Post-reflux Swallow-induced Peristaltic Wave Index Research Articles

Reflux characteristics triggering post-reflux swallow-induced peristaltic wave (PSPW) in patients with GERD symptoms.

BackgroundEsophageal chemical clearance has been evaluated with the post‐reflux swallow‐induced peristaltic wave (PSPW) index. The factors triggering PSPW in Gastro‐esophageal reflux disease (GERD) have not yet been investigated. This multicenter study was aimed at evaluating the characteristics of reflux episodes associated with PSPW occurrence in patients with typical GERD symptoms.MethodsImpedance‐pH tracings from patients with typical reflux symptoms were analyzed. Sixteen healthy subjects were included for comparison. Multivariate analysis was performed to determine predictors of PSPW events.Key resultsImpedance‐pH tracings from 60 patients and 16 healthy subjects were evaluated. A total of 3454 refluxes were recorded. In patients, comparing reflux episodes followed with those not followed by a PSPW, significantly higher proportions of acid (79% vs. 74%, p: 0.02), mixed (47% vs. 32%, p: 0.0001) and proximal refluxes (34% vs. 20%, p: 0.0001) were observed. A multivariate analysis, acid (OR: 1.3, 95% CI: 1.05–1.6), mixed (OR: 2, 95% CI: 1.6–2.3), and proximal (OR: 2.1, 95% CI: 1.7–2.5) refluxes were independently associated with PSPWs. Reflux episodes followed by a PSPW were characterized by a significantly higher bolus clearing time [(mean ± SD) 41 s ± 6 s vs. 30 s ± 5 s, p < 0.05] whereas nadir pH value of reflux events preceding PSPWs was tangentially but not significantly lower [(mean ± SD) 2.61 ± 1.22 vs. 2.74 ± 1.26, p: 0.057].Conclusions and inferencesAcid, mixed and proximal refluxes, and their duration are key factors in eliciting PSPWs. PSPW represents a response to reflux directly related to the potential harmfulness of reflux contents.

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

Background/Aims: The incidence of reflux esophagitis (RE) has a striking predominance in males. Conversely, non-erosive reflux disease (NERD) is more common in females. This imbalance of gastroesophageal reflux disease (GERD) implies sex-related differences in its pathogenesis. However, limited studies have analyzed the sex-based differences in pH parameters and esophageal impedance of GERD patients.Methods: This study evaluated sex-based pathogenesis differences by comparing reflux episodes, mean nocturnal baseline impedance (MNBI) values, and post-reflux swallow-induced peristaltic wave (PSPW) index values of males with GERD and females with GERD using 24-h multichannel intraluminal impedance and pH monitoring.Results: We analyzed 181 patients (102 males and 79 females) with GERD. Reflux symptom index (RSI) scores were higher in females than that in males (P < 0.05). Males had significantly longer acid exposure times, higher DeMeester scores, and more acid reflux episodes than females (P < 0.05). Females had more instances of weakly acidic reflux than males (P < 0.01). The PSPW index values of males and females were similar (P > 0.05). Compared with females, males had lower MNBI values for the mid and distal esophagus (P < 0.05). However, with increasing age, the MNBI values of females decreased more rapidly than those of males. MNBI values of elderly patients of both sexes older than 60 years were similar.Conclusions: Acid reflux is more likely to occur in males; however, females tend to have more instances of weakly acid reflux. The integrity of the esophageal mucosa is more fragile in males than in females; however, the esophageal mucosal barrier attenuates more rapidly with increasing age in females than in males.

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.

Novel physiologic nomogram discriminates symptom outcome in patients with erosive esophagitis.

