Skin grafts are an excellent modality used to reconstruct wound located on the limbs and other areas of the body
With ideal wound conditions, 95 to 100% survival of the skin graft is expected
After healing takes place, the skin graft should provide a durable covering over the wound
Definition of a skin graft
- A skin graft is a piece of skin that has been totally removed from the body and placed on a wound. Blood vessels in the wound bed will quickly grow into the underside of the skin graft, thus bringing it back to life. If the blood vessels cannot grow quickly enough into the the underside of the skin graft, the graft will die. For this reason the wound must be adequate to nutritionally support the graft and the surgeon must very carefully prepare the skin graft so that vessels will be able to grow into the graft.
Indications for skin grafts
- Skin grafts are used for wounds that are caused by
- traumatic accidents
- oncological surgery (tumor removal)
- thermal burns
- chemical burns
- vesicant burns – injected medications such as chemotherapeutic medications or some injectable anesthetics
- The procedure has the advantage of requiring only one surgery once the wound bed is adequately prepared for grafting.
Contraindications for skin grafts
- Skin grafts frequently do not “take” (die) in the following cases
- radiation has been administered to the area prior to surgery
- over bone
- over tendons and ligaments
- poorly vascular wound beds
- high motion locations that cannot be immobilized
- infection in the wound
Types of skin grafts that are used to repair wounds
- Full-thickness skin grafts are most commonly used in dogs and cats. This involves removing the a piece of skin and removing the fat from the underside of the skin. The donor site must have enough surrounding loose skin so that the incision can be closed. The survival (“take”) of a full-thickness skin graft is the same as a partial-thickness skin graft.
- Partial-thickness skin grafts skin grafts involve shaving a very thin layer of skin off the donor site. No hair will grow from this skin graft because the hair follicles are in the deeper layers of the skin. The donor site will heal on its own and does not involve closure of an incision. This type of graft donor site can be more painful, as the raw donor site will have many exposed nerve endings that need to heal over with time. The indication for partial thickness skin grafting is for cases in which a dog has massive skin loss (especially a burn victim) and there is limited normal skin that is available to be used for skin grafting.
Phases of healing of a skin graft
- Imbibition: the small blood vessels on the under side of the skin graft soak up fluid (serum) from the wound bed,which provides oxygen and nutrients during the first 2 days after surgery.
- Inosculation: to “inosculate” means to “kiss”. Small blood vessels (capillaries) in the wound bed meet up (kiss) and connect with cut vessels of the skin graft. At this time blood begins to circulate in the skin graft and provide it nutrition. Inosculation typically occurs within 48 hours after surgery, depending on the condition of the wound bed.
- Revascularization: small capillary blood vessels bud and grow into the capillary vessels of the skin graft like a snake would slide down a tunnel, thus providing a great source of blood to the skin graft. Revascularization of the graft takes place from day 4 to 7 after surgery.
Wound preparation and skin grafting procedure
Care at home
- With an ideal wound bed, about 95 to 100% “take” of the skin graft is expected.
- Survival of the skin graft is dependant on restricting your pets activity, especially during the first week
- Skin grafts frequently do not grow hair, but provide a durable covering over the wound (see photo right of a skin graft 7 weeks after surgery).
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