Efficacy of narrow-band imaging for detecting intestinal metaplasia in adult patients with symptoms of dyspepsia.

Introduction and objective: Atrophy and intestinal metaplasia are early phenotypic markers in gastric carcinogenesis. White light endoscopy does not allow direct biopsy of intestinal metaplasia due to a lack of contrast of the mucosa. Narrow-band imaging is known to enhance the visibility of intestinal metaplasia, to reduce sampling error, and to increase the diagnostic yield of endoscopy for intestinal metaplasia in Asian patients. The aim of our study was to validate the diagnostic performance of narrow-band imaging using 1.5 x electronic zoom endoscopy (with no high magnification) to diagnose intestinal metaplasia in Mexican patients. Materials and methods: A retrospective cohort study was conducted on consecutive patients with dyspeptic symptoms at a private endoscopy center within the time frame of January 2015 to December 2016. Results: A total of 338 patients (63 +/- 8.4 years of age, 40% women) were enrolled. The prevalence of H. pylori infection was 10.9% and the incidence of intestinal metaplasia in the gastric antrum and corpus was 23.9 and 5.9%, respectively. Among the patients with intestinal metaplasia, 65.3% had the incomplete type, 42.7% had multifocal disease, and one third had extension to the gastric corpus. Two patients had low-grade dysplasia. The sensitivity of white light endoscopy was 71.2%, with a false negative rate of 9.9%. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of narrow-band imaging (with a positive light blue crest) were 85, 98, 86.8, 97.7, and 87.2%, respectively. Conclusion: The prevalence of H. pylori infection and intestinal metaplasia in dyspeptic Mexican patients was not high. Through the assessment of the microsurface structure and light blue crest sign, non-optical zoom narrow-band imaging had high predictive values for detecting intestinal metaplasia in patients from a general Western setting. (C) 2018 Asociacion Mexicana de Gastroenterologia. Published by Masson Doyma Mexico S.A. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).