Definition and Overview
Skin grafts refer to a surgical procedure performed to replace skin with a new skin covering. Grafting usually becomes necessary due to injury or illness and is done either for temporary or permanent purposes. There are many ways to perform the procedure, but the most common is to take the patient's own skin from a different body part and move it to the affected area. With proper care and preparation, complications can be easily minimized and even avoided.
Who should undergo and expected results
Skin grafting is used for a variety of purposes but is most beneficial for its medical uses, such as in the treatment of:
- Severe burns
- Non-healing wounds, such as diabetic ulcers and infected wounds
- Large, open wounds that cannot be sutured
- Skin cancers
- Severely infected wounds
- Open fractures of the legs
Covering burns is a crucial part of treatment because without an outer skin covering, there is a high risk of fluid loss and infection. Skin grafts also help prevent scarring. Wounds and burns that are left to heal without assistance may cause severe scars due to the skin's tendency to contract during the healing process.
A skin graft is expected to improve the health of the wounded site and prevent any long-term complications often linked to complicated skin injuries. Within 36 hours, the blood vessels in the donor skin will begin to grow in the transplant area. At this point, the doctor can tell whether the procedure has been successful.
How the procedure works
The exact manner the procedure is done depends on the specific type of grafting involved. The two types of skin grafts, based on skin thickness, are:
- Split-level thickness graft – In a split-level thickness grafting procedure, only the outermost layers of the skin, namely the dermis and the epidermis, are removed from the donor body part and transferred to the affected area. This type is more suitable when there is a large area to be covered. However, since only a thin layer of skin is moved, these grafts are more fragile and do not grow with the patient; this means that if a person receives a split-level thickness graft in childhood, he may require additional grafts over time. Split-level grafts have a pale and shiny appearance.
- Full-thickness graft – In a full-thickness graft procedure, the skin graft taken from the donor site includes all the skin layers as well as the muscles and blood vessels underneath. This type is more suitable for smaller wounds that are more visible, such as those on the face. A full-thickness skin graft grows with and usually blends well with the rest of the patient's skin. Common donor sites are the back and the abdomen, which then have to be covered with a split-thickness graft.
There are also three types of grafts based on the source of the new skin; these are:
- Autograft – This is a graft taken from the patient's own body, usually from the buttocks or inner thigh because these are easily hidden.
- Allograft – Allografts are donor skin taken from cadavers and frozen for preservation. Allografts are used as temporary skin coverings because the immune system eventually rejects them.
- Xenograft – Xenografts are donor skin taken from animals, usually pigs. Like an allograft, a xenograft will be rejected by the patient's body within seven days and must thus be replaced with an autograft.
Skin grafts are performed in the operating room of hospitals, and always require general anesthesia so that the patient sleeps through the procedure without feeling any pain. In a split-thickness graft, the donor skin is removed using a dermatome, a special instrument that can slice tissue thinly. In a full graft, the skin and tissue are removed using a scalpel.
The procedure typically follows the same steps:
- Anesthetizing the patient
- Rinsing the wound with a saline solution or diluted antiseptic and removing any dead tissue
- Stopping the flow of blood either by tying off the blood vessels or with the help of epinephrine, a medication that makes blood vessels constrict
- Harvesting the donor skin, which is usually enlarged by 3 to 5 percent to prepare for possible skin shrinkage
- Placing the graft in the wounded area and suturing it in place
- Dressing the wound to protect it during the healing process
- Covering the donor site with a split-thickness graft (if a full-thickness graft was taken from it)
Recovery from a grafting procedure may take several months. During the first 10 days, patients are advised to remain in bed, especially if the grafts are in the leg area. For the next 2 to 3 weeks, any activities that will put pressure on or stretch the transplant area should be avoided. For the succeeding months, the graft needs to be supported with bandages or stockings to help reduce the risk of contractures. It must also be moisturized or lubricated with mineral oil to keep the skin from drying. This is because grafted skin do not have oil and sweat glands to lubricate them.
Possible risks and complications
There are a number of possible complications that may arise both during and after a skin grafting procedure. These include:
- Allergic response to medications or anesthetics
- Severe bleeding
- Breathing issues
If the procedure involves an allograft, there is also a risk of the transmission of an infectious disease from the donor patient.
There is also a risk that the graft will fail due to:
- Improper preparation of the wounded site
- Inadequate blood flow
- Presence of an infection
- Formation of hematoma
For a skin graft to be successful and for complications to be avoided, it is important that the wounded area:
- Has adequate blood supply
- Has not been exposed to or damaged by radiation treatment
- Is free from any dead tissue or bacterial infection
Thus, if there is any dead tissue, it should first be removed through debridement. Likewise, if there is an active infection, it should first be treated prior to the skin graft procedure.
- Scherer-Pietramaggiori SS, Pietramaggiori G, Orgill DP. Skin graft. In: Neligan PC, ed. Plastic Surgery. 3rd ed. Philadelphia, PA: Elsevier; 2013:chap 17.