The added value of quantitative analysis of on-therapy impedance-pH parameters in distinguishing refractory non-erosive reflux disease from functional heartburn

Background By analysis of symptom‐reflux association, endoscopy‐negative refractory heartburn can be related to acid/non‐acid refluxes with impedance‐pH monitoring. Unfortunately, patients frequently do not report symptoms during the test. We aimed to assess the contribution of quantitative analysis of impedance‐pH parameters added to symptom‐reflux association in evaluating patients with endoscopy‐negative heartburn refractory to high‐dose proton pump inhibitor therapy. Methods The symptom association probability (SAP), the symptom index (SI), the esophageal acid exposure time and the number of distal and proximal refluxes were assessed at on‐therapy impedance‐pH monitoring. Relationships with hiatal hernia and manometric findings were also evaluated. Key Results Eighty patients were prospectively studied. Refractory heartburn was more frequently related to reflux by a positive SAP/SI and/or abnormal impedance‐pH parameters (52/80 cases) (65%) than by a positive SAP/SI only (38/80 cases) (47%) (P = 0.038). In patients with refractory non‐erosive reflux disease (NERD) defined by a positive SAP/SI and/or abnormal impedance‐pH parameters, the prevalence of hiatal hernia was significantly higher (56%vs 21%, P = 0.007) and the mean lower esophageal sphincter tone was significantly lower (18.7 vs 25.8 mmHg, P = 0.005) than in those (35%) with reflux‐unrelated, i.e., functional heartburn (FH). On the contrary, no significant difference was observed subdividing patients according to a positive SAP/SI only. Conclusions & Inferences Quantitative analysis of impedance‐pH parameters added to symptom‐reflux association allows a subdivision of refractory‐heartburn patients into refractory NERD and FH which is substantiated by pathophysiological findings and which restricts the diagnosis of FH to one third of cases.     

Increased TRPV1 gene expression in esophageal mucosa of patients with non‐erosive and erosive reflux disease

Background Transient receptor potential channel vanilloid subfamily member‐1 (TRPV1) may play a role in esophageal perception. TRPV1 mRNA and protein expression were examined in the esophageal mucosa of non‐erosive reflux disease (NERD) and erosive esophagitis (EE) patients and correlated to esophageal acid exposure. Methods Seventeen NERD patients, eight EE patients and 10 healthy subjects underwent endoscopy after a 3‐week washout from proton pump inhibitors or H2 antagonists. Biopsies, obtained from the distal esophagus, were used for conventional histology, for Western blot analysis and/or quantitative real‐time polymerase chain reaction (qPCR). Overall 13 NERD patients, four EE patients and five controls underwent ambulatory pH‐testing. Key Results TRPV1 expression was increased in all NERD and EE patients, as measured by Western blot analysis (0.65 ± 0.07 and 0.8 ± 0.05 VS 0.34 ± 0.04 in controls; P < 0.01) and by qPCR (1.98 ± 0.21 and 2.52 ± 0.46 VS 1.00 ± 0.06; P < 0.01). Neutrophilic infiltration, in the mucosa, was detected only in EE patients. Conclusions & Inferences Non‐erosive reflux disease and EE patients presented increased TRPV1 receptors mRNA and protein, although no correlation with acid exposure was demonstrated. Increased TRPV1 in the esophageal mucosa may contribute to symptoms both in NERD and EE patients and possibly account for peripheral mechanisms responsible for esophageal hypersensitivity in NERD patients.     

Relationship between baseline impedance levels and esophageal mucosal integrity in children with erosive and non-erosive reflux disease

