Kiyoji Motomura

Comparative Study on Excimer, CO2 and Nd: YAG Laser for Biological Tissue Cutting

The mechanism of biological tissue cutting was investigated using excimer laser compared with CO2 and ND-YAG lasers. Tissue cutting by excimer laser is different from others. Tissues are cut sharply, and bleeding from tissue can not be coagurated by using excimer laser. No or a minimal thermal effect can be observed from the postoperative tissues. Many hypotheses have been published the mechanism of tissue cutting by excimer laser; thermal effect, photochemical effect, photon effect, plasma effect and others. From thermographic analysis and histological studies, we confirmed that biological tissues are destroyed by cutting organelle, especially mitochondria. Cells and tissue blow out following to the organelle explosion. It is true that the generation of heat causes and sometimes makes carbonated layer. But the generation of heat is the result following to tissue explosion, The energy balance, between generated and lost heat, makes defferences of tissue effect.