Narrow band imaging in Barrett's esophagus—where are we standing?

Abstract

Narrow band imaging (NBI) with or without magnification endoscopy is a new endoscopic technique for improved visualization of mucosal surfaces and capillary networks without using dyes. Barrett's esophagus (BE) is defined as the presence of columnar epithelium in the distal esophagus that histologically contains specialized intestinal metaplasia. The presence of BE carries a risk of future malignant transformation to esophageal adenocarcinoma. Detection of the short form of BE and surveillance of patients with known BE for dysplasia are diagnostic challenges. Standard endoscopy without biopsies can detect columnar-lined esophagus but cannot confirm specialized intestinal metaplasia or detect early neoplasia (dysplasia). Therefore, random 4-quadrant biopsy is the current standard in the diagnosis and surveillance of patients with BE. 1 Sampliner R.E. Practice guidelines on the diagnosis, surveillance, and therapy of Barrett's esophagus: the Practice Parameters Committee of the American College of Gastroenterology. Am J Gastroenterol. 1998; 93: 1028-1032 Crossref PubMed Scopus (630) Google Scholar In the last decade several attempts have been made to improve endoscopic techniques for the detection of BE and early neoplasia. Magnification endoscopy, chromoendoscopy with different stains, and instillation of acetic acid have been examined and found to improve the endoscopic diagnosis of BE and the detection rates of dysplasia compared with standard endoscopy in clinical trials. 2 Canto M.I. Setrakian S. Willis J. et al. Methylene blue–directed biopsies improve detection of intestinal metaplasia and dysplasia in Barrett's esophagus. Gastrointest Endosc. 2000; 51: 560-568 Abstract Full Text Full Text PDF PubMed Scopus (255) Google Scholar , 3 Endo T. Awakawa T. Takahashi H. et al. Classification of Barrett's epithelium by magnifying endoscopy. Gastrointest Endosc. 2002; 55: 641-647 Abstract Full Text Full Text PDF PubMed Scopus (211) Google Scholar , 4 Sharma P. Weston A.P. Topalovski M. et al. Magnification chromoendoscopy for the detection of intestinal metaplasia and dysplasia in Barrett's esophagus. Gut. 2003; 52: 24-27 Crossref PubMed Scopus (303) Google Scholar , 5 Guelrud M. Herrera I. Essenfeld H. et al. Enhanced magnification endoscopy: a new technique to identify specialized intestinal metaplasia in Barrett's esophagus. Gastrointest Endosc. 2001; 53: 559-565 Abstract Full Text Full Text PDF PubMed Scopus (255) Google Scholar Different classifications of mucosal surface patterns have been introduced (5 types of pit pattern, 3 Endo T. Awakawa T. Takahashi H. et al. Classification of Barrett's epithelium by magnifying endoscopy. Gastrointest Endosc. 2002; 55: 641-647 Abstract Full Text Full Text PDF PubMed Scopus (211) Google Scholar “ridged/villous” vs “circular” vs “irregular/ distorted,” 4 Sharma P. Weston A.P. Topalovski M. et al. Magnification chromoendoscopy for the detection of intestinal metaplasia and dysplasia in Barrett's esophagus. Gut. 2003; 52: 24-27 Crossref PubMed Scopus (303) Google Scholar “round pits” vs “reticular” vs “villous” vs “ridged” 5 Guelrud M. Herrera I. Essenfeld H. et al. Enhanced magnification endoscopy: a new technique to identify specialized intestinal metaplasia in Barrett's esophagus. Gastrointest Endosc. 2001; 53: 559-565 Abstract Full Text Full Text PDF PubMed Scopus (255) Google Scholar ). However, none of these classifications has reached general clinical practice thus far, probably because of the complexity of the procedures and the difficulties with pattern interpretation outside expert centers. Recently, narrow-band imaging (NBI) with or without magnification endoscopy was developed as a new endoscopic technique for improved visualization of mucosal surfaces and capillary networks without the use of dyes. 6 Gono K. Yamazaki K. Doguchi N. et al. Endoscopic observation of tissue by narrow-band illumination. Opt Rev. 2003; 10: 1-5 Crossref Scopus (267) Google Scholar Narrow band imaging (NBI) with or without magnification endoscopy is a new endoscopic technique for improved visualization of mucosal surfaces and capillary networks without using dyes.