title: Reproducibility of esophageal high-resolution manometry.
abstract: BACKGROUND
  Esophageal high-resolution manometry (HRM) is a novel method for esophageal function testing that has prompted the development of new parameters for quantitative analysis of esophageal function. Until now, the reproducibility of these parameters has not been investigated.
  
  
  METHODS
  Twenty healthy volunteers underwent HRM on two separate days. Standard HRM parameters were measured. In addition, in conventional (virtual) line tracings, lower esophageal sphincter (LES) resting pressure, relaxation pressure, and relative relaxation pressure were measured. Firstly, for each variable, the mean percentage of covariation (100×SD/mean: %COV) was derived as a measure of inter- and intra-individual variation. Secondly, Kendall's coefficients of concordance (W values) were calculated. Thirdly, Bland-Altman plots were used to express concordance graphically.
  
  
  RESULTS
  Statistically significant concordance values were found for upper esophageal sphincter (UES) pressure (W=0.90, P=0.02), transition zone length (W=0.92, P=0.01), LES length (W=0.81, P=0.04), LES pressure (W=0.75, P=0.05), LES relaxation pressure (W=0.75, P=0.03), relative LES relaxation pressure (W=0.78, P=0.05), gastric pressure (W=0.81, P=0.04), and contraction amplitude 5cm above the LES (W=0.86, P=0.03). In conventional setting, only LES resting pressure (W=0.835, P=0.03) proved significant. In HRM tracings, concordance values for contraction wave parameters, and in conventional line tracings, LES relaxation pressure and relative relaxation pressure did not reach levels of statistical significance.
  
  
  CONCLUSIONS
  Esophageal HRM yields reproducible results. Parameters that represent anatomic structures show better reproducibility than contraction wave parameters. The reproducibility of LES resting and relaxation pressure assessed with HRM is better than with conventional manometry and further supports the clinical use of HRM.
authors.affiliation: Gastrointestinal Research Unit, Department of Gastroenterology and Hepatology, University Medical Center, Utrecht, The Netherlands. a.bogte@umcutrecht.nl
authors.forename: A
authors.initials: A
authors.lastname: Bogte
authors.forename: A J
authors.initials: AJ
authors.lastname: Bredenoord
authors.forename: J
authors.initials: J
authors.lastname: Oors
authors.forename: P D
authors.initials: PD
authors.lastname: Siersema
authors.forename: A J P M
authors.initials: AJ
authors.lastname: Smout
mesh_terms: D000328:Adult; D049630:Esophageal Sphincter, Lower / Q000502:physiology; D049631:Esophageal Sphincter, Upper / Q000502:physiology; D004947:Esophagus / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008365:Manometry / Q000379:methods*; D008875:Middle Aged; D011312:Pressure; D015203:Reproducibility of Results