切開・剥離法（ESD）に必要な胃癌術前診断―内視鏡診断―側方進展診断を中心に―通常・色素内視鏡

Preoperative Diagnosis of Early Gastric Cancer for ESD―Diagnosis of Large Superficial-type Carcinoma by Conventional and Dye Endoscopy

要旨　近年ESDの開発・導入により，表層進展発育型の大きな病変であっても一括切除可能となり，そのような病変の境界診断を正確に行うことがますます重要となってきている．これまでの通常・色素内視鏡観察を併用し行ってきた病変境界診断の有用性をESDの対象となる適応拡大病変2例について検討した．大きな表層進展発育型病変の範囲診断を行うにあたり，範囲診断の誤差はほとんどみられず，通常・色素内視鏡診断はESD治療現場においても十分実際的な境界診断技術と位置づけられると考えた．また，ESD切除標本は病変の大きさにかかわらず平均して約20mmの安全域が確保されており，ESDの手技そのものが，今回症例に呈示したような明瞭な境界を示す病変以外においても十分以上の安全域を確保できる治療手段であるとの査証になると考えられた．未分化型癌においては必ずしも病変境界が線で追えるとは限らないが，この点においてもESDが一括切除しつつ十分な安全域を確保できる唯一の治療手段となっていくと考えられた．

　In these days it has become possible to resect at once large lesions spreading superficially by using the endoscopic submucosal dissection (ESD) method. So it is now all the more important to diagnose the border line of such a lesion correctly. We studied whether it is useful or not to use the ordinary diagnostic method for determining the border line of lesions, using the dying method for two such large lesions. The result we obtained was that marking by the ordinary method using dying endoscopy coincided almost exactly with the margin which was diagnosed pathologically. Because of this we conclude that the ordinary method including the dying method which has been used so far for determining the border line of the lesion is sufficient for large lesion where ESD is indicated. In our 209 cases of ESD usage the resected margin is almost over 2 cm outside the pathological margin of the lesion, no matter what the size of the lesion may be, so we can conclude that ESD is a safe enough technique of endoscopic resection because it operate with margin of safety to avoid any residual cancer. Even in cases of resection of undifferentiated cancer we think that ESD is the safest method of resection to avoid residual cancer.