Skin Grafting: Types, Procedure And Complications

Skin grafting or skin transplant is a medical procedure that involves the transplantation of skin. The transplanted tissue is called a skin graft. The procedure comprises removing the skin from one part of the body and transplanting it to another part in the body ^[1] . A skin graft is done when an individual has lost the protective covering of skin due to an injury, burns or illness. It is commonly used to treat extensive skin loss due to skin cancers or infections such as necrotizing fasciitis or purpura fulminans ^[2] .

The part of the body from where the skin will be taken is known as the donor site, which is mostly the buttocks and thighs. The healthy skin from the donor site is placed into the wounded area so a to reduce the long-term treatments and to improve the appearance and function of the area being treated. The surgery will be done in a hospital, using general anaesthesia so that the person undergoing the procedure does not feel any pain or discomfort ^[3] .

Types Of Skin Graft

The three basic types of the medical procedure are categorised in accordance with the nature and thickness of the skin removed. However, before getting to know about the different types of skin grafting, it is necessary to gather knowledge on the common types of skin grafts ^[4] . That is, the donor site from where the skin has been extracted from and an individual's experience with skin grafting is asserted to be varied, depending on the type of graft received ^[5] , ^[6] , ^[7] .

• Autograft: It is also known as an autologous graft, in which the donor skin comes from a different site on the individual's body. It is considered to be the most successful due to the genetic match in the skin.
• Allogeneic graft: The skin will be taken from another person.
• Isogeneic graft: The recipient and the donor will be genetically identical (identical twins).
• Xenograft: Also termed as xenogeneic, the donor and the recipient will be of different species. Mostly for this, pigs are used and the grafts are temporary.
• Laboratory-grown: Under this one, the skin cells will be taken the patient or the donor, so as to grow new skin (in a laboratory setting).
• Prosthetic: The procedure will be done using prosthetic implants, that is, synthetic materials such as metal, plastic, or ceramic.

Further, the medical procedure is classified by the thickness and the nature of the skin that has been removed. And depending upon the size as well as the location of the wound, the types of the graft to be received is determined ^[8] .

And the three major types of skin grafting procedure are as follows ^[9] , ^[10] , ^[11] :

1. Split-thickness

Also termed as STSG or split-thickness skin graft, this procedure involves the epidermis and part of the dermis; and removing the top layer of the skin. The grafts extracted are further categorised as thin, intermediate, or thick based on the thickness of the dermis taken for grafting. The skin can be stretched out nine times more than its original size, and the stretching is done by making it into a mesh. It is made processed into a mesh using a skin mesher, which will allow the skin to cover large areas.

STSG tend to contract over time, making the area of surgery look a little odd. Hence, it is usually used for larger areas and is avoided when it comes to joints and other places because the contraction of the skin can cause hindrance in ease of movement.

2. Full-thickness

This procedure involves removing the entire thickness of the dermis and epidermis from the donor site. In comparison to STSG, full-thickness is less painful to have a more natural and aesthetically pleasing end-result. It is used for smaller areas such as hands or face, in line with cosmetic concerns. These blend well with the skin and has a better outcome than other methods. This is done when there is plenty of tissue loss such as an open fracture.

3. Composite

Under this one, skin and underlying cartilage from the donor site will be used. For example, a graft from the ear will be used to treat the nose. The cartilage under the skin is to add form during the process.

Purpose Of Skin Grafting

The medical procedure is carried out with the intention of promoting healing of an injury, burn, or in certain cases illness. Skin grafting not only improves the physical appearance after the surgery is done but also has the ability to improve the health-related outcomes ^[12] . Skin grafting is recommended when there is a large amount of skin loss due to various reasons, as aforementioned. One of the most common uses of skin grafting is associated with burn victims. Apart from these, skin grafting is recommended for the following ^[13] :

• Cosmetic reasons or reconstructive surgeries
• Surgeries that require the healing of skin grafts
• Skin cancer surgery
• A wound that the surgeon has not been able to close properly
• Venous ulcers, pressure ulcers, or diabetic ulcers that do not heal
• Very large wounds

Procedure Of Skin Grafting

The first and foremost step involved in the medical procedure is choosing the current type of skin graft and the donor site. Skin grafting, as mentioned before, will be conducted under general anaesthesia so that the patient does not feel any pain and will be unconscious ^[14] .

