Evaluation of gastric cancer diagnosis using new ultrathin transnasal endoscopy with narrow-band imaging: Preliminary study

Abstract

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 3mm. 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 3mm). 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.