Most of patients with erosive esophagitis (EE) are of LA grade A&B with low reflux burden, therefore require further esophageal function tests (EFTs). One-third of them respond poorly to pump proton inhibitor (PPI) treatment. The aim was to establish and validate a physiologic nomogram to discriminate symptom outcome to PPI treatment in patients with EE. A total of 79 EE patients with heartburn who underwent EFTs and received PPI therapy were randomly assigned into a training set (n = 55) and a validation set (n = 24). Clinical data including physiologic parameters from EFTs were collected. Significant factors for the positive symptomatic outcome were identified using logistic regression analysis. Physiologic signature was developed using the least absolute shrinkage and selection operator algorithm. The nomogram was established by combining significant factors and physiologic signature, and its performance was evaluated and validated in the training and validation set. The clinical value of the nomogram was measured by decision curve analysis. Significant factors for positive symptomatic response to PPI treatment were identified as follows: acid exposure time, total number of reflux episodes, and two novel metrics including mean nocturnal baseline impedance and post-reflux swallow-induced peristaltic wave index. The nomogram which incorporated both significant factors and physiologic signature demonstrated good performance in the training and validation sets [C-index: 0.938 (95% CI 0.882-0.995); 0.839 (95% CI 0.678-0.995), respectively]. Decision curves showed significant clinical usefulness. The first physiologic nomogram was developed to discriminate the individualized response to PPI therapy among EE patients.

Post-reflux swallow-induced peristaltic wave (PSPW): physiology, triggering factors and role in reflux clearance in healthy subjects

Background and aimsThe underlying physiology of post-reflux swallow-induced peristaltic wave (PSPW) is unclear. We aimed to: 1) calculate the probability of a random association between reflux and PSPW; 2) characterize factors that could underlie triggering of PSPW and 3) assess the chemical clearance effect of PSPW in healthy asymptomatic subjects.MethodsA total of 251 impedance–pH tracings from healthy asymptomatic subjects were analysed. Twenty consecutive tracings from this pool with 20–40 reflux episodes/24 h and a PSPW index higher than 50% were separately analyzed to evaluate the probability of a random association between reflux and PSPW. The characteristics of reflux episodes followed by a PSPW were compared with those not associated with PSPW.ResultsA mean time interval of 29.3 s between a reflux episode and the first swallow captured 71% of total reflux episodes, and 67% of accompanying swallows were non-random. Compared to reflux without PSPW, reflux episodes with PSPW were more frequently acidic (P = 0.048), mixed with gas (P < 0.0001), of high proximal extent (P < 0.0001), while awake (P < 0.0001), and with shorter chemical clearance time (P = 0.040). High proximal extent, gas presence and occurring while awake were independent factors associated with PSPW (P < 0.0001).ConclusionUsing a time window between reflux and PSPW of around 30 s, the probability of a chance association is around 30%. Reflux episodes with high proximal extent, containing gas and occurring while awake are important factors associated with PSPW in healthy subjects. Reflux episodes with PSPW have a shorter chemical clearance time.

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

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. 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. Of 296 patients (52.8±0.8yr, 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). 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.

New developments in esophageal function testing and esophageal manifestations of connective tissue disorders.

This work summarizes new and emerging metrics and tools in esophageal function testing and their potential clinical impact. Because the diagnostic sensitivity and reliability of conventional impedance-pH variables are suboptimal, several novel impedance parameters, such as the postreflux swallow-induced peristaltic wave index and the mean nocturnal baseline impedance, as well as mucosal impedance, are entering a validation stage prior to general clinical use. The accurate diagnosis of behavioral disorders in patients with rumination syndrome and supragastric belching using ambulatory multiple intraluminal impedance-pH can lead directly to behavioral interventions in patients with refractory gastroesophageal reflux disease (GERD). New provocative measures, such as multiple rapid swallows and the rapid drink challenge, have been developed to overcome the limitations of standard high-resolution esophageal manometry, aiming at further clarifying esophageal dysmotility. Furthermore, the current diagnostic and therapeutic challenges in patients with esophageal involvement in Sjogren's syndrome and scleroderma, who tend to have severe forms of GERD, are entering a new investigative and clinical phase.

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

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

Factors of Reflux Episodes With Post-reflux Swallow-induced Peristaltic Wave in Gastroesophageal Reflux Disease.

