长脉宽1064 nm Nd:YAG激光对兔耳软骨组织学及生物力学的改变

Histological and biomechanical changes of rabbit ear cartilage induced by long pulse width 1064 nm Nd:YAG laser

目的探讨长脉宽1064 nm Nd:YAG激光对兔耳软骨组织学及生物力学的改变情况。方法选择新西兰兔7只,体质量2.0~2.5 kg,雄性,4~6个月龄。进行自身对照,右耳为激光照射组,左耳为正常对照组。每只兔耳划分1个3 cm×1 cm,3个2 cm×1 cm,1个1 cm×1 cm实验区域。对照组无特殊处理。激光照射组采用长脉宽1064 nm Nd:YAG激光对激光照射组实验区域照射后,即刻切取实验兔双耳各3块2 cm×1 cm软骨进行HE、天狼星红、Masson染色,观察软骨细胞组织学变化;切取每只兔耳3 cm×1 cm、1 cm×1 cm软骨行生物力学检测,观察术后即刻兔耳软骨的拉伸、断裂、弹性模量、压缩等生物力学特性改变。结果组织学观察显示激光辐射带上软骨细胞变小,基质染色深,折光明显,胶原相对增多。经长脉宽1064 nm Nd:YAG激光照射后,激光照射组兔耳软骨所得拉伸应力峰值、拉伸弹性模量、拉伸断裂载荷、压缩应力峰值、压缩弹性模量、压缩破坏载荷分别为(5.22±0.80)MPa、(42.40±9.78)MPa、(22.86±4.85)N、(16.04±5.57)MPa、(28.71±13.97)MPa、(1211.63±427.86)N,均小于对照组的(6.07±0.64)MPa、(48.44±6.30)MPa、(26.94±4.91)N、(25.12±9.10)MPa、(45.30±19.24)MPa、(1962.83±896.71)N,差异均有统计学意义(P<0.05)。结论长脉宽1064 nm Nd:YAG激光作用后的兔耳软骨抵抗弹性变形的应力减小,形态更易改变,重塑形效果更稳定。

Objective To investigate the histological and biomechanical changes of rabbit ear cartilage induced by long pulse width 1064 nm Nd:YAGlaser.Methods Seven New Zealand rabbits weighing 2.0-2.5 kg,male,4-6 months old were selected.For a self-control,the right ear was irradiated by laser and the left ear was the normal control group.Each rabbit ear was divided into 3 cm×1 cm,three 2 cm×1 cm and 1 cm×1 cm experimental area.After the experimental area of the laser irradiation group was irradiated by long pulse width 1064 nm Nd:YAG laser,Three pieces of 2 cm×1 cm cartilage in each ear of the experimental rabbits were immediately cut and stained with HE,Sirius red and Masson to observe the histological changes of chondrocytes.The 3 cm×1 cm and 1 cm×1 cm cartilage of each rabbit ear was cut for biomechanical examination,and the changes of biomechanical properties such as tension,fracture,elastic modulus and compression of rabbit ear cartilage were observed immediately after the operation.Results Histological observation showed that the chondrocytes became small,the matrix was stained deeply,the refraction was obvious/evident and the collagen was relatively increased.After being irradiated by long pulse width 1064 nm Nd:YAG laser,the peak tensile stress,tensile elastic modulus,tensile fracture load,compressive stress peak,compressive elastic modulus and compressive failure load of rabbit ear cartilage in laser irradiation group were(5.22±0.80)MPa,(42.40±9.78)MPa,(22.86±4.85)N,(16.04±5.57)MPa,(28.71±13.97)MPa,(1211.63±427.86)N.All of them were smaller than those of the control group[(6.07±0.64)MPa,(48.44±6.30)MPa,(26.94±4.19)N,(25.12±9.10)MPa,(45.30±19.24)MPa,(1962.83±896.71)N],and the difference was statistically significant(P<0.05).Conclusions After the operation of long pulse width 1064 nm Nd:YAG laser,the stress of rabbit ear cartilage resisting elastic deformation is reduced,the shape is easier to change,and the remodeling effect is more stable.