Esophageal Impedance Monitoring Research Articles

British Society of Gastroenterology guidelines for oesophageal manometry and oesophageal reflux monitoring

These guidelines on oesophageal manometry and gastro-oesophageal reflux monitoring supersede those produced in 2006. Since 2006 there have been significant technological advances, in particular, the development of high resolution manometry...

Esophageal pH and impedance reflux parameters in relation to body mass index, obesity-related hormones, and bariatric procedures.

Introduction Obese patients have a higher risk of gastroesophageal reflux disease (GERD), but obesity‑related hormonal changes associated with GERD and the effects of bariatric therapy on reflux are unclear. Objectives The aim of the study was to assess reflux parameters in relation to bariatric therapy and hormonal changes in obese patients. Patients and methods This prospective observational study with a 1‑year follow‑up included 53 obese patients undergoing bariatric therapies. Esophageal pH and impedance monitoring tests were performed and circulating hormone levels were analyzed. Results Esophageal acid exposure time (%AET) and the number of refluxes correlated positively with body mass index. There were several significant, although weak, correlations of pH and impedance parameters with ghrelin and omentin levels. Patients with abnormal %AET had lower ghrelin levels and those with abnormal reflux number had lower omentin levels than patients with normal parameters. Although we observed certain changes including increased %AET and bolus clearance time (BCT) after laparoscopic sleeve gastrectomy, a reduced BCT and number of refluxes after gastric band, and nonsignificant changes after intragastric balloon, the overall bariatric therapy did not significantly impact on the final GERD diagnosis. GERD before and after therapy was present in 42% of patients. De novo GERD developed in 17.8% of patients, while a similar percentage of patients with initial GERD had normal pH and impedance after therapy. Patients with de novo or persistent GERD had a similar percentage of weight loss as patients without GERD. Conclusions Bariatric therapy and percentage of weight loss do not significantly affect GERD. The observed hormonal changes alone do not fully explain the high prevalence of GERD in obese patients.

Evaluation of gastro-oesophageal reflux disease in wheezy infants using 24-h oesophageal combined impedance and pH monitoring

Background and study aimsGastro-oesophageal reflux disease (GERD) is incriminated as a cause of non-asthmatic infantile wheeze. To date, no diagnostic test is considered standard for GERD-related airway reflux diagnosis. Oesophageal combined multiple channel intraluminal impedance and pH (MII-pH) monitoring is proposed to be a sensitive tool for evaluation of all GERD including infantile wheeze. We aimed to determine the GERD prevalence amongst wheezy infants in the first year of life using combined MII-pH versus pH monitoring alone and evaluate the sensitivity and specificity of objective MII-pH monitoring parameters in GERD-associated infantile wheeze diagnosis compared to those of lipid-laden macrophage index (LLMI). Patients and methodsThirty-eight wheezy infants below 1year of age were evaluated for GERD using oesophageal combined MII-pH monitoring and LLMI. ResultsTotally, 60.5% of cases had abnormal MII-pH; only 7.9% of them had abnormal pH monitoring. LLMI was significantly higher in wheezy infants with abnormal MII-pH than infants with normal MII-pH monitoring (112±88 versus 70±48; P=0.036). The current definitions of abnormal MII-pH study, reflux index≥10% and distal reflux episodes≥100, had low sensitivity (23%) but high specificity (100% and 96%, respectively) in GERD-related aspiration diagnosis defined by LLMI≥100. Using ROC curves, bolus contact time≥2.4% and proximal reflux episodes≥46 had 61% and 54% sensitivity and 64% and 76% specificity, respectively, in GERD-related aspiration diagnosis. ConclusionCombined MII-pH is superior to pH monitoring in reflux-associated infantile wheeze diagnosis. Objective data including proximal reflux episodes and bolus contact time should be combined with the current parameters used in reflux-associated infantile wheeze diagnosis.

The selective metabotropic glutamate receptor 5 antagonist mavoglurant (AFQ056) reduces the incidence of reflux episodes in dogs and patients with moderate to severe gastroesophageal reflux disease.