Background/AimsIt is known that post-reflux swallow-induced peristaltic wave (PSPW) index represents the chemical clearance of the esophagus. However, few studies have explored why some reflux episodes could induce PSPW while others in the same patient could not. The purpose of this study is to investigate the characteristics of reflux episodes which could elicit PSPW.MethodsIn this study, 269 reflux episodes were detected, of which 90 with a PSPW and 179 without a PSPW. Comparisons were made between the characteristics of reflux episodes with a PSPW and without a PSPW. The characteristics were including nadir pH, pH drop, proximal extent (cm, sec), ascending velocity (cm/sec), volume clearance time, acid clearance time, percentage acidic (%), 15 to 60-minute acid burden (seconds), and 15- to 60-minute volume burden (seconds). The characteristics between the 2 groups were compared through performing Wilcoxon signed rank test.ResultsReflux episodes followed by a PSPW were significantly associated with a higher proximal extent than those without a PSPW. After the reflux episodes, higher volume clearance time and larger volume burden were more likely to trigger a PSPW. However, there were no significant differences between the 2 groups in nadir pH, pH drop, ascending velocity, acid clearance time, percentage acidic, or acid burden.ConclusionsThe role of acid seems to be less important in a reflux episode inducing a PSPW. Proximal reflux episodes are more likely to induce a PSPW. The depression of volume clearance may also be an important factor in eliciting a PSPW.

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

Mean nocturnal baseline impedance (MNBI) and postreflux swallow-induced peristaltic wave (PSPW) index are novel impedance-based markers of reflux, but the effect of bile reflux on these metrics is unknown. The aim of this study was to evaluate bile reflux, MNBI, and PSPW index in patients with endoscopy-negative GERD partially responsive to PPI therapy. All patients underwent off-PPI endoscopy, esophageal manometry, multichannel intraluminal impedance pH (MII-pH), and bile reflux monitoring. Abnormal esophageal acid exposure time (AET) was required for inclusion. Symptom intensity (using 10-cm visual analog scales), and conventional and novel MII-pH metrics were compared between patients with and without abnormal bile reflux. We evaluated 42 NERD patients (29 males, mean age: 53.4±13.years), mean AET 6.1±2%, of which 21 had abnormal bile reflux (Group A, 10.2±4.9%), and 21 had normal bile reflux (Group B, 0.4±0.1%, P<.05 compared with Group A). Heartburn reporting on PPI was higher in Group A (7.2±2.1 vs 5.8±0.9; P=.002), but AET, number of reflux events (acidic and weakly acidic), did not differ between the two groups. However, both PSPW index and MNBI were lower in Group A (P<.001). A strong inverse linear correlation was found between bile reflux and both MNBI (Pearson's test; R=-0.714; P<.001) and PSPW index (R=-0.722; P<.001). Compared to acid reflux alone, the presence of bile in an acidic esophageal environment is associated with more severe heartburn, lesser relief from PPI therapy, higher impairment of esophageal mucosal integrity and less effective chemical clearance.

Diagnosis of gastroesophageal reflux: an update on current and emerging modalities.

Gastroesophageal reflux disease (GERD) is a common condition characterized by troublesome symptoms or esophageal mucosal lesions attributed to excessive esophageal acid exposure. Various pathophysiological mechanisms account for GERD, including impaired esophageal peristalsis and anatomical or physiological defects at the esophagogastric junction (EGJ). Endoscopy identifies GERD complications and detects potential alternative diagnoses. However, if symptoms persist despite proton pump inhibitor therapy, functional esophageal tests are useful to characterize reflux burden and define the symptom association profile. Ambulatory pH or pH-impedance monitoring measures the 24-h acid exposure time, which remains the most reproducible reflux metric and predicts response to antireflux therapy. Apart from identifying peristaltic dysfunction, esophageal high-resolution manometry defines the morphology and contractile vigor (EGJ-CI) of the EGJ. Novel metrics obtained from pH-impedance monitoring include the postreflux swallow-induced peristaltic wave index and mean nocturnal baseline impedance, which augment the diagnostic value of pH-impedance testing. Mucosal impedance can also be recorded using a probe inserted through a gastroscope, or a novel balloon catheter with arrays of impedance electrodes inserted following sedated endoscopy. The latest developments in functional esophageal tests define the GERD phenotype based on pathogenesis, reflux exposure, structural or motility disorders, and symptom burden, facilitating appropriate treatment.

Impact of ineffective esophageal motility on chemical clearance in patients with gastroesophageal reflux symptoms.

