Use of Narrow Band Imaging (NBI) To Detect Esophagitis in Non Erosive Reflux Disease (NERD)

Abstract

Purpose: Most patients with reflux symptoms do not have signs of mucosal injury on routine endoscopy. In patients with non erosive reflux disease (NERD) chromoendoscopy with Lugol's iodine and confocal laser endomicroscopy have been reported to identify lesions with histologic evidence of esophagitis. However, both procedures are time consuming and require the use of contrast agents. Narrow band imaging (NBI) is known to display macroscopic lesions such as ulcers with high contrast and clarity. We report our findings in an initial group of patients with persistent reflux symptoms and a normal esophagus on white light (WL) endoscopy to see if erosive lesions could be detected with high contrast NBI endoscopy. Methods: The Olympus GIF-H180 gastroscope was used in five patients; 3 male, 2 female, with a mean age of 49 (range 22–63) who underwent upper endoscopy for persistent reflux symptoms (heartburn at least 3 times per week for more than 3 months). On finding no evidence of esophagitis on WL endoscopy in all 5 patients, the NBI mode was switched on and the esophagus re-examined. Any discrete lesions were photographed and biopsies taken with cold forceps for histology. If no lesions were seen, biopsies were taken from the distal esophagus. Results: In asymptomatic individuals, NBI displays the normal esophagus with an even blue color. On switching to narrow band imaging (NBI) mucosal breaks or erosions were seen in 4 out of 5 patients (80%). These consisted of: 1) discrete, depressed erosions of up to 1 mm in diameter, surrounded by an even, bluish appearing normal squamous mucosa; 2) larger, flat, depressed, magenta colored patches of up to 10 mm in diameter, with visible raised margins. Targeted biopsies from these lesions showed microscopic evidence of reflux esophagitis in all 4 patients (100%). Biopsies from the distal esophagus of the patient without mucosal lesions were normal. Conclusion: These early findings suggest that high contrast imaging methods such as NBI may be useful in unmasking subtle erosive changes in the esophagus of patients with reflux symptoms that are not readily visible on routine white light endoscopy. High contrast imaging with NBI is a rapid and easy technique that does not require complex instrumentation or dyes. If these initial findings are verified by future studies, this may become a useful technique for identifying erosive lesions and targeting biopsies in patients with presumed NERD.