Applying Split-Thickness Skin Grafts: A Step-by-Step Clinical Guide and Nursing Implications
Healing by second intention is the most predictable method in the terminal phase of wound healing. It is also the most damaging, frustrating, time consuming, (and) economically devastating.1
Split-thickness skin graft application is typically indicated for temporary or permanent coverage of cutaneous defects.2
These grafts traditionally are used to cover large areas of skin loss, granulating tissue beds, tissue loss across joints in areas where contraction will cause deformity, and where epithelialization alone will produce an unstable wound cover.3 Split-thickness autografts include epidermis and part of the dermis, depending on graft thickness. Some dermal skin appendages (eg, sweat glands, hair follicles, and sebaceous glands) remain at the donor site, which heals by epithelialization.4
Graft survival is predicated on several physiological events; the initial "take" (or incorporation) occurs by diffusion of nutrition from the recipient site (termed "plasmatic imbibition"). Revascularization generally occurs between days 3 and 5 by reconnection of blood vessels in the graft to recipient site vessels or by ingrowth of vessels from the recipient site into the graft. This phenomena is referred to as inosculation.5
Split-thickness skin grafts must be placed on well-vascularized beds with low bacterial counts to prevent infection. In addition, the grafts must be immobilized to prevent shearing and the formation of hematoma/seroma. The skin should be vented by fenestration ("pie crusting") or meshing and may ultimately have to undergo evacuation of excessive fluid build-up by aspiration or other means to prevent graft slough. Skin grafts generally will not "take" on poorly vascularized beds such as bare tendons, cortical bone without periosteum, heavily irradiated areas, or infected wounds. However, once cultivated, virtually any tissue type with a vascular granulating stroma may be an acceptable bed for grafting.1
Many different wounds may require skin grafts, including chronic nonhealing venous ulcers, traumatic lower extremity wounds, diabetic wounds, burns, and pressure ulcers, among others. Although each of these conditions has its own idiosyncrasies, the implications for nursing care of the graft and donor site are usually the same.
The following pictorial outlines a reliable and reproducible technique for split-thickness skin grafting that fosters fibrin adhesion, plasmatic imbibition, and inosculation. It also will aid dramatically in reducing the potential complications of hematoma, shearing, poor revascularization, and infection.
The specialized instruments used in skin grafting procedures are shown in Figures 1-3, and include:
* Zimmer air dermatome (Zimmer Patient Care, Dover, Ohio) with 1-, 2-, and 3-inch templates
* skin graft carrier (1.5:1 or 3:1)
* 2 wooden tongue blades
* marking pen
* jet lavage.
Applying Split-Thickness Skin Grafts
Step 1. The patient is brought into the operating room, appropriately positioned, and prepped and draped in the usual sterile manner. The length, width, and depth of the wound are measured to determine the size of the donor site (see Figure 4). All undermining must be taken into account and excised before grafting. When the skin is meshed, it will cover a larger surface area. If the wound is going to be excised rather than debrided, the depth of the lesion may increase dramatically and a larger piece of skin will be required for coverage. The template for the dermatome also should be selected at this time.
Step 2. The measurements are carefully drawn at the donor site with a surgical marking pen (see Figure 5). The donor site can be in various locations, including the outer thigh, the inguinal ligament region, the posterior leg, the lateral malleolus, the popliteal fossa, or the dorsal foot. The area is then prepped with sterile mineral oil. Tongue blades work best in the application of this substance as gauze will absorb too much of the oil.
The template and dermatome blade also are coated with a thin layer of the oil (see Figure 6). At this juncture, the thickness of the graft is determined and can range from 0.0008 of an inch to 0.020 of an inch. The author prefers a harvested graft of 0.0015 of an inch, if feasible. Each patient has different requirements (the thinner the graft, the better the "take").
