大鼠深Ⅱ度烧伤创面保留变性真皮并覆盖自体皮疗效观察

目的为探讨自体皮覆盖变性真皮修复深Ⅱ度烧伤创面的可行性提供实验依据。方法在大鼠背部造成直径3.5cm深Ⅱ度烧伤创面。伤后2—5d行创面浅层削痂保留变性真皮,同时在局部移植大张自体断层皮片。移植前和移植后不同时相点分别切取植皮区全层皮肤,光镜下观察其形态学及胶原纤维变化,并检测其生物力学改变。取移植大鼠同体背部正常皮肤作为对照指标。结果(1)保留的变性真皮为玻璃样变性。(2)大鼠自体皮移植术后7d,皮片与创面融合无法分离,光镜下可见真皮乳头及网状层。术后21d移植部位皮肤厚度、结构、形态与正常组织相似,有萎缩毛囊,胶原纤维条索密度逐渐增大接近融合。(3)鼠皮抗拉强度、最大应变值在术后逐渐增大,至60d时接近正常。结论将自体皮覆盖于变性真皮上用以修复深Ⅱ度烧伤创面,变性真皮能够逐渐复苏,使其结构、形态接近正常。

Experimental study of autologous skin grafting on retained denatured dermis for the treatment of partial thickness burn wound

OBJECTIVE: To provide experimental evidence for the feasibility of repair of deep partial thickness burn wounds with autologous skin grafting on retained denatured dermis. METHODS: Deep partial thickness burn wounds 3.5 cm x 3.5 cm in size were produced on the back of SD rats. Superficial tangential excision was performed on the burn wounds on 2 - 5 postburn days with the preservation of denatured dermis. Split thickness autoskin was grafted on the wounds immediately. Tissue samples of whole layer of the skin were harvested from the grafted sites at different time points after the skin grafting, with 8 rats in each group. The morphology and the changes in the collagen fibres in the above tissue samples were observed by light microscopy (LM) and the changes in the biodynamics were determined. The normal skin from the same rat receiving skin grafting was employed as the control. RESULTS: (1) Vitreous degeneration was observed in the preserved denatured dermis. (2) The grafted skin was fused to the burn wound on the 7th day after autoskin grafting in rats. The dermal papillae and reticular layer could be discernible under LM. The thickness, structure and morphology of the skin on the grafted area were similar to normal tissue on the 21st day after grafting with atrophic hair follicles. The density of collagen fiber cord increased gradually, and almost fused at last. (3) The tensile strength, and maximum strain value of the rat skin after operation increased gradually, approaching normal on 60 post-operational day. CONCLUSION: The denatured dermis can recover gradually with normal structure and morphology after the application of autoskin on it for the repair of deep partial thickness burn wounds.