This article is more than 5 years old. Information may no longer be current.
Measuring Mucosal Impedance Differentiated GERD, Non-GERD, EoE
Click Here to Manage Email Alerts
Using a prototype device, researchers found that mucosal impedance measurements detected GERD more accurately than wireless pH monitoring and was able to discriminate between GERD and non-GERD conditions, including eosinophilic esophagitis.
“The current testing modalities for GERD are suboptimal because they take only a snapshot of what is occurring in the esophagus on a given day or two,” Michael F. Vaezi, MD, from the division of gastroenterology, hepatology and nutrition at Vanderbilt University Medical Center in Nashville, Tenn., told Healio Gastroenterology. “The tests do not consider the consequence of reflux on esophageal epithelium. Mucosal impedance (MI) is a novel device that assesses mucosal consequence of chronic reflux. It measures if the epithelium is healthy or not and differentiates GERD from non-GERD as well as eosinophilic esophagitis (EoE) patients.”
Michael F. Vaezi
Aiming to assess test characteristics by evaluating MI patterns in GERD (before and after proton pump inhibitors) and non-GERD conditions, and to compare MI performance with wireless pH testing, Vaezi and colleagues conducted a prospective longitudinal study involving patients with upper gastrointestinal symptoms referred for diagnostic testing for GERD, and patients with EoE and achalasia. They measured MI before and after acid suppressive therapy at the site of esophagitis and above the squamocolumnar junction in 61 patients with erosive esophagitis, 81 with nonerosive but pH-abnormal GERD, 93 without GERD, 18 with achalasia and 15 with EoE. They compared their findings with those from wireless pH monitoring.
They found that overall MI measurements were lower in patients with GERD or EoE compared with non-GERD patients (P<.001). MI patterns differed between patients with GERD, non-GERD and EoE; MI measurements increased numerically from the distal to proximal esophagus in GERD and non-GERD patients with lowest levels at the site of mucosal erosion or esophagitis. Median MI values were lower at all esophageal sites of GERD compared with non-GERD patients (P<.001). Proton pump inhibitor therapy increased MI values in patients with erosive esophagitis (P<.001). MI was superior at detecting esophagitis, with higher levels of specificity (95%) and positive predictive values (96%) compared with wireless pH monitoring (64% and 40%, respectively).
“This technology is a giant step forward in the antiquated means by which we now diagnose GERD,” Vaezi said.
MI is unlikely to replace current tests that assess the extent of GERD, but it is an attractive diagnostic tool due to its simplicity and immediate results, according to an accompanying editorial written by Ronnie Fass, MD, department of medicine, MetroHealth Medical Center, Case Western Reserve University.
“The technique is very well equipped to differentiate between GERD and functional heartburn patients, a common dilemma in clinical practice,” Fass wrote. “It is also possible that MI will complement the other esophageal function tests and will provide additional information regarding integrity of the esophageal mucosal structure.
“More research is needed to further determine the exact role of MI in clinical practice and specifically in evaluating patients with GERD-related symptoms,” he wrote. — by Adam Leitenberger
For more information:
Ates F. Gastroenterology. 2015;148:334-343.
Fass R. Gastroenterology. 2015;148:282-285.
Disclosure: One of the researchers is affiliated with Sandhill Scientific, which jointly holds a patent on the mucosal impedance concept and device with Vanderbilt University. Fass reports no relevant financial disclosures.