Ineffective esophageal motility (IEM) is the most common manometric abnormality in gastroesophageal reflux disease (GERD). However, the impact of IEM on esophageal chemical clearance has not been fully investigated. This study aimed to determine the impact of IEM on esophageal chemical clearance in patients with GERD. A total of 369 patients with GERD symptoms who underwent upper endoscopy and high-resolution manometry (HRM) test were retrospectively analyzed. The relationship between IEM and erosive esophagitis was examined. In addition, the impact of IEM on chemical clearance was examined in patients who underwent an additional combined multichannel intraluminal impedance-pH (MII-pH) test. Esophageal chemical clearance capability was evaluated via postreflux swallow-induced peristaltic wave (PSPW) index and acid clearance time (ACT). Of 369 patients, 181 (49.1%) had esophageal motility disorders, of which 78 (21.1%) had IEM. The proportion of IEM patients in those with erosive esophagitis and those without were 16.2% and 21.7%, respectively, and no significant difference was observed (P = 0.53). After excluding patients other than those with IEM and normal esophageal motility, 64 subsequently underwent MII-pH test. The median values of the PSPW index in the IEM and normal esophageal motility group were 11.1% (4.2%-20.0%) and 17.1% (9.8%-30.6%), respectively. The PSPW index was significantly lower in the IEM group than in the normal esophageal motility group (P < 0.05). The median ACT values in the IEM group and normal esophageal motility group were 125.5 (54.0-183.5)seconds and 60.0 (27.2-105.7)seconds, respectively. The ACT was significantly longer in the IEM group than in the normal esophageal motility group (P < 0.05). In conclusion, IEM was found to be associated with chemical clearance dysfunction as measured against the PSPW index and ACT. As this condition could be a risk factor for GERD, future treatments should be developed with a focus on chemical clearance.

Role of Esophageal Mean Nocturnal Baseline Impedance and Post-reflux Swallow-induced Peristaltic Wave Index in Discriminating Chinese Patients With Heartburn.

Background/AimsRecently, esophageal mean nocturnal baseline impedance (MNBI) and post-reflux swallow-induced peristaltic wave (PSPW) index have been proposed, which can increase the diagnostic role of multichannel intraluminal impedance and pH recording (MII/pH) for differentiating patients with heartburn. Therefore, our aim is to investigate the role of esophageal proximal MNBI, distal MNBI, and PSPW index in differentiating Chinese patients with heartburn.MethodsPatients with heartburn from the Beijing Anzhen Hospital, who underwent upper gastrointestinal endoscopy and 24-hour MII/pH, were enrolled in this study.ResultsIn all, 24 erosive esophagitis (EE), 46 non-erosive reflux disease (NERD), 52 reflux hypersensitivity (RH), and 78 functional heartburn (FH) patients were recruited. The respective median values for the EE, NERD, RH, and FH groups were as follows: proximal MNBI 1858.0, 2147.5, 2374.3, and 2329.0 Ω (P = 0.053); distal MNBI 1243.4, 1506.5, 2451.2, and 2477.3 Ω (P < 0.001); and PSPWI 15.0%, 25.0%, 25.0%, and 45.0% (P < 0.001). Spearman correlation analysis showed that distal MNBI and PSPW index were significantly negatively correlated with acid and bolus exposure time and acid reflux events. Receiver operating characteristic analyses showed that distal MNBI and PSPW index significantly discriminated FH from EE, NERD, and RH (P < 0.001), with cut-off values of 1890.6 Ω and 27.5% and areas under the curve of 0.721 and 0.779, respectively.ConclusionEsophageal distal MNBI and PSPW index could increase the diagnostic role of MII/pH, especially for differentiating Chinese patients with heartburn.

