早期食道癌存在診断・質的診断の進歩―経鼻内視鏡の立場から

Transnasal Endoscopy for Detection of Superficial Esophageal Cancer

要旨　経鼻内視鏡検査は経口内視鏡検査に比べて苦痛が少ないという理由で，最近急速に普及しつつある．しかし，経口内視鏡に比べて画質や明るさ，吸引能力などの点で明らかに劣る経鼻内視鏡の診断能に疑問の声も多い．そのような不利な条件で早期食道癌を発見するためには，食道観察を妨げる粘液と麻酔用ゼリーを極力排除する前処置や咽頭反射を誘発しない挿入法の工夫が必要であった．その結果，当院で施行した経鼻内視鏡4,001例中6例（0.15％）に食道癌が発見され，そのうち早期癌は4例で，すべて内視鏡的に切除された．また早期胃癌も26例発見され，そのうち15例（58％）は10mm以下の小胃癌であった．いまだ画質などに問題はあるものの，経鼻内視鏡の性能は著しく向上してきており，今後スクリーニング内視鏡のニュースタンダードとなりうると思われた．

　Recently, transnasal endoscopy has been adopted as a part of screening endoscopy for the reason that it causes less pain than conventional endoscopy. However, there are some disadvantages compared with conventional endoscopy : brightness, image resolution, suction ability, etc. In order to discover an early esophageal cancer in such disadvantageous conditions, preparation which removes the mucus, the jelly for anesthesia of the esophagus, and the technique in using endoscopy so as not to induce a pharyngeal reflex were very useful. As a result, 6 cases（0.15%）of esophageal cancer were detected by transnasal endoscopy, and 4 cases（0.10%）of early esophageal cancer were all excised endoscopically. Moreover, 26 cases of early gastric cancer were detected, 15 cases（58%）of which were tiny gastric cancers（≦ 10 mm in diameter）. According to the progress of the image resolution of endoscope, transnasal endoscopy is surely accepted as a screening endoscopy by appropriate preparation and careful observation of GI tract.