Overview of Wound Grafts
Skin grafting is a surgery often performed to treat people who have experienced significant burns, traumatic injuries, or wounds that aren’t healing properly. This procedure helps to enhance their life by improving the appearance and health of their skin. One of the essential things that it accomplishes is restoring the skin’s protective functions.
Different types of skin grafts exist such as xenografts, allografts, and autografts. Xenografts come from different species; pig skin is most commonly used as temporary dressings on wounds. Allografts are skin grafts taken from human donors and are useful for treating wounds until a patient’s body can accept an autograft. An autograft is a skin graft taken from the patient’s own body, which ensures a perfect match and allows for permanent skin healing.
There are also skin substitutes available. These are developed either to replace the outer layer of skin (known as the epidermis) or the inner layer (known as the dermis). Skin substitutes can be costly, and they each have their pros and cons. Epidermis substitutes might not be as elastic or strong since they lack dermis and subcutaneous tissue. Dermis substitutes, meanwhile, do not have an outer skin layer and require a longer healing time for the outer skin layer to grow over the wound.
The most widely used skin substitute is the cultured epidermal autograft. With this, a skin biopsy is taken from the patient, and then the skin cells are used to create a new outer layer. Still, these grafts can be delicate and require long periods of rest to avoid injury.
Another substitute is a matrix of collagen, a protein in our skin, and glycosaminoglycans, which are long chains of sugar molecules. One popular product, Alloderm, is obtained from human donor skin and provides promising cosmetic results, but its high cost has limited its use and study.
There are also newer products that use a patient’s own skin cells, more specifically from the junction between the dermis and epidermis. These are then sprayed onto the wound to encourage healing. For instance, one product named Integra uses bovine collagen and glycosaminoglycans with a silicone sheet, acting as a temporary skin. This is then replaced with a split-thickness skin graft (a skin graft including part of the dermis layer) as the patient’s body produces its own collagen matrix.
While these skin substitutes offer promising avenues for treatment, they can be costly, and further research is needed to guarantee satisfactory cosmetic outcomes and long-term wound coverage.
Why do People Need Wound Grafts
Skin grafting, which is a surgical procedure to transplant skin, can be beneficial in several situations. These include when someone has severe burns that reach deep into the skin, injuries that cause significant damage to the skin, or wounds that are very large or are not healing on their own.
People who may need skin grafts include those who have been burned, those with wounds that aren’t getting better (like foot wounds in people with diabetes), and those who have had a lot of skin removed because of serious infections such as necrotizing fasciitis, which is a severe type of soft tissue infection.
When a Person Should Avoid Wound Grafts
Only certain situations may prevent the use of wound grafts, which are ways to help heal larger wounds. These include:
If the wound is infected, a graft may not be successful.
A wound graft may also not work on patients who haven’t received enough medical treatment and stabilization after injury or during a serious illness.
Preparing for Wound Grafts
There are certain tools and steps needed to successfully perform a procedure called a wound grafting, which is a way to help a wound heal by using skin from another area of the body. The tools needed include a Watson knife, Goulian blade, scalpel, a tool used to burn off skin abnormalities called an electrocautery, a tool that removes thin layers of skin called a dermatome, mineral oil, a skin mesher which stretches the skin, and stitches or staples to secure the graft.
The team that works to complete the graft usually includes a surgeon, anaesthesiologist (a doctor that administers anaesthesia), scrub tech (a specialist who assists during surgery), and scrub nurse (a nurse who assists during the surgical procedure).
One of the key things the team needs to do is to prepare the wound to receive the graft. This involves removing unhealthy tissue and cleaning the area where the graft will go. Surgery performed early, combined with debridement (the process of removing dead tissue), helps the graft heal better. This proactive approach also reduces the risk of infection, scarring, and stiffness around the wound, and speeds up the patient’s recovery time.
Doctors use the Watson knife or the Goulian blade to strip away the dead tissue layer by layer until they see small spots of bleeding, which shows they’ve reached healthy tissue. However, stripping away skin over a joint needs to be done early and carefully to prevent the joint from becoming too stiff.
