摘要：Objective The Effect of different expansion ways, including repeatedly rapid expansion, rapid expansion and conventional expansion, on the ultrastructure and contraction rate of skin was studied to explore the best skin expansion way for the clinical practice. Methods New Zealand white rabbits were randomly divided into five groups: the repeatedly rapid expansion (group A), the rapid expansion (group B), conventional expansion (group C), embedding without expansion (group D) and the control group (group E). After the expansion for 1 week, 2 weeks, 3 weeks, 4 weeks and 6 weeks, the expanded skin flap was observed under transmission electron microscopy to observe the ultrastructure changes, and contraction rate was calculated by measurement of sub-grid method. Results After expansion for one week, basal cells of group A, B, C were in columnar shape and there were a few cytoplasm filaments on the surface. The basement membrane partly ruptured. There were great number of rough endoplasmic reticulums in fibroblasts cytoplasm. The number of mitochondria increased. The cell function was most active in group A. After expansion for four weeks, the cell basement membrane in group A, B, C restored the normal structure. The cytoplasm of fibroblast cell reduced apparently and there were fusion of mitochondrial membrane or ridge. The contraction rates of group A, B, C and D were higher than that of group E (P<0.05); The contraction rates of group A, B and C had a decreasing trend. After expansion for 1,2,3,4 weeks, the contraction rates of group A and C were lower than that of Group B (P<0.05). After expansion for 1, 2, weeks, the contraction rates of group C were lower than that of Group A (P<0.05). Conclusion The repeatedly rapid expansion may obtain the same contraction rates and quality of skin flap, while shorten the clinical period.%目的 研究反复快速扩张、单纯快速扩张及常规扩张对皮瓣的超微结构和回缩率的影响,以探讨适合于临床的最佳皮肤扩张方式.方法 用兔制备动物模型,随机将动物分为反复快速扩张组(A组)、单纯快速扩张组(B组)、常规扩张组(C组)、植入不扩组(D组)和正常对照组(E组),扩张后分别维持1周、2周、3周、4周以及6周,透射电镜下观察扩张皮瓣超微结构的变化,分格测量法计算回缩率.结果 透射电镜观察:维持扩张1周后,A、B、C三组的基底细胞胞质可见少量的表面张力细丝,基底膜部分断裂,成纤维细胞胞质内,有丰富的粗面内质网,线粒体数量明显增加,A组的细胞功能最为活跃；维持扩张4周后,A、B、C三组基底膜基本恢复,成纤维细胞胞质内,细胞器数量明显减少,线粒体大部分嵴或膜融合.回缩率比较:A、B、C及D组在相同扩张维持期,回缩率均高于E组；A、B、C组回缩率随时间延长均呈下降趋势；A、C组与B组比较,维持1、2、3和4周,回缩率均下降；A组与C组比较,维持1和2周,回缩率增加.结论 采用反复快速扩张方式,能获取回缩率及质量相同的皮瓣,并可缩短疗程.
