Advantages and important pointers
Over the years, I have had good success with mesh grafts, getting about 95% to 100% of the grafts to take or heal (Figures 1A & 1B). This degree of success has also been attained by faculty colleagues, surgical residents, and private practitioners. The
success of mesh grafts is attributed to overcoming the three main reasons grafts do not take or heal.
Figure 1A. A degloving wound on a dog’s distal limb.
- First, meshing allows drainage of any hemorrhage from under the graft that would separate the graft from the wound. Thus,
the graft revascularizes quickly as it lies in contact with the wound.
- Second, any exudate that might be associated with the wound can drain away into a bandage. If it accumulated under a graft,
exudate could also separate the graft from the wound and interfere with revascularization. In addition, exudate contains enzymes
that can digest the fibrin that helps hold a graft in place.
- Third, tacking sutures can be placed to immobilize the graft without the concern of hemorrhage from suture placement accumulating
under the graft.
I have also noted that mesh grafts heal or take more quickly in cats than in dogs. This is attributed to the thinner skin
of cats, which revascularizes faster.
Figure 1B. After the wound on the dog in Figure 1A healed as much as possible by second intention, final closure was accomplished
with a mesh graft.
One disadvantage of skin grafts compared with skin flaps is that more bandaging is required. Also, occasionally, a graft will
have a partial-thickness take, whereby the lower dermal tissues revascularize and that part of the graft and its adnexal content
survive. However, the epidermis and upper portion of the dermis die, forming a hard crust (eschar) over the graft or certain
parts of the graft. Do not give up on such a graft. When the eschar sloughs, viable skin graft will be under it. The part
of the dermis that revascularizes will be viable and will epithelialize from the adnexal structures it contains. Thus, it
is a viable graft, but it will have sparse hair growth because of the loss of some hair follicles in the sloughed upper dermis.
PUNCH GRAFTS IN POCKETS
Wounds that are in an area that is difficult to bandage or immobilize are a big challenge. Punch grafts placed in pockets
provide a means of closing these wounds while letting the wound tissue act as a bandage.
Treat the wound as an open wound until a healthy bed of granulation tissue is present. Then prepare a graft donor area on
the ventral craniolateral thoracic area. Starting at the top of the wound, make a row of slitlike pockets in the granulation
tissue by inserting a No. 15 scalpel blade down into the granulation tissue almost parallel to the surface of the wound with
the openings upward. Using a 6- to 8-mm-diameter skin biopsy punch, harvest grafts from the donor area. After making each
pocket, place a graft in it. Close each donor area with a simple interrupted suture.
Figure 2A. A bed of granulation tissue over the dorsum of a dog's nasal area.