早期胃癌に対する切開・剥離法の治療成績と問題点―ITナイフ

Result of Submucosal Dissection EMR Using an IT Knife

要旨　EMRは，早期胃癌に対し有益な治療法であるがその適応を誤ったり，不完全に切除された場合には，生命予後を大きく左右する危険性を含んでいる．それ故，切除後の正確な組織学的検索は必須であり病変の一括切除が望ましい．1987年から2002年までに国立がんセンター中央病院にてEMRが施行された1,441病変において，77％が一括切除され23％が分割切除であった．判定不能症例は一括切除例において4％に，分割切除例では30％に認めた．ここ3年間の切開・剥離EMR法の一括切除率は97％で，そのうち治癒切除が96％であった．施行時間は，2時間を超える症例が14％あり手技の改良・開発の必要がある．偶発症は，穿孔が4％，止血目的の内視鏡再挿入を必要とした症例が2％であった．

　EMR is widely accepted as a useful treatment for early gastric cancer. The benefit of EMR can be achieved only through careful histologic examination, so an en-bloc resection is recommended. Among 1,441 lesions treated by EMR from 1987 to 2002 at the National Cancer Center Hospital, the percentage of tumors removed by en-bloc resection was 77 ％ and, by piecemeal resection, it was 23 ％. In histologic assessment, the not-evaluable resection was only 4 ％ in the group of en-bloc resection compared with 30 ％ in the piecemeal resection group. In the last 3 years, submucosal dissection EMR using an IT knife was performed for almost all early gastric cancers in our division. 97 ％ of the tumors were able to be removed en-bloc. However, submucosal dissection EMR using an IT knife is technically difficult. Actually, in 14 ％ of the cases, the procedure took over 2 hours. Also major complications such as perforation and bleeding occurred in 4 ％ and 2 ％, respectively. Although submucosal dissection EMR proved effective for a large percentage of cases, considering the high level of skill required, it is obvious that efforts should be made to develop safe and easy techniques.

　1) Endoscopy Division, National Cancer Center Hospital, Tokyo