胃癌の切除範囲をどう決めるのか―X線・内視鏡診断と術中色素散布法

How to Determine the Resection Line in Gastric Cancer: Radiographic and Endoscopic Diagnosis and Intraoperative Dye-spraying Method

要旨　胃癌の手術で胃の切除線を決定する方法について述べ症例を呈示した．①噴門部癌食道浸潤範囲の診断：通常はX線，内視鏡で食道粘膜表面の状態を描出すればよい．しかし癌が食道の管腔表面には露出せず粘膜固有層を浸潤することがあるので，病巣の口側粘膜の生検を行っておくことが必要である．②粘膜内の癌浸潤範囲の診断：(A)術前診断：X線，内視鏡で境界が鮮鋭な場合は，その口側を生検し癌陰性であることを確かめておけばよい．口側が随伴Ⅱb，Ⅱb，浅いⅡcを示す場合は以下の手順が有用である．(a)境界と思われる部にクリッピングを行う．(b)留置されたクリップの口側より生検を行い，口側に癌がないことを確かめる．(c)その後にX線検査を施行し，食道胃接合部よりクリップまでの距離を確認する．(d)このとき，クリップを目安として病変部境界がバリウムの付着異常として描出されればなおよい．(B)術中診断：術前にクリップなどで癌浸潤範囲が“線”として確認できていればクリップを目標に切除線を決定する．術前診断が不十分であればopen gastrectomyを行い，色素を散布して粘膜面の微細な変化を確認したうえで切除線を決定する．以上の論旨に基づき症例を呈示した．

　Means for determination of the proximal resection line in gastric cancer were described and cases were presented.

　1. Diagnosis of the border of esophageal infiltration in cardial cancer: It is ordinarily sufficient to demonstrate the mucosal surface of the esophagus clearly by radiography and endoscopy. However, as in some cases, cancer is not exposed to the luminal surface but infiltrates the lamina propria, it is required to take biopsy specimens from the mucosa proximal to the cancerous lesion.

　2. Diagnosis of the extent of intramucosal cancerous infiltration:

　A. Preoperative diagnosis: In case the border of the extent of the cancer is clear-cut, it is sufficient to confirm by biopsy that the proximal mucosa is cancernegative. When there is an associated Ⅱb, Ⅱb or shallow Ⅱc lesion in the proximal mucosa, the following measures are useful. 1) Clips are wedged along the endoscopically suspected border. 2) Biopsy specimens are taken from the sites proximal to the wedged clips to confirm that the proximal mucosa is cancernegative. 3) Subsequently an upper gastrointestinal series is performed to confirm the distance from E-G junction to the clips. 4) It is more satisfactory if the border of the lesion is finely demonstrated on x-ray films as a difference of barium coating.

　B. Intraoperative diagnosis: When the border of the cancerous lesion is clearly recognizable as a line on preoperative examinations, the resection line is determined by wedged clips as a mark. When preoperative diagnosis is insufficient, the dye-spraying method under an open gastrectomy is employed to confirm minute changes of mucosal pattern and to determine the resection line. Cases were presented based on the description outlined above.