ObjectiveTo observe the effect of thermal damage in the fresh isolated kidneys of New Zealand white rabbits caused by domestic holmiumlaser. MethodsIn the operation room (constant temperature 22℃, humidity 60%), Guangdong electric (POTENT) domestic holmium laser equipment was chosen. The fresh isolated kidney of New Zealand white rabbit was put into a disposable sterilized syringe with 50 mL normal saline, then the holmium laser optical fiber (550 μm) was put into it, and the temperature of normal saline was measured by a mercury thermometer. The parameters of holmium laser were setted as frequency 20 Hz, energy 2 J, stimulating time 15 seconds, intermittent time 5 seconds, which was repeated. The temperature was measured 2, 5 and 7 minutes after stimulation. Then the kidney was dissected, phtographed, haematoxylin-eosin stained, and pathologically examined.ResultsAt the 2nd minute of stimulation, the temperature of normal saline in the syringe increased from 22℃ to 38℃; the cortex and medulla of rabbit kidney were ruddy, and the cortex, medulla and ureter were almost normal in pathological section. At the 5-minute point, the temperature increased to 57℃, and the cortex turned to be white, while the medulla remained ruddy, but the demarcation between the cortex and medulla was not very clear. At the 7th minute, the temperature was 78℃, and the cortex and medulla were both white and solidification with no clear demarcation. Pathological examination showed severe degeneration and necrosis of glomerulus and renal tubule.ConclusionCommon power of domestic holmium laser would produce increasing thermal damage, which may cause tissue damage in the human body when the temperature increases above 50℃.