Post-reflux swallow-induced peristaltic wave index and mean nocturnal baseline impedance predict PPI response in GERD patients with extra esophageal symptoms

BackgroundMean nocturnal baseline impedance (MNBI) and post-reflux swallow-induced peristaltic wave (PSPW) index are able to increase the diagnostic yield of impedance-pH and are associated to proton pump inhibitor (PPI) response. Few data concerning these variables in patients with extra-esophageal symptoms (EES) are available. AimsTo evaluate, in EES patients, the role of the conventional and new impedance-pH variables in diagnosing GERD and the predictive value of impedance-pH variables for PPI response. MethodsConsecutive patients presenting suspected GERD-related EES underwent impedance-pH. Patients treated in the last six months with double dose PPI therapy were enrolled. The presence of concomitant typical symptoms was assessed. Results239 EES patients were studied; 102 responders and 137 non-responders. Eighty-one (34%) were affected by non-erosive reflux disease (NERD), 61 (26%) presented reflux hypersensitivity (RH) and 97 (40%) were non-GERD. In NERD and RH groups, a significantly higher proportion of patients with pathological PSPW index or MNBI values compared to non-GERD group was observed. 24 (25%) non-GERD patients presented a pathological PSPW index and/or MNBI. Pathological PSPW index, MNBI and presence of typical symptoms were associated to PPI response. ConclusionsMNBI and PSPW index measurement increases the diagnostic yield of impedance-pH; abnormal values are associated with a satisfactory response to acid-suppressive therapy in EES patients.

Role of Reflux in the Pathogenesis of Eosinophilic Esophagitis: Comprehensive Appraisal With Off- and On PPI Impedance-pH Monitoring.

Role of reflux and mechanisms of response to proton pump inhibitor (PPI) therapy in eosinophilic esophagitis (EoE) have not yet been fully elucidated. Comprehensive assessment by impedance-pH monitoring could clarify these issues. Prospective multicenter study comparing EoE patients with healthy controls and gastroesophageal reflux disease cases. Patients with EoE were evaluated off- and on PPI; responsiveness was assessed by histology. Impedance-pH appraisal included chemical clearance, assessed with the postreflux swallow-induced peristaltic wave (PSPW) index, and mucosal integrity measured with mean nocturnal baseline impedance (MNBI). Sixty consecutive patients with EoE were compared with 60 age- and sex-matched healthy controls and 60 subjects with gastroesophageal reflux disease. The number of total refluxes was higher, while the PSPW index was lower in patients with EoE than in healthy controls. Off PPI, a lower MNBI gradient between the mid and distal esophagus distinguished 20 patients with PPI-refractory EoE from 40 patients with PPI-responsive EoE and was a predictor of PPI failure. On PPI, a lower PSPW index was the sole reflux parameter distinguishing PPI-refractory from PPI-responsive EoE; all reflux parameters improved in PPI-responsive patients, whereas the PSPW index was not modified in PPI-refractory cases and was independently associated with PPI-responsiveness. MNBI in the distal and mid esophagus improved much more in PPI-responsive than in PPI-refractory EoE. Reflux plays a role in the pathogenesis of EoE, more relevant in PPI-responsive cases. Low impedance gradient between the mid and distal esophagus may be useful to predict PPI refractoriness. PPIs mainly act by improving chemical clearance, i.e., by an antireflux action supporting long-term prescription in PPI-responsive EoE.

New Parameters for Impedance–pH Monitoring in Diagnosing Gastroesophageal Reflux Disease and Predicting its Severity

