An Experimental Study on the Bladder Tissue Damage with Neodymium-YAG Laser Irradiation in Rabbit

Kwon, Sung Won

Abstract

In the surgical use of lasers in medicine, the laser light energy is transformed into heat within the tissue. As the result of this generation of heat, coagulation occurs and the tissue is carbonized and vaporized. The thermal effect depends upon the energy of the light radiation, its power and the irradiation time, the beam geometry, and the optical properties of the tissue itself, and also upon the thermal .parameters of the tissue such as its thermal conductivity and specific heat. In this experiment, to investigate the Neodymium-YAG laser effect on the bladder tissue and the extend of tissue damage at the various power and irradiation time under the same laser energy were aimed. Immediate after irradiation, the bladder tissues were fixed with formalin solution and H& E stained The extend of tissue damage was examined with light microscope. The following results were obtained: The effect of Neodymium-YAG laser irradiation on the bladder tissue was like a burn effect. Although the energy delivered to the tissue was the same, the resultant lesions created by the energy differed. The delivery of same energy in a low-power, long-duration manner made more tissue damage than a high-power, short-duration. Judging from the results of this experiment, it may be believed that a long period of irradiation time that there is sufficient time for the heat to be conducted into the surrounding tissue increases the zone of thermal damage and the coagulation necrosis.