Does methylene blue detect intestinal metaplasia in Barrett's esophagus?

Background: Methylene blue has been used to selectively stain areas of specialized intestinal metaplasia in Barrett's esophagus. The sensitivity, specificity, and negative and positive predictive values for the detection of specialized intestinal metaplasia by methylene blue chromoendoscopy were determined in patients with Barrett's esophagus. Methods: Thirty patients with Barrett's esophagus underwent endoscopy with biopsy specimens obtained from areas that stained positive and negative with methylene blue. Histopathologic findings were compared with methylene blue chromoendoscopy findings. Results: Two hundred ninety-two biopsy specimens (mean 9.7/patient) were obtained: 203 from stained and 89 from unstained areas. Sensitivity, specificity, and negative and positive predictive values for detection of specialized intestinal metaplasia were, respectively, 72%, 46%, 22%, and 89%. Comparing 187 biopsy specimens from patients with long-segment Barrett's esophagus with 105 specimens from patients with short-segment Barrett's esophagus, the sensitivity, specificity, and negative and positive predictive values were, respectively, 77% versus 63% (p = 0.044), 79% versus 21% (p < 0.002),28% versus 14% (p = 0.219), and 97% versus 73% (p < 0.002). The odds ratio for detection of specialized intestinal metaplasia in stained areas was 12.40 in long-segment and 0.45 in short-segment Barrett's esophagus. Conclusions: Data from this study confirm the value of methylene blue chromoendoscopy for detection of specialized intestinal metaplasia in long-segment Barrett's esophagus, but not in short-segment Barrett's esophagus.