Nd:YAG激光对兔咽部黏膜热损伤的研究

Nd:YAG laser thermal injury on rabbit pharynx mucosa

目的 :探讨Nd :YAG激光功率密度与黏膜组织热损伤程度的关系 ,以及激光照射后黏膜组织愈合的过程。方法 :激光功率密度 2 2 1W/cm2 (10W )、4 4 2W /cm2 (2 0W )、6 6 3W /cm2 (30W )、884W /cm2 (40W ) ,持续时间 5s ,非接触照射新西兰兔舌和咽后壁黏膜组织 ,测量急性热损伤的深度 ;相同剂量照射兔咽后壁 ,术后 1、3、7、14d观察咽后壁愈合情况。结果 :2 2 1W/cm2 (10W )时 ,组织热损伤深度为 0 32～ 0 53mm ;4 4 2W /cm2(2 0W )时 ,为 0 .6 1～ 1.2 7mm ;6 6 3/cm2 (30W )时 ,为 1.2 2～ 1.76mm ;884W /cm2 (40W )时 ,为 1 6 8～ 2 2 9mm。激光照射后 ,黏膜组织主要表现为凝固性坏死和继发性炎症反应 ,创面愈合过程主要是创面炎症渗出和表皮凝固坏死痂皮下直接愈合。组织热损伤深度随激光功率密度增强而增加。结论 :在激光治疗中 ,采用适宜剂量参数的Nd :YAG激光非接触照射安全。

Objective:To assess the relation between the degree of tissue thermal injury and the power density of the Nd:YAG laser.Methods:The tissues of New Zealand breed rabbits was uncontactly irradiated by Nd:YAG laser for 5 seconds at 10W(221W/cm 2),20W(442W/cm 2),30W(663W/cm 2),40W(884W/cm 2) of output power of the end of the optical fibre.The depth of thermal injury of tongue and pharyngeal mucosa were examined immediately after irradiated by laser.The pharyngeal mucosa was treated with the same output power.Biopsy taken at 1,3,7,14 days after irradiation was examined and analyzed using histopathological methods.Results:The depth of thermal injury was 0.32～0.53mm at 10W(221W/cm 2).0.61～1.27mm at 20W(442W/cm 2),1.22～1.76mm at 30W(663W/cm 2),1.68～2.29mm at 40W(884W/cm 2).Coagulation and inflammation were found in the tissue irradiated by laser.The wound was repaired by the epithelium around the lesion.Conclusion:The Nd:YAG laser uncontact irradiation with appropriate parameter is effective and safe.