长脉冲1064nm Nd：YAG激光治疗兔耳增生性瘢痕的实验研究

Therapeutic efficacy of long-pulsed 1064 nm Nd ：YAG laser on hyperplastic scar in rabbit ear model

目的通过建立兔耳增生性瘢痕模型，评价长脉冲1064nm激光治疗增生性瘢痕的疗效。方法选用新西兰长耳白兔10只，雌雄各半，体质量2．0～2．5kg。在所有兔耳腹侧面建立增生性瘢痕模型，每只兔耳4处1．5cm×1．5cm正方形造模。10只兔子共80个创面形成增生性瘢痕74处，将左侧和右侧兔耳增生性瘢痕块分为对照组和治疗组，治疗组应用长脉冲1064nm激光照射，对照组未予治疗。30d后观察实验组及对照组瘢痕的颜色、质地；彩色超声测量瘢痕厚度；瘢痕取材，HE染色和CD31免疫组化染色，记数瘢痕成纤维细胞密度和微血管密度；Masson染色观察胶原纤维。结果激光治疗组较对照组瘢痕颜色变浅，质地变柔软，瘢痕厚度变薄，对照组瘢痕的平均厚度为3．089mm，治疗组为2．137mm，两组比较，t=5．72，P〈0．01。对照组血管密度均值为68．056个／mm^2，治疗组为38．333个／mm^2，两组比较，t：4．93，P〈0．01，治疗组血管密度较对照组明显降低。成纤维细胞数量均值对照组为355．000个／mm^2，治疗组为166．940个／mm^2，两组比较，t=13．36，P〈0．01，治疗组成纤维细胞数量明显减少。Masson染色观察对照组胶原纤维排列紊乱，治疗组胶原纤维排列疏松，规则。结论长脉冲1064nm激光可以促进早期增生性瘢痕消退，对瘢痕增生具有抑制作用。

Objective To evaluate the therapeutic effect of long-pulsed Nd：YAG 1064 laser on hyperplastic sears by using a rabbit ear model. Methods Five female and five male New Zealand long-ear white rabbits weighting 2.0 - 2.5 kg were used in this experiment. Four square full-thickness skin wounds sized 1.5 cm × 1.5 cm were created on the ventral surface of each ear to develop a model of hyperp]astic scar. Finally, a total of 74 hyperplastie sears developed on the 80 wounds, and the scars on the left and right ears served as the control （unirradiated） and treatment （irradiated with long-pulsed 1064 nm Nd：YAG laser） group, respectively. After 30 days of irradiation, the color and texture of scars were observed and the scar thickness was measured by color Doppler ultrasonography. Then, the sears were harvested followed by the analysis of density of fibro- blasts and mierovessels as well as the changes in collagen fibers in scars by HE staining, CD31 staining and Masson staining, respectively. Results A decrease was observed in the color, hardness and thickness of scars in the irradiated ears compared with the unirradiated ears. The average thickness of scars, microvessel density and fibroblast density in scars were significantly lower in the treatment group than in the control group （2.137 vs. 3.089 nm, t = 5.72, P 〈 0.01; 38.333/mm^2 vs. 68.056/mm^2, t = 4.93, P 〈 0.01; 166.940/mm^2 vs. 355.000/mm^2, t = 13.36, P 〈 0.01 ）. Masson staining revealed a disorganized arrangement of collagen fibers in the control group but a sparse and regular alignment in the treatment group. Conclusion Long-pulsed 1064 nm Nd：YAG laser may promote the shrinkage and suppress the hyperplasia of scars.