A prediction model of abnormal acid reflux in gastroesophageal reflux disease.

BACKGROUND AND AIM: The measurement of esophageal acid exposure time (AET) using combined multichannel intraluminal impedance-pH (MII-pH) tests is the gold standard for diagnosing gastroesophageal reflux disease (GERD). However, this catheter-based 24-h test can cause considerable patient discomfort. Our aim is to identify factors affecting AET and to develop a scoring model for predicting AET abnormalities before conducting the MII-pH test. METHODS: Of the 366 patients who underwent MII-pH test at two facilities in Japan and Vietnam, 255 patients who also had esophagogastroduodenoscopy and high-resolution manometry were included in this study. Logistic regression analysis was conducted using risk factors for AET > 6% identified from a derivation cohort (n = 109). A scoring system predicting AET > 6% was then constructed and externally validated with a separate cohort (n = 146). RESULTS: Three variables were derived from the prediction model: male gender, Hill grades III-IV, and weak mean distal contractile integrals. Based on these scores, patients were classified into low (0 point), intermediate (1-3 points), and high (4 points) risk groups. The probabilities of having an AET > 6% were 6%, 34%, and 100% for these groups, respectively. A score of < 1 excluded patients with abnormal AET, with a negative predictive value of 93.8% in the derivation cohort and 80.0% in the validation cohort. CONCLUSIONS: We derived and externally validated a prediction model for abnormal AET. This system could assist in guiding the appropriate treatment strategies for GERD.

Long-term disease-specific quality of life after laparoscopic Nissen fundoplication in patients with borderline GERD.

BACKGROUND: Historically, DeMeester score over 14.7 has been used to diagnose GERD. The 2022 American Gastroenterological Association clinical guidelines define GERD based on acid exposure time (AET) instead of DeMeester score. We aim to compare outcomes after laparoscopic Nissen fundoplication (LNF) in patients based on differing GERD diagnostic criteria. METHODS: Patients who underwent first-time LNF between 2009 and 2017 were identified. Demographics, objective GERD evaluation, and outcomes were maintained in an IRB-approved database. Disease-specific quality of life was assessed with a survey (GERD-HRQL) with higher values representing more symptomatic disease. Descriptive statistics, Fischer's exact test and logistic regression were used to analyze the data, p-value < 0.05. RESULTS: 225 patients were stratified into two groups: borderline GERD (AET 4-6%, n = 25.11%) and GERD (AET ≥ 6%, n = 200.89%). The mean age was 50.1 ± 13.4 years and 169 (75%) were female. Baseline GERD-HRQL was lower in the borderline group (24.3 vs 30.0, p = 0.031). Short-term (5 weeks [IQR 4, 8]), medium-term (14 months [IQR 7.25, 31]) and long-term (6.75 years [IQR 5.5, 8]) follow-up was performed. GERD-HRQL scores did not differ between borderline and GERD patients at short-(6.0 vs 7.1, p = 0.630), medium-(12.0 vs 12.1, p = 0.818), or long-term follow-up (10.0 vs 9.0, p = 0.757). The absolute long-term improvement in GERD-HRQL was -12.3 (p = 0.022) vs. -21.3 (p < 0.001). At long-term follow-up there was no difference in PPI use (50% vs 47%, p = 0.852), satisfaction (58% vs 76%, p = 0.187), willingness to repeat the procedure given the benefit of hindsight (75% vs 85%, p = 0.386), or need for reoperation (14% vs 13%, p = 0.910). CONCLUSION: Both patients with borderline GERD and GERD achieve GERD-HRQL improvements at 7 years following laparoscopic Nissen fundoplication and demonstrate similar long-term PPI usage and satisfaction with surgical results. Borderline GERD patients have lower GERD-HRQL at baseline, and thus have smaller improvements in their QOL scores. Anti-reflux surgery should be considered for patients with a diagnosis of borderline GERD refractory to medical therapy.

Acid exposure time better predicts outcomes following anti-reflux surgery than DeMeester score.

