早期胃癌に対する腹腔鏡下手術―外科の立場からみた内視鏡的粘膜切除への提言

Indications for Laparoscopic Curative Surgery for Early Gastric Cancer, with Different Indications for Endoscopic Mucosal Resection

　要旨　われわれは早期胃癌の中でも，①術前深達度診断でm，②Ⅱaでは長径25mm以下，③Ⅱcでは長径15mm以下かつUl（－）を満たす症例に対して，リンパ節転移の危険性がほとんどないことから局所切除の適応と判断し，lesion lifting法による腹腔鏡下胃局所切除術ならびに腹腔鏡下胃内粘膜切除術の2種類の手術を積極的に実施してきた．これらの手術と内視鏡的粘膜切除（EMR）との相違は，腹腔鏡下手術では水平方向，垂直方向ともに十分なsurgical marginを確保した一括完全切除と，その組織を用いた十分な病理組織学的検索がより確実に行えることである．当教室では一括完全切除を根治切除の原則とする立場から，EMRの適応を長径10mm以下としている．悪性疾患とはいえ外科的切除によりほぼ完治が期待される胃粘膜癌に対しては根治性の確保が最も重要である．EMRや腹腔鏡下手術の今後の発展を期待するうえでも，適応については厳格な対応が重要であり，完全切除を確認しえない場合や，経過観察中に癌の局所再発を認める症例では躊躇せず手術による根治的治療を実施すべきである．

　The detection rate of early gastric cancer has been increased by an established screening system and popularization of the videoendoscope. Local resection for early gastric cancer can be accepted as curative only in cases where there is 1) no lymph node metastasis, 2) resectability with sufficient surgical margin, 3) availability of histopathological investigation of the resected specimen. From these standpoints, our indication for curative local resection is as follows ; 1) mucosal cancer, 2) ≦25 mm, if the lesion is the protruded type, 3) ≦15 mm and ulcer (－), if the lesion is the depressed type. Laparoscopic surgery can be applied in these cases, but endoscopic mucosal resection (EMR) should be applied only in selected cases such as cancers smaller than 10 mm in diameter and, histologically, welldifferentiated type.

　We have successfully treated 40 patients with early gastric cancer by using two different laparoscopic procedures since March 1992. These procedures are laparoscopic wedge resection of the stomach using a lesionlifting method (n＝25) and laparoscopic intragastric mucosal resection (n＝15) . All patients were discharged within 4-8 days uneventfully. The resected specimens were 66±16 mm and 48±8 mm in diameter respectively, and had a sufficient surgical margin horizontally and vertically. Histology revealed they were all curative surgeries except for one case in whom an additional gastrectomy with lymph node dissection by laparotomy was required one month after surgery because lymphatic invasion had been revealed by pathology.

　In conclusion, endoscopic and laparoscopic treatment for early gastric cancer should be applied only for selected cases after precise preopertive evaluation.