24- and 48-hour tests, and to ascertain whether any gain in diagnostic terms was of genuine clinical utility. Patients with suspected GERD underwent 4-day PPI-off wireless pH monitoring of the distal esophagus. The capsule was inserted under endoscopic control, 6 cm above the squamocolumnar junction. Average acid exposure time was calculated after 24, 48, and 96 hours of recording. Ninety-nine patients completed the 96 hour test, and formed the study sample. The wireless test method was used in 42 patients (42.4%) unable to tolerate the traditional pH-monitoring catheter, and in 57 (57.6%) with a previous negative pH study despite symptoms suggestive of GERD. On complete analysis, 47 patients (47.5%) had a pathological test result: 19 patients within the first 24 hours (19.2%, 24 hour group); another 16 after 48 hours (+16.2%, 48 hour group), and a further 12 (+12.1%, 96 hour group) only after 96 hours of monitoring. All 47 patients with an abnormal acid exposure were offered and accepted surgery (10 patients) or medical therapy (37 patients). Clinical follow-up was obtained in all patients with a positive Bravo test result after a median 67 months (IQR: 38-98) using a validated symptom questionnaire. A good outcome after fundoplication or medical therapy was achieved in 73.7% of patients in the 24 hour group, in 62.5% of those in the 48 hour group, and in only 25% of those in the 96 hour group, P = 0.02. Long-term wireless pH monitoring enables an increase in the diagnostic yield over traditional 24- and 48-hour pH studies, but prolonging the test may constitute an unwanted bias and prompt the recruitment of more complex patients, in whom the outcome of surgical or medical therapy may prove less than satisfactory. These findings should be taken into account when establishing the guidelines for assessing GERD with such long-term pH monitoring methods.

Impedance-pH Monitoring for Diagnosis of Reflux Disease: New Perspectives

Heartburn is the most specific symptom of gastroesophageal reflux disease (GERD). In clinical practice, heartburn relief by a proton pump inhibitor (PPI) trial does suffice to confirm GERD. However, an objective diagnosis of GERD is required before anti-reflux endoscopic or surgical interventions, independently from PPI response. Thus, since normal findings at upper endoscopy are detected in the majority of patients with heartburn, reflux monitoring is often required. When traditional catheter-based or wireless pH tests are used, reflux episodes are conventionally identified by pH drops below 4.0 units. Combined impedance-pH monitoring has the advantage to provide a comprehensive assessment of both physical and chemical properties of refluxate and the distinction between acid and weakly acidic refluxes, both proven to cause heartburn. Unfortunately, the conventional impedance-pH parameters, namely acid exposure time and number of reflux events, are characterized by suboptimal diagnostic sensitivity, and the reliability of symptom-reflux association indexes remains questionable. Therefore, novel impedance parameters, namely the post-reflux swallow-induced peristaltic wave (PSPW) index and the mean nocturnal baseline impedance (MNBI), have recently been proposed in order to achieve a better diagnostic yield. In fact, they proved to be highly accurate in distinguishing reflux-related from reflux-unrelated heartburn, off- as well as on-PPI therapy. Currently, manual review of impedance-pH tracings is needed because of the modest accuracy of available software tools for automated analysis. PSPW index and MNBI are highly applicable and reproducible, and their calculation requires a few additional minutes during the manual review of impedance-pH tracings. So far, we believe that PSPW index and MNBI are ready for prime time and should become part of the standard analysis of impedance-pH tracings for GERD diagnosis in patients with endoscopy-negative heartburn.

Endoscopic-Guided Measurement of Mucosal Admittance can Discriminate Gastroesophageal Reflux Disease from Functional Heartburn

Objectives:

A novel catheter that can measure mucosal admittance (MA), the inverse of impedance, was developed recently. In this pilot study, we aimed to clarify the usefulness of measuring MA for diagnosing gastroesophageal reflux disease (GERD).

Methods:

We conducted two prospective studies. In the first study, esophageal MA was evaluated in 120 participants (24 with erosive esophagitis, 82 with heartburn but non-erosive esophagitis, and 14 healthy volunteers) and compared with the endoscopic findings. In the second study, multichannel intraluminal impedance combined with pH (MII-pH) tests was conducted followed by an MA measurement in 33 patients with non-erosive esophagitis and proton pump inhibitor (PPI)-refractory heartburn. Based on the MII-pH test results, patients were divided into GERD or functional heartburn (FH). MA was compared between the GERD and FH groups and also compared with the baseline impedance (BI) and acid exposure time (AET).