Before transplanting the skin from the donor site to the affected area, it will be prepared thoroughly. That is, all the damaged skin will be removed from the area which is called debridement so as to ensure that the area is thoroughly free of bacteria ^[15] . In some cases, the affected area will be treated with antibiotics and if it is bleeding, saline will be used to clear the area off of any residues ^[16] .

The procedure involves a dermatome, the device used to harvest the healthy skin which will strip away even and thin layers of skin for the purpose of skin grafting. Smaller portions of skin will be harvested using a drum dermatome ^[17] , ^[18] . Once the harvesting is done, the type of graft to opt will be decided in accordance with whether it is a split or full thickness graft. A full thickness graft donor sites will be sutured closed, and the split-thickness graft donor sites will be dressed and left to heal via reepithelialization.

If the procedure is split-thickness graft, the skin will be processed through a skin mesher before being applied to the area, giving the skin a meshed appearance. This enables covering a wider portion of the skin with less harvested skin. Consequently, the holes in the mesh will enable the easy passing of fluids, thereby preventing the development of hematoma ^[19] .

Once the skin graft is placed securely and properly on the affected area, the dressing will be applied which will help in providing equal pressure and help keep the skin graft in place. The dressing also helps in promoting the healing process.

The surgery will be scheduled several weeks in advance so that the patient gets plenty of time to be prepared for it ^[20] .

Before the surgery: It is necessary that you inform your surgeon about the medications you are taking, even if it is herbs or drugs that you have brought without a proper prescription. The doctor must also be informed about your drinking habits.

Apart from that, there are certain steps you have to take before undergoing the procedure; such as ^[21] :

• You may be required to stop medications that can prevent your blood from clotting, such as aspirin, ibuprofen, warfarin etc.
• Stop smoking, as it will significantly slow down the healing process.

On the day of the surgery: Strictly follow the instructions provided by your doctor or health care provider regarding your eating and drinking habits. Timely consume the medicines prescribed by your doctor.

After the grafting is done, the dressing will be kept there three days to a week, so as to avoid any complications. The healing process involves fibrin adhesion, plasmatic imbibition and capillary growth and inosculation. After one week, the dressing will be changed - however that does not mean that it is completely healed. Skin grafting takes a long time to heal, such as two to three months or more ^[21] , ^[22] .

Caring For Your Skin Graft

Once the procedure is carried out, you will be required to stay in the hospital for one to two weeks ^[23] ; depending on the type of skin grafting received. If the kin grafting is extensive, you will be required to stay for a longer period of time. It is critical that you listen to the health care provider to ensure an effective and speedy recovery ^[24] .

• Rest well: Even though it is not recommended that you stay in the bed till you recover, it is best to avoid moving too often. Let the affected area be untouched and do not work the muscles in the surrounding area as well. Do not exercise until your doctor advises you to.
• Take prescribed medications: Timely consumption of the antibiotics and pain killers are necessary to manage the healing process.
• Avoid direct sun contact: Do not go directly into the sunlight for at least six months because direct exposure can result in scarring and skin discolouration.
• Keep dressings dry: You have to be extremely careful in not getting the donor site exposed to water. Once the initial dressing is removed, you can gently wash the graft with soap and water. Avoid taking showers and clean yourself using damp clothes. Always keep the dressing dry and clean.
• Do not miss out on appointments: Go to all the follow-up appointments so as to avoid any possible complications with the recovery process.

Complications Of Skin Grafting

It is unavoidable that major surgeries will pose some complications. Apart from infection and scarring, the following are some of the risks associated with the medical procedure ^[25] , ^[26] .

• Graft rejection
• Graft vs. host disease (GvHD)
• Graft failure
• Hematoma
• Increased or decreased sensitivity
• Bleeding
• Chronic pain
• Uneven skin surface
• Skin discolouration