Changes in gastric mucosal patterns seen by magnifying NBI during H. pylori eradication

Background: Magnifying narrow-band imaging (NBI) endoscopy visualizes superficial gastric mucosal and capillary patterns. We aimed to investigate changes in gastric mucosal patterns seen by magnifying NBI endoscopy after Helicobacter pylori eradication. Methods: Gastric mucosal patterns in non-pathological gastric corpus were observed by magnifying NBI endoscopy before and 12 weeks after H. pylori eradication in thirty patients. By using paired photographs of each case, changes in NBI mucosal patterns during H. pylori eradication were judged in a consensus manner by three blinded endoscopists. Results: At 12 weeks after H. pylori eradication, 20 of 24 subjects who had been successfully treated showed remarkable changes in gastric mucosal patterns (sensitivity 83.3%, specificity 100%). In the specimens from these subjects, the patterns of enlarged or elongated pits were improved to small oval or pinhole-like round pits, and the density of fine irregular vessels was decreased. Histological assessment showed alleviation of chronic inflammation in all subjects (p < 0.0001), while such a change was not observed for four subjects showing severe gastric atrophy and intestinal metaplasia. When the subjects were divided according to the presence of severe gastric atrophy, the diagnostic efficacy of magnifying NBI for predicting the results of H. pylori eradication was excellent in subjects without severe gastric atrophy and intestinal metaplasia (sensitivity and specificity, 100%). However, no change in the NBI mucosal pattern was observed in subjects with severe gastric atrophy and intestinal metaplasia, regardless of the H. pylori eradication result. Conclusions: At least in subjects without severe gastric atrophy or intestinal metaplasia, successful H. pylori eradication treatment shows improvements in gastric mucosal patterns with the use of magnifying NBI endoscopy early after successful treatment.