Transient lower esophageal sphincter relaxations (TLESRs) induced by gastric distension are modulated by the metabotropic glutamate receptor 5 (mGluR5) that influences the vagal reflex loop. We therefore aimed to examine the effects of the selective mGluR5 antagonist mavoglurant (AFQ056) on the number of TLESRs in dogs and reflux episodes in patients with gastroesophageal reflux disease (GERD). In a dog model, the number of meal-induced TLESRs was determined after intravenous (0.03, 0.1, 0.3, and 1mgkg-1 ) and oral (1, 3, and 10mgkg-1 ) doses of mavoglurant with reference to vehicle. In a multicenter, randomized, double-blind, placebo-controlled, three-period crossover study, the incidence of meal-induced reflux episodes was assessed by esophageal impedance monitoring after single, oral doses of mavoglurant (50 and 400mg) or baclofen (40mg) in 30 patients with moderate to severe GERD. In dogs, mavoglurant reduced the number of TLESRs after intravenous and oral administration. In patients with GERD, the incidence of postprandial reflux episodes was significantly lower at a dose of 400mg mavoglurant (-37.5% ; 90% confidence interval [CI]: -57.8, -17.2), whereas there was no significant difference at 50mg of mavoglurant compared to placebo. A significantly lower incidence of reflux episodes was also noted with the active comparator baclofen (-50.3%; 90% CI: -66.2, -34.3), thereby validating this study. These data suggest a potential clinical benefit of mGluR5 antagonists such as mavoglurant in patients with GERD, particularly in those with persisting symptoms despite treatment with proton pump inhibitors.

Liquid-containing Refluxes and Acid Refluxes May Be Less Frequent in the Japanese Population Than in Other Populations: Normal Values of 24- hour Esophageal Impedance and pH Monitoring.

Background/AimsTwenty-four-hour esophageal impedance and pH monitoring allows detection of all types of reflux episodes and is considered the best technique for identifying gastroesophageal refluxes. However, normative data for the Japanese population are lacking. This multicenter study aimed to establish the normal range of 24-hour esophageal impedance and pH data both in the distal and the proximal esophagus in Japanese subjects.MethodsForty-two healthy volunteers (25 men and 17 women) with a mean ± standard deviation age of 33.3 ± 12.4 years (range: 22–72 years) underwent a combined 24-hour esophageal impedance and pH monitoring. According to the physical and pH properties, distal or proximal esophageal reflux events were categorized.ResultsMedian 45 reflux events occurred in 24 hours, and the 95th percentile was 85 events. Unlike previous reports, liquid-containing reflux events are median 25/24 hours with the 95th percentile of 62/24 hours. Acidic reflux events were median 11/24 hours with the 95th percentile of 39/24 hours. Non-acidic gas reflux events were median 15/24 hours with the 95th percentile of 39/24 hours. Proximal reflux events accounted for 80% of the total reflux events and were mainly non-acidic gas refluxes. About 19% of liquid and mixed refluxes reached the proximal esophagus.ConclusionsUnlike previous studies, liquid-containing and acidic reflux events may be less frequent in the Japanese population. Non-acidic gas reflux events may be frequent and a cause of frequent proximal reflux events. This study provides important normative data for 24-hour impedance and pH monitoring in both the distal and the proximal esophagus in the Japanese population.

Continuing Medical Education: September 2016

Esophageal Impedance Monitoring: Clinical Pearls and Pitfalls The American College of Gastroenterology is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The American College of Gastroenterology designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 Credit™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Supragastric belching.

Supragastric belching has recently gained recognition as a belching disorder of behavioral origin that can be accurately diagnosed on esophageal impedance monitoring. Its contribution to numerous other gastrointestinal disorders is beginning to be appreciated. Improved knowledge of its pathophysiology has enabled identification of therapeutic goals, some of which have been subject to formal study and demonstrated good outcomes. This review sets out to present and discuss new findings related to the improved understanding of the relationship between supragastric belching and other gastrointestinal disorders, as well as fresh concepts in terms of management. Supragastric belching is now shown to be associated with globus, as well as reflux symptoms in proton pump inhibitor nonresponders. Patients with supragastric belching experience higher frequency of belching events if they have concurrent esophageal hypomotility. Gum chewing and sleeve gastrectomy have no impact on supragastric belching. Pediatric studies suggest an overlap with aerophagia that is not observed in adults. Successful treatments trialed recently include psychoeducation and behavioral therapy delivered by a health psychologist with expertise in gastroenterology. With the foreseeable increase in recognition and diagnosis of pathological supragastric belching, there is a clear need to better understand its pathophysiology, especially in terms of its emerging importance in relation to other gastrointestinal disorders. Further study is justified to uncover additional therapeutic options for this benign but disabling condition.

