830 nm半导体激光照射后兔脑的组织病理学变化

Histopathologic Changes in Rabbit Brains after Thermotherapy with 830 nm Diode Laser

目的观察830 nm半导体激光照射兔脑的病理学变化。方法以输出功率为5、10和15 W及作用时间为5、10、15、20、25、30、35和40s不同组合的半导体激光照射兔脑组织。24 h后空气栓塞处死实验兔,取完整兔脑制备HE染色切片,光镜下观察兔脑毁损灶的组织病理学变化,测量毁损范围。结果兔脑组织毁损灶呈典型的带状改变,自中心向周边分:炭化区、凝固区、水肿区。不同功率与照射时间半导体激光作用后兔脑热毁损灶病理变化相似,毁损灶范围随激光功率与作用时间的增加而逐渐加大。毁损灶外兔脑未发现相似变化。根据实验观察结果建立了兔脑组织毁损范围与半导体激光输出功率和作用时间的对应关系的数学模型。结论830 nm半导体激光具有凝固,切割,气化,止血作用,对周围组织无显著影响。

Objective To investigate histopathologic changes in rabbit brains after thermotherapy with 830 nm diode laser. Methods The experiments were performed in normal rabbit brains using diode lasers, produced by bare fibers of HOP-100 diode laser scalpel, with different output（5,10 and 15 W） and irradiation duration（5,10,15,20,25,30,35 and 40 s）. Twenty four hours after lesion, rabbits were sacrificed by means of air embolism in vein and the brains were dissected. After the histological sections prepared, the histopathologic changes in lesion areas were studied under a microscopy,the diameter of lesions was measured. Results The histopathologic changes in lesion areas surrounding the end of bare fibers showed a distinct zonal architecture, It was a vaporization cavity surrounded with carbonization tissues in the central part of lesion area. Around the central part of lesion area, there was a zonal coagulation characterized by pyknosis, hyperchromasia and dysmorphosis of nerve cell nucleus. In the peripheral part of lesion area, there was a zonal edema characterized by oligochromasia, tissue rarefaction, vascular dilation and hyperemia, as well as infiltration of intlammatory cell. All changes were similar with different output and irradiation duration. The scope of lesion areas enlarged with increase in the output and the irradiation duration. In the other areas, no significant changes were observed. We also established a mathematical model of the relationship between the size of lesion and the diode laser output and irradiation time. Conclusions Diode laser scalpel has local actions of coagulation, incision, vaporization and hemostasis on areas surrounding bare fibers, but no any important affection on the other areas.