Severe Degloving Wound
An 11 year old, MN shepherd mix was hit by a truck and suffered a severe degloving wound of the right forepaw. Degloving wounds are a common type of wound seen after trauma and is the result of abrasion of the limb against another surface causing substantial loss of superficial tissue in many traumatized patients. Due to the severity of the damage the options of amputation versus reconstructive surgery were discussed with the clients. After initial stabilization the damaged regions of tissue were removed and wound care with local bandages was performed. Initial surgery to reconstruct and salvage the partially damaged sections of the pad and amputation of several digits were performed concurrently. The patient was then treated with intermittent bandage changes for another 2-3 weeks when the wounds were completely covered with a healthy granulation tissue. At that time a fenestrated full thickness skin graft was harvested from the chest wall and applied to the wound. The graft was supported with a bandage/splint to protect the healing wound/graft complex. The graft appearance at 5 days post-op was good with evidence of early revascularization and graft "take" occurring. (Figure 5). The wound was then protected with additional bandage changes for another ~ 3-4 weeks post-op when the splint/bandages were finally removed (Figure 6). Even with the loss of the 5th digit and partial loss of the carpal pad, the patient went on to make a full recovery and the owners report full functional use of the right forelimb and good cosmesis to include hair regrowth on much of the graft (Figures 7a/7b/7c).
A free skin graft is a segment of skin that is completely removed from another portion of the body and placed on a separate wound. Blood vessels contained within the in the wound bed quickly grow into the underside of the skin graft, thus bringing it “back to life”. If the blood supply does not re-establish itself quickly enough into the skin graft, the graft will die. Skin grafts are commonly used for wounds that are associated with; traumatic accidents, oncological surgery (tumor removal), burns caused by heat, chemicals or some injectable agents. It is very important that the graft has a good wound bed that is adequately prepared for grafting. Skin grafts frequently do not "take" (die) in cases where radiation has been administered to the area, over exposed bone, tendons or ligament or poorly vascular wound beds. In addition, two significant causes for skin graft failure include high motion locations that cannot be immobilized and infection of the wound.
There are two main types of skin grafts that are used in human/veterinary medicine. Full-thickness skin grafts are more commonly used in dogs and cats. This procedure involves removing the entire segment of skin and then 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 and has the additional advantage of being able to regrow hair as long as the hair follicles are not damaged during graft preparation. 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 sites will heal on their own without need for closure of donor site. The primary indication for partial thickness skin grafting in veterinary patients is in cases where there is massive skin loss (especially a burn victim) and there is limited normal skin that is available to be used for skin grafting.
Prognosis for wounds treated with a well performed skin graft tends to be good to excellent. If there is good pre-surgical preparation of the wound bed, about 95 to 100% "take" of the skin graft is expected. However, survival of the skin graft is dependent on restricting the pet’s activity, especially during the first week to prevent motion at the site of the graft, as well as bandage to protect the graft from infection. Skin grafts frequently do not grow hair, but provide a durable covering over the wound, especially in distal limb wounds and over joint where chronic scar tissue would not provide a good long term functional or cosmetic outcome.