Mucosal Impedance Discriminates GERD From Non-GERD Conditions

doi:10.1053/j.gastro.2014.10.010

Gastroenterology

Volume 148, Issue 2, February 2015, Pages 334-343

https://doi.org/10.1053/j.gastro.2014.10.010 Get rights and content

Background & Aims

Current diagnostic tests for gastroesophageal reflux disease (GERD) are suboptimal and do not accurately and reliably measure chronicity of reflux. A minimally invasive device has been developed to assess esophageal mucosal impedance (MI) as a marker of chronic reflux. We performed a prospective longitudinal study to investigate MI patterns in patients with GERD and common nonreflux conditions, to assess MI patterns before and after treatment with proton pump inhibitors and to compare the performance of MI and wireless pH tests.

Methods

We evaluated MI in 61 patients with erosive esophagitis, 81 with nonerosive but pH-abnormal GERD, 93 without GERD, 18 with achalasia, and 15 with eosinophilic esophagitis. MI was measured at the site of esophagitis and at 2, 5, and 10 cm above the squamocolumnar junction in all participants. MI was measured before and after acid suppressive therapy, and findings were compared with those from wireless pH monitoring.

Results

MI values were signiﬁcantly lower in patients with GERD (erosive esophagitis or nonerosive but pH-abnormal GERD) or eosinophilic esophagitis than in patients without GERD or patients with achalasia (P < .001). The pattern of MI in patients with GERD differed from that in patients without GERD or patients with eosinophilic esophagitis; patients with GERD had low MI closer to the squamocolumnar junction, and values increased axially along the esophagus. These patterns normalized with acid suppressive therapy. MI patterns identified patients with esophagitis with higher levels of specificity (95%) and positive predictive values (96%) than wireless pH monitoring (64% and 40%, respectively).

Conclusions

Based on a prospective study using a prototype device, measurements of MI detect GERD with higher levels of specificity and positive predictive values than wireless pH monitoring. Clinical Trials.gov, Number: NCT01556919.

Section snippets

Patients and Methods

This study was performed in accordance with the Declaration of Helsinki, Good Clinical Practice, and applicable regulatory requirements. Each patient signed a consent form before undergoing any study-related procedures. The Vanderbilt Institutional Review Board approved this clinical trial (IRB# 101109; NCT01556919). All authors had access to the study data and reviewed and approved the final manuscript.

Demographics

A total of 268 patients were studied and stratified into those with E+ (n = 61) (LA grade A, 28; grade B, 18; grade C, 10; and grade D, 5), E−/pH+ (n = 81), E−/pH− (n = 93), achalasia (n = 18), and EoE (n = 15) (Table 1). As expected, patients with EoE were younger than those in other groups; in addition, like patients with achalasia, patients with EoE were mostly male (P < .001) and had significantly more dysphagia as the presenting symptom than those in other groups (P < .001). There were no

Discussion

In this prospective study, we showed the clinical performance of an innovative MI measurement device in patients with GERD. Important observations from our study include the following: (1) the MI pattern is unique in GERD compared with non-GERD patients; (2) low MI is an important determinant of changes along the esophageal epithelium, which is similar for GERD and those with EoE, but the MI pattern along the esophagus is distinctive in the 2 conditions; (3) GERD-related low MI recovers after

Acknowledgments

Partial support for Dr. Ates’s salary was made possible by a kind financial contribution from The Bill and Carol Latimer Charitable Trust.

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There is a need for a real-time objective tool to assess the mucosal health of the gastrointestinal (GI) tract during endoscopy. Our aim was to develop, design, and validate a low-cost mucosal impedance (MI) device and determine its role in differentiating diseased mucosa from normal mucosa.
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Citation Excerpt :
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Gastroesophageal reflux disease (GERD) is often seen in obese patients. Many studies reported a positive association between GERD and obesity.^1–11 A recent meta-analysis showed that obesity (BMI≥30 kg/m²) is one of the risk factors for GERD together with age, smoking, and nonsteroidal antiinflammation drug/aspirin use. Its odds ratio was 1.73 (95% CI: 1.46–2.06) compared to nonobese individuals. A dose-dependent association was shown between reflux symptoms and BMI (i.e., larger BMI more frequent or severe reflux symptoms),^1–4,10 and two longitudinal studies found that weight gain during approximately 10 years increased the risk of developing reflux symptoms.^3,8 Complications of GERD such as reflux esophagitis, Barrett’s esophagus, and esophageal adenocarcinoma are also related to obesity.^7,10,12 The mechanisms by which obesity causes GERD can be explained by its effects on structural and physiological functions of the gastroesophageal antireflux barrier.

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: Conflicts of interest The authors disclose the following: J.M. is affiliated with Sandhill Scientific Inc (Denver, CO), which helped design the special mucosal impedance catheter used in this study. His involvement in the study was provision of technical support for the catheter design. He had no influence on the study design, conduct, analysis, or final manuscript. Vanderbilt University and Sandhill Scientific Inc jointly hold a patent on the mucosal impedance concept and device. Otherwise, there are no financial relationships between any of the other authors and Sandhill Scientific Inc. This was disclosed to the patients who participated in this study. The remaining authors disclose no conflicts.

View full text

Original ResearchFull Report: Clinical—Alimentary TractMucosal Impedance Discriminates GERD From Non-GERD Conditions

Background & Aims

Methods

Results

Conclusions

Section snippets

Patients and Methods

Demographics

Discussion

Acknowledgments

Gastroenterology

Am J Gastroenterol

Gastroenterology

Am J Med

Gastroenterology

Gastroenterology

Gastroenterology

Am J Gastroenterol

Dig Liver Dis

Clin Gastroenterol Hepatol

Clin Gastroenterol Hepatol

Am J Gastroenterol

Gastroenterology

J Am Coll Surg

Clin Gastroenterol Hepatol

The Montreal definition and classification of gastroesophageal reflux disease: a global evidence-based consensus

Am J Gastroenterol

Racial differences in the frequency of symptoms and complications of gastro-oesophageal reflux disease

Aliment Pharmacol Ther

The burden of gastrointestinal and liver diseases, 2006

Am J Gastroenterol

The cost of treating the 10 most prevalent diseases in men 50 years of age or older

Am J Manag Care

Refractory GERD: what is it?

Curr Gastroenterol Rep

How to manage refractory GERD

Nat Clin Pract Gastroenterol Hepatol

Gastro-oesophageal reflux disease

Digestion

American Gastroenterological Association Institute technical review on the management of gastroesophageal reflux disease

Gastroenterology

Reproducibility of proximal probe pH parameters in 24-hour ambulatory esophageal pH monitoring

Am J Gastroenterol

Original Research
Full Report: Clinical—Alimentary Tract
Mucosal Impedance Discriminates GERD From Non-GERD Conditions