Aim. The present articleidentifies possible correlations between new parameters for impedance–pH monitoring, such as mean nocturnal baseline impedance (MNBI); post-reflux swallow-induced peristaltic wave index (PSPW); and the main parameter, acid exposure time (AET), as well as esophageal motor function. The authors set out to assess the values of MNBI and the PSPW index as additional criteria improving the diagnostic efficacy of impedance-pH monitoring, the completeness of clinical phenotyping of gastroesophageal reflux disease (GERD), as well as determining the probability of a more severe disease course. Materials and methods. A total of 60 patients aged 19 to 71 (mean age 44.7 years) participated in the study: 30 patients with erosive reflux disease (ERD), 30 with non-erosive reflux disease (NERD) and 20 healthy volunteers aged 26 to 65 (mean age 45.2 years). All of them underwent 24-hour combined esophageal impedance–pH monitoring (Gastroscan-IAM, JSC RPE Istok-Sistema, Fryazino) and high-resolution esophageal manometry using a 22-channel water-perfusion catheter (Solar GI MMS, The Netherlands). The authors studied such parameters as AET, GER number, MNBI level, PSPW index, distal contractile integral (DCI), resting pressure in the lower esophageal sphincter (LES), peristaltic break. Statistical processing was performed using Statistica for Windows 10.0 (StatSoft Inc.) and Prism 8 (GraphPad).Results. The examination of patients revealed that MNBI, the PSPW index and DCI significantly decrease with the development of more severe GERD (r = -0.79; p = 0.0000, r = -0.4; p = 0.0002, r = -0.49; p = 0.0000, respectively). A negative correlation was found between AET and the PSPW index (r = -0.38; p = 0.0003) and the MNBI level (r = -0.59; p = 0.0000). A correlation was determined between the value of MNBI and the following parameters: LES resting pressure (r = 0.26; p = 0.0006), DCI (r = 0.35; p = 0.00004), peristaltic break (r = -0.21; p = 0.007), the PSPW index (r = 0.41; p = 0.0000), and GER number (r = -0.59; p = 0.0). A correlation between the PSPW index and DCI (r = 0.22; p = 0.001) was found as well.In the group of ERD patients, the median values of PSPW and MNBI constitute 0.23 [0.17; 0.33] and 1.13 [0.63; 1.53], respectively. Also, a correlation between AET and the MNBI level was found in this group of patients (r=-0.53; p=0.000036). In turn, MNBI correlated with LES resting pressure (r = 0.46; p = 0.0004), DCI (r = 0.36; p = 0.005), peristaltic break (r = -0.37; p = 0.004), and GER number (r = -0,42; p = 0,0000).In the group of NERD patients, the median values of PSPW and MNBI constitute 0.56 [0.51; 0.75] and 3.3 [2.57; 4.8], respectively. A correlation was also found between the MNBI level and AET (r = -0.35; p = 0.005), GER number (r = -0.39; p = 0.00005), as well as between AET and the PSPW index (r = -0.26; p = 0.0000).In the control group, the median values of PSPW and MNBI constitute 0.42 [0.3; 0.5] and 5.83 [5.21; 6.48], respectively. A statistically significant difference (p = 0.02) was found between the median values of MNBI in patients with ERD, NERD, and the control group. A statistically significant difference (p = 0.0) between the median values of the PSPW index in patients with ERD, NERD and the control group was found as well.Conclusions. The revealed correlations between AET, esophageal motor function and new parameters for impedance-pH monitoring allow them to be used as additional criteria improving the diagnostic efficacy of impedance-pH monitoring and the completeness of GERD clinical phenotyping. A decrease in the level of these parameters in patients reflects the probability of a more severe disease course.

Wireless 24, 48, and 96Hour or Impedance or Oropharyngeal Prolonged pH Monitoring: Which Test, When, and Why for GERD?

pH monitoring technologies are routinely utilized in practice to further evaluate symptoms of gastro-esophageal reflux disease and laryngopharyngeal reflux (LPR). This is a review of the recent literature of the available pH monitoring technology and creates an algorithm in the diagnostic work up of a patient with GERD or LPR. The catheter-free wireless pH monitor traditionally collects data for 48h. Recent studies have found that extending to 96h can be helpful in patients with conflicting results on the first 2days of the study. In addition, 96h can allow for testing both on and off of PPI therapy. The oropharyngeal monitoring device is a newer technology that is designed to aid in the diagnoses of LPR. There are limitations with this technology as there is no universal abnormal cutoff and some studies have suggested a poor correlation between multichannel intraluminal impedance-pH (MII-pH) and the oropharyngeal monitoring device. MII-pH has recently developed two additional parameters, the measurement of three 10-min nighttime periods and the post-reflux swallow-induced peristaltic wave (PSPW) index, both of which may increase accuracy of testing. Each of these technologies can provide unique data regarding acid reflux exposure in the esophagus and oropharynx. The wireless pH monitor performed off of PPI therapy can help to establish or exclude the diagnosis of GERD. For those patients with refractory symptoms on PPI, MII-pH study can be performed while on therapy and provides data regarding the response to treatment. Oropharyngeal pH monitoring is being utilized in some practices to aid in diagnosis of LPR, but the scientific validity is controversial.

