保留不同厚度脂肪组织对猪烧伤创面收缩的影响

The influence of retention of different amount of fat on wound contraction of burn in pigs

目的:研究在烧伤创面愈合过程中脂肪组织与创面愈合速度和创面收缩率的关系,并探讨其机制。方法:小型香猪6头,用固体汽油燃烧50s制成背部2.5cm×2.5cm全层皮肤烧伤创面,随机分为3组:未保留脂肪组织组,1/2脂肪组织保留组及全层脂肪组织保留组。各组创面切痂后保留相应的脂肪组织,并用大体观察、光镜、电镜、免疫组化等方法观察比较不同创面的愈合速度和创面收缩率。结果:保留不同厚度的脂肪组织对创面的愈合速度没有影响,3组愈合时间分别为(26.25±1.60)d,(27.28±1.97)d和(26.41±1.83)d,3组比较无统计学差异。但脂肪组织的存在可明显影响创面的收缩率:两保留脂肪组的创面收缩率明显少于未保留组(P<0.01)。与保留脂肪组对比,未保留脂肪组伤后7d肉芽组织中血管增生及细胞增生均较差,肌成纤维细胞出现早,早期创面修复组织中胶原纤维由细、短转化为粗、长纤维所用时间明显缩短。14d时未保留脂肪组新生组织中胶原束较厚,肌成纤维细胞含量高,弹性纤维增生较重。电镜下未保留脂肪组肌成纤维细胞浆内可见到大量粗面内质网及分泌颗粒,波形核膜及微丝等结构。而保留脂肪组虽然也可见具有肌成纤维细胞特点的细胞,但其微丝结构较少。伤后2个月3组瘢痕在组织结构上无明显差别。结论:脂肪组织可能影响早期创面的愈合机制。保留脂肪组织有利于提高创面的愈合质量。

Objective： To evaluate the effects of adipose tissue in wound healing by observing the healing time and the rate of wound contraction,and to explore the mechanism of these effects. Methods：Whole thickness burned wound was produced with napalm flame in 6 pigs. The healing time and the rate of wound contraction of wounds with retention of whole layer of subcutaneous fat （n=2） ,or with half of amount of subcutaneous fat（n=12）, and total excision of fat（n=12） in burned pigs were compared after excision of eschar by observation with naked eye, light microscope , electron microscope and immunohistoehemistry methods. Results： There was no difference in healing time among the three groups [（26.25±1.60）d, （27. 28±1. 97）d and （26.41±1. 83）d, P〉0.05]. On the other hand , the amount of retained adipose tissue can obviously affect the rate of wound contraction. The wounds with retention of whole layer of subcutaneous fat and half amount of subcutaneous fat were seen to be less contracted than that with removal of all fat layer（P〈0.01）. The microvascular density in wound with whole subcutaneous fat group and half amount of subcutaneous fat group were heavier than that with all fat removed group 7 days after excision of eschar. In total fat removal group, fibroblasts appeared earlier and the collagen fibers were thicker and longer than that in the two other groups 14 days after excision of eschar. Under electron microscope, there were more rough endoplasmic reticulum, secretory granule,crumpled nuclear membrane, and with fibriles in fibroblast. There was little difference in histological picture among the three groups 2 months later. Conclusion： These results suggest that adipose tissue may possibly exert some influence on healing of burn wound in early healing period. Retention of adipose tissue in burn wound can improve the quality of wound healing.