Results:

Median MA at the distal esophagus was significantly higher in patients with erosive esophagitis compared with that in patients with non-erosive esophagitis and healthy volunteers (46.8, 13.1 and 6.5, respectively, P<0.01). In patients with PPI-refractory heartburn, the median MA at the distal esophagus was significantly higher in patients with GERD than those with FH (19.3 vs. 7.2, P<0.05). There was a negative correlation between MA and BI, and a positive correlation between MA and AET at the distal esophagus (r=−0.46 and r=0.53, P<0.05).

Conclusions:

Real-time measurement of MA is useful to distinguish GERD from non-GERD.

Salivary Pepsin Test: Useful and simple tool for the laryngopharyngeal reflux diagnosis

INTRODUCTION AND OBJECTIVES

Laryngopharyngeal Reflux (LPR) is a disease characterized by the presence of symptoms, signs and tissue damage caused by retrograde flow of gastric contents to the upper aerodigestive tract. It represents up to 10% of otolaryngology consultations. The aim of the study is to describe the findings obtained by applying the salivary pepsin test (PEP-test) in a sample of patients with the clinical suspicion of LPR.

MATERIAL AND METHODS

Our descriptive clinical study included 142 subjects with symptoms suggestive of LPR and a score above 13 on the RSI scale. The subjects underwent laryngeal endoscopy to rule out other pathologies that could justify the symptoms and the salivary pepsin test (PEP-test). The latter was carried out on fasting subjects and a second test one hour after eating, only on those with negative results.

RESULTS

The results obtained in the tests performed on the 142 patients included in the study were: 105 (73.94%) presented positive results in some of the salivary pepsin tests and the results of both tests were negative in 37 subjects (26.06%).

CONCLUSION

The salivary pepsin test is a simple, low-cost, non-invasive and easily repeatable tool which could minimize empirical treatments and invasive tests for LPR diagnosis, although further research is needed for its validation.

Does my patient still have reflux when ppi therapy does not work?

Gastroesophageal reflux disease (GERD) is a common condition around the world. The management of this disease is less than satisfying given complexity of patient presentation and suboptimal diagnostic testing when employed for those poorly responsive to acid suppressive therapy. In this mini review, we discuss some new strategies employed for patients with suspected GERD to better understand disease pathophysiology. We compare the strategies and outline a clinically relevant approach in this difficult group of patients.

The normal squamocolumnar junction is circumferentially even and minimal irregularities are manifestations of gastroesophageal acid reflux

BACKGROUND

The macroscopic appearance of the normal squamocolumnar junction (SCJ) is often described as serrated with short projections of columnar mucosa that extend into the esophagus. As studies of the normal SCJ are sparse, the aim of this study was to test the hypothesis that the normal SCJ is even and that irregularities are manifestations of acid reflux.

METHOD

Fifty asymptomatic subjects and 149 patients with symptoms suggestive of gastroesophageal reflux disease underwent endoscopy and 48-h pH monitoring with a pH electrode positioned immediately above the SCJ. The shape of the SCJ was assessed according to the Z-line appearance classification and correlated with clinical characteristics and the degree of esophageal acid exposure in the most distal esophagus.

RESULTS

Even SCJs without irregularities were significantly more common in asymptomatic subjects compared with patients (50% versus 10%, p < .001) and were never found in patients with erosive esophagitis. The median degree of distal esophageal acid exposure in individuals with an even SCJ was within normal limits. With increasing degree of irregularity of the SCJ, the frequency and duration of reflux episodes, the degree of distal esophageal acid exposure, and the prevalence of abnormal acid exposure increased progressively and significantly.

CONCLUSION

The shape of the normal SCJ is even and also minimal irregularities are a consequence of acid reflux, likely due to the formation of small areas of metaplastic columnar mucosa.