Step 3. At the donor site, the tongue blades are placed distal and proximal for the purpose of applying some tension. The dermatome is positioned at approximately a 45-degree angle so the underlining skin markings can be visualized before taking the skin (see Figure 7). The dermatome moves downward until contact is made with the skin. The instrument then moves almost parallel to the donor site. Steady and equal pressure is applied while the skin is under tension until the appropriate amount of donor skin has been procured. The dermatome is then slowly angulated upward, releasing the skin from the site. During this process, having an assistant tease the skin from the dermatome to prevent it from getting caught in the blade is important. The donor site is then allowed to sanguinate for several minutes before it is covered with xeroform (Medline Industries, Inc., Mundelein, Ill.) gauze. This will aid in adherence to the site and will be less problematic for the patient.
Step 4. The donor skin is transferred (dermal side up to avoid any confusion regarding orientation) to a skin graft carrier in preparation for meshing (the skin will curl toward the dermis. See Figure 8). Atraumatic forceps should be used to prevent tearing the skin. The clinician should make certain that the dermal carrier is ridged side up or the skin will not mesh. This side of the carrier is usually marked; clinicians can feel the ridges with their fingers.
The skin is prepped with saline, gently spread out so no curled edges or air bubbles are visible, and the carrier is placed in the mesher (see Figure 9). As the skin is being meshed, an assistant should tease the skin away from the mesher to prevent shredding. This author prefers the 1.5:1 mesh; the 3:1 is also useful, especially for larger defects. The skin is covered with moistened saline gauze. If a mesher is not available or the skin is too large to fit the carrier, it can be "pie-crusted" to facilitate drainage which is easily performed with an #11 blade.
Step 5. The wound site should be debrided with cold steel or excised, including any undermining. During debridement, the edges of the wound will need to be "freshened" or excised (see Figure 10) and then flushed with jet lavage (see Figure 11) to thoroughly cleanse the wound bed. The author prefers to incorporate antibiotics such as bacitracin or polymyxin in this solution; however, normal saline is also acceptable. All bleeders are clamped and/or cauterized at this time to prevent the formation of hematoma.
Step 6. The carrier is held adjacent to the wound, and the skin is teased off this device and placed directly over the defect (see Figure 12). The harvested skin had been placed on the carrier dermal side up, so repositioning is unnecessary.
Step 7. A stent dressing is fabricated by creating at least four long sutures opposing each other at the wound site. Several materials can be used to fabricate this dressing. The author places moistened gauze in a large piece of Vaseline(R) gauze (Chesebrough-Ponds Inc., Greenwich, Conn.) and folds it, creating a "ball" of petroleum jelly. He applies this gauze to the wound site and sutures it in place with long sutures (see Figure 14). This dressing creates continuous compression of the harvested skin against the wound bed.
Step 8. The donor site is dressed with xeroform, sterile gauze, and a mild compression dressing (see Figures 15a-15c). Although the author prefers foam tape, paper tape is also acceptable.
Step 9. The wound is dressed with sterile gauze, fluffs, ABD pads or combine dressing (Surgipad, Johnson and Johnson, Arlington, Tex.), and a soft gauze wrap. A posterior splint is applied under a double 6-inch Ace (Becton, Dickinson, and Company, Franklin Lakes, NJ) wrap (see Figure 16).
Step 10. The patient is required to stay in the hospital for 23 hours at full bed rest and is discharged with no weight bearing on the affected limb. After gait training from a physical therapist, a walker is usually dispensed to aid mobility. The original dressing is left intact for approximately 1 week unless deleterious signs such as pain, fever, or bleeding are present. A home healthcare nurse will visit the patient for the first 3 days postoperatively to assess circulation of the limb and to monitor vital signs. The patient is then seen weekly by the clinician and the splint is incorporated in the dressing for a period of at least 2 weeks.
The gauze at the donor site is usually removed several days postoperatively (see Figure 17); the xeroform gauze is usually left intact and allowed to dry to peel off. Although this appears to be contrary to the precepts of moist wound healing, it seems to be the most efficient and least problematic option for the patient. The physician should be aware that the donor site can be more painful for the patient than the graft site.
A topical antibiotic such as Bactroban (SmithKline Beecham, Philadelphia, Pa.) or Silvadene (Monarch Pharmaceuticals, Bristol, Tenn.) should be applied to the wound site for 1 week before surgery to decrease bacterial colonization.