BACKGROUND: Criteria to diagnose gastroesophageal reflux disease (GERD) vary. The American Gastroenterology Association (AGA) 2022 Expert Review on GERD focuses on acid exposure time (AET) rather than DeMeester score from ambulatory pH testing (BRAVO). We aim to review outcomes following anti-reflux surgery (ARS) at our institution, grouped by differing criteria for the diagnosis of GERD. METHODS: A retrospective review of a prospective gastroesophageal quality database was performed for all patients undergoing evaluation for ARS with preoperative BRAVO ≥ 48 h. Group comparisons were made using two-tailed Wilcoxon rank-sum and Fisher's exact tests and two-tailed statistical significance of p < 0.05. RESULTS: Between 2010 and 2022, 253 patients underwent an evaluation for ARS with BRAVO testing. Most patients (86.9%) met our institution's historical criteria: LA C/D esophagitis, Barrett's, or DeMeester ≥ 14.72 on 1+ days. Fewer patients (67.2%) met new AGA criteria: LA B/C/D esophagitis, Barrett's, or AET ≥ 6% on 2+ days. Sixty-one patients (24%) met historical criteria only, with significantly lower BMI, ASA, less hiatal hernias, and less DeMeester and AET-positive days, a less severe GERD phenotype. There were no differences between groups in perioperative outcomes or % symptom resolution. Objective GERD outcomes (need for dilation, esophagitis, and postop BRAVO) were equivalent between groups. Patient-reported quality of life scores, including GERD-HRQL, RSI, and Dysphagia Score did not differ between groups from preop through 1 year postop. Those who met our historical criteria only reported significantly worse RSI scores (p = 0.03) and worse GERD-HRQL scores at 2 years postop, though not statistically significant (p = 0.07). CONCLUSION: Updated AGA GERD guidelines exclude a portion of patients who historically would have been diagnosed with and surgically treated for GERD. This cohort appears to have a less severe GERD phenotype but equivalent outcomes up to 1 year, with more atypical GERD symptoms at 2 years postop. AET may better define who should be offered ARS than DeMeester score.

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.

Phenotyping patients with borderline elevated esophageal acid exposure.

Acid exposure time (AET) <4% on ambulatory reflux monitoring definitively rules out pathologic gastroesophageal acid reflux, while AET >6% indicates pathologic reflux per the Lyon Consensus, leaving AET of 4-6% as borderline. We aimed to elucidate the borderline AET population and identify metrics that could help differentiate this group. A total of 50 subjects in each group, AET <4, 4-6, and >6% on pH-impedance monitoring between 2015 and 2019, were retrospectively reviewed. In addition to demographic and clinical information, the extracted data included mean nocturnal baseline impedance (MNBI) on reflux study and high-resolution manometry (HRM) parameters and diagnosis. After excluding patients with prior foregut surgery, major esophageal motility disorder, or unreliable impedance testing, a total of 89 subjects were included in the analysis (25 with normal AET < 4%, 38 with borderline 4-6%, 26 with abnormal >6%). MNBI in borderline AET patients was significantly lower compared to normal AET (1607.7 vs. 2524.0 ohms, P < 0.01), and higher than abnormal AET (951.5 ohms, P < 0.01). Borderline subjects had a greater frequency of ineffective esophageal motility (IEM) diagnosis per Chicago classification v3.0 (42.1 vs. 8.0%, P = 0.01), but did not demonstrate any differences compared to abnormal subjects (34.6%, P = 0.56). Patients with borderline AET had an average MNBI that was in between normal AET and abnormal AET. Borderline AET patients also commonly demonstrate IEM on HRM, similar to those with abnormal AET. Our findings can be potentially useful in assigning higher clinical significance for patients found to have borderline AET with concomitant low MNBI and IEM on manometry.

Diagnostic accuracy of multichannel intraluminal impedance-pH monitoring for gastroesophageal reflux-induced chronic cough.

OBJECTIVES: To elucidate the accuracy and advantages of Multichannel intraluminal impedance-pH monitoring (MII-pH) in diagnosing gastroesophageal reflux-induced chronic cough (GERC). METHODS: The patients with suspected GERC were recruited and underwent MII-pH, GERC was confirmed by subsequent anti-reflux treatment despite the findings of MII-pH. Its diagnostic accuracy in identifying GERC were evaluated by receiver operating characteristic (ROC) analysis and compared with that of 24-h esophageal pH monitoring. RESULTS: Among 158 patients completing both MII-pH and anti-reflux therapy, GERC was diagnosed in 136 patients, including acid GERC in 96 patients (70.6%), non-acid GERC in 30 patients (22.0%), neither one of both GERC in 10 patients (7.4%). For the identification of GERC, MII-pH presented with the sensitivity of 92.6%, specificity of 63.6%, positive predictive value of 94.0%, negative predictive value of 58.3% and area under ROC curve of 0.863, which was totally superior to 24-h esophageal pH monitoring. As the essential criteria of MII-pH, esophageal acid exposure time and symptom associated probability had a limited diagnostic value when used alone, but improved greatly the diagnostic yield when used in combination, even with a suboptimal efficacy. CONCLUSION: MII-pH is a more sensitive test for identifying GERC, but with a suboptimal diagnostic efficacy.

