RESUMEN
【Objective】 To investigate the effects of 450 nm diode blue laser on the morphological changes and thermal damage of renal pelvis under different conditions. 【Methods】 An ex vivo study was conducted on a fresh porcine pelvis model (7 cm×5 cm×3 cm). The laser fiber was fixed on the mechanical arm perpendicular to the renal pelvis tissue, and the distance between them was 1-2 mm. The renal pelvis tissue was incised at a speed of 1-2 mm/s and power of 5-30 W. After the incised tissue was fixed in formalin (4%), the morphology, depth, width and coagulation thickness were observed with naked eyes and a microscope. 【Results】 The different powers had different vaporization and incision effects. When the operating distance was 2 mm, the speed was 2 mm/s and power was 5 W, the vaporization depth, width and coagulation thickness were approximately 0 9 mm, 0.25 mm and 0.35 mm, respectively. With the increase of power, the vaporization width and depth increased, and the coagulation thickness was 0.35-0.50 mm. When the power was more than 10 W, the renal pelvis tissue was easily penetrated. When the laser power was 20 W, the section of the renal pelvis showed an irregular shape of vaporization. When the operating distance was 1 mm, the whole renal pelvis tissue was easily vaporized. When it was 2 mm, a wide and safe energy treatment window was produced. 【Conclusion】 The 450 nm diode blue laser can vaporize and incise renal pelvis tissue safely and effectively, with high precision and little thermal damage. It is expected to be a new surgical tool in the treatment of renal pelvis lesions.
RESUMEN
This study describes the acute and chronic responses of brain tissue to injury by nonfocused argon (Ar) laser beam with equal power density.Cortices of 26 rabbits were exposed to laser pulses for 6 s and examined 0.5 hour, 24 hours, half a month and 1 month after injury respectively.Histologically, all brain tissues were sharply demarcated by hemispheroidal defects with a vaporized center surrounded by a zone of coagulation, necrosis and edema.The depth of this vaporized center is 2 mm, and the width is 3mm.The width of the zone of coagulation, necrosis and edema was less than 1 mm.The thermal damage caused by the argon Laser beam was minimal in the surrounding tissue.One Month after injury, a core of coagulation and necrsis surrounded by mild fibrillary gliosis was observed.