Some surgeons advise examining the graft site within 4 days postoperatively for the purpose of evacuating hematoma/seroma, if necessary. The author has found that proper application of the stent dressing has virtually eliminated this problem.
At the first dressing change, before the stent is removed, the bolus may be saturated with hydrogen peroxide. The bolus will expand like a sponge and pull away from the wound so it can be teased away without lifting up the grafted skin. Hydrogen peroxide can be cytotoxic; therefore, care should be taken to avoid the wound itself.
The use of prophylactic antibiotics is controversial; however, the author recommends Ancef (SmithKline Beecham, Philadelphia, Pa.) 1 gram IV, 1/2 hour before surgery and then every 8 hours while the patient is in the hospital. For patients with penicillin allergy, the author recommends clindamycin 600 mg IV in the same regimen as above or Levaquin IV (Ortho-McNeil, Raritan, NJ) 500 mg every 24 hours.
Donor site. During the procedure, the physician will apply xeroform, which remains in place until it exfoliates on its own. The xeroform can be trimmed as it peels away from the donor site. The clinician should make sure a protective dressing, such as lyofoam, is applied until the site is healed.
The clinician will need to instruct the patient that he or she may have more pain at the donor site than at the graft site. Pain relief measures should be offered, as well as information on donor site care.
Graft site. The clinician will perform the first dressing change approximately 7 days after the procedure, which involves the following:
* Remove the dressing slowly. Keep in mind that moistening the dressing with saline may be necessary to avoid damage to the graft. If a stent dressing is in place, the physician or nurse who is skilled in this area should perform the removal. Hydrogen peroxide is sometimes used to lift the dressing from the graft site. However, this substance can be cytotoxic; therefore, it should not come into contact with the graft, if possible.
* Note amount, color, and odor of drainage.
* Gently cleanse the site with saline irrigation and pat with dry gauze.
* Apply Adaptic (Johnnson + Johnson, Somerville, NJ), Mepitel (Molnlycke Health Care, Eddystone, Pa.), or a similar dressing material directly onto the graft. Then cover it with lyofoam, gauze, gauze roll, and mild compression with a 3- to 4-inch Coban (Medline, Mundelein, Ill.). You may slit the top of the Coban to allow for any swelling. If the physician has recommended a splint, reapply per the physician's order for the prescribed length of time.
* With each dressing change, assess the site for any signs of maceration. If excessive maceration occurs, apply xeroform and lyofoam, or a plain hydrocellular dressing.
* Protect the area from pressure and/or shear injury
. * Assess for signs and symptoms of wound infection and report these to the physician as needed.
* Assess the graft site for signs of graft failure and report these to the physician as needed.
* This dressing remains in place for 5 to 7 days.
The clinician will perform the second dressing change 5 to 7 days later, which involves the following:
* Gently and slowly remove the dressing. If the dressing sticks, moisten it with saline.
* If a large amount of drainage is noted, increasing dressing changes to every 3 to 5 days may be necessary.
* Assess the area for signs and symptoms of infection and report these to the physician.
* Assess the graft site for signs of failure and report these to the physician.
* The previous dressing may be continued if no problems with maceration are evident. If maceration is a problem, use xeroform with lyofoam or lyofoam alone.
* The frequency of dressing changes after 2 weeks following the graft will depend on the status of the wound and physician orders.
Expectations at the graft site. Moderate drainage and scant malodor with absence of signs of infection may be due to the length of time the dressing has been in place and is usually no reason for alarm. The physician may incorporate a splint in the dressing for at least 2 weeks and prescribe a walker or wheelchair initially to help prevent weightbearing on the affected limb.
The services of a home healthcare nurse during the first 3 to 4 days after discharge will be helpful in assessing any complications.
Clinicians always should remember that caring for both the graft and donor sites should incorporate good wound care techniques. In order to avoid graft failure, clinicians should stress patient cooperation, compliance, and education.
Split-thickness skin grafting represents a reliable procedure for coverage of many cutaneous lesions. This paper has outlined a technique that helps foster fibrin adhesion, plasmatic imbibition, and inosculation. By following the basic precepts of wound healing along with meticulous tissue handling, split-thickness skin grafting has the potential to play an important role in wound management and limb salvage.- OWM