A graft is a piece of living tissue, bone, or synthetic material that is surgically moved from one location to another to repair or replace damaged tissue. The transplanted material can come from your own body, a donor, or even a manufactured source. Grafts are among the most common procedures in modern medicine, used in everything from burn treatment and dental implants to heart bypass surgery.
How Grafts Are Classified by Source
The single biggest factor in how a graft behaves is where the tissue comes from. Surgeons categorize grafts into a few key types based on the donor source.
An autograft uses tissue taken from your own body. A surgeon might harvest bone from your hip to rebuild your jaw, or take skin from your thigh to cover a burn on your arm. Because the tissue is yours, your immune system recognizes it and the risk of rejection is essentially zero. Autografts are generally considered the gold standard, but they require a second surgical site on your body, which means additional pain and healing time.
An allograft comes from another human, often a cadaver donor. Bone and skin from tissue banks are common examples. Allografts eliminate the need for a second wound on your body, but they carry a small risk of immune rejection and must be carefully processed and screened before use.
A xenograft uses tissue from a different species entirely. Processed animal bone (typically from cows) is widely used in dental procedures. Pig heart valves have been used in cardiac surgery for decades. These materials are treated to remove cells that would trigger an immune response, leaving behind a scaffold that your body can gradually incorporate.
Synthetic grafts are lab-manufactured materials designed to mimic the function of natural tissue. In vascular surgery, tubes made from materials like PTFE or Dacron have been standard bypass conduits for decades, replacing or rerouting damaged blood vessels when a patient’s own veins aren’t available.
Skin Grafts
Skin grafting is one of the most recognizable graft procedures, commonly performed after burns, traumatic injuries, or surgical removal of skin cancer. There are two main types, and the choice between them depends on the size and location of the wound.
A split-thickness skin graft takes the outer layer of skin (the epidermis) plus only part of the underlying dermis. Because the donor site retains deeper portions of the dermis, including stem cells, it can heal on its own within two to three weeks and can even be reused later if needed. Split-thickness grafts cover larger areas and have a reported success rate of 70% to 90%. The trade-off is that they tend to contract more as they heal and may show more noticeable changes in pigmentation compared to surrounding skin.
A full-thickness skin graft takes the epidermis and the entire dermis. These grafts produce better cosmetic results, with less secondary contraction and more natural color matching. For that reason, they’re preferred for visible areas like the face, eyelids, and around the mouth. However, the donor site can’t regenerate on its own and must be closed with stitches, which limits how much tissue can be harvested at once.
Bone Grafts
Bone grafts work through a few distinct biological processes. The graft material can act as a scaffold, providing a physical surface for new bone to grow across. This is similar to how ivy climbs a trellis. The graft can also contain proteins that recruit immature cells in the area and stimulate them to develop into bone-forming cells, actively triggering new bone growth rather than just supporting it.
Autografts from your own body can do all of these things at once, which is why they remain the most effective option for bone repair. Allografts and xenografts primarily serve as scaffolds. Synthetic bone substitutes, made from materials like calcium phosphate ceramics, fill a similar structural role.
In dental medicine, bone grafts are especially common. After a tooth is extracted, the surrounding jawbone begins to shrink. A bone graft placed into the empty socket preserves the bone volume needed to support a future dental implant. Grafts are also used in sinus lift procedures, where the floor of the sinus cavity is raised to create enough bone depth for implant placement.
Vascular Grafts
When a blood vessel is severely narrowed or damaged, surgeons can bypass it using a graft. The preferred option is typically your own saphenous vein (a long vein running up the inside of the leg) or the mammary artery from the chest wall. These are autografts, and they tend to stay open longer than synthetic alternatives.
When a patient’s own vessels aren’t suitable, synthetic tubes made from PTFE or Dacron serve as the replacement conduit. These work well for larger arteries but have higher rates of clotting and infection in smaller vessels, which is why surgeons still prefer natural tissue when it’s available.
What Makes a Graft Succeed or Fail
For any graft to survive, it needs to establish a blood supply from the surrounding tissue. In the first hours and days, the graft absorbs nutrients passively from the wound bed, almost like a sponge. Over the following days, tiny blood vessels from the recipient site grow into the graft and begin delivering oxygen and nutrients directly. If this process is disrupted, the graft dies.
The most common reasons for failure are fluid buildup and movement. Blood or fluid collecting between the graft and the wound bed creates a barrier that prevents those new blood vessels from connecting. Shearing forces, where the graft slides against the wound, tear apart the fragile new connections. This is why grafted areas are typically immobilized after surgery. For skin grafts on the leg, the traditional approach calls for five to seven days of bed rest with the leg elevated to reduce swelling and protect the healing graft.
Patient health matters significantly. People with diabetes, heart failure, or weakened immune systems tend to have slower healing at both the graft site and the donor site. Older skin has less blood flow and is more vulnerable to damage. Even something as simple as placing a skin graft upside down will cause it to fail completely.
What Recovery Looks Like
Recovery depends heavily on the type of graft. For split-thickness skin grafts, the grafted area is covered with a dressing that stays in place for several days to protect the fragile new tissue. You’ll likely need to keep the area still and elevated. The donor site, which looks similar to a scrape or rug burn, typically heals within two to three weeks.
Bone grafts in the jaw may take several months to fully integrate before an implant can be placed on top of them. During that time, you’ll avoid chewing on that side and follow a modified diet.
Regardless of the graft type, some degree of scarring and contraction is normal. Full-thickness skin grafts generally look more natural over time, while split-thickness grafts may appear slightly different in color or texture from the surrounding skin. Bone grafts gradually remodel as your body replaces the graft material with its own living bone, a process that can continue for a year or more.