Esophageal Impedance Monitoring: Clinical Pearls and Pitfalls.

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

Association between respiratory events and nocturnal gastroesophageal reflux events in patients with coexisting obstructive sleep apnea and gastroesophageal reflux disease

BackgroundLiterature has addressed the increased prevalence of gastroesophageal reflux disease (GERD) in obstructive sleep apnea (OSA). Significant improvement of GERD has been found after OSA treatment. However, precise mechanisms underlying this correlation remain unclear. We examined the association between nocturnal gastroesophageal reflux (GER) and sleep events in patients with coexisting OSA and GERD. MethodsA case-crossover study among 12 patients with coexisting moderate–severe OSA and GERD was conducted. Participants underwent simultaneous polysomnography and esophageal impedance and pH monitoring. GER subtypes (ie, acid reflux, non-acid reflux) were defined as outcomes. Respective control time points were selected in all eligible control periods. Each sleep event was assessed individually. Estimated odds ratios (ORs) and 95% confidence intervals (CIs) were analyzed. A p-value of < 0.05 was considered significant. ResultsPatients were determined as moderate to severe OSA (respiratory disturbance index of 42.66 [±22.09]). There were a total of 50 GER episodes, 22 acid reflux and 28 non-acid reflux. Arousals and awakenings were significantly associated with subsequent GER events. The OR for GER following an arousal was 2.31 (95% CI 1.39–3.68; p < 0.001) and following an awakening was 3.71 (95% CI 1.81–7.63; p < 0.001). GER events were significantly less likely to occur after other respiratory events (OR 0.38 [95% CI 0.18–0.82]; p = 0.01). No sleep events followed GER events (p > 0.05). ConclusionsBoth awakening and arousal appear to precipitate any subtype of GER events in patients with coexisting GERD and moderate to severe OSA. However, GER events were significantly less likely to occur after other respiratory events and did not appear to cause sleep-related events.

Association of Acute Gastroesophageal Reflux Disease With Esophageal Histologic Changes.

The histologic changes associated with acute gastroesophageal reflux disease (GERD) have not been studied prospectively in humans. Recent studies in animals have challenged the traditional notion that reflux esophagitis develops when esophageal surface epithelial cells are exposed to lethal chemical injury from refluxed acid. To evaluate histologic features of esophageal inflammation in acute GERD to study its pathogenesis. Patients from the Dallas Veterans Affairs Medical Center who had reflux esophagitis successfully treated with proton pump inhibitors (PPIs) began 24-hour esophageal pH and impedance monitoring and esophagoscopy (including confocal laser endomicroscopy [CLE]) with biopsies from noneroded areas of distal esophagus at baseline (taking PPIs) and at 1 week and 2 weeks after stopping the PPI medication. Enrollment began May 2013 and follow-up ended July 2015. PPIs stopped for 2 weeks. Twelve patients (men, 11; mean age, 57.6 year [SD, 13.1]) completed the study. Primary outcome was change in esophageal inflammation 2 weeks after stopping the PPI medication, determined by comparing lymphocyte, eosinophil, and neutrophil infiltrates (each scored on a 0-3 scale) in esophageal biopsies. Also evaluated were changes in epithelial basal cell and papillary hyperplasia, surface erosions, intercellular space width, endoscopic grade of esophagitis, esophageal acid exposure, and mucosal impedance (an index of mucosal integrity). At 1 week and 2 weeks after discontinuation of PPIs, biopsies showed significant increases in intraepithelial lymphocytes, which were predominantly T cells (median [range]: 0 (0-2) at baseline vs 1 (1-2) at both 1 week [P = .005] and 2 weeks [P = .002]); neutrophils and eosinophils were few or absent. Biopsies also showed widening of intercellular spaces (confirmed by CLE), and basal cell and papillary hyperplasia developed without surface erosions. Two weeks after stopping the PPI medication, esophageal acid exposure increased (median: 1.2% at baseline to 17.8% at 2 weeks; Δ, 16.2% [95% CI, 4.4%-26.5%], P = .005), mucosal impedance decreased (mean: 2671.3 Ω at baseline to 1508.4 Ω at 2 weeks; Δ, 1162.9 Ω [95% CI, 629.9-1695.9], P = .001), and all patients had evidence of esophagitis. In this preliminary study of 12 patients with severe reflux esophagitis successfully treated with PPI therapy, stopping PPI medication was associated with T lymphocyte-predominant esophageal inflammation and basal cell and papillary hyperplasia without loss of surface cells. If replicated, these findings suggest that the pathogenesis of reflux esophagitis may be cytokine-mediated rather than the result of chemical injury. clinicaltrials.gov Identifier: NCT01733810.