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.

Mean Nocturnal Baseline Impedance Correlates With Symptom Outcome When Acid Exposure Time Is Inconclusive on Esophageal Reflux Monitoring.

BACKGROUND & AIMS: Abnormal acid exposure time (AET) is associated with good outcomes of symptoms from antireflux therapy. Low esophageal mean nocturnal baseline impedance (MNBI) is an additional marker of reflux disease. We aimed to evaluate the value of MNBI when analysis of AET produces borderline or inconclusive results. METHODS: We studied a retrospective cohort of 371 patients (mean age, 54.5 ± 0.7 y; 60.0% female) who had persistent reflux symptoms after treatment and underwent ambulatory pH-impedance monitoring off antisecretory therapy at 1 tertiary center in Europe or 1 in the United States. Total AET was determined from pH impedance studies (pathologic, >6%; physiologic, <4%; borderline or inconclusive, 4%-6%). Baseline impedance values were calculated at the 5-cm impedance channel at 3 nocturnal 10-minute periods and averaged to yield MNBI (abnormal, <2292 ohms). The primary outcome was response to antireflux therapy, defined as global symptom improvement of 50% or greater on patients' answers on standardized visual analog scales. RESULTS: Among the 371 patients, 107 (28.8%) had pathologic AET and 234 (63.1%) had abnormal MNBI. Low MNBI was concordant in 99.1% of patients with pathologic AET, in 91.2% with borderline AET, and in 33.7% with physiologic AET. During 38.7 ± 0.8 months of follow-up evaluation, 43.0% of patients had improved symptoms with medical therapy and 76.2% had improved symptoms with surgical antireflux therapy (P < .0001). When MNBI was low, response to medical therapy did not differ significantly between patients with borderline AET and patients with pathologic AET (P = .44), but did differ significantly when each group was compared with patients with physiologic AET, regardless of whether MNBI was normal or low (P < .0001 for each comparison). CONCLUSIONS: When low, MNBI identifies patients with pathologic and borderline AET who respond to antireflux therapy. MNBI analysis complements AET in defining esophageal reflux burden. MNBI correlates with response of symptoms to antireflux therapy.

Impedance-high resolution manometry analysis of patients with nonerosive reflux disease.

BACKGROUND & AIMS: Transient lower esophageal sphincter relaxations (TLESRs) contribute to episodes of reflux. Few studies have assessed the frequencies or compositions of TLESRs and reflux episodes in patients with reflux disease. We used combined high-resolution manometry and impedance monitoring to analyze reflux episodes and esophageal motility in these patients, compared with those of healthy individuals. METHODS: We evaluated the frequency of TLESRs and the relationship between the reflux pattern and esophageal pressures during TLESRs in 14 patients with nonerosive reflux disease (NERD) and 11 controls. Study participants underwent combined high-resolution manometry and impedance monitoring before and 60 minutes after a solid and liquid meal. The diagnosis of NERD was confirmed by a 24-hour pH impedance test. RESULTS: The frequency of TLESRs did not differ between patients with NERD and controls. In patients with NERD, TLESRs were associated more often with reflux episodes than in controls (93% ± 6% vs 66% ± 19%; P < .05). Patients with NERD had a higher percentage of pure liquid reflux episodes (33% ± 15% vs 10% ± 2%; P < .05), whereas controls had a higher percentage of mixed reflux episodes (45% ± 16% vs 67% ± 17% in patients with NERD; P < .05). Patients with NERD also had a higher percentage of reflux (liquid and mixed) associated with common cavities (74% ± 18% vs 50% ± 20% in controls; P < .05). CONCLUSIONS: In contrast to previous studies, we found that TLESRs are associated more often with reflux in patients with NERD than control subjects; this association increases when only liquid and mixed refluxes are considered. These findings indicate that factors involved in the occurrence of reflux in patients with NERD during TLESRs are different from those in healthy subjects.