Background Baseline impedance measurement has been reported to be related to esophageal acid exposure and hypothesized to be a marker of microscopic changes of the esophageal mucosa. Aims of the study were to establish whether any relationship existed between the magnitude of intercellular space diameter (ISD) of esophageal mucosa and baseline impedance levels in children with gastro‐esophageal reflux disease (GERD), and to compare baseline impedance levels between children with non erosive (NERD) and erosive (ERD) reflux disease. Methods Fifteen children (median age: 11.2 years) with NERD, and 11 with ERD (median age: 9.6 years) were prospectively studied. All patients underwent upper endoscopy. Biopsies were taken 2–3 cm above the Z‐line, and ISD was measured using transmission electron microscopy. All patients underwent impedance pH‐monitoring, and baseline impedance levels were assessed in the most distal impedance channel. Key Results Mean (±SD) ISD did not differ between NERD (1.0 ± 0.3 μm) and ERD (1.1 ± 0.3 μm, ns). Considering all patients together, no correlation was found between distal baseline impedance and ISD (r: ?0.15; ns). Conversely, negative correlations were found between distal baseline impedance and acid exposure time (r: ?0.76; P < 0.001), long‐lasting reflux episodes (r: ?0.78; P < 0.001), acid reflux episodes (r: ?0.62; P < 0.001), and acid clearance time (r: ?0.79; P < 0.001). Distal baseline impedance was significantly lower in ERD [1455 (947–2338) Ω] than in NERD children [3065 (2253–3771) Ω; P < 0.01]. Conclusions & Inferences In children with GERD baseline impedance levels are not useful in predicting reflux‐induced ultrastructural changes in the esophageal mucosa, despite their ability to discriminate between NERD and ERD.     

Concomitant irritable bowel syndrome is associated with failure of step‐down on‐demand proton pump inhibitor treatment in patients with gastro‐esophageal reflux disease

Background The predictors for treatment failure of on‐demand proton pump inhibitor (PPI) therapy in gastro‐esophageal reflux disease (GERD) patients are unclear. We studied the efficacy and predictors for treatment failure of step‐down on‐demand PPI therapy in patients with non‐erosive reflux disease (NERD) and those with low grade erosive esophagitis. Methods Consecutive symptomatic GERD patients who had positive esophageal pH studies and complete symptom resolution with initial treatment of esomeprazole were given step‐down on‐demand esomeprazole for 26 weeks. Patients with esophagitis of Los Angeles (LA) grade C or above and recent use of PPI were excluded. Treatment failure was defined as an inadequate relief of reflux symptoms using global symptom assessment. Potential predictors of treatment failure were determined using multivariate analysis. Key Results One hundred and sixty three NERD and 102 esophagitis patients were studied. The 26‐week probability of treatment failure was 36.2% (95% CI: 23.9–46.5%) in NERD group and 20.1% (95% CI: 10.9–28.3%) in esophagitis group, respectively (P = 0.021). Irritable bowel syndrome (adjusted HR: 2.1, 95% CI: 1.5–3.8, P = 0.01), in addition to daily reflux symptom (adjusted hazard ratio: 2.7, 95% CI: 1.9–4.2, P = 0.001) and concomitant dyspepsia (adjusted hazard ratio: 1.7, 95% CI: 1.1–2.8, P = 0.04), were independent predictors for treatment failure. Conclusions & Inferences Compared to patients with esophagitis, NERD patients have higher failure rate of on‐demand PPI therapy. Concomitant irritable bowel syndrome, in addition to daily reflux symptom and dyspepsia, is associated with the failure of on‐demand PPI in these patients.     

Regional oesophageal sensitivity to acid and weakly acidic reflux in patients with non-erosive reflux disease

Abstract  The mechanisms underlying symptoms in non-erosive reflux disease (NERD) remain to be elucidated. Non-erosive reflux disease patients appear to be more sensitive to intraluminal stimula than erosive patients, the proximal oesophagus being the most sensitive. In order to assess regional oesophageal changes in reflux acidity and sensitivity to reflux, according either to the acidity or the composition of the refluxate, combined multiple pH and multiple pH-impedance (pH-MII) was performed in 16 NERD patients. According to multiple pH-metry, 29% and 12% of reflux events reached the middle and proximal oesophagus respectively, and 35% and 19% according to conventional pH-MII ( P  < 0.05). The per-individual analysis confirmed the difference between the two techniques. According to combined distal and proximal pH-MII, approximately 30% of distal acid reflux became weakly acidic at the proximal oesophagus. In all patients, the frequency of symptomatic refluxes, both acid and weakly acidic, was significantly higher at the proximal, compared with distal oesophagus (25 ± 8% vs 11 ± 2% for acid reflux and 27 ± 8% vs 8 ± 2% for weakly acidic reflux; P  < 0.05). Compared with multiple pH-metry, pH-MII shows a higher sensitivity in the detection of proximal reflux. As approximately 30% of acid reflux becomes weakly acidic along the oesophageal body, to better characterize proximal reflux, in clinical practice, combined proximal pH-impedance monitoring should be used. In NERD patients, the proximal oesophagus seems to be more sensitive to both acid and weakly acidic reflux.     