World Gastroenterology Organisation Global Guidelines: GERD Global Perspective on Gastroesophageal Reflux Disease.

PROBIOTICS—THE CONCEPTHistory and DefinitionsA century ago, Elie Metchnikoff (a Russian scientist, Nobel laureate, and professor at the Pasteur Institute in Paris) postulated that lactic acid bacteria (LAB) offered health benefits capable of promoting longevity. He suggested that “intestinal autoint

Esophageal testing: What we have so far.

Gastroesophageal reflux disease (GERD) is a common disorder of the gastrointestinal tract. In the last few decades, new technologies have evolved and have been applied to the functional study of the esophagus, allowing for the improvement of our knowledge of the pathophysiology of GERD. High-resolution manometry (HRM) permits greater understanding of the function of the esophagogastric junction and the risks associated with hiatal hernia. Moreover, HRM has been found to be more reproducible and sensitive than conventional water-perfused manometry to detect the presence of transient lower esophageal sphincter relaxation. Esophageal 24-h pH-metry with or without combined impedance is usually performed in patients with negative endoscopy and reflux symptoms who have a poor response to anti-reflux medical therapy to assess esophageal acid exposure and symptom-reflux correlations. In particular, esophageal 24-h impedance and pH monitoring can detect acid and non-acid reflux events. EndoFLIP is a recent technique poorly applied in clinical practice, although it provides a large amount of information about the esophagogastric junction. In the coming years, laryngopharyngeal symptoms could be evaluated with up and coming non-invasive or minimally invasive techniques, such as pepsin detection in saliva or pharyngeal pH-metry. Future studies are required of these techniques to evaluate their diagnostic accuracy and usefulness, although the available data are promising.

G366(P) Impedance monitoring in paediatric gastro-oesophageal reflux disease: an evaluation of its use and clinical value

We sought to evaluate the use of combined oesophageal multichannel intraluminal impedance and pH (MII-pH) monitoring in the Paediatric department of a large tertiary hospital, and to determine whether there is added value of MII-pH monitoring beyond that of conventional pH monitoring. We conducted a retrospective study of all paediatric patients who underwent MII-pH monitoring during a two year period (01/01/2012–31/12/2013) in a large tertiary hospital. We analysed the demographics, indications for investigation and MII-pH results for each patient. We assessed the effect of anti-reflux treatment on MII-pH results and compared the relative contribution of MII data with pH data in each test. 96 studies were performed on 96 patients (mean age 3 years 8 months, range 2 months to 16 years, 55 male, 41 female). 57 studies produced interpretable results of greater than 20 h’ duration. Respiratory symptoms were the most common indication for study. Patients who had taken anti-reflux medication at any point in the week prior to the study were significantly less likely to have an abnormal reflux index (RI; p This study provides a comprehensive review of the use of MII-pH monitoring in a large tertiary centre. It reinforces previous literature findings that anti-reflux medication reduces oesophageal acid exposure, but does not necessarily reduce total reflux frequency or symptom correlation. The value added by MII-pH monitoring beyond that of conventional pH monitoring remains to be established. The results here support the use of RI (derived from pH monitoring) as an indicator for reflux disease in patients off treatment.

Normal values of 24-hour ambulatory esophageal impedance-pH monitoring in a rural South African cohort of healthy participants.