Patterns of reflux in gastroesophageal reflux disease in pediatric population of New South Wales

This study is to determine the association of ambulatory pH monitoring (24hr pH) with symptoms of gastroesophageal reflux and its other investigations. The clinical and epidemiological profiles of subjects referred for reflux disorders are also studied. Symptoms or group of symptoms, profiles and prior investigations of 1259 consecutive pediatric subjects (with 1332 24hr pH studies performed) referred for evaluation of reflux disorders between 1988 and 2012 were retrospectively studied. Chi-square or fisher exact test was used for hypothesis testing, student t-test for the comparison of means and the Wilcoxon rank-sum test for comparing medians of continuous variables. Gastroesophageal reflux disease (GERD), defined as reflux causing major symptoms and complications, was diagnosed in 57.5% subjects of the total sample. Forty-three percent were girls and 56.7% were boys. The most common age group was between 4 months and 2 years (51.2%). Vomiting (64.4%) and irritability (74%) were the most common symptoms with the neurological conditions (23.2%) being the most frequent underlying condition. The parameters used in 24hr pH were significantly higher in those diagnosed with GERD (P < 0.0001). The prevalence of GERD was found to be significantly higher when both gastrointestinal and respiratory symptoms were present (P = 0.008) at 66.4% than when compared with gastrointestinal (56.5%) and respiratory (52.2%) symptoms in isolation. Symptoms alone were not reliable in diagnosing GERD. Only 57.5% had GERD among patients referred for reflux disorders. 24hr pH is reliable and should be considered routine in reflux disorders, as it identifies patients with pathologic reflux and avoids a needless surgery.

Changes in symptom reflux association using dynamic pH thresholds during ambulatory pH monitoring: an observational cross-sectional study

Symptom reflux association (SRA) assesses symptoms associated with reflux events defined by pH <4.0, but limited symptoms associate with reflux events. We evaluated the impact of alternate pH thresholds on SRA in a large ambulatory pH database. Acid exposure time (AET), reflux events, and associated symptoms (within 2 minutes following a reflux event) were extracted from ambulatory pH studies performed off antireflux therapy (722 patients, 49.1 ± 0.5 years, 66.8% F) over a 7-year period. Symptom association probability (SAP) and symptom index (SI) were calculated at pH 3.5, 4.0, 4.5, and 5. Receiver operating characteristics (ROC) were generated using SRA at any pH as gold standard; areas under the curve (AUCs) were determined. Discordant cases were reanalyzed to determine changes in SRA and predictors of change using multivariate regression. At pH 4.0, 41% had a positive SAP, and 34% had a positive SI. While there was sustained gain in SI positivity from acidic to more weakly acidic pH thresholds, SAP positivity was highest at pH 4.5. On ROC analysis, performance characteristics were best at pH 4.0 (AUC 0.97) for SAP, and at pH 4.5 and 5.0 (AUC 0.92-0.94) for SI. On multivariate logistic regression adjusting for age, gender, and change in AET and reflux events, only number of associated symptoms predicted change in SRA (P < 0.0001). Changing pH thresholds for reflux events augments SRA by increasing reflux events associated with existing symptoms, while symptom recording remains the principal determinant of SRA.

Distal mean nocturnal baseline impedance on pH-impedance monitoring predicts reflux burden and symptomatic outcome in gastro-oesophageal reflux disease

BACKGROUND

Mean nocturnal baseline impedance (MNBI), a novel pH-impedance metric, may be a surrogate marker of reflux burden.

AIM

To assess the predictive value of MNBI on symptomatic outcomes after anti-reflux therapy.

METHODS

In this prospective observational cohort study, pH-impedance studies performed over a 5-year period were reviewed. Baseline impedance was extracted from six channels at three stable nocturnal 10-min time periods, and averaged to yield MNBI. Distal and proximal oesophageal MNBI values were calculated by averaging MNBI values at 3, 5, 7 and 9 cm, and 15 and 17 cm respectively. Symptomatic outcomes were measured as changes in global symptom severity (GSS, rated on 100-mm visual analogue scales) on prospective follow-up after medical or surgical anti-reflux therapy. Univariate and multivariate analyses assessed the predictive value of MNBI on symptomatic outcomes.

