Acute Burn Excision / Skin Grafting | Excision, graft types and donor sites

Tangential excision is the preferred method for many deep dermal burns. The surgeon shaves thin layers of burned skin until punctate bleeding or viable dermis appears, preserving underlying viable tissue and body contour better than removing all skin and fat to fascia. Small deeper third-degree areas may be excised until viable bright yellow fat is exposed. Pinpoint capillary bleeding marks a wound bed that can support a skin graft. An inadequately excised wound is more likely to become infected and unsuitable for graft take. It is used mainly when the burn is deep enough that it will not heal within about three weeks.

The dead eschar blocks healing and can harbor infection; removing it exposes viable tissue with capillary bleeding, which supports graft take. Tangential excision removes thin layers until healthy tissue appears, while deeper full-thickness burns may need excision to fascia to reduce bleeding and speed surgery, though scarring and contour may be worse. Hemostasis and patient stability matter before grafting. A healthy bed with punctate bleeding helps the graft survive. Excision technique depends on burn size, depth, site and patient factors; often a combination is used to create the best wound bed. Donor skin is then placed on the freshly excised bed after bleeding is controlled.

Split-thickness grafts are thinner, can cover larger areas, and their donor sites heal from deeper skin appendages. Full-thickness grafts contain the whole dermis, resemble normal skin more closely, contract less secondarily, and may help contracture over joints, but they need a better recipient bed and donor-site closure. The choice depends on wound size, depth, location, donor availability, and desired function and appearance. Full-thickness grafts also establish better sensibility and contain more epidermal appendages, while split-thickness grafts may be meshed for extensive burns. Both require a clean, well-vascularized wound bed and good graft contact. Thicker split grafts may reduce contraction but can scar more at donor site.

Meshing creates small openings that let fluid, blood or bacteria drain, which can improve graft take, especially when the wound bed is less than ideal. It also expands the graft so a smaller donor area can cover a larger burn. Sheet grafts are usually preferred for exposed or cosmetically important areas such as the face, hands and forearms because they look and function better. Meshed grafts can leave a checkered or cobblestone appearance, and widely expanded mesh may scar more. Some studies show no significant difference in function or appearance after about one year, but the choice depends on donor availability and wound condition. It can also contour better over uneven surfaces.

For the face, matching color and quality matters most; scalp skin often matches best but may transfer unwanted hair, so the upper back is an alternative, and facial grafts are placed unmeshed along aesthetic units. For hands, donor skin should match as closely as possible, minimal hair is important, and the best skin is often saved for the face if needed. For larger body areas, flat hidden sites such as the thighs, hips, back or scalp are commonly used; in extensive burns, donor sites are limited and skin may be taken from any available unburned area, including the axilla, mons pubis or scrotum. The choice also depends on burn size and available unburned skin.

A split-thickness donor site heals as surface skin regrows, usually over 1 to 2 weeks depending on age, donor-site size and graft thickness. The donor site heals spontaneously, and thinner grafts may leave less scarring while thicker grafts give more durable coverage but may scar more. In major burns, donor sites are precious and need meticulous care to optimize healing, minimize infection and allow possible reharvesting. Dressings vary by center and may include petroleum gauze, alginate or silver foam; they aim to support moist healing while limiting pain. Donor sites generally heal in 10 to 14 days and can often be reharvested after about 2 weeks when healed.

Large burns may need staged excision and grafting over days to weeks because donor sites are limited. Temporary coverage such as cadaver or pig skin can protect the wound while the body becomes less hypermetabolic; it eventually sloughs. Other options include donated skin, skin substitutes, or laboratory-grown skin cells, each with trade-offs in durability and handling. Donor sites can usually be reused after healing in two to three weeks, but repeated harvesting heals more slowly. Priority areas such as joints, hands, neck, and face are often covered earlier to protect function. The plan depends on burn depth, stability and resources.

Allografts can be used as temporary dressing after excision when healthy skin is not immediately available, especially in major burns where burned and healthy skin surfaces mismatch. Allograft skin can become adherent and vascularized on a viable wound bed, then be rejected in about three weeks. They may also cover widely meshed autografts, help test wound-bed viability, or allow staged definitive grafting after exudate reduction or hemostasis. Xenografts are another temporary option, mainly for partial-thickness burns after superficial debridement and donor sites, but they do not vascularize. Amniotic membrane can cover superficial burns, including irregular surfaces such as the face, reducing dressing changes without shortening healing time or scarring.

Burn surgery is not one-size-fits-all. The technique depends on burn size, site, depth and patient factors. For safety, each operation may be limited to a portion of the burn, and larger burns may need staged excision with temporary coverage when donor skin is limited. Burns of 30–40% body surface area may be treated in two sessions 10–14 days apart, while 15–20% may be excised in one session in healthy people. Massive burns over 60% may need widely meshed grafts or substitutes. The operating team also limits each session to what the patient can safely tolerate and may pause if hypothermia or bleeding occurs.

Blood loss depends on excised area, time since injury, excision type, and infection. Hemostasis may include epinephrine-soaked gauze, topical thrombin, cauterization, pressure, elevation, wrapping and fibrin sealant; fascial excision and tumescent epinephrine infiltration may reduce bleeding, and tourniquets can help on limbs. One cited source estimates up to 100–200 ml blood loss per 1% TBSA excised. Hypothermia during surgery can worsen bleeding and coagulopathy; patients with more than 20% burns have impaired thermoregulation, so the operating room may be kept at 37°C with warm blankets, Bair huggers and warmed intravenous fluids, with close monitoring as clinically indicated, to help prevent hypothermia, and surgery may be paused if temperature drops below 35°C.