扩张皮肤移植后的生物力学变化

Biomechanical changes after transplantation of expanded skin

目的:探讨扩张皮肤移植后的生物力学变化。方法:成年狗8只,每只背部置入4个150ml扩张器,两个不扩张作为对照。注水8周取出扩张器,扩张组:切取标本后形成和基底大小一致的皮瓣原位移植;对照组:一侧切取标本,另一侧取出扩张器后皮瓣原位缝合,以作远期观察。然后随机将8只狗平均分为4组,皮瓣移植后3周、6周、3个月、6个月时在实验部位取1cm×4cm大小的皮肤3块,分别进行应力-应变、应力松弛、极限抗拉强度测定。结果:扩张后皮肤的粘弹性及强度均下降,前者于移植后半年恢复,后者恢复较慢,移植后6个月仍未完全恢复。结论:皮肤扩张后的改变是一种暂时的现象,扩张皮肤于移植后6个月物理特性基本恢复正常。

Objective To study the biomechanical changes after transplantation of expanded skin. Methods 8 adult dogs were used. On each animal＇s back, four 150ml rectangular expanders were implanted beneath the skin and panniculus carnosus bilaterally under general anesthesia. Two of them were selected as controls. Expanders were filled to capacity by weekly injections over a 8-week period. One week after the final injection, expanded flaps were raised and replaced its bed without tension after the skin samples were taken from the distance. In the control groups, the specimens were taken as above at one side of dogs, another side, flaps were elevated and sutured in place. Then 8 dogs were equally divided into four groups. 3 weeks, 6 weeks, 3 months and 6 months after inset of the flaps respectively, the specimens were taken to test biomechanical proterties in stress-strain, stress relaxation, tensile strength. Results The viscoelasticity and strength of expanded skin weakened. The former recovered half a year later, but the latter was slower, it did not return to normal even 6 months post-inset. Conclusion The changes after skin expansion were temporary. 6 months post-transplantation, its physical properties returned to normal.