経鼻内視鏡スクリーニングの実態と問題点―外来診療の立場から

Status and Issue of Screening by Transnasal Endoscopy: From the Standpoint of Out Patient Clinic

要旨　近年，第一線の医療機関を中心に経鼻内視鏡は急速に普及し続けている．現在本邦で行われている年間約1,200万件の上部消化管内視鏡検査のうち，約300万件（約25％）が経鼻内視鏡によるものと推計される．その比率は年々高まる傾向にあり，診断能は経口内視鏡と経鼻内視鏡との間に差はなく，今後スクリーニング検査の主流になっていくものと思われる．当面，高い受容性と安全性が求められる胃がん検診の逐年検査に活用されていく可能性が高い．一方，CCD，光源，スコープ軟性部を構成する部材の改良や開発，画像強調機能の技術も進んでおり，経鼻内視鏡の性能の向上に伴い，活用される分野も漸次拡大してゆくものと思われる．しかし，前処置法やスコープの操作法に混乱がみられ，経鼻内視鏡は二極化する傾向がみられる．今後，機器の改良とともに，経鼻内視鏡に特化した専門医養成や認定制度，ガイドラインの策定が検討課題になるものと思われ，教育研修システムの確立が急がれる．

　In recent years, the use of nasal endoscopes has rapidly become widespread, especially in front-line medical institutions. Of the about 12 million cases of upper digestive tract endoscopy currently conducted per year in Japan, an estimated 3 million cases（approximately 25％）use nasal endoscopes. This ratio is on a rising trend every year, but no significant differences were observed in diagnostic performance of nasal and oral endoscopes, and the assumption is that the nasal endoscope will become the mainstream method of screening tests in the future. In the immediate future, there is a high possibility that nasal endoscopes will be used for mass screening of gastric cancer in repeat annual examinations where high acceptability is required. Also, improvements and developments have been made in the materials for making the CCD, light scope, and flexible sections of the scope, and there have been advances in image contrast function technology. With these improvements in the performance of the nasal endoscope, it is expected that the areas of application will eventually expand. However, as with many examination technologies, the nasal endoscope is tending towards bipolarization in terms of skills, due to the differences in pretreatment and scope operation methods. It is expected that the establishment of specialist education systems, accreditation systems, and guidelines specific to nasal endoscopes will be the subject of studies concerning the improvement in devices, and there will be an urgent need to establish an education and training system.