Poor effectiveness of proton pump inhibitors in non‐erosive reflux disease: the truth in the end!

Despite acid secretion being normal in the majority of patients with gastro‐esophageal reflux disease (GERD) or Barrett’s esophagus, acid inhibition represents the mainstay of treatment for both these conditions, with the aim of reducing the aggressive nature of the refluxate toward the esophageal mucosa. Proton pump inhibitors (PPIs) represent, therefore, the first choice medical treatment for GERD, in that they are able to provide an 80–85% healing rate for esophageal lesions, a 56–76% symptom relief and also reduce the incidence of complications, such as strictures as well as dysplasia and adenocarcinoma in Barrett’s esophagus. According to a widely quoted systematic review, compared to patients with erosive esophagitis, patients with non‐erosive reflux disease (i.e., NERD) display a reduced symptom relief with PPIs, with about 20% reduction of therapeutic gain. In this issue of NeuroGastroenterology & Motility, Weijenborg et al. address for the first time the PPI efficacy in subpopulations of patients with NERD. The study shows clearly that, when the diagnosis is accurately made by including a functional test, NERD patients respond to PPI therapy in a similar way to those with erosive disease. Although not as frequent as previously suggested, however, PPI‐refractory heartburn does exist. Some 20% (range: 15–27%) of correctly diagnosed and appropriately treated patients do not respond to PPI treatment at standard doses. Although the pathophysiology underlying PPI failure in GERD is complex and likely multifactorial, acid (be it the sole component of refluxate or not) still remains a major causative factor. A better and more predictable form of acid suppression should therefore be pursued.     

Platelet‐activating factor and distinct chemokines are elevated in mucosal biopsies of erosive compared with non‐erosive reflux disease patients and controls

Background A distinction between symptomatic non‐erosive reflux disease (NERD) and erosive esophagitis (EE) patients is supported by the presence of inflammatory response in the mucosa of EE patients, leading to a damage of mucosal integrity. To explore the underlying mechanism of this difference, we assessed inflammatory mediators in mucosal biopsies from EE and NERD patients and compared them with controls. Methods Nineteen NERD patients, 15 EE patients, and 16 healthy subjects underwent endoscopy after a 3‐week washout from PPI or H₂ antagonists. Biopsies obtained from the distal esophagus were examined by quantitative real‐time polymerase chain reaction (qPCR) and multiplex enzyme‐linked immunosorbent assay for selected chemokines and lyso‐PAF acetyltransferase (LysoPAF‐AT), the enzyme responsible for production of platelet‐activating factor (PAF). Key Results Expression of LysoPAF‐AT and multiple chemokines was significantly increased in mucosal biopsies derived from EE patients, when compared with NERD patients and healthy controls. Upregulated chemokines included interleukin 8, eotaxin‐1, ‐2, and ‐3, macrophage inflammatory protein‐1α (MIP‐1α), and monocyte chemoattractant protein‐1 (MCP‐1). LysoPAF‐AT and the chemokine profile in NERD patients were comparable with healthy controls. Conclusions & Inferences Levels of selected cytokines and Lyso‐PAF AT were significantly higher in the esophageal mucosa of EE patients compared with NERD and control patients. This difference may explain the distinct inflammatory response occurring in EE patients’ mucosa. In contrast, as no significant differences existed between the levels of all mediators in NERD and control subjects, an inflammatory response does not appear to play a major role in the pathogenesis of the abnormalities found in NERD patients.     

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.     

