右側臥位による内視鏡検査法の有用性―linitis plastica型スキルス胃癌の早期発見のために

Usefullness of Gastrofiberscopic Examination in Right Recumbent Posture: Early Detection of Linitis Plastica Type Schirrous Gastric Cancer

要旨　胃の実測立体模型を作製して左右側臥位の内視鏡像の違いを検討し，胃体部の観察には従来の左側臥位よりも右側臥位のほうが合理的であることが明らかとなった．左側臥位のみの内視鏡検査で7年5か月間に発見した96例の胃癌と，右側臥位での検査を追加した内視鏡検査で4年間に発見した胃癌50例のCMA領域別の早期癌比率を比較すると右側臥位を併用して以降はC領域40％，M領域39％，A領域41％と均一で，従来の左側臥位のみの検査での早期癌発見率の部位による偏りがなくなった．また小彎側への偏りも改善され，胃体部大彎の胃底腺および腺境界領域に深達度mの3例の未分化型早期癌と1例の分化型早期癌も発見されている．検査体位としての右側臥位の併用は，内視鏡検査における盲点の改善に寄与するものと思われた．

　Up until this time, gastrofiberscopic examination has usually been performed in the left recumbent posture in our country. It is true that the left recumbent posture is suited for expanding the antral and angular regions of the stomach during the examination. The gastric body, however, is not always expanded well in that posture. Therefore, the author thought that in order to observe well the upper part of the stomach, above the angle, gastrofiberscopic examination in the right recumbent posture would be more reasonable than in the left recumbent posture.

　To examine the validity of that hypothesis the author manufactured three-dimensional and actual sized transparent resinous models of the stomach based on the measurement of the author's stomach by CT scanning in both right and left recumbent postures for endoscopic examination.

　Gastric body of the left recumbent model was compressed because of the hepatic weight on the lesser curvature. The lesser curvature was thus elongated, flat and ellipse on the cross section. The gastric body of the right recumbent model, on the contrary, was expanded like a rugby ball resulting in the longer distance between the lesser and greater curvatures. The lesser curvature of the right recumbent model, however, was half as long as that of the left recumbent model.

　Since June, 1985 the author tried to perform gastrofiberscopic examination in the right recumbent posture in addition to the routine method in the left recumbent posture in all cases. This effort made it possible to detect flat minute cancerous lesions between the folds of the greater curvature of the gastric body.

　In group "A" of 2,631 cases in which the conventional endoscopy in the left recumbent posture was performed, 96 cases of gastric cancer were detected in 7 years and 5 months from January, 1978 to May, 1985. In group "B" of 1,554 cases in which the right recumbent examination was added to the conventional one, 50 cases of gastric cancer were found in 4 years from June, 1985 to May, 1989. The proportion of early gastric cancer among all cancer was compared between group A and B according to CMA divisions of the stomach. The early gastric cancer rate for group B was about 40% in each CMA division, i.e., 40% in the C division, 39% in the M and 41% in the A.

　As to the distribution of the lesions of early gastric cancer the lesser curvature side was more involved than the greater curvature side (21/10) in gruop A, in contrast to the even distribution of both curvatures (10/10) in group B.

　Therefore, to help solve the problem of dead angle or blind spots in endoscopy, additional procedure in the right recumbent posture to the conventional way seems to be useful and effective.