title: Electrical tissue impedance spectroscopy: a novel device to measure esophageal mucosal integrity changes during endoscopy.
abstract: BACKGROUND
  Patients with gastroesophageal reflux disease (GERD) have impaired esophageal mucosal integrity. Measurement of the mucosal integrity is complex and time-consuming. Electrical tissue impedance spectroscopy (ETIS) is a device that measures impedance of tissue in vivo during endoscopy. In this study, we aimed to validate ETIS as a measure of esophageal mucosal integrity.
  
  
  METHODS
  Electrical tissue impedance spectroscopy measurements were performed during upper endoscopy in 12 GERD patients and 11 healthy controls after cessation of proton pump inhibition. During endoscopy biopsies of the distal esophagus were obtained for transmission electron microscopy to determine dilation of intercellular spaces (DIS) and for Ussing chamber experiments to determine transepithelial permeability and transepithelial electrical resistance.
  
  
  RESULTS
  Extracellular impedance measured in vivo by ETIS was significantly lower in GERD patients compared to controls [mean (SD) 5621 (3299) Ω.m and 8834 (2542) Ω.m, respectively, P < 0.05]. We found a strong inverse relation between extracellular impedance determined by ETIS and DIS (r = -0.76, P < 0.05), and between extracellular resistance in vivo and transepithelial permeability of esophageal biopsies (r = -0.65, P < 0.01).
  
  
  CONCLUSIONS
  Electrical tissue impedance spectroscopy is a new tool that can be used to evaluate esophageal mucosal integrity changes during endoscopy.
authors.affiliation: Department of Gastroenterology and Hepatology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: P W
authors.initials: PW
authors.lastname: Weijenborg
authors.forename: W O A
authors.initials: WO
authors.lastname: Rohof
authors.forename: L M A
authors.initials: LM
authors.lastname: Akkermans
authors.forename: J
authors.initials: J
authors.lastname: Verheij
authors.forename: A J P M
authors.initials: AJ
authors.lastname: Smout
authors.forename: A J
authors.initials: AJ
authors.lastname: Bredenoord
mesh_terms: D000328:Adult; D000368:Aged; D003938:Diagnostic Techniques, Digestive System / Q000295:instrumentation; D058266:Dielectric Spectroscopy; D017097:Electric Impedance; D016145:Endoscopy, Digestive System; D004947:Esophagus / Q000503:physiopathology* / Q000648:ultrastructure; D005260:Female; D005764:Gastroesophageal Reflux / Q000175:diagnosis*; D006801:Humans; D008297:Male; D046529:Microscopy, Electron, Transmission; D008875:Middle Aged; D009092:Mucous Membrane / Q000503:physiopathology* / Q000648:ultrastructure; D018408:Patch-Clamp Techniques; D055815:Young Adult
keywords: dilated intercellular spaces; esophagus; gastroesophageal reflux disease; mucosal integrity; spectroscopy