title: Esophageal motility and impedance characteristics in patients with Barrett's esophagus before and after radiofrequency ablation.
abstract: BACKGROUND
  Radiofrequency ablation (RFA) is a valuable treatment option in Barrett's esophagus resulting in eradication of dysplasia and conversion of all Barrett's epithelium into normal squamous epithelium. In Barrett's esophagus, esophageal impedance monitoring is hampered by low baseline impedance values. Whether these low baselines are caused by an intrinsically low impedance of cylindrical epithelium or by the excessive reflux itself is hitherto unknown. Data on esophageal motility after RFA are scarce. Our aim was to examine the effect of RFA on esophageal motility and esophageal baseline impedance in patients with Barrett's esophagus.
  
  
  METHODS
  In 10 patients, conventional esophageal manometry and 24-h pH-impedance measurements were performed before and after RFA. The number and type of reflux episodes were assessed and baseline impedance values were measured in all recording segments. In another five patients, high-resolution manometry was performed before and after RFA.
  
  
  RESULTS
  Complete regression of all Barrett's epithelium was achieved in all 15 patients after 3 ± 1 RFA sessions. Overall, no significant motility changes were found after RFA. Patients had excessive acid exposure times before and after RFA [25 (17-42) and 16 (9-24)%, respectively]. Baseline esophageal impedance values were low, with the lowest values in the distal recording segments. RFA increased baseline impedance in all recording segments in the upright position; in the supine position, the effect just failed to reach statistically significant levels.
  
  
  CONCLUSIONS
  RFA did not alter esophageal motility significantly. Low esophageal baseline impedance levels in patients with Barrett's esophagus reflect, at least in part, intrinsic impedance properties of cylindrical epithelium, as baselines increased after conversion into neosquamous epithelium.
authors.affiliation: aDepartment of Gastroenterology, St Antonius Hospital, Nieuwegein bDepartment of Gastroenterology, Academic Medical Centre, Amsterdam, The Netherlands.
authors.forename: Gerrit J M
authors.initials: GJ
authors.lastname: Hemmink
authors.forename: Lorenza
authors.initials: L
authors.lastname: Alvarez Herrero
authors.forename: Auke
authors.initials: A
authors.lastname: Bogte
authors.forename: Albert J
authors.initials: AJ
authors.lastname: Bredenoord
authors.forename: Jaques J
authors.initials: JJ
authors.lastname: Bergman
authors.forename: André J P M
authors.initials: AJ
authors.lastname: Smout
authors.forename: Bas L A M
authors.initials: BL
authors.lastname: Weusten
mesh_terms: D001471:Barrett Esophagus / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation; D017097:Electric Impedance; D050782:Esophageal pH Monitoring; D004945:Esophagoscopy; D004947:Esophagus / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D005764:Gastroesophageal Reflux / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D005769:Gastrointestinal Motility; D006801:Humans; D008365:Manometry; D009092:Mucous Membrane / Q000473:pathology / Q000601:surgery; D016896:Treatment Outcome