title: Esophagogastric junction opening during relaxation distinguishes nonhernia reflux patients, hernia patients, and normal subjects.
abstract: OBJECTIVE
  Flow across the esophagogastric junction (EGJ) is strongly related to opening dimensions. This study aimed to determine whether opening of the relaxed EGJ was altered in patients with gastroesophageal reflux disease (GERD).
  
  
  METHODS
  Seven normal subjects (NL), 9 GERD patients without hiatus hernia (NHH), and 7 with hiatus hernia (HH) were studied. Cross-sectional area (CSA) of the relaxed EGJ was measured during low-pressure distention using a modified barostat technique that resulted in filling a compliant bag straddling the EGJ with renograffin to the set pressure. Swallows were imaged fluoroscopically at distensive pressures of 2-12 mm Hg. The diameter of the narrowest point of the EGJ in PA and lateral projections was measured from digitized images. CSA was determined as a function of intrabag pressure.
  
  
  RESULTS
  The minimal EGJ opening aperture occurred at the diaphragmatic hiatus in all subjects. At pressures </=0 mm Hg, EGJ opening was observed only in HH patients, making it plausible for these patients to reflux during deglutitive relaxation. At pressures >0 mm Hg, there were significant increases in EGJ CSA both for HH and NHH compared with NL (P < 0.001) and for HH compared with NHH (P < 0.005). This difference may explain the diminished air/water discrimination seen during transient lower esophageal sphincter (LES) relaxation-associated reflux in GERD patients.
  
  
  CONCLUSIONS
  Anatomic degradation of the EGJ distinguishes GERD patients from normal subjects, and these changes may impact on both the observed mechanisms of reflux and the constituents of reflux during transient LES relaxation. Therapy focused on EGJ compliance may benefit GERD patients.
mesh_terms: D000328:Adult; D000388:Air; D003187:Compliance; D003937:Diagnosis, Differential; D004383:Duodenogastric Reflux / Q000175:diagnosis* / Q000503:physiopathology*; D004943:Esophagogastric Junction / Q000503:physiopathology*; D005260:Female; D006551:Hernia, Hiatal / Q000175:diagnosis* / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008365:Manometry; D011312:Pressure; D014867:Water
chemical_list: D014867:Water