―治療面からみた実態と問題点―早期胃癌の腹腔鏡下切除の適応基準

Indications for Laparoscopic Surgery for Early Gastric Cancer

要旨　早期胃癌に対する腹腔鏡下胃局所切除術の原則的適応は，①リンパ節転移の可能性がほとんどなく，②EMRでは安全かつ確実な切除が達成されない可能性のある病変である．当科では，開腹胃切除例におけるリンパ節転移の解析結果に基づき，①肉眼的粘膜癌，②隆起性病変では長径25mm以下，③陥凹性病変では長径15mm以下でUl(－)，という基準を用いてきた．一方，腹腔鏡補助下遠位胃切除術の原則的適応は，リンパ節転移の可能性が第1群および一部の第2群リンパ節に限られた病変であるが，一定した見解は必ずしも得られていなかった．日本胃癌学会ガイドラインでは，早期胃癌に対する腹腔鏡下手術は臨床研究に分類され，適応基準が示された．早期胃癌に対し腹腔鏡下手術を行う場合には，日常診療として推奨される開腹縮小手術，および臨床研究として適応のあるEMRの選択機会を患者に保障するよう，各方法の長所・短所を十分説明することが必要である．

　General indications for laparoscopic partial gastrectomy for early gastric cancer are: ① Very low possibility of lymph node metastases, and ② Endoscopic mucosal resection (EMR) is technically difficult to apply due to the size or the site of the lesion. We determined our definite indications, from an analysis of lymph node metastases in patients with early gastric cancer who underwent gastrectomy with lymph node dissection, as follows: ① preoperatively diagnosed mucosal cancer, ②＜25 mm diameter elevated lesions; and ③＜15 mm diameter depressed lesions without ulcer formation. On the other hand, the general indication for laposcope-assisted distal gastrectomy is lesions where the possibility of lymph node metastases is limited to the first group and a part of the second group, but we have not reached consensus concerning definite indications for such sugery. The gastric cancer treatment guidelines (GL) issued by The Japanese Gastric Cancer Association categorized laparoscopic surgeries as optional treatments for early gastric cancer and described indications. It is necessary to explain sufficiently the advantages and disadvantages of each treatment, when surgeons are going to offer laparoscopic surgery to patients with early gastric cancer. This will assure that patients can choose other available treatments including modified open gastrectomy, which is recommended as a standard treatment in GL, and EMR, which is also categorized as a optional treatment in GL.