Changes of biomechanical properties and collages of expansive skin in different maintenance and expansion periods / 中华医学美学美容杂志

ABSTRACT

Objective The study was to investigate a new method of rapid expansion by biomechanical methods. Methods Dogs were set up as animal models. Six areas, 5 cm?8 cm each, were symmetrically designed on a dog. Expanders of 240 ml were implanted in each area. Four groups were divided A. Injection of 2 weeks. B. Injection of 6 weeks. C. Sham operation group. D. Blank control group. The first two groups were subdivided into three groups respectively according to maintaining times one week, two weeks and four weeks. The following indexes were measured on the second stage surgery biomechanical properties of the skin, stress strength, stress strain, stress relaxation and creep, the collagen content and alignment of skin. Results After expansion, maximal stress strength fell off, and stress strain curve moved backward. Relaxation curve fell off as well, as creep curve rose up. With elongation of the maintaining period, viscoelasticity of the skin gradually approximated normal skin, and had less relation with injection time. With the maintaining period increased, the collage content increased distinctly, and the alignment became much order. Conclusion Two week maintaining period is very important for expanded skin to recover the biomechanical properties and the content of collagen and alignment.