RESULTS

Of 266 patients, 135 (50.8%) were tested off proton pump inhibitor (PPI) therapy and formed the study cohort (52.1 ± 1.1 years, 63.7% F). The 59 with elevated acid exposure time (AET) had lower composite and distal MNBI values than those with physiological AET (P < 0.0001), but similar proximal MNBI (P = 0.62). Linear AET negatively correlated with distal MNBI, both individually and collectively (Pearson's r = -0.5, P < 0.001), but not proximal MNBI (Pearson's r = 0, P = 0.72). After prospective follow-up (94 patients were followed up for 3.1 ± 0.2 years), univariate and multivariate regression models showed that distal MNBI, but not proximal MNBI, was independently predictive of linear GSS improvement.

CONCLUSIONS

Distal oesophageal MNBI negatively correlates with AET and, when assessed off PPI therapy, is independently predictive of symptomatic improvement following anti-reflux therapy.

Interrogation of esophagogastric junction barrier function using the esophagogastric junction contractile integral: an observational cohort study

The esophagogastric junction contractile integral (EGJ-CI), designed similar to distal contractile integral (DCI), has been proposed as a metric to evaluate EGJ barrier function. We determined normative values and evaluated EGJ-CI in predicting esophageal acid exposure time (AET) and symptomatic outcome in this observational cohort study. High-resolution manometry (HRM) studies were reviewed in 188 patients (55.2 ± 0.9 years, 64% female) undergoing ambulatory pH monitoring off therapy. Dominant symptoms and global symptom severity (GSS) were determined on questionnaires initially and upon follow-up. EGJ-CI was measured using the DCI tool placed across the EGJ and compared to normal controls (n = 21, 27.6 ± 0.6 years, 52% female). EGJ-CI was calculated both for a single respiratory cycle (SRC, in mmHg.cm.s) and corrected for respiratory cycle (CRC, mmHg.cm). Univariate and multivariate analyses determined the predictive potential of EGJ-CI in terms of AET and post-therapy GSS at follow-up, controlling for medical versus surgical therapy. Mean EGJ-CI values were significantly lower when AET was abnormal; EGJ-CI/SRC and EGJ-CI/CRC were 86% concordant (r = 0.84). Using receiver operating characteristic analysis, values below 121.8 mmHg.cm.s (EGJ-CI/SRC) and 39.3 mmHg.cm (EGJ-CI/CRC) predicted abnormal AET best (sensitivity 0.61 and 0.65, specificity 0.61 and 0.57, respectively). On univariate and multivariate analysis, the EGJ-CI discriminated normal from abnormal AET better than conventional LES parameters (P ≤ 0.02). After 2.7 ± 0.1 years follow-up, EGJ-CI below identified thresholds predicted better symptom response to antireflux surgery compared to medical therapy (P = 0.009). EGJ-CI is a novel HRM metric that has potential to complement or replace currently used basal LES and EGJ parameters.

Bronchial reacutization and gastroesophageal reflux: is there a potential clinical correlation?

BACKGROUND

Pepsin plays a role in gastroesophageal reflux (GER). Aims of this study were to verify if pepsin could be the cause of frequent bronchial exacerbations and to check if the persistence of chronic respiratory symptoms were correlated with pre-existing respiratory diseases.

METHODS

From January to May 2016, 42 patients underwent a diagnostic bronchoscopy. All patients had a history of at least one bronchial exacerbation during the previous year. Bronchial lavage fluid specimens were obtained. A semiquantitative assessment of pepsin in the samples was carried out based on the intensity of the test sample.

RESULTS

Pepsin was present in 37 patients (88%), but in patients with bronchial asthma and chronic obstructive pulmonary disease (COPD), the finding of pepsin in the bronchoalveolar fluid was 100%. There was a strong positive statistical correlation between pepsin detection and radiological signs of GER (ρ=0.662), and between pepsin detection and diagnosis (ρ=0.682). No correlation was found between the bacteriology and the presence of pepsin in the airways (ρ=0.006).

CONCLUSIONS

The presence of pepsin in the airways shows the occurrence of reflux. The persistence of respiratory symptoms by at least 2 months suggest an endoscopic bronchial examination. This straightforward test confirms the cause possible irritation of the airways and may prevent further diagnostic tests, such as an EGD or pH monitoring esophageal.

