臨牀消化器内科 Vol.30 No.9(3-2)


特集名 大腸LST(側方発育型腫瘍)の新展開
題名 分割EMR,ESDの治療成績
発刊年月 2015年 08月
著者 岡 志郎 広島大学病院内視鏡診療科
著者 田中 信治 広島大学病院内視鏡診療科
著者 田丸 弓弦 広島大学病院消化器・代謝内科
著者 二宮 悠樹 広島大学病院消化器・代謝内科
著者 朝山 直樹 広島大学病院消化器・代謝内科
著者 鴫田 賢次郎 広島大学病院消化器・代謝内科
著者 林 奈那 広島大学病院内視鏡診療科
著者 茶山 一彰 広島大学病院消化器・代謝内科
【 要旨 】 内視鏡的粘膜切除術(endoscopic mucosal resection;EMR)で分割切除となる大腸腫瘍に対しても,内視鏡的粘膜下層剝離術(endoscopic submucosal dissection;ESD)で一括摘除が可能である.ただし,径20mm以上の大腸腫瘍の多くは腺腫主体の側方発育型腫瘍(laterally spreading tumor;LST)であり,とくにLST‒G顆粒均一型やLST‒G結節混在型の一部は,拡大観察にて術前に粘膜下層(SM)浸潤や癌が疑われる部位を正確に術前診断できるため,癌の部分をスネアで一括切除できれば計画的分割EMRで病理診断に支障をきたすことはなく根治できる.LSTに対するESDの適応基準は,計画的分割EMRが困難なLST‒G結節混在型およびLST‒NG平坦隆起型,多中心性にSM浸潤し拡大観察でSM浸潤部の同定が困難なLST‒NG偽陥凹型である.LSTに対する適切な治療選択(EMR/分割EMR,ESD,外科手術)には,LSTの肉眼形態と拡大観察所見を総合評価して判断することが重要である.
Theme New Development of Laterally Spreading Tumor
Title Indications and Outcomes of Endoscopic Resection for Laterally Spreading Tumors of the Colorectum
Author Shiro Oka Department of Endoscopy, Hiroshima University Hospital
Author Shinji Tanaka Department of Endoscopy, Hiroshima University Hospital
Author Yuzuru Tamaru Department of Gastroenterology and Metabolism, Hiroshima University Hospital
Author Yuki Ninomiya Department of Gastroenterology and Metabolism, Hiroshima University Hospital
Author Naoki Asayama Department of Gastroenterology and Metabolism, Hiroshima University Hospital
Author Kenjiro Shigita Department of Gastroenterology and Metabolism, Hiroshima University Hospital
Author Nana Hayashi Department of Endoscopy, Hiroshima University Hospital
Author Kazuaki Chayama Department of Gastroenterology and Metabolism, Hiroshima University Hospital
[ Summary ] Most colorectal tumors larger than 20 mm in size are laterally spreading tumor (LSTs). Endoscopic submucosal dissection (ESD) is used to treat large LSTs. Recently, the safety and standardization of colorectal ESD techniques have been established. However, recognition of the subtypes of LST and the use of magnifying endoscopy enables us to recognize the cancerous area in the LST‒G and the LST‒NG flat elevated types precisely. Therefore, adenomatous large LST‒G and the LST‒NG flat elevated type can be cured using planned piecemeal endoscopic mucosal resection (EMR). Several studies have reported that adenomatous large LST‒G can be cured by piecemeal EMR. To reduce the size of the residual tumor and reduce the risk of local recurrence after EMR, it is important to observe the margin of the ulcer by using magnifying endoscopy and to perform appropriate trimming. The LST‒G nodular mixed type with large nodules and the LST‒NG pseudo‒depressed type has a relatively high risk for submucosal invasion. However, it is difficult to correctly recognize the submucosal invasive area with magnifying observation. Therefore, en block resection is necessary in cases of the LST‒NG pseudo‒depressed type or the LST‒G nodular mixed type with large nodules. The rationale for choosing between piecemeal EMR and ESD for large LSTs should be based on the LST subtype, the endoscopist's skill level, and the patient's condition.
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