Characteristics of gastro‐esophageal reflux episodes in Barrett’s esophagus,erosive esophagitis and healthy volunteers

Background Gastro‐esophageal reflux is considered a major culprit in the pathogenesis of Barrett’s esophagus (BE). Still, there is controversy on the role of weakly acidic and weakly alkaline reflux in BE. To compare characteristics of reflux episodes patients with BE, erosive esophagitis (EE), and healthy volunteers (HV). Methods One hundred consecutive patients with BE (75 short‐segment BE, 25 long‐segment BE), 50 with EE and 48 HV underwent multichannel intraluminal impedance‐pH off‐therapy. We quantified esophageal acid exposure, characteristics, and proximal extension of reflux episodes. Key Results Total and acid reflux episodes gradually increased from HV [28 (17.5–43) and 18 (8–31)] to EE [73.5 (54–96) and 52 (39–68)], short‐segment BE (SSBE) [83 (73.2–131) and 65 (43.3–95)] and long‐segment BE (LSBE) [105 (102–187) and 77 (75–107)]. Weakly acidic reflux episodes were significantly higher (P < 0.05) in LSBE [36 (27.5–50.5)] and SSBE [34 (18.5–41)] compared to EE [21.5 (15–37)] and HV [19 (14–25)]. No differences in terms of proportion of acid, weakly acidic and weakly alkaline reflux were found [HV (49%–49%–2%) vs EE (68%–32%–1%) vs SSBE (65%–34%–1%) vs LSBE (69%–30%–1%); P = ns]. In LSBE, a higher percentage of reflux episodes (P < 0.05) reached the proximal esophagus (59%) compared with SSBE (43%). Conclusions & Inferences Barrett esophagus patients have more severe reflux as shown by the number of acid and weakly acidic reflux episodes, re‐reflux episodes and proximal migration. Given that PPI change only the pH of the refluxate, the role of weakly acidic reflux in Barrett’s patients on acid suppressive therapy warrants further investigation.     

Cardiovascular compression of the esophagus and spread of gastro‐esophageal reflux

Background Factors that determine the spread of gastro‐esophageal reflux (GER) along the length of the esophagus are not known. We investigated if cardiovascular (CV) compressions on the esophagus may determine the spread of refluxate into the proximal esophagus. Methods High‐resolution manometry (HRM) and multi‐channel intra‐luminal impedance recording (MIIR) were performed simultaneously in 10 normal subjects in the recumbent and upright positions. Pulsatile pressure increases on the esophagus (marker of CV compression) were identified on the HRM. Spread of refluxate into the esophagus was determined by the MIIR. Key Results Cardiovascular compression zones were observed in the esophagus in 9 out of 10 subjects in recumbent position. Forty percent of GER episodes were limited to the distal esophagus in the recumbent position and CV compression pressure was greater than distal esophageal pressure at the time of GER in all such cases. On the other hand, distal esophageal pressure was greater than CV compression pressure when the refluxate extended into the proximal esophagus. In the upright position, CV compression was less frequent than recumbent position and only 12% of GER episodes were limited to the distal esophagus. Conclusions & Inferences Cardiovascular compression of the esophagus is frequently observed in normal healthy subject and restricts the spread of refluxate into the proximal esophagus.     

Postprandial proximal gastric acid pocket in patients after distal gastrectomy

Background An unbuffered postprandial proximal gastric acid pocket (PPGAP) has been noticed in the majority of normal individuals and patients with gastroesophageal reflux disease. The role of gastric anatomy, specifically the antrum, in the physiology of the PPGAP is not yet fully elucidated. This study aims to analyze the presence of PPGAP in patients submitted to distal gastrectomy. Methods A total of 15 patients who had a distal gastrectomy plus DII lymphadenectomy and Roux‐en‐Y reconstruction for gastric adenocarcinoma (mean age 64.3 ± 8.4 years, 12 females) were studied. All patients were free of foregut symptoms after the operation. Patients underwent a high‐resolution manometry. A station pull‐through pH monitoring was performed from 5 cm below the lower border of the lower esophageal sphincter (LBLES) to the LBLES in increments of 1 cm in a fasting state and 10 min after a standardized fatty meal. Postprandial proximal gastric acid pocket was defined by the presence of acid reading (pH<4) in a segment of the proximal stomach between non‐acid segments distally (food) and proximally (LBLES). The PPGAP extent was recorded. The protocol was approved by local ethics committee. Key Results Acidity was not detected in the stomach of nine patients before meal. After meal, PPGAP was not found in three patients. In three patients (20%), a PPGAP was noted with an extension of 1, 1 and 3 cm. Conclusions & Inferences In conclusion, PPGAP is present in a minority of patients after distal gastrectomy; this finding may suggest that the gastric antrum may play a role in the genesis of the PPGAP.     

