赤外レーザー内視鏡による胃癌の深達度診断

抄録

Infrared (IR) laser endoscopy was applied to the diagnosis of the depth of invasion of early gastric cancer. The beam of IR laser produced by a krypton dye laser was led to the gastric lumen by the light guide bundle of a gastrofiberscope or by a fiber bundle through a foreceps channel of an electronic endoscope. The lumen was illuminated by the laster with an output of 200 to 400 mw at a wavelength of 805 nm. IR images were visualized on the TV monitor by an IR vidicon attached at the eye piece of the fiberscope or a CCD at the tip of the electronic endoscope. The vessels of the gastric wall were observed in positive image. Then, 1 to 5 mg/kg of indocyanine green (ICG) which had the maximum absorption peak at 805 nm, was injected intravenously to enhance the vascular network of the deeper layers.
Fifty-four cases were examined by this method. The characteristic findings of IR laser endoscopy are as follows;(1) disappearance of normal vascular network with thin stain in mucosal carcinoma, (2) thick stain and pooling phenomena in submucosal one. Further, these are confirmed in part by endoscopic ultrasonography The method using the electronic endoscope was superior in the manipulation to that us ing the fiberscope and the IR vidicon, but more improvements were required in the quality of IR images.