Evaluating acidic gastroesophageal reflux with wireless pH monitoring in French bulldogs with sliding hiatal herniation.

BACKGROUND: Sliding hiatal herniation (SHH) and gastroesophageal reflux (GER) commonly occur in French bulldogs. Wireless pH monitoring can quantitatively assess acidic GER in dogs affected by SHH. HYPOTHESIS/OBJECTIVES: Measure acidic GER in French bulldogs with SHH, pre- and post-brachycephalic obstructive airway syndrome (BOAS) surgery, utilizing a wireless pH capsule (Bravo Calibration-free, Medtronic, Minnesota), and correlate with owners' observations of regurgitation. ANIMALS: Eleven French bulldogs diagnosed with SHH via swallowing fluoroscopy. METHODS: Prospective cohort study. A pH capsule was endoscopically placed in the esophagus. Up to 96 hours of data were acquired as the owner logged clinical signs. Spearman's correlation and Wilcoxon rank-sum tests evaluated factors correlated with acid exposure time (AET), defined by the % time pH < 4. In 4/11 dogs, Bravo monitoring was repeated 2-4 months after BOAS surgery. RESULTS: Medians (Q1-Q3) for age and weight were 21 months (17-35.5) and 10.0 kg (8.9-11.5). BOAS severity was mild (3), moderate (4), or severe (4). Medians (Q1-Q3) for AET and reflux events were 3.3% (2.6-6.4) and 70 (34-173). Clinical score (P = .82) and BOAS severity (P = .60) were not correlated with AET, but age was negatively correlated (rho = -.66, P = .03). Median probability (Q1-Q3) that regurgitation was associated with a reflux event was 72.5% (0-99). Percent AET numerically improved in all 4 dogs that underwent BOAS surgery although not statistically assessed. CONCLUSIONS AND CLINICAL IMPORTANCE: Wireless pH monitoring documented acidic GER in French bulldogs with SHH, captured subclinical events, and showed improvements after BOAS surgery.

Roles of swallowing and belching in different phenotypes of gastroesophageal reflux disease.

BACKGROUND: The contributions of swallowing and belching to specific gastroesophageal reflux disease (GERD) phenotypes are unclear. METHODS: This study retrospectively analyzed esophageal pH/impedance studies, comparing reflux events preceded by gastric belching (GB), supragastric belching (SGB), air swallowing, and liquid/solid swallowing based on reflux position, lower esophageal sphincter (LES) pressure, and acid exposure time (AET). KEY RESULTS: 20 GERD patients and 10 controls were studied. Upright GERD patients and controls had a higher proportion of reflux events with a preceding swallow or belch (0.64, 0.64) than the supine group (0.38, p = 0.043). The upright group and controls trended toward a higher proportion of reflux events preceded by overall swallowing (0.61, 0.50) and air swallowing (0.55, 0.48) than the supine group (0.32, 0.31 p = 0.064, p = 0.11), but the three groups had similar rates of liquid/solid swallowing (0.032, 0.024, 0.017, p = 0.69). LES pressure did not correlate with reflux events preceded by swallowing (R2 = 0.021, p = 0.44). There was a higher rate of events preceded by gastric belching in the control group (0.14) than in the upright (0.032) and supine groups (0.066, p = 0.049). LES pressure did not correlate with the rate of events preceded by belching (R2 = 0.000093, p = 0.96). Normal AET patients had a higher rate of events preceded by GB (0.12) than those with increased acid exposure (0.030, p = 0.0083), but the two groups had similar rates of preceding air (0.43, 0.47, p = 0.68), liquid/solid (0.018, 0.032, p = 0.30), and overall swallowing (0.44, 0.53, p = 0.38). CONCLUSIONS AND INFERENCES: Swallowing more than belching is a dominant mechanism for reflux irrespective of GERD position, LES pressure, and AET.

The impact of gastroesophageal reflux disease on upper esophageal sphincter function: Insights from PH impedance and high-resolution manometry.

