Gastroesophageal reflux disease (GERD) affects up to 28 percent of the U.S. adult population, but it has remained challenging to diagnose and treat. Barriers to diagnosing GERD include its high symptom overlap with non-GERD conditions (such as eosinophilic esophagitis, or EoE) and the burden of prolonged ambulatory monitoring (pH or impedance), which discourages many patients.
A new diagnostic technology may resolve these problems soon, says Michael Vaezi, M.D., Director of the Center for Swallowing and Esophageal Disorders at Vanderbilt University Medical Center. Vaezi and colleagues have developed a novel technology compatible with standard endoscopy that directly measures mucosal impedance (MI) and recognizes the unique epithelial signature of GERD and other esophageal conditions.
“We hope direct MI testing will change the practice of how GERD is diagnosed within a year’s time.”
“We’re excited because the signals from the direct MI technology are really unique and can give us a conclusive diagnosis,” said Vaezi. “We hope direct MI testing will change the practice of how GERD is diagnosed within a year’s time.”
Earlier, more accurate diagnosis of GERD would translate directly into improved patient outcomes, Vaezi adds. “As we all know, reflux can predispose patients to cancer by advancing to Barrett’s esophagus. By intervening sooner and more effectively to reduce severity of reflux, we can reduce the likelihood of that progression.”
GERD Diagnosis with Direct MI
Unlike other available diagnostics, the direct MI approach in development at Vanderbilt identifies a unique signature of change in the esophageal lining caused by reflux. Using a novel probe placed through the working channel of the endoscope, mucosal conductivity is measured directly through surface contact.
“These signatures – as we call them – are very unique,” Vaezi explained. “With GERD, the lining of the esophagus alters in a different way than with EoE. Because each signature is different, we can also look for other diagnoses like gastroparesis that may mimic some of the symptoms of GERD.”
The direct MI evaluation offers vastly greater diagnostic specificity: “Instead of inserting a catheter in the nose that just measures acidity or esophageal exposure to acidity, we have a direct view of changes in the lining of the esophagus we can associate with a specific chronic condition like reflux,” Vaezi said.
Vanderbilt has conducted several studies showing effectiveness of the direct MI technology for diagnosing GERD versus EoE and other esophageal conditions, and for GERD diagnosis in patients with extraesophageal symptoms. Another study in patients with EoE showed that direct MI evaluation could be used to measure treatment response.
The next steps for the technology are multi-center studies and an industry partnership to help make the device widely available. “We’re in the process of writing our most up-to-date paper. After that, our emphasis will be the multi-center studies to verify our findings. We’ve also partnered with industry to help improve the diagnostic specifics,” Vaezi said.
The Increasing Value of Specialty Centers
The direct MI technology is one of several innovations for GERD treatment being explored at Vanderbilt. “We’re also investigating a novel pharmaceutical agent as an add-on therapy for patients on proton pump inhibitors (PPIs), who may not be improving on PPI therapy alone,” Vaezi said. A multi-center, randomized controlled trial of the add-on therapy has shown its promise in reducing heartburn and regurgitation in patients who continue to have symptoms despite treatment with PPIs.
As the tool kit expands for GERD and other esophageal diseases, Vaezi sees the importance of multidisciplinary, specialty centers growing as well, to assist community providers and patients with evaluating the range of treatment options. “As the diagnoses become more challenging, you need the variety of resources in medicine, surgery, radiology and pathology to consider all the options and make the right treatment plan for the patient,” Vaezi said.
“Esophageal disease is all that I see, personally, along with many of my colleagues in the center,” said Vaezi. “That combined with our multidisciplinary resources gives us unique ability to help providers in the community make appropriate diagnoses for their patients and treat them best.”