Skin grafting is a type of organ transplant involving the transplantation of skin. The transplanted tissue is called a skin graft. An organ transplant is the transplantation of a whole or partial organ from one body to another (or from a donor site on the patients own body), for the purpose of replacing the recipients damaged or failing organ with a working one from the donor site. ... Diagram of the layers of human skin In zootomy and dermatology, skin is an organ of the integumentary system composed of a layer of tissues that protect underlying muscles and organs. ... Biological tissue is any substance made up of cells that perform a similar function within an organism. ...

Indications

They are often used in treatment or rehabilitation of animals with:

• Extensive wounds or trauma
• Burns
• Areas of prior infection with extensive skin loss
• Specific surgeries that may require skin grafts for healing to occur

Skin grafts are often employed after serious injuries when some of the body’s skin is damaged. Surgical removal (excision or debridement) of the damaged skin followed by skin grafting. The grafting serves two purposes: it can reduce the course of treatment needed (and time in the hospital), and it can improve the function and appearance of the area of the body which receives the skin graft.

Donor selection

The best skin grafts come from the patient’s own skin (donor sites on other parts of the body). These autografts (or autologous grafts) usually come from areas that are not ordinarily visible (such as the buttock or inner thigh) and are refered to as split-thickness|partial-thickness skin grafts since only the top layer of skin is removed from the donor site The selection should consider the visibility of the donor skin and color match. Sometime grafts are taken from other animals[heterologous grafts]

For more extensive tissue loss, full-thickness skin graft, which includes the entire thickness of the skin, may be necessary. This can happen, for example, with open fractures of the lower leg. This is a more complicated procedure in which a flap of skin with underlying muscle and blood supply is transplanted to the area to be grafted. Common donor sites include skin and muscle flaps from the back or abdominal wall. Also, the underlying muscle and blood supply can come from one site, for example the back and the skin from another site, for example the leg.

Cell cultured, epithelial autograft procedures take skin cells from the animal to grow new skin cells in sheets in a laboratory. The new sheets are used as grafts, and because the original skin cells came from the animal, the body does not reject them.

Surgical procedure

In order to remove the thin and well preserved skin slices and stripes from the donor, surgeons use a special surgical instrument called dermatome. This usually produces a split-thickness skin graft, which contains the epidermis with only a portion of the dermis. The dermis left behind at the donor site contains hair folliclesand sebacious glands , both of which contain epidermal cells which gradually proliferate out to form a new layer of epidermis.

The graft is carefully spread on the bare area to be covered. It is held in place by a few small stitches or surgical staples. New blood vessels begin growing from the recipient area into the transplanted skin within 36 hours. To prevent the accumulation of fluid under the graft which can prevent its attachment and revascularization, the graft is frequently formed into a mesh by making lengthwise rows of short, interrupted cuts, each a few milimiters long, with each row offset by half a cut length (like bricks in a wall). In addition to allowing for drainage, this alows the graft to both stretch and cover a larger area as well as to more closely approximate the contours of the recipient area.

Risks

Risks for the skin graft surgery are:

• Bleeding
• Infection
• Loss of grafted skin

Rejection may occur in heterologous skin grafts. To prevent this, the patient usually must be treated for a long time with immunosuppressing drugs.

Prognosis

Most skin grafts are successful, but in some cases they don't heal well and require repeat grafting. The graft should also be monitored for good circulation. The recovery from surgery is usually rapid after split thickness skin grafting. The skin graft must be protected from trauma or significant stretching for 2-3 weeks. Depending on the location of the graft, a dressing may be necessary for 1-2 weeks. Exercise that might stretch or injure the graft should be avoided for 3-4 weeks. Full-thickness grafts require a longer period of recovery, with 1-2 week hospital stays in most cases.

External link

• Skin graft. MedlinePlus Medical Encyclopedia. Parts of this US Federal Government public domain text were used in the article.