Decreased sympathetic inhibition in gastroesophageal reflux disease

This study was undertaken to evaluate autonomic nervous system function in patients with gastroesophageal reflux disease. Based on clinical criteria, 28 consecutive patients with no history of heart, metabolic, or neurologic disease (mean age 41 y, range 20–62 y) reporting with upper gastrointestinal symptoms typical of gastroesophageal reflux underwent esophageal manometry, ambulatory 24-hour pH study with electrocardiographic monitoring, power spectral analysis of heart rate variability, and cardiovascular tests. Twelve healthy subjects served as controls. A positive result of prolonged esophageal pH study (pH in the distal esophagus less than 4, lasting more than 4.2% of recording time) was observed in 21 patients (reflux group); seven patients were categorized in the nonreflux group. No patient showed arrhythmias or any correlation between heart rate variability changes during electrocardiographic monitoring and episodes of reflux (pH less than 4, lasting more than 5 minutes). A decrease of sympathetic function occurred only in the reflux group (p<0.05) supported by the lower increase of systolic/diastolic blood pressure at sustained handgrip. No other cardiovascular tests showed statistically significant differences in the control or nonreflux groups. Total time reflux showed an inverse correlation with sympathetic function in the reflux group (r=-0.415, p<0.028). We concluded that there is some evidence for a slightly decreased sympathetic function in patients with gastroesophaged reflux disease that is inversely correlated with total time reflux. In these patients, decreased sympathetic function may cause dysfunction of intrinsic inhibitory control with increased transient spontaneous lower-esophageal sphincter relaxations, thus resulting in gastroesophageal reflux disease.     

PPI therapy is equally effective in well-defined non-erosive reflux disease and in reflux esophagitis: a meta-analysis

Background Symptomatic response to proton pump inhibitor (PPI) therapy in patients with non‐erosive reflux disease (NERD) is often reported as lower than in patients with erosive reflux disease (ERD). However, the definition of NERD differs across clinical trials. This meta‐analysis aims to estimate the rate of symptom relief in response to PPI in NERD patients. Methods MEDLINE (1966–2010), Cochrane Comprehensive Trial Register (1997–2010) and EMBASE (1985–2010) databases were searched and manual searches from studies’ references were performed. Randomized clinical trials were selected that included patients with heartburn, and analyzed the effect of short‐term PPI treatment. The primary outcome of selected studies was defined as complete or partial heartburn relief. Two reviewers independently extracted data and assessed study quality of selected articles. Random effects models and meta‐regression were used to combine and analyze results. Key Results The pooled estimate of complete relief of heartburn after 4 weeks of PPI therapy in patients with ERD was 0.72 (95% CI 0.69–0.74) (32 studies), vs 0.50 (0.43–0.57) (eight studies) in empirically treated patients, 0.49 (0.44–0.55) (12 studies) in patients defined as non‐erosive by negative endoscopy, and 0.73 (0.69–0.77) (two studies) in patients defined as non‐erosive by both negative endoscopy and a positive pH‐test. Conclusions & Inferences In well‐defined NERD patients, the estimated complete symptom response rate after PPI therapy is comparable to the response rate in patients with ERD. The previously reported low response rate in studies with patients classified as NERD is likely the result of inclusion of patients with upper gastrointestinal symptoms that do not have reflux disease.     

