ENDOSCOPIC Nd-YAG LASER TREATMENT FOR EARLY GASTIC CANCER USING ULTRASONIC ENDOSCOPE

-EXPERIMENTAL AND CLINICAL STUDIES ON JUDGEMENT OF THE EFFECT AFTER LASER THERAPY-

Abstract

Ultrasonic endoscope is extremely useful for judgement of the effect after laser irradiation to early gastric cancer. The regions of coagulaed degeneration and necrosis irradiated by Nd-YAG laser are visualized hyper echoic on the image of an ultrasonic endoscope. By using ultrasonic endoscope immediately after laser therapy, we can correctly diagnose the area and depth of the effect of laser irradiation. We can judge laser therapy for early gastric cancer to be effective when a low echoic area of cancer lesion is observed to change to a hyper echoic region, or when a hyper echoic region is recognized to reach the submucosal layer. Until now, it has been difficult to diagnose the effect after laser irradiation whether cancer celles remain on the border or below of laser irradiated area. But using ultrasonic endoscope together with laser endoscope, we could solve these problems and treat early gastric cancer by laser photocoagulation more precisely.