There are no data on 24-hour multichannel intraluminal impedance and pH monitoring in African populations. The purpose of this study was to provide the normal values of esophageal impedance and pH monitoring in a rural African populations. South African healthy rural participants were recruited and underwent 24 hours of esophageal impedance and pH monitoring. The median and the 95th percentiles of the total reflux episodes were 49 and 97, respectively, of which the corresponding number of acidic, weakly acidic, and weakly alkaline reflux were 15 and 55, 17 and 51, and 8 and 36, respectively. The compositions of the total reflux were 5 and 21 for liquid, 27 and 72 for mixed, and 10 and 39 for gas reflux, respectively. The median bolus clearance was 18 seconds and the median bolus exposure was 14 minutes/24 hours. The proximal extent was 6%. The 95th percent time of esophageal exposure to acid was 8.6 in 24 hours. Female and overweight participants were associated with an increased number of reflux events. There were more reflux episodes, and of which, more were weakly alkaline compared with previous similar studies. The findings provide reference values of gastroesophageal reflux for a South African rural population.

Evaluation of Proton Pump Inhibitor-Resistant Nonerosive Reflux Disease by Esophageal Manometry and 24-Hour Esophageal Impedance and pH Monitoring

Background: Patients with proton pump inhibitor (PPI)-resistant nonerosive reflux disease (NERD) include subgroups that have markedly different pathophysiology. This study aimed to clarify the pathophysiology of NERD by esophageal manometry with 24-hour esophageal impedance and pH monitoring. Methods: Eighteen consecutive outpatients referred to our expert center for functional gastrointestinal motility with suspected PPI-resistant NERD were enrolled. Manometry was performed to detect esophageal motility disorders. Subsequently, 24-hour esophageal impedance and pH monitoring was done while patients were on PPI therapy. Results: Manometry revealed 1 case of achalasia, 1 case of nutcracker esophagus and 3 cases of diffuse esophageal spasm. Three patients had ineffective esophageal motility, with impedance and pH monitoring being performed in 2 of them. Esophageal acid exposure (%time pH <4) was normal in both, but the symptom index (SI) was positive for nonacidic reflux in 1 patient. One of the 10 patients with normal esophageal motility had abnormal esophageal acid exposure. The SI was positive for weakly acidic and nonacidic reflux in 3 of the remaining 9 patients with normal esophageal acid exposure. Five of the other 6 patients seemed to have functional heartburn. Conclusion: A substantial percentage (28%) of patients with suspected PPI-resistant NERD had primary esophageal motility disorders. Both nonacidic reflux and weakly acidic reflux are important contributors to the symptoms of patients with PPI-resistant NERD. Esophageal manometry is required to exclude motility disorders, while 24-hour esophageal impedance and pH monitoring is invaluable for assessing symptom-reflux associations and the indications for fundoplication in patients with suspected PPI-resistant NERD.

667 Accuracy of the Diagnosis of Gastroesophageal Reflux Disease by GERDQ Questionnaire, Esophageal Impedance Monitoring and Histology

667 Accuracy of the Diagnosis of Gastroesophageal Reflux Disease by GERDQ Questionnaire, Esophageal Impedance Monitoring and Histology

Tu1886 A Substantial Percentage of Suspected PPI-Resistant NERD Patients Have Primary Esophageal Motility Disorders: Results of High Resolution Manometry and 24-HR Esophageal Impedance and pH Monitoring

Tu1886 A Substantial Percentage of Suspected PPI-Resistant NERD Patients Have Primary Esophageal Motility Disorders: Results of High Resolution Manometry and 24-HR Esophageal Impedance and pH Monitoring

Effect of acid suppression therapy on gastroesophageal reflux and cough in idiopathic pulmonary fibrosis: an intervention study.

