The largest organ in the body is the skin, which is the first line of defense against infection, temperature extremes or contamination with dirt or chemicals. Merck Manuals, an online medical library, reports that severe skin burns cause between 3,000 to 4,000 deaths and more than 2 million visits to the doctor each year in the United States. The four main types of skin grafts for the treatment of severe burns are autografts, allografts, xenografts and synthetic tissue.
Autograft
An autograft is the skin burn victim's own healthy skin transplanted from one place on the body to cover the wound caused by the burn. The NYU Langone Medical Center notes that autografts are the first choice for skin grafts, but other types of skin grafts are used when there is not enough healthy skin to graft onto the burn wounds. According to Merck Manuals, the burned skin is first removed, and autografts are transplanted as a solid piece of skin that's placed over the wound. If more than 40 percent of the body is burned, the skin may be "meshed" before being applied to the wounds. Meshed autografts are created by making a series of very small incisions at regular intervals in the skin. Meshed autografts can cover much larger wounds than solid pieces of skin. However, the meshed skin grafts heal much more unevenly and with less aesthetic appeal. The type of autograft used depends on the size of the burn wounds and the availability of healthy skin available.
Allograft
The NYU Langone Medical Center describes an allograft as a skin transplant from another person. This type of skin graft is often taken from a cadaver. However, the skin still has to be viable, meaning that the cells are still alive. Thus, skin transplants from cadavers may only be taken from the very recently deceased. Merck Manuals notes that allografts are not permanent skin grafts, because the body's immune system attacks the graft, resulting in rejection. Rejection sometimes occurs as soon as 10 days following the application of the graft. Ultimately, the wounds temporarily covered by allografts are either covered with autografts or with synthetic skin.
Xenograft
A xenograft is a skin graft in which the donor skin is from a different species, usually a pig. Like allografts, the body's immune system eventually attacks the donor skin, causing rejection often within a week or two. Like allografts, the wounds temporarily covered with xenografts are ultimately covered with autografts.
Synthetic Skin
Another option for skin grafts is to cover burn wounds with synthetic skin, which is man-made. One type of synthetic skin, as reported by the National Institute of General Medical Sciences, is Integra, made by Integra Life Sciences Corporation. This engineered skin is made of fibrous cow protein called collagen and a type of carbohydrate. The skin is placed over the burn wound for two to four weeks, allowing the body's own skin cells to grow into the engineered matrix.
