[Artificial dermis]

An artificial dermis, composed of an inner layer of collagen sponge and an outer silicone layer, was developed by modifying the material reported by Yannas et al. When the artificial dermis is placed on full 14-thickness skin defects, the pores of the inner collagen sponge are infiltrated by fibroblasts and capillaries. This cell-infiltrated membrane is gradually converted into a synthesized connective tissue matrix, similar to true dermis, as the original network of collagen sponge is biodegraded. The secondary skin graft takes easily and postoperative contraction is minimal even if a very thin split-thickness skin graft is used. The requirement for two-stage surgery and long hospitalization remain disadvantages of the material. Consequently, application of the material is limited to cases in which the advantages outweigh the disadvantages. Deep skin defects with partial exposure of bone or muscle appear to be the most suitable indications for the material. Shallow but very wide skin defects also seem to benefit from the application of the material.