High‐resolution esophageal pressure topography is superior to conventional sleeve manometry for the detection of transient lower esophageal sphincter relaxations associated with a reflux event

Background Transient lower esophageal sphincter relaxations (TLESRs) are the main mechanism underlying gastro‐esophageal reflux and are detected during manometric studies using well defined criteria. Recently, high‐resolution esophageal pressure topography (HREPT) has been introduced and is now considered as the new standard to study esophageal and lower esophageal sphincter (LES) function. In this study we performed a head‐to‐head comparison between HREPT and conventional sleeve manometry for the detection of TLESRs. Methods A setup with two synchronized MMS‐solar systems was used. A solid state HREPT catheter, a water‐perfused sleeve catheter, and a multi intraluminal impedance pH (MII‐pH) catheter were introduced in 10 healthy volunteers (M6F4, age 19–56). Subjects were studied 0.5 h before and 3 h after ingestion of a standardized meal. Tracings were blinded and analyzed by the three authors according to the TLESR criteria. Key Results In the HREPT mode 156 TLESRs were scored, vs 143 during sleeve manometry (P = 0.10). Hundred and twenty‐three TLESRs were scored by both techniques. Of all TLESRs (177), 138 were associated with reflux (78%). High‐resolution esophageal pressure topography detected significantly more TLESRs associated with a reflux event (132 vs 119, P = 0.015) resulting in a sensitivity for detection of TLESRs with reflux of 96% compared to 86% respectively. Analysis of the discordant TLESRs associated with reflux showed that TLESRs were missed by sleeve manometry due to low basal LES pressure (N = 5), unstable pharyngeal signal (N = 4), and residual sleeve pressure >2 mmHg (N = 10). Conclusions & Inferences The HREPT is superior to sleeve manometry for the detection of TLESRs associated with reflux. However, rigid HREPT criteria are awaited.     

High resolution manometry patterns distinguish acid sensitivity in non-cardiac chest pain

Background High resolution manometry (HRM) has demonstrated two distinct smooth muscle contraction segments in the esophageal body; changes in these segments typify certain esophageal disorders. We investigated segmental characteristics in subgroups of non‐cardiac chest pain (NCCP). Methods 32 NCCP subjects were segregated into a GERD group (ambulatory pH testing off antisecretory therapy showing elevated total acid exposure time, AET ≥ 4.0% and positive symptom association probability, SAP) and an acid sensitive group (normal AET and positive SAP). HRM Clouse plots were analyzed; smooth muscle segment lengths, pressure amplitude peaks were measured for segment 2 and segment 3 (proximal and distal smooth muscle segments). Pressure volumes were determined in mmHg cm^?1 s^?1 for each peristaltic segment, and ratios of segment 3 : segment 2 calculated. Values were compared to a cohort of 14 normal controls. Key Results A distinctive shift in peak contraction amplitude to segment 3 was evident in the acid sensitive group (segment 2, 100.03 ± 11.06 mmHg, segment 3, 145.23 ± 10.29 mmHg, P = 0.006). Pressure volumes were similarly shifted to segment 3 (segment 2: 855.3 ± 135.1 mmHg cm^?1 s^?1, segment 3: 2115.2 ± 218.6 mmHg cm^?1 s^?1, P < 0.005). In contrast, peak amplitude and pressure volume were near equal in the two segments in GERD and control groups. A threshold segment 3 : segment 2 pressure volume ratio of 1.9 had the best performance characteristic for segregating acid sensitivity subjects from all GERD and control subjects. Conclusions & Inferences Shift in contractile vigor to the third peristaltic segment may be seen in acid sensitive subjects. HRM characteristics of smooth muscle contraction segments are of value in making this determination.     

Effect of oesophagitis on proximal extent of gastro-oesophageal reflux

Proximal oesophageal acid reflux is increased in gastro-oesophageal reflux disease (GORD) patients with oesophageal and extra-oesophageal symptoms, the latter particularly in presence of oesophagitis. This study was aimed to assess the proximal extent of reflux, both acid and weakly acidic, in GORD patients with and without oesophagitis and to characterize, using an animal model of GORD, the relationship between acute oesophagitis and proximal extent of reflux. Proximal extent of reflux was evaluated during 24-h pH-impedance monitoring in 17 oesophagitis, 27 non-erosive reflux disease (NERD) patients and 10 asymptomatic controls. In five adult cats, reflux events were simulated by intra-oesophageal retrograde injection of a radiopaque solution. Proximal extent of simulated reflux was fluoroscopically assessed before and after inducing acute oesophagitis. The percentage of proximal reflux was 11% in controls, 22% in NERD and 38% in oesophagitis patients (P < 0.05 vs NERD). Weakly acidic reflux showed higher proximal extent in oesophagitis than in NERD patients but it was less proximally propagated than acid reflux. In cats, proximal reflux was significantly increased during acute oesophagitis. Oesophagitis patients show higher proximal extent of reflux, acid and weakly acidic, when compared with NERD patients and controls. In the experimental model, acute oesophagitis favours proximal migration of simulated reflux.     

