3436 Enhanced magnification endoscopy: a new technique to identify specialized intestinal metaplasia in barrett's esophagus.

Abstract

Specialized intestinal metaplasia (SIM) in Barrett's esophagus (BE) is not identifiable by standard endoscopy (SE). Magnification endoscopy (ME) may be useful in the endoscopic recognition of BE. Acetic acid (AA) instillation improves visualization of columnar epithelium at the squamocolumnar union (Gastrointest Endosc 1998;47:512). Enhanced magnification endoscopy (EME) combines the use of ME and AA. Aim: To evaluate the usefulness of EME for the detection of SIM in BE. Methods: Patients undergoing endoscopic surveillance of BE underwent EME with an Olympus GIF-200Z (zoom 35X) and 1.5% AA instillation. SE was followed by ME and repeated after AA spraying. AA surface patterns were characterized prior to AA-directed biopsy of suspected areas and compare with histology results. A pathologist blinded to the biopsy methods read each biopsy. Logistic regression was performed to determine if surface patterns could predict SIM in suspected areas. Results: 49 patients with short segment BE were studied. One was excluded due to unclear definition of the surface pattern after EME. Four different endoscopic patterns were identified. I: round pits, II: reticular, III: villous, and IV: ridged. The table shows the percentage of endoscopic patterns observed with each endoscopic technique. The yield of detecting SIM according to the endoscopic pattern were: Pattern I:0%, II:11%(2/18), III:87%(40/46), and IV:100% (17/17). Odds ratio for Pattern IV for detecting SIM compared with Pattern I was 14 (p=0.015), ROC=0.95. Sensitivity, specificity, and positive and negative predicted values are 96.6%, 90.2%, 89.0%, and 97.0%. Total accuracy 93.1%. Conclusions: EME is an accurate method of predicting SIM in BE. It appears to be able to distinguish gastric epithelium from SIM and may be useful in directing biopsies and identifying SIM before and after ablation therapy.