CLINICAL-ALIMENTARY TRACT Chromoendoscopy and Narrow-Band Imaging Compared With High-Resolution Magnification Endoscopy in Barrett's Esophagus

Background & Aims: The aim of this study was to compare magnified still images obtained with high-resolution white light endoscopy, indigo carmine chromoendoscopy, acetic acid chromoendoscopy, and narrow-band imaging to determine the best technique for use in Barrett’s esophagus. Methods: We obtained magnified images from 22 areas with the 4 aforementioned techniques. Seven endoscopists with no specific expertise in Barrett’s esophagus or advanced imaging techniques and 5 international experts in thisfield evaluated these 22 areas for overall image quality, mucosal image quality, and vascular image quality. In addition, the regularity of mucosal and vascular patterns and the presence of abnormal blood vessels were evaluated, and this was correlated with histology. Results: The interobserver agreement for the 3 features of mucosal morphology with white light images ranged from 0.51 (95% confidence interval [CI]: 0.46‐0.55) to 0.53 (95% CI: 0.50‐0.57) for all observers, from 0.43 (95% CI: 0.33‐0.54) to 0.53 (95% CI: 0.41‐0.64) for experts, and from 0.51 (95% CI: 0.15‐0.33) to 0.64 (95% CI: 0.58‐0.70) for nonexperts. The interobserver agreement in these groups did not improve by adding one of the enhancement techniques. The yield for identifying early neoplasia with white light images was 86% for all observers, 90% for experts, and 84% for nonexperts. The addition of enhancement techniques did not improve the yield neoplasia. Conclusions: The addition of indigo carmine chromoendoscopy, acetic acid chromoendoscopy, or narrow-band imaging to white light images did not improve interobserver agreement or yield identifying early neoplasia in Barrett’s esophagus. C hromoendoscopy is a technique in which staining agents are sprayed on the mucosal surface of the gastrointestinal tract to enhance the endoscopic evaluation of the mucosa. This enables endoscopic detection of surface patterns or functional characteristics that may predict the presence of early neoplasia, lesions that may be difficult to detect with standard endoscopy only. Chromoendoscopy is usually combined with magnifying endoscopy for best results. In Barrett’s esophagus (BE), the typically used contrast enhancement agents are indigo carmine and acetic acid. Indigo carmine enhances the mucosal surface by pooling in the grooves between the mucosal villi, thus enabling the visualization of the pattern formed by mucosal folds and pits. Acetic acid achieves the same goal by means of reversible denaturation of superficial mucosal proteins. Both agents have been reported to recognize typical arrangements of the mucosal pit patterns that may corre