Effect of proximal gastric volume on hiatal hernia

Background Spatial separation of the diaphragm and the lower esophageal sphincter (LES) occurs frequently and intermittently in patients with a sliding hiatus hernia and favors gastro‐esophageal reflux. This can be studied with high‐resolution manometry. Although fundic accommodation is associated with a lower basal LES pressure, its effect on esophagogastric junction configuration and hiatal hernia is unknown. Therefore, the aim of this study was to investigate the relationship between proximal gastric volume, the presence of a hiatal hernia profile and acid reflux. Methods Twenty gastro‐esophageal reflux disease (GERD) patients were studied and compared to 20 healthy controls. High‐resolution manometry and pH recording were performed for 1 h before and 2 h following meal ingestion (500 mL per 300 kcal). Volume of the proximal stomach was assessed with three‐dimensional ultrasonography before and every 15 min after meal ingestion. Key Results During fasting, the hernia profile [2 separate high‐pressure zones (HPZs) at manometry] was present for 31.9 ± 4.9 min h^?1 (53.2%) in GERD patients, and 8.7 ± 3.3 min h^?1 (14.5%) in controls (P < 0.001). In GERD patients, the presence of hernia profile decreased during the first postprandial hour to 15.9 ± 4.2 min h^?1, 26.5%, P < 0.01 whilst this phenomenon was not observed in controls. The rate of transition between the two profiles was 5.7 ± 1.1 per hour in GERD patients and 2.5 ± 1.0 per hour in controls (P < 0.001). The pre and postprandial acid reflux rate in GERD patients during the hernia profile (6.4 ± 1.1 per hour and 18.4 ± 4.3 per hour respectively) was significantly higher than during reduced hernia (2.1 ± 0.6 per hour; P < 0.05 and 3.8 ± 0.9 per hour; P < 0.05). A similar difference was found in controls. Furthermore, an inverse correlation was found between fundic volume and the time the hernia profile was present (r = ?0.45; P < 0.05) in GERD patients, but not in controls. Conclusions & Inferences (i) In GERD patients a postprandial increase in proximal gastric volume is accompanied by a decrease in hernia prevalence, which can be explained by a reduction of the intra‐thoracic part of the stomach. (ii) A temporal hernia profile also occurs in healthy subjects. (iii) During the hernia profile, acid reflux is more prevalent, especially after meal ingestion.     

Increase of weakly acidic gas esophagopharyngeal reflux (EPR) and swallowing‐induced acidic/weakly acidic EPR in patients with chronic cough responding to proton pump inhibitors

Background Gastro‐esophageal reflux disease (GERD)‐related chronic cough (CC) may have multifactorial causes. To clarify the characteristics of esophagopharyngeal reflux (EPR) events in CC patients whose cough was apparently influenced by gastro‐esophageal reflux (GER), we studied patients with CC clearly responding to full‐dose proton pump inhibitor (PPI) therapy (CC patients). Methods Ten CC patients, 10 GERD patients, and 10 healthy controls underwent 24‐h ambulatory pharyngo‐esophageal impedance and pH monitoring. Weakly acidic reflux was defined as a decrease of pH by >1 unit with a nadir pH >4. In six CC patients, monitoring was repeated after 8 weeks of PPI therapy. The number of each EPR event and the symptom association probability (SAP) were calculated. Symptoms were evaluated by a validated GERD symptom questionnaire. Key Results Weakly acidic gas EPR and swallowing‐induced acidic/weakly acidic EPR only occurred in CC patients, and the numbers of such events was significantly higher in the CC group than in the other two groups (P < 0.05, respectively). Symptom association probability analysis revealed a positive association between GER and cough in three CC patients. Proton pump inhibitor therapy abolished swallowing‐induced acidic/weakly acidic EPR, reduced weakly acidic gas EPR, and improved symptoms (all P < 0.05). Conclusions & Inferences Most patients with CC responding to PPI therapy had weakly acidic gas EPR and swallowing‐induced acidic/weakly acidic EPR. A direct effect of acidic mist or liquid refluxing into the pharynx may contribute to chronic cough, while cough may also arise indirectly from reflux via a vago‐vagal reflex in some patients.     