Lower esophageal sphincter (LES) pathophysiology has been established in gastroesophageal reflux disease (GERD); however, less is understood regarding the role the upper esophageal sphincter (UES) plays in preventing laryngopharynphageal reflux. Sustained UES basal pressure prevents reflux into the pharynx while allowing relaxation during ingestion. We investigate whether GERD influences UES function via HRM and pH Impedance testing. A retrospective analysis of 318 patients who underwent high-resolution manometry with trans-nasally placed manometric catheter and 24-h multichannel intraluminal impedance pH monitoring. One hundred and forty-seven patients met Lyon consensus criteria for GERD based on acid exposure time >6%. The most common chief concern was heartburn or reflux, present in 59% of these patients. Upper esophageal sphincter basal and residual pressures were not significantly different between patients with GERD when compared to those without GERD, including a subanalysis of patients with extraesophageal symptoms. The LES basal and residual pressures, DCI and MNBI are statistically lower in patients with pathologic GERD. HRM and pH Impedance testing demonstrates no difference in UES basal and residual pressures based on pH diagnosis of GERD. We redemonstrate the association with hypotonic LES, diminished DCI and MNBI with GERD.

Characteristics of reflux and gastric electrical activity in gastroesophageal reflux disease with ineffective esophageal motility.

OBJECTIVES: The impact of ineffective esophageal motility (IEM) on gastroesophageal reflux disease (GERD) remains unknown, and abnormal esophageal motility often coexists with abnormal gastric motility. We aimed to investigate the role of IEM in GERD and its relationship with gastric electrical activity. METHODS: Patients diagnosed as GERD based on GERD-questionnaire score ≥8 in our hospital from January 2020 to June 2022 were included. All patients underwent 24-h multichannel intraluminal impedance-pH monitoring, high-resolution manometry, and electrogastrogram and were categorized into the normal esophageal motility (NEM) and IEM groups, respectively. Reflux characteristics and gastric electric activity were compared between the two groups, and the correlation between gastric electric activity and reflux was analyzed. RESULTS: Acid exposure time, total reflux episodes, and DeMeester score in the IEM group were higher than those in the NEM group. Distal mean nocturnal baseline impedance was significantly lower in the IEM group. Compared with the NEM group, the power ratio (PR) of fundus, antrum and pylorus and premeal and postmeal normal wave ratio of antrum were significantly lower in IEM. The total reflux episodes were negatively correlated with the PR of fundus and pylorus, and the DeMeester score was negatively correlated with the PR of corpus and pylorus. CONCLUSIONS: IEM may lead to increased reflux, resulting in esophageal mucosal damage. There may be consistency between abnormal esophageal motility and gastric motility.

Is there a direct relationship between hiatal hernia size, esophageal body hypomotility and symptomatic perception of gastroesophageal reflux episodes?

Background: The esophagogastric junction (EGJ) is classified into 3 anatomical subtypes according to lower esophageal sphincter-crural diaphragm (LES-CD) separation. We aimed to assess their relationship to esophageal motility, reflux characteristics, and symptom perception. Methods: We analyzed data from 1740 consecutive patients with typical reflux symptoms, who underwent high resolution manometry and a 24-h pH-impedance study during a 13-year period. A diagnosis of gastroesophageal reflux disease (GERD) was made if acid exposure time (AET) was >6%. EGJ types were classified as 1, 2, or 3, if LES-CD separation was up to 1 cm, 1-3 cm, or ≥3 cm, respectively. Results: EGJ type distribution was 72.2%, 22.1% and 5.7%, for types 1, 2 and 3, respectively. GERD was diagnosed in 31.2% and was more common among patients with EGJ type 2/3 vs. 1 (P<0.001). Length of LES-CD separation significantly correlated with AET and number of reflux episodes. Patients with type 2 or 3 EGJ more often showed ineffective or absent peristalsis compared with type 1 (P=0.008 and P<0.001 respectively). In the multivariate analysis, EGJ type 2/3 correlated with AET (P=0.001) and reflux episodes (P=0.041) but not with positive symptomatic markers or with ineffective/absent peristalsis. Conclusions: Our study confirms that EGJ anatomical morphology is a strong risk factor for GERD and correlates with both AET and the number of reflux events, though the length of separation is more important than the type. The multivariate analysis revealed that EGJ type 2 or 3 was not correlated with symptom perception or esophageal hypomotility.

