（3）経鼻内視鏡検査

Transnasal Endoscopy

要旨　経鼻内視鏡は，被検者の苦痛が少なく，検査中の循環動態や酸素飽和度が安定しているという利点を有するが，挿入時の鼻腔痛や画質と操作性が通常径内視鏡より劣るという欠点も併せもっている．そのため，スクリーニング検査といえども，その適応は慎重に決定する必要がある．また，癌の見逃しを防ぐには，前処置の工夫や，熟達した内視鏡医による丹念な観察が求められる．今後は，偽陰性癌の検討など，経鼻内視鏡検査の診断精度評価が急務である．

　Transnasal endoscopy has the benefits of involving less pain to the subject and keeping the subject's hemodynamics and oxygen saturation stable during the examination, but in comparison to endoscopy with a conventional endoscope it also has the demerits of causing pain in the nasal cavity during insertion and offering poorer image quality and maneuverability. Even though transnasal endoscopy can serve as a screening test, careful determination must be made as to whether it is indicated. In addition, refinement of pretreatment and close observation by an experienced endoscopist are needed to prevent cancer from being overlooked. Assessment of the diagnostic accuracy of transnasal endoscopy through research as well as studies on false negative cancers missed by the procedure is an urgent task for the future.