Tu1136 - Postreflux Swallow-Induced Peristaltic Wave Index and Mean Nocturnal Baseline Impedance are Decreased in Gerd Patients with Barrett's Esophagus

Tu1136 - Postreflux Swallow-Induced Peristaltic Wave Index and Mean Nocturnal Baseline Impedance are Decreased in Gerd Patients with Barrett's Esophagus

Lack of improvement of impaired chemical clearance characterizes PPI-refractory reflux-related heartburn.

Heartburn is the most specific symptom of reflux disease and is highly responsive to proton pump inhibitor (PPI) therapy. Some patients do not respond to PPIs, but mechanisms of refractoriness have not yet been fully elucidated. Impedance-pH monitoring, allowing comprehensive on-therapy assessment of reflux, represents a valuable test to investigate PPI refractoriness. Prospective multicenter study comparing endoscopy-negative patients with PPI-refractory and PPI-responsive heartburn. Reflux disease was demonstrated by off-PPI impedance-pH monitoring and mechanisms of refractoriness were studied with on-PPI impedance-pH monitoring. Assessment of impedance-pH tracings comprised conventional parameters, post-reflux swallow-induced peristaltic wave (PSPW) index, and mean nocturnal baseline impedance (MNBI). Sixty-four patients entered the study, 32 with PPI-refractory and 32 with PPI-responsive heartburn. On PPI, median percentage gastric and esophageal acid exposure time and number of acid refluxes did not differ between the two groups; conversely, number of total and weakly acidic refluxes and percentage bolus exposure were significantly higher while PSPW index and MNBI were significantly lower in PPI-refractory cases. At multivariate logistic regression analysis, PSPW index was the sole independent risk factor for PPI refractoriness (OR 1.082, 95% CI 1.022-1.146, P = 0.007). Comparing off- and on-PPI parameters, median PSPW index did not change in PPI-refractory patients (24% vs. 26%, P = 0.327) but increased significantly in PPI-responsive cases (29% vs. 46%, P < 0.001). Lack of improvement of impaired chemical clearance is a major determinant of PPI refractoriness. Timely post-reflux salivary swallowing represents a key defensive mechanism and a potential target for future treatment modalities in PPI-refractory reflux-related heartburn.

Impaired Esophageal Motility and Clearance Post-Lung Transplant: Risk For Chronic Allograft Failure

Objectives:Gastroesophageal reflux is common in patients post-lung transplantation (LTx) and thus considered a risk factor for aspiration and consequently allograft rejection and the development of chronic allograft failure. However, evidence supporting this remains unclear and often contradictory. Our aim was to examine the role played by esophageal motility on gastroesophageal reflux exposure, along with its clearance and that of boluses swallowed, and the relationship to development of obstructive chronic lung allograft dysfunction (o-CLAD).Methods:Patients post-LTx (n=50, 26 female; mean age 55 years (range, 20–73 years)) completed high-resolution impedance manometry and 24-h pH/impedance. Esophageal motility abnormalities were classified based upon the Chicago Classification version 3.0.Results:Esophagogastric junction outflow obstruction alone (EGJOOa) (P=0.01), incomplete bolus transit (IBT) (P=0.006) and proximal reflux (P=0.042) increased the risk for o-CLAD. Patients with EGJOOa were most likely to present with o-CLAD (77%); despite being less likely to exhibit abnormal numbers of reflux events (10%) compared with those with normal motility (o-CLAD: 29%, P<0.05; abnormal reflux events: 64%, P<0.05). Patients with EGJOOa had lower total reflux bolus exposure time than those with normal motility (0.6 vs. 1.5% P<0.05). In addition, poor esophageal clearance documented by abnormal post-reflux swallow-induced peristaltic wave index associated with o-CLAD; inversely correlating with the proportion of reflux events reaching the proximal esophagus (r=−0.251; P=0.052).Conclusions:These observations support esophageal dysmotility, especially EGJOOa, and impaired clearance of swallowed bolus or refluxed contents, more so than just the presence of gastroesophageal reflux alone, as important risk factors in the development of o-CLAD.