抄録
We have been deveroping new laser device for orthopedic surgery. Although various kinds of laser have become to utilize to these devices, their reaction to the living tissue has not been clarified yet. The objective of this study is to compare the tissue reaction difference between high output diode laser, Erb: YAG laser, Nd: YAG laser and Electrocautery. Rat gluteal muscle was used for this study. Immediatly after cutting muscle with these instruments, specimens were treated for histological observation with light microscope and Scanning Electron Microscope (SEM). A fiber chip was used for tissue cutting with CW lasers. Four layers of heat influences were observed in very wide range with electrocautery cutting; from surface, char layer, necrotic layer, degeneration layer transient zone and normal layer. These four layers were also recognized on the tissue with CW laser cutting such as diode laser and Nd: YAG laser. On the other hand, the cutting surface by Erb: YAG laser with high peak power and few Hz of pulse rate condition, was very sharp, and almost normal tissue was naked under the microscopic and SEM observation. However, very thin layered heat influence appeared on the surface at the irradiating condition of low peak power and above several Hz of pulse rates.
