3)胃 (3)ESD ① Hookナイフ

Endoscopic Submucosal Dissection for Gastric Neoplasms Using a Hook Knife

要旨　Hookナイフは先端が直角に曲がったナイフである．この部分を利用して，粘膜や粘膜下層の線維を把持し，固有筋層から遠ざかる方向に切開・剝離操作を行う．よって，穿孔の危険が非常に少なく，安全なESDが可能である．2003年11月から2005年9月まで，当施設でHookナイフを用いた胃ESD 170病変の成績は，一括切除率95.3％，一括完全切除率88.2％であり，同期間に行った従来のEMRと比較して，良好な成績であった．穿孔率は1.8％であり，EMRと差はなかった．安全なESDを行うにあたり，Hookナイフは有用なディバイスである．

　A hook knife is an excellent device for endoscopic submucosal dissection (ESD). Its tip is bent at a right angle. Using this part, the mucosa and the fibrous tissue of the submucosa are hooked. To minimize the risk of perforation and thus facilitate safe ESD, mucosal cutting and submucosal dissection are then carried out in the direction away from the muscularis propria.

　From November, 2003 to September, 2005, 170 lesions were treated by ESD using a hook knife in our institution. The en bloc resection rate was 95.3％. The rate of complete resection, i.e., achievement of histologically negative lateral and vertical margins for cancer cells, was 88.2％. Compared with conventional endoscopic mucosal resection (EMR), the complete resection rate in the same period was better in ESD. Concerning perforation, it occurred in only 1.8％ of the patients treated by ESD, which was comparable to that of EMR.

　We conclude that a hook knife is very effective in performing safe ESD.