Esophageal Mucosal Impedance Pattern is Distinct in Patients With Extraesophageal Reflux Symptoms and Pathologic Acid Reflux

Abstract

Current diagnostic tests for gastroesophageal reflux disease (GERD) do not consistently measure chronicity of reflux. Mucosal impedance (MI) is a minimally invasive measurement to assess esophageal conductivity changes due to GERD. We aimed to investigate MI pattern in patients with symptoms of extraesophageal reflux (EER) in a prospective longitudinal cohort study. Patients with potential symptoms of EER undergoing esophagogastroduodenoscopy (EGD) with wireless pH monitoring were studied. Participants included those with erosive esophagitis (E+), normal EGD/abnormal pH (E-/pH+), and normal EGD/normal pH (E-/pH-). MI was measured from the site of injury in patients with E+, as well as at 2, 5, and 10 cm above the squamocolumnar junction (SCJ) in all participants. Forty-one patients with symptoms of EER were studied. MI measurements at 2 cm above the SCJ were significantly (P = 0.04) different among the three groups, with MI lowest for E+ and greatest for E-/pH- patients. Although not statistically significant, there is a graded increase in median (interquartile range) MI axially along the esophagus at 5 cm (P = 0.20) and at 10 cm (P = 0.27) above the SCJ, with those with reflux (E+ and E-/pH+) having a lower MI than those without. Patients with symptoms of EER and evidence of acid reflux have an MI lower than those without at 2 cm above the SCJ, with a trend at 5 cm and 10 cm as well. MI may be a tool to assess presence of GERD in patients presenting with EER symptoms.