Transient lower oesophageal sphincter relaxations play an insignificant role in gastro-oesophageal reflux to the proximal oesophagus.

Gastro-oesophageal reflux to the proximal oesophagus may cause atypical symptoms of gastro-oesophageal reflux disease (GORD). The motor abnormalities underlying reflux into the proximal oesophagus are still unclear. The aim of this study was to analyse the oesophageal motility during reflux into the proximal oesophagus in a group of healthy subjects and in patients with atypical symptoms of GORD. We concentrated particularly on lower oesophageal sphincter (LOS) activity and transient lower oesophageal sphincter relaxations (TLOSRs). Ten patients (7M, 3F, age 25-51 years) with mild oesophagitis (Savary-Miller grade I-II) and 10 healthy subjects (6M, 4F, age 23-54 years) underwent a 24-h dual pH-metric and manometric recording, using an electronic portable device. This recorded distal and proximal oesophageal pH values, oesophageal body and LOS motility. GORD patients had more distal and proximal reflux (DR and PR) compared with healthy controls (DR P < 0.001; PR P < 0.05). TLOSRs were the most frequent event during reflux into the distal oesophagus, whereas TLOSR frequency was much lower during reflux to the proximal oesophagus in GORD patients and in healthy controls (P < 0.05 and P < 0.01 vs. distal reflux, respectively). A significant relationship between TLOSRs and distal refluxes was present but no relationship with proximal reflux was detected. We conclude that TLOSRs are much less frequent during reflux to the proximal oesophagus than distal oesophageal reflux in patients with mild GORD suffering from atypical manifestations. The mechanism of acid reflux to the proximal oesophagus is unclear.     

Increasing body weight enhances prevalence and proximal extent of reflux in GERD patients ‘on’ and ‘off’ PPI therapy

Background Increased body weight is associated with higher intragastric pressure. Proximal extent of reflux is a determinant of symptoms in patients with gastro‐esophageal reflux disease (GERD). We aimed to investigate the association between body mass index (BMI) and abdominal circumference on the incidence and proximal extent of reflux. Methods A total of 95 patients [37 men, age 51(16–82) years] with typical and/or atypical GERD symptoms underwent 24 h impedance‐pH monitoring. Forty‐nine patients were studied ‘off’ and 46 ‘on’ proton pump inhibitors (PPI) treatment. Reflux was classified as acid (pH < 4) or weakly acidic (pH 4–7). Proximal extent was defined as the number of reflux events reaching ≥15 cm above the lower esophageal sphincter. Body mass index and abdominal circumference (cm) were assessed. Key Results In patients ‘off’ PPI, there was a correlation between BMI and esophageal acid exposure (ρ = 0.53, P < 0.001), volume exposure (ρ = 0.48, P < 0.001), total number of reflux events (ρ = 0.47, P < 0.001) and number of acid reflux events (ρ = 0.49, P < 0.001). In patients ‘on’ PPI there was a correlation between BMI and esophageal acid exposure (ρ = 0.32, P = 0.03), volume exposure (ρ = 0.46, P < 0.01) and total number of reflux events (ρ = 0.33, P = 0.03). Similar correlations were found between abdominal circumference and reflux. A correlation between BMI and proximal extent of reflux was present in patients ‘off’ PPI (ρ = 0.32, P = 0.03). In patients ‘on’ PPI, we found a correlation between abdominal circumference and proximal extent (ρ = 0.31, P = 0.03). Conclusions & Inferences Body mass index and abdominal circumference may contribute to GER and its proximal extent, in patients ‘on and ‘off’ PPI. Further studies investigating the role of weight reduction in the control of GERD symptoms are warranted.