BackgroundChronic cough affects more than 70 percent of patients with Idiopathic Pulmonary Fibrosis and causes significant morbidity. Gastroesophageal reflux is the cause of some cases of chronic cough; and also has a postulated role in the aetiology of Idiopathic Pulmonary Fibrosis. A high prevalence of acid; and more recently non-acid, reflux has been observed in Idiopathic Pulmonary Fibrosis cohorts. Therefore, gastroesophageal reflux may be implicated in the pathogenesis of cough in Idiopathic Pulmonary Fibrosis.MethodsEighteen subjects with Idiopathic Pulmonary Fibrosis underwent 24-hour oesophageal impedance and cough count monitoring after the careful exclusion of causes of chronic cough other than gastroesophageal reflux. All 18 were then treated with high dose acid suppression therapies. Fourteen subjects underwent repeat 24-hour oesophageal impedance and cough count monitoring after eight weeks.ResultsTotal reflux and acid reflux frequencies were within the normal range in the majority of this cohort. The frequencies of non-acid and proximal reflux events were above the normal range. Following high dose acid suppression therapy there was a significant decrease in the number of acid reflux events (p = 0.02), but an increase in the number of non-acid reflux events (p = 0.01). There was no change in cough frequency (p = 0.70).ConclusionsThis study confirms that non-acid reflux is prevalent; and that proximal oesophageal reflux occurs in the majority, of subjects with Idiopathic Pulmonary Fibrosis. It is the first study to investigate the effect of acid suppression therapy on gastroesophageal reflux and cough in patients with Idiopathic Pulmonary Fibrosis. The observation that cough frequency does not improve despite verifiable reductions in oesophageal acid exposure challenges the role of acid reflux in Idiopathic Pulmonary Fibrosis associated cough. The finding that non-acid reflux is increased following the use of acid suppression therapies cautions against the widespread use of acid suppression in patients with Idiopathic Pulmonary Fibrosis given the potential role for non-acid reflux in the pathogenesis of cough and Idiopathic Pulmonary Fibrosis itself.Study registrationThe study was registered with the Cardiff and Vale University Local Health Board Research and Development Committee (09/CMC/4619) and the South East Wales Ethics Committee (09/WSE04/57).

Accuracy of diagnosing gastroesophageal reflux disease by GerdQ, esophageal impedance monitoring and histology

To assess the performance of self-assessment gastroesophageal reflux disease questionnaire (GerdQ), 24-h impedance monitoring, proton pump inhibitor (PPI) test and intercellular space of esophageal mucosal epithelial cells in the diagnosis of gastroesophageal reflux disease (GERD). Patients with symptoms suspected of GERD were administered the GerdQ and underwent endoscopy (measurement of intercellular space in the biopsy specimen sampling at 2 cm above the Z-line) and 24-h impedance pH monitoring, together with a 2-week experimental treatment with esomeprazole. A total of 636 patients were included for the final analysis, including 352 with GERD. The sensitivity and specificity of GerdQ and 24-h impedance monitoring for diagnosing GERD were 57.7% and 48.9%, and 66.4% and 43.3%, respectively. The sensitivity of 24-h impedance pH monitoring increased to 93.7%. The sensitivity and specificity of dilated intercellular spaces (DIS) (≥0.9 μm) for diagnosing GERD were 61.2% and 56.1%, respectively, whereas those for PPI test were 70.5% and 44.4%. GerdQ score or PPI test alone cannot accurately diagnose GERD in a Chinese population suspected of GERD. A definitive diagnosis of GERD still depends on endoscopy or 24-h pH monitoring. 24-h impedance pH monitoring may increase the sensitivity for diagnosing GERD by 20%; however, when used alone, it results in poor specificity in patients without acid suppressive therapy.

Esophageal motility and impedance characteristics in patients with Barrett’s esophagus before and after radiofrequency ablation

Radiofrequency ablation (RFA) is a valuable treatment option in Barrett's esophagus resulting in eradication of dysplasia and conversion of all Barrett's epithelium into normal squamous epithelium. In Barrett's esophagus, esophageal impedance monitoring is hampered by low baseline impedance values. Whether these low baselines are caused by an intrinsically low impedance of cylindrical epithelium or by the excessive reflux itself is hitherto unknown. Data on esophageal motility after RFA are scarce. Our aim was to examine the effect of RFA on esophageal motility and esophageal baseline impedance in patients with Barrett's esophagus. In 10 patients, conventional esophageal manometry and 24-h pH-impedance measurements were performed before and after RFA. The number and type of reflux episodes were assessed and baseline impedance values were measured in all recording segments. In another five patients, high-resolution manometry was performed before and after RFA. Complete regression of all Barrett's epithelium was achieved in all 15 patients after 3 ± 1 RFA sessions. Overall, no significant motility changes were found after RFA. Patients had excessive acid exposure times before and after RFA [25 (17-42) and 16 (9-24)%, respectively]. Baseline esophageal impedance values were low, with the lowest values in the distal recording segments. RFA increased baseline impedance in all recording segments in the upright position; in the supine position, the effect just failed to reach statistically significant levels. RFA did not alter esophageal motility significantly. Low esophageal baseline impedance levels in patients with Barrett's esophagus reflect, at least in part, intrinsic impedance properties of cylindrical epithelium, as baselines increased after conversion into neosquamous epithelium.