Progression or regression of Barrett's esophagsus - It all in the eye of the beholder?

Objectives: Accurate measurements of Barrett's esophagus length are important in clinical follow-up as well as in studies of therapeutic intervention in Barrett's esophagus. Our aim was to evaluate both the inter- and intraobserver reliability in measuring Barrett's length during two consecutive endoscopies by either the same or different experienced endoscopists. The relationship between Barrett's mucosa length and the absolute change in Barrett's length measurements on a follow-up endoscopy was also evaluated. Methods: A total of 96 Barrett's patients underwent two consecutive endoscopies. The diagnosis of Barrett's esophagus was confirmed by the presence of intestinal metaplasia on biopsy. The Barrett's esophagus length was carefully measured and recorded during the two endoscopies. Procedures were performed by only two experienced endoscopists, who were not aware of previous endoscopic measurements. Only patients with long-segment (greater than or equal to3 cm) Barrett's esophagus were included in this study. Results: The 55 patients who had their consecutive endoscopies performed by the same endoscopist had a mean 1.6-cm difference between the two measurements as compared to 1.4 cm in the 41 patients who had their endoscopies performed by different endoscopists (p=0.3). The agreement between the two Barrett's length measurements was high in both groups, although it was slightly higher for endoscopies performed by the same endoscopist (r=0.79 vs r=0.67). Linear regression analysis of the absolute change in Barrett's length between the two endoscopic measurements and Barrett's mucosa length demonstrated a significant relationship (r=0.28, p=0.005). For every 1-cm increase in the mean length of Barrett's mucosa, a 0.15-cm increase in the absolute difference between two consecutive endoscopic measurements of Barrett's length was observed. Conclusions: Consecutive measurements of Barrett's length performed by different experienced endoscopists or by the same experienced endoscopist demonstrated a high degree of agreement. A range of variability in Barrett's length measurement was determined (+/-1.4-1.6 cm). True regression or progression of Barrett's mucosa should be considered only if the change is greater than the range of variability. In addition, endoscopists should be well aware that the longer the Barrett's mucosa the greater the absolute difference in Barrett's length measurement on follow-up endoscopy.