In short. How split-thickness and full-thickness skin grafts work, what a graft needs in order to take, and why graft failure is not the same thing as infection.
Key points
- A graft that does not take is most often a mechanical or vascular problem: fluid collected underneath it, it sheared against the dressing, the bed was too poorly supplied, or the patient’s circulation or nutrition could not support it.
- Infection is a separate and much less common cause, and it announces itself differently, with spreading redness, warmth, discharge and fever rather than a quietly dark patch.
- The distinction matters because the treatments are completely different.
A skin graft is a sheet of skin lifted completely from one part of the body and laid onto a wound somewhere else. Because it is cut off from its original blood supply, it has no circulation of its own when it is placed. It survives only by reconnecting to the wound bed beneath it, a process called take. That single fact explains almost everything about how grafts behave.
Split-thickness and full-thickness
A split-thickness graft takes the epidermis and part of the dermis, usually with a blade or a powered dermatome. It is thin, so it survives on demanding beds, can be meshed and stretched to cover a large area, and the donor site heals by itself. The price is contraction and a poorer colour and texture match. A full-thickness graft takes the whole dermis and is closed with sutures, most often on the face, the eyelid, the nose or the hand. It contracts far less and matches far better, but it needs a cleaner, well-vascularised bed, and its donor site must be closed directly as a line.
How a graft takes
Take happens in stages over roughly the first week. For the first day or two the graft survives by absorbing fluid from the bed. Capillaries then grow into it, and by about the fifth day it has a circulation again. Three things must be true throughout: the bed must be clean and bleeding, the graft must be pressed evenly against it, and it must not move. A collection of blood or serum lifting the graft off the bed is one of the commonest reasons a graft fails, which is why dressings, sutures or staples, and sometimes a tie-over bolster, matter so much.
Failure is not the same as infection
A graft that does not take is most often a mechanical or vascular problem: fluid collected underneath it, it sheared against the dressing, the bed was too poorly supplied, or the patient’s circulation or nutrition could not support it. Infection is a separate and much less common cause, and it announces itself differently, with spreading redness, warmth, discharge and fever rather than a quietly dark patch. The distinction matters because the treatments are completely different.
Recovery and aftercare
Grafts are usually left undisturbed for around five days, then checked. A graft that has taken looks pink and blanches when pressed. Over the following months it softens, and its colour slowly settles, though it rarely becomes identical to the surrounding skin. Sun protection matters for at least a year, because grafted skin pigments unevenly. Sensation is reduced and returns only partly.
Honest limits
Grafts can fail partly or completely, and a second graft may be needed. Contracture is a real risk, particularly with thin grafts over joints. The donor site is a second wound with its own scar. Final appearance is judged at six to twelve months, and no result can be promised in advance.
Contact the team urgently if
- The graft turns dark, grey, cold or black, or stops bleeding when pricked with a needle.
- A dressing becomes soaked with blood, or fluid collects and lifts the graft away from the wound.
- Fever, spreading redness, increasing pain or a foul discharge develops around the graft or its donor site.
Frequently asked questions
What is the difference between a split-thickness and a full-thickness graft?
A split-thickness graft takes the epidermis and part of the dermis; it is thin, survives on demanding beds, can cover a large area, and its donor site heals by itself, but it contracts and matches colour poorly. A full-thickness graft takes the whole dermis, contracts far less and matches better, but needs a cleaner bed.
How long does a graft take to take?
Roughly a week. For the first day or two the graft survives by absorbing fluid from the bed, then capillaries grow into it, and by about the fifth day it has a circulation again. Throughout, the bed must be clean and bleeding, the graft pressed evenly against it, and it must not move.
What happens if a skin graft fails?
Grafts can fail partly or completely, and a second graft may be needed. Failure is most often mechanical or vascular rather than infective: fluid collected beneath the graft, shearing against the dressing, or a bed too poorly supplied. Contracture is a real risk, particularly with thin grafts over joints.
Risks & Limitations
- Partial or complete failure of a graft or flap, which may need further surgery.
- Donor-site scarring, delayed healing and pain. A donor site leaves its own permanent scar.
- Infection, bleeding under a graft, or fluid collecting beneath a graft or flap.
- Contracture, and recurrence of contracture after a release procedure.
- Reconstruction is usually staged: more than one operation and months of healing are normal.
- Colour, texture and contour mismatch between reconstructed skin and the surrounding area.
- Reduced or altered sensation in grafts, flaps and donor sites.
- Scars are permanent. They mature and fade but never disappear.
- Final assessment is made at 6–12 months, and longer in growing children.
When to Seek Care
- A graft or flap that turns dark, cold, dusky, purple or black, or stops bleeding when pricked.
- A dressing soaked with blood, or bleeding that does not stop with gentle pressure.
- Fever above 38 °C, or spreading redness, warmth or discharge around a wound.
- New or severe pain, or rapid swelling under a graft or flap in the first days.
- A limb that becomes pale, cold or numb after flap surgery.
- Any change in a grafted or flap-covered area that concerns you, however minor.
References & Further Reading
- American Society of Plastic Surgeons (ASPS) — reconstructive surgery and skin graft guidance
- Cochrane Library — systematic reviews in wound care and surgical reconstruction
- Wounds International — wound bed preparation and graft survival guidance
- Chinese Medical Association, Plastic Surgery Branch — clinical guidance
This page is patient education, not medical advice, and it does not cite individual studies. Discuss your own case with a qualified clinician. To arrange an assessment at Chongqing West District Hospital, see Contact & Consultation.