Esophageal Impedance Monitoring: Clinical Pearls and Pitfalls

The development of intraluminal esophageal impedance monitoring has improved our ability to detect and measure gastroesophageal reflux without dependence on acid content. This ability to detect previously unrecognized weak or nonacid reflux episodes has had important clinical implications in the diagnosis and management of gastroesophageal reflux disease (GERD). In addition, with the ability to assess bolus transit within the esophageal lumen, impedance monitoring has enhanced the recognition and characterization of esophageal motility disorders in patients with nonobstructive dysphagia. The assessment of the intraluminal movement of gas and liquid has also been proven to be of diagnostic value in conditions such as rumination syndrome and excessive belching. Further, alternative applications of impedance monitoring, such as the measurement of mucosal impedance, have provided novel insights into assessing esophageal mucosal integrity changes as a consequence of inflammatory change. Future applications for esophageal impedance monitoring also hold promise in esophageal conditions other than GERD. However, despite all of the clinical benefits afforded by esophageal impedance monitoring, important clinical and technical shortcomings limit its diagnostic value and must be considered when interpreting study results. Overinterpretation of studies or application of impedance monitoring in patients can have deleterious clinical implications. This review will highlight the clinical benefits and limitations of esophageal impedance monitoring and provide clinical pearls and pitfalls associated with this technology.

Prevalence, characteristics, and treatment outcomes of reflux hypersensitivity detected on pH-impedance monitoring

BACKGROUND

Positive symptom association probability (SAP) with physiologic esophageal acid exposure time (AET) on pH-impedance monitoring defines reflux hypersensitivity (RH), a correlate of acid sensitivity on pH monitoring. We evaluated prevalence, clinical characteristics, and symptomatic outcomes of RH in a prospective observational cohort with reflux symptoms undergoing pH-impedance monitoring.

METHODS

Reflux hypersensitivity was diagnosed when SAP was positive with pH- and/or impedance-detected reflux events with physiologic AET. Symptom burden was assessed using dominant symptom intensity (DSI, product of symptom severity and frequency on 5-point Likert scales) and global symptom severity (GSS, global esophageal symptoms on 100-mm visual analog scales) by questionnaire, both at baseline and on prospective follow-up. Clinical characteristics and predictors of symptomatic improvement were assessed with univariate and multivariate analyses.

KEY RESULTS

Seventy-seven patients (29%) met criteria for RH, of which 53 patients (53.7 ± 1.8 years, 66% F) were contacted after 3.3 ± 0.2 years for follow-up. Reflux hypersensitivity was detected on pH-impedance testing both on and off antisecretory therapy; pH alone missed 51% of RH. About 57% reported ≥50% GSS improvement. Sixteen patients undergoing antireflux surgery (ARS) reported better symptom improvement compared to 37 patients treated medically (GSS change: p = 0.005; DSI change: p = 0.04). Hiatus hernia (p = 0.03) and surgical management (p ≤ 0.04) predicted symptom improvement on univariate analysis, while acid sensitivity was a negative predictor for outcome on both univariate (p = 0.02) and multivariate analyses (p ≤ 0.04).

CONCLUSIONS & INFERENCES

Reflux hypersensitivity is a mechanism for persistent reflux symptoms in almost one-third of patients undergoing pH-impedance testing. While acid sensitivity predicts suboptimal symptom improvement, antireflux therapy may improve RH in select settings.

Short-segment and intrasphincteric gastroesophageal reflux

PURPOSE OF REVIEW

The traditional gold standard for measuring gastroesophageal acid reflux has been by placing a pH sensor 5 cm proximal to the lower esophageal sphincter. It is known that damage induced by reflux is maximal near to the gastroesophageal junction and this has stimulated interest in determining acid reflux at that site.

RECENT FINDINGS

The extent of esophageal exposure from refluxing gastric acid is inversely related to the distance proximal to the gastroesophageal junction. In addition, the pH transition point from gastric to esophageal pH can be displaced proximally within the lower esophageal sphincter without complete loss of sphincter tone. This intrasphincteric reflux is associated with proximal extension of cardia mucosa because of columnar metaplasia of the most distal esophageal squamous mucosa.

SUMMARY

The most distal esophageal mucosa is exposed to substantially greater gastric acid refluxate than that recorded at the traditional site 5 cm proximal to the lower esophageal sphincter.