Abstract
Nd-YAG laser was irradiated to the normal membranous portion of dog's trachea over one to four rings in the direction of major axis at 40W×2 seconds for a total of 14 places of 7 dogs and chronological changes from the pathological aspects were discussed. Each irradiation was applied at the distance of 10mm and by the angle of 30°C with the continuous wave until the mucous membrane turned white. The average dose was 650 joules per cm2. The chronological changes after irradiation were classified into the ulceration stage, granulation stage, and scar stage The depths of irradiation reached to adventitia in the 7 places out of 9 which was irradiated over two rings or more in the direction of major axis. We should irradiate very carefully to the perforation of the membranous portion which is consisted without cartilage tissue.