Before the graft is placed, any excess tissue should be removed as it can contain harmful bacteria. The edges of the wound also need to be cleaned to expose fresh skin. It’s crucial to stop any bleeding and make sure the area is dry before adding the graft, as any leftover blood (or a hematoma) may cause the graft to fail. To summarize, grafting is a specialized medical procedure involving careful preparation and a skilled medical team to be successful.
How is Wound Grafts performed
Full-thickness skin grafts refer to transplantation of skin sections that include both the outer and inner layers of the skin, also known as the epidermis and dermis. When choosing the donor site for the graft, doctors consider aesthetic aspects like color matching, texture and skin thickness. These grafts help to minimize skin tightening across joints and on the face and fingers. Common areas for extracting these grafts include the side of the body, groin, base of the little finger, area behind the ears, or the forearm.
The process involves shaving the skin and injecting fluid into the area below the intended donor site. The skin is then delicately harvested using a blade, with the shape customized to fit the area receiving the graft. Some fatty tissue is also removed with the graft. Afterward, this excess tissue is removed, and the donor site is stitched up. When placing the skin graft, it is stitched along the edges using dissolving sutures. Large grafts are prone to failure because of their size, hence special care is taken.
Split-thickness skin grafts (STSGs) are the most commonly placed type of wound grafts. These grafts are ideal because they cover larger areas with smaller amounts of harvested skin. The harvested area heals quickly, and can be reused as a donor site if needed. The anterolateral thigh is a great choice for a donor site because it is easy to access and bandage. Meshing STSGs can help increase coverage when limited donor skin is available. However, meshing can leave scars on the wound site and lead to skin tightening during healing.
Additional techniques help the process run smoothly. For instance, the practitioner adjusts the “dermatome” – a specialized instrument used to remove layers of skin – to the correct height to get the desired thickness of the graft. Oil is applied at the donor site to decrease resistance. Pressure is applied to the donor site to make it flat, and the dermatome is introduced at a 45-degree angle to slice off the surface. Once that’s completed, the site is cleaned and covered for protection.
When dressing the graft and donor sites, the graft must be firmly secured in place to avoid jeopardizing the healing process. Negative pressure wound therapy has been shown to be an effective dressing method for this purpose. On the other hand, the dressing on the donor site must be gentle to prevent disturbing the healing skin. The dressing is usually changed around the fifth day after surgery.
Possible Complications of Wound Grafts
Problems with the skin graft, or transplant, can happen due to a buildup of fluid under the graft, infection, tearing or pulling of the skin, putting too much strain on the graft, or poor blood supply to the wound area. By preparing the wound area correctly and making sure all blood is cleaned from the wound (hemostasis), we can typically prevent these complications.
The graft is further protected by keeping it secure and covered in dressings. It’s important to be careful at every step to give the graft the best chance of staying healthy. Over time, the wound might tighten and leave a scar. This tightening, called contracture, can cause problems if it’s over a joint, like a knee or elbow. However, starting to move the joint early can help with this, but that must be done very carefully so the graft underneath does not get injured.
What Else Should I Know About Wound Grafts?
Skin grafts, a procedure where a piece of healthy skin is moved from one part of your body to another part that’s been injured, can massively improve lives – especially for folks with large wounds that wouldn’t heal otherwise. How it looks afterwards (cosmesis) often relies on quick treatment and cleaning of the wound (debridement), sometimes needing the skills of specialist centers if the wound is big enough.
It’s key for everyone involved in the process to work well together to ensure that the wound is cleaned and the skin grafted as quickly as possible, to give the best possible results for the patient. People with widespread injuries or burns might not have enough of their own healthy skin left to use for grafting, and in these cases, skin substitutes might be a good option.
It’s really important to get the skin back to normal again, as it helps prevent infections, reduces the loss of body fluids, and contributes to a better quality of life for the patient.