Effect of aging and obesity on esophageal mucosal integrity as measured by baseline impedance.

AIM: Low mean nocturnal baseline impedance (MNBI) values support gastroesophageal reflux disease (GERD) diagnosis. Recent data denote that age and obesity may affect MNBI. We aimed to evaluate diagnostic MNBI cutoffs as also the effect of aging and body mass index (BMI) on MNBI. METHODS: In total 311 patients (M/F: 139/172, mean age: 47 ± 13) referred for typical GERD symptoms that have undertaken both high-resolution manometry (HRM) and pH-Impedance studies off PPI were evaluated. MNBI at 3, 5, and 17 cm over lower esophageal sphincter (LES) were evaluated. GERD was diagnosed if acid exposure time (AET) >6%. RESULTS: Mean BMI was 26.6 ± 5.9 kg/cm2 . GERD was diagnosed in 39.2% and 13.5% had inconclusive GERD. MNBI was correlated to patients' age, BMI, AET, and the length of LES-CD separation and at 3 cm also to the total number of reflux and LES hypotension. In the multivariate analysis MNBI at 3 and 5 cm was independently correlated only to age, BMI, and AET. Patients with definite GERD showed lower MNBI at 3 cm compared with inconclusive GERD though both showed lower values when compared with GERD absence. At 3 cm MNBI ability for diagnosing GERD was good (0.815, p < 0.001 95% CI: 0.766-0.863) with an optimal cutoff point of 1281 Ohm. CONCLUSION: According to our study findings age and BMI affect independently lower esophageal MNBI values in patients evaluated for GERD. MNBI significantly aids toward GERD diagnosis though in a real-life setting MNBI values much lower than the one previously proposed should be used.

The Lyon Consensus Criteria for GERD Diagnosis in a Greek Population: The Clinical Impact and Changes in GERD Diagnosis in a Real-World, Retrospective Study.

(1) Introduction/aim: Gastroesophageal reflux disease (GERD) affects 8−33% globally. The gold standard examination technique in diagnosing GERD is 24 h pHmetry ± impedance. Recently, new diagnostic criteria were introduced by the Lyon Consensus for GERD diagnosis. Our aim was to investigate the diagnostic yield of pHmetry + impedance using the Lyon Consensus criteria in a real-world study. (2) Patients and methods: Our study included 249 consecutive patients (M/F: 120/129, mean age 50 ± 15 years) who underwent 24 h pH+ impedance monitoring in our department, during a 5-year period. Epidemiological, endoscopic, clinical, and 24 h pH+ impedance data were retrospectively collected. (3) Results: Typical GERD symptoms were reported by 140/249 (56.2%) patients, whereas 99/249 (39.6%) patients reported various extraesophageal symptoms. Endoscopic findings supportive of GERD based on the Lyon Consensus were present in 42/185 (22.7%). An AET value of >6% was observed in 60/249 (24.1%). GERD diagnosis according to the Lyon Consensus criteria was set in 63/249 (25.3%) patients; a rate significantly lower than that observed by implementing the older criteria (32.1%), p < 0.001. In the multivariate analysis, the existence of endoscopic findings supportive of GERD diagnosis as defined by the Lyon Consensus (p = 0.036), a De Meester score of over 14.7, and the presence of typical GERD symptoms were correlated to GERD diagnosis (p < 0.001, respectively) using the criteria defined for pH−impedance monitoring. (4) Conclusions: Changes in the diagnostic criteria concerning the 24 h pH−impedance monitoring of GERD based on the Lyon Consensus led to a conclusive GERD diagnosis in approximately 25% of the patients. This rate of GERD diagnosis is reduced in comparison to the one confirmed with the use of previously established criteria.

The relationship between esophageal acidity and symptom frequency in symptomatic nonerosive gastroesophageal reflux disease.

