Skin Grafting

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Updated: Apr 16, 2015
  • Author: Donald J Grande, MD; Chief Editor: Dirk M Elston, MD  more...
Overview

History of the Procedure

In its most basic sense, skin grafting is the transplanting of skin and, occasionally, other underlying tissue types to another location of the body. The technique of skin harvesting and transplantation was initially described approximately 2500-3000 years ago with the Hindu Tilemaker Caste, in which skin grafting was used to reconstruct noses that were amputated as a means of judicial punishment. [1] More modern uses of skin grafting were described in the mid-to-late 19th century, including Reverdin's use of the pinch graft in 1869 [2] ; Ollier's and Thiersch's uses of the split-thickness graft in 1872 and 1886, respectively [3, 4] ; and Wolfe's and Krause's use of the full-thickness graft in 1875 and 1893, respectively. [5] Today, skin grafting is commonly used in dermatologic surgery.

Skin grafting is only one means of reconstructing a defect in the skin, regardless of the cause of the defect. Most commonly, it is used for reconstruction after the surgical removal of cutaneous malignancies; however, skin grafts are also used to cover chronic nonhealing cutaneous ulcers, to replace tissue lost in full-thickness burns, and to restore hair to areas of alopecia. As skin cancer continues to be prevalent, more defects will be produced in the surgical treatment of these tumors, and, as a consequence, individuals who perform cutaneous reconstructive surgery should acquire a thorough understanding of the techniques of skin grafting.

The Medscape Dermatology Surgery Resource Center and Aesthetic Medicine Resource Center may be helpful. The following Medscape Reference articles on skin grafting may be of interest:

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Indications

Generally, skin grafting is used when, in the opinion of the reconstructive surgeon, other methods of reconstruction such as primary closure, second-intention healing, or local skin flaps are inappropriate, are unavailable, or would produce a suboptimal result. Skin grafts are divided into 2 major categories: full-thickness skin grafts (FTSGs) and split-thickness skin grafts (STSGs). STSGs may be subdivided into thin (0.008- to 0.012-mm), medium (0.012- to 0.018-mm), and thick (0.018- to 0.030-mm) grafts. Although the use of skin grafts is indicated primarily in reconstruction after surgical excision of malignancies, skin grafting has several other applications and considerations.

STSGs are most commonly used when cosmesis is not a primary concern or when the defect to be corrected is of a substantial size that precludes the use of an FTSG. Other uses of STSGs are the coverage of chronic unhealing cutaneous ulcers, temporary coverage to allow observation of possible tumor recurrence, surgical correction of depigmenting disorders with the use of suction blister grafts to line cavities such as the orbit, and coverage of burn areas to accelerate wound healing and to reduce fluid loss.

FTSGs can be used to achieve excellent outcomes when the donor site is selected appropriately and when both the donor graft and recipient bed are carefully prepared before the graft is sutured in place. The use of FTSGs is indicated in defects in which the adjacent tissues are immobile or scarce. FTSG use is also indicated if that adjacent tissue has premalignant or malignant lesions and precludes the use of a flap. Specific locations that lend themselves well to FTSGs include the nasal tip, helical rim, forehead, eyelids, medial canthus, concha, and digits.