title: Esophageal Mucosal Impedance Pattern is Distinct in Patients With Extraesophageal Reflux Symptoms and Pathologic Acid Reflux.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors: Section of Gastroenterology, Hepatology, and Nutrition, University of Chicago, Chicago, Illinois.
authors: Robert T
authors: RT
authors: Kavitt
authors: Division of Gastroenterology, Hepatology, and Nutrition, Vanderbilt University Medical Center, Nashville, Tennessee.
authors: Pooja
authors: P
authors: Lal
authors: Izmir Ataturk Teaching and Research Hospital, Katip Celebi University, Izmir, Turkey.
authors: Elif Saritas
authors: ES
authors: Yuksel
authors: Mersin University, Mersin, Turkey.
authors: Fehmi
authors: F
authors: Ates
authors: Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, Tennessee.
authors: James C
authors: JC
authors: Slaughter
authors: Vanderbilt Voice Center, Vanderbilt University Medical Center, Nashville, Tennessee.
authors: C Gaelyn
authors: CG
authors: Garrett
authors: Division of Gastroenterology, Hepatology, and Nutrition, Vanderbilt University Medical Center, Nashville, Tennessee.
authors: Tina
authors: T
authors: Higginbotham
authors: Division of Gastroenterology, Hepatology, and Nutrition, Vanderbilt University Medical Center, Nashville, Tennessee. Electronic address: Michael.vaezi@vanderbilt.edu.
authors: Michael F
authors: MF
authors: Vaezi
mesh_terms: D000328:Adult; D057785:Catheters; D017097:Electric Impedance; D016145:Endoscopy, Digestive System; D000071041:Esophageal Mucosa / Q000503:physiopathology*; D050782:Esophageal pH Monitoring / Q000379:methods; D004941:Esophagitis / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D005764:Gastroesophageal Reflux / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000295:instrumentation / Q000379:methods*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D013686:Telemetry / Q000295:instrumentation; D014159:Transducers
keywords: GERD; diagnosis; extraesophageal reflux; mucosal impedance; reflux