3528 USEFULNESS OF DOUBLE DYE STAINING (METHYLENE BLUE AND CRYSTAL VIOLET) FOR THE MAGNIFYING OBSERVATION OF INTESTINAL METAPLASIA IN BARRETT'S ESOPHAGUS.

Abstract

Backgroud: Barrett's esophagus (BE) is the metaplastic replacement of normal squamous epithelium by columnar epithelium. <i>Canto</i> et al. have reported (<i>Gastrointest Endosc</i> 1996) that the value of methylene blue(MB) staining of visible columnar epithelium in the esophagus to help obtain targeted biopsies with the purpose of improving diagnostic yield of intestinal metaplasia (IM). MB staining is sometimes unclear to observe a fine surface structure of Barrett's epithelium. Aim:To determine MB staining is useful to detect IM in Barrett's patients or not. Next,to evaluate the accuracy of representing a surface structure of IM in magnifying endoscopic observation with double dye staining. Methods: Twenty-eight consecutive patients undergoing high-resolution magnifying endoscopy (Fujinon EG- 410CR) with dye staining for Barrett's patients and non BE patients (atrophic gastritis). Eight patients had long segment BE (length of columnar lined epithelium>2cm), 10 patients had short segment Barrett's esophagus (SSBE) and 10 patients had no Barrett's (normal EG-junction). Staining proceeding: The first procedure was washing out the mucous in the esophagus with a bolus water and MB 0.5 % (10ml) was sprayed, after 4 minutes the surface was cleaned with water. MB stained area of columnar epithelium in the esophagus and near the EG-junction (non BE) were classified into 4 grades; grade 0: 0%, grade 1: 10-30%, grade 2: 30-60%, grade3:60-100%. Then, 0.05% crystal violet (CV; 5ml) was sprayed and magnified surface structure was observed. Target biopsies were performed from these areas (grade0-3). Results: 1) BE and SSBE subject; non-MB staining sites (grade 0) on target biopsies revealed IM in 0/28 (0 %). Patchy (grade 1), Focal (grade2), and Diffuse (grade 3) staining sites revealed IM, 11/33 (33%), 32/48 (67%), and8/8 (100%). 2) non BE and no SSBE subject; Target biopsies revealed IM were as follows: grade 0; 0/10 (0%), grade 1 (4/5) 80%, grade 2; 7/8 (88%), grade 3; 2/2 (100 %). All biopsies sites were considered at the cardiac area nearby EG-junction. 3) CV solution directly dyes the surface of the Barrett's epithelium, and enhanced the MB stained mucosa, so a very clear and fine mucosal patterns was observed. Conclusions: In this prospective study, MB staining with target biopsies improve the diagnostic yield for BE and SSBE, furthermore, double dye staining (MB and CV) is very useful to observe the mucosal structure of Barrett's epithelium.