早期胃癌に対する切開・剥離術の治療成績と問題点―フックナイフ

Endoscopic Submucosal Dissection with the Hook Knife

要旨　2000年1月から2003年8月までに切開・剥離術を試行した胃上皮性腫瘍312例を対象とした．一括切除率は腫瘍長径20mm以下群で98％(202/207)，21mm以上群で95％(103/109)，全体で97％(301/312)であった．切除断端陽性は11例で，いずれも術前診断の誤りが原因であり一括完全切除率は93％(290/312)であった．穿孔を0.96％(3/312)に認めたがいずれもpin holeでありclip 1個で閉鎖しえた．輸血を要した症例は高度の肝硬変1例(0.3％)のみであった．手技が安定した2001年以降は大部分の症例をトレーニング中の術者が施行してきたが，上述のような成績を得た．したがって基本を守ればフックナイフを用いた切開・剥離術は安全な手技と思われた．

　Endoscopic submucosal dissection was developed to resect mucosal cancers more precisely. The hook knife was used to cut the mucosa around the lesion and to dissect the submucosal fibers. To prevent perforation, the direction of the hook knife should be controlled by keeping it parallel with the proper muscular layer.

　The hook knife was also useful for stopping bleeding. When it caused bleeding, we touched the bleeding vessels with the backside of the hook knife and were able to stop the bleeding by spray mode coagulation.

　When we found vessels in the submucosal layer, we were able to prevent the bleeding by cutting the vessels using APC mode coagulation current.

　The histological examination for both the range of lateral spreading and depth of invasion can be more precisely performed by obtaining a one-piece resected specimen.

　The one-piece resection rate was 97 ％ (301/312) and the perforation rate was 0.96 ％ (3/312). Endoscopic submucosal dissection with the hook knife is a new useful and more precise method for the EMR of larger lesions.

　1) Department of Gastroenterology, Saku Central Hospital, Nagano, Japan

　2) Department of Endoscopy, Saku Central Hospital, Nagano, Japan