Background and Aim: Newly developed ultrathin transnasal endoscope, the GIF-XP290N, makes possible a resolving power similar to the GIF-H260 at a distance of 3 mm. We conducted surveillance of subjects with Barrett's esophagus using this ultrathin transnasal endoscopy. In Japan the lower margin of the lower esophageal palisade vessels is defined the gastroesophageal junction in deep inspiration. We diagnose Barrett's esophagus if columnar epithelium is present on the oral side of the gastroesophageal junction. Methods and Results: Barrett's esophagus was confirmed in 116 out of 135 subjects (85.9%), with 17 cases of short-segment Barrett's esophagus (SSBE) and 99 of ultra-shortsegment Barrett's esophagus. Close observation of the Barrett's esophagus mucosal structural pattern using narrow band imaging revealed 29 cases with an oval or round pattern, 29 with a long straight pattern, 47 with a villous pattern, 8 with a cerebriform pattern, and 6 with an irregular pattern according to Goda classification. Mucosal biopsies from all subjects with SSBE are examined. Histological examination revealed intestinal metaplasia in only eight subjects. We grouped the oval/round and long straight patterns as closed type, and the villous, cerebriform, and irregular patterns as open type. Analysis of the relationship between these mucosal patterns and background factors revealed a significant correlation between intestinal metaplasia and the open-type pattern. Conclusion: We consider this new ultrathin transnasal endoscopy to be a useful technique for surveillance of Barrett's esophagus, especially SSBE.

Background and Aim: The new developed ultrathin transnasal endoscope, the GIF-XP290N, makes possible a resolving power similar to the GIF-H260 at a distance of 3 mm. In this study, using the GIF-XP290N, we evaluated whether endoscopic diagnosis (discrimination between benign and malignant) of gastric lesions is possible using nonmagnified narrow-band imaging (NBI) endoscopy. Methods: The subjects were 255 consecutive patients who underwent screening of the gastrointestinal tract using new ultrathin transnasal endoscopy. Their average age was 65.2 ± 11.4 years. The male-female ratio was 2.5:1. All cases were examined using conventional white-light imaging (WLI) and nonmagnified NBI. When a depressed lesion was detected in the stomach, it was examined using WLI, then NBI close examination (at about 3 mm). We observed the mucosal structure of the lesion using close visualization with NBI. Concerning mucosal structural changes, we looked for a clear demarcation line between the lesion and the surrounding mucosa, and loss, irregularity, or nonuniformity of the lesion mucosal microsurface pattern. Results: A total of 52 depressed lesions were examined. The histological diagnosis was cancer for 8 lesions, and noncancer for 44 lesions. WLI examination yielded a sensitivity of 50.0% (4/8), specificity of 63.6% (28/44), and accuracy 61.5% (32/52). On the other hand, NBI close examination yielded a sensitivity of 87.5% (7/8), specificity of 93.2% (41/44), and accuracy of 92.3% (48/52), significantly higher. Conclusion: NBI close examination using ultrathin transnasal endoscopy enables mucosal diagnosis even without magnification and was considered to be an effective technique for improving endoscopic diagnosis.