Nd: YAG laser has been evaluated to act the living tissue by its thermal effect and coagulation. Many urologists have carried out by using Nd: YAG laser for the urological surgery, i. e.. transurethral laser surgery of bladder tumor (TULS-BT), laser plasty of urethral stricture and laser lithotripsy. Most of the reports were concentrated in the high power effect to the tissue irradiated, while the effects of lower power laser have not been concluded in terms of the relations between power density and tissue damage. In this report, we tried to demonstrate the relationship between the laser power and tissue damage, which was investigated by H-E staining and enzyme histochemistry using Alkaline phosphatase.
Al-P staining was performed after the irradiation. Compared with H-E staining, the lesions of carbonization, coagulation and edematous changes became negative for Al-P staining, and were clearly distinguished from surrounding positive area. Therefore; Al-P staining showed useful to determine the extent of the laser thermal effect. It became clear that thermal effect was induced even in the lower safety power of Nd: YAG laser.