The present paper examines the extent to which novel measures of esophageal acid exposure can elucidate possible relationships between symptom perception and esophageal acidity in subjects with nonerosive gastroesophageal reflux disease. Recordings of esophageal pH and symptom occurrence from 20 subjects with nonerosive gastroesophageal reflux disease were analyzed. Interval esophageal acid exposure was calculated in two different ways for the interval that preceded each symptom in each subject. Interval esophageal acidity was calculated as the time-weighted acid concentration for the interval. Interval esophageal acid exposure time was calculated as the percentage of the total recording time that esophageal pH was less than pH 4 for the interval. There was a negative relationship between the probability of a symptom and interval esophageal acid exposure indicating the paradoxical finding that the lower the value of esophageal acid exposure, the higher the probability of a symptom. The time courses of symptoms and cumulative esophageal acidity resolved this paradox by indicating that esophageal acid exposure oscillates between longer periods of low esophageal acid exposure with a high number of symptoms reflecting high esophageal acid sensitivity, and shorter periods of high esophageal acid exposure with fewer symptoms reflecting low esophageal acid sensitivity. Thus, the present analyses show how novel measures of acidity can identify and also resolve a previously unrecognized paradoxical relationship between esophageal acid exposure and symptom frequency in subjects with nonerosive gastroesophageal reflux disease.

Devices for esophageal function testing.

BACKGROUND AND AIMS: Esophageal function testing is an integral component of the evaluation of refractory GERD and esophageal motility disorders. This review summarizes the current technologies available for esophageal function testing, including the functional luminal imaging probe (FLIP), high-resolution esophageal manometry (HRM), and multichannel intraluminal impedance (MII) and pH monitoring. METHODS: We performed a MEDLINE, PubMed, and MAUDE database literature search to identify pertinent clinical studies through March 2021 using the following key words: esophageal manometry, HRM, esophageal impedance, FLIP, MII, and esophageal pH testing. Technical data were gathered from traditional and web-based publications, proprietary publications, and informal communications with pertinent vendors. The report was drafted, reviewed, and edited by the American Society for Gastrointestinal Endoscopy Technology Committee and approved by the Governing Board of the American Society for Gastrointestinal Endoscopy. RESULTS: FLIP is a high-resolution impedance planimetry system used for pressure and dimension measurement in the esophagus, pylorus, and anal sphincter. FLIP provides complementary information to HRM for esophageal motility disorders, especially achalasia. The Chicago classification, based on HRM data, is a widely adopted algorithmic scheme used to diagnose esophageal motility disorders. MII detects intraluminal bolus movement and, combined with pH measurement or manometry, provides information on acid and non-acid gastroesophageal reflux and bolus transit in patients with refractory GERD and for preoperative evaluation for anti-reflux procedures. CONCLUSIONS: Esophageal function testing techniques (FLIP, HRM, and MII-pH) have diagnostic and prognostic value in the evaluation of esophageal motility disorders and refractory GERD. Newer technologies and classification systems have enabled an increased understanding of these diseases.

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.

Can acid exposure time replace the DeMeester score in the diagnosis of gastroesophageal reflux-induced cough?

BACKGROUND: The objective of this study was to compare the predictive accuracy of the acid exposure time (AET) with the DeMeester score (DMS) for gastroesophageal reflux-induced cough (GERC). METHODS: A total of 277 patients who underwent multichannel intraluminal impedance pH monitoring (MII-pH) were enrolled, and their clinical information and laboratory results were retrospectively analyzed. The diagnostic value of AET for GERC was compared with that of the DMS, symptom association probability (SAP), and symptom index (SI). RESULTS: A total of 236 patients met the inclusion criteria, 150 patients (63.65%) were definitely diagnosed with GERC, including 111(74%) acid GERC and 39 (26%) nonacid GERC. The optimal cutoff value of AET for diagnosing GERC was AET > 4.8%, and its diagnostic value was equal to that of DMS > 14.7 (AUC = 0.827 versus 0.818, p = 0.519) and was superior to that of SAP (AUC = 0.827 versus 0.689, p = 0.000) and SI (AUC = 0.827 versus 0.688, p = 0.000). When using both DMS > 14.7 and AET > 4.8% or either of the two for the diagnosis of GERC, the diagnosis rate was not improved over using DMS > 14.7 alone. The diagnostic value of AET and DMS for acid GERC were both high and equivalent (AUC = 0.925 versus 0.922, p = 0.95). The optimal cutoff value of AET for diagnosing acid GERC was AET > 6.2%. CONCLUSION: AET and DMS are both equal in discriminating GERC. A GERC diagnosis should be considered when AET > 4.8%, whereas an acid GERC diagnosis should be considered when AET > 6.2%.