GRAFTS AND FLAP REPAIRS IN THE HEAD AND NECK INTRODUCTION
The simplest and longest established method of filling a skin defect is by the use of a split-skin graft. The principle of split-skin grafting is to take a partial thickness of the outer layer of skin (epidermis) from a suitable donor site, and to lay it on a raw area where it will survive and ultimately produce an acceptable quality of skin cover. This can be achieved where the defect to be filled consists simply of skin and the underlying soft tissue, but skin grafts will not take on surfaces such as bone. A split-skin graft is harvested using a special knife (Figure 114, page 518) or a power-operated dermatome, with the usual donor site being the thigh or the upper arm. The knife or dermatome is set to cut a graft at a thickness of approximately 12 thousandths of an inch. At this thickness, a piece of skin is produced which can easily be shaped to cover a defect, while the donor surface will heal over a period of a few weeks to leave some slight scarring but perfectly good skin cover. The recipient site where the graft is to be placed must be completely dry and free of bleeding or infection, otherwise the graft will fail to take. For this reason it is common practice to apply a delayed primary skin graft some 24h after excising the area of skin concerned, the graft being harvested at the same time of the
excision and kept at 4°C until the following day when all bleeding will have stopped, and the graft will take readily on the dry but still-clean surface. Skin grafts are covered by a dressing for a few days to exert pressure, and are then inspected to ensure that they are taking well and to allow the release of any serum which may have accumulated beneath them. The final results are usually good, but the texture and thickness of the skin is different from that of the surrounding area. The cosmetic appearance may therefore be less than satisfactory, particularly in the face.