[Experimental study and clinical application of composite skin grafting]

To explore an ideal skin substitute with its appearance and texture similar to normal skin, to repair wounds with full-thickness skin defect.

Composite skin (CS) in question was composed of allo/xenogeneic acellular dermal matrix (ADM) and razor thin autoskin. One step skin grafting was employed in the experimental study and clinical trial. Razor thin autoskin alone was used as the control in the study. Changes in the antigenicity of ADM and the reformation of basement membrane (BM) structure at epidermis-dermis junction (EDJ) of ADMs were studied at designated time points after the grafting with biochemical and immunohistochemical methods. Fifty-three patients with full thickness skin defects due to various causes, including scar excision were grafted with CS, and survival rate and long-term result were observed.

The grafted CS survived satisfactory. The reformation of the basement membrane structure was clearly observed at the 28th post-graft week. The basement membrane cells grew with polarization in an undulating arrangement. There was reformation of dermal papillae and ridges. The antigenicity of allo-ADM was obviously lower than that of xeno-ADM. Sixty-five out of 70 pieces of CS grafting (92.9%) survived totally, two of them survived partially, and three failed due to infection. The longest follow-up period was 8 and a half years. The grafted CS appeared similar to the normal skin in regard to the texture and color, especially allo-ADM, and no evident rejection reaction was seen.

ADM possessed very low antigenicity, thus serving a lasting framework after grafting. In addition, it could serve as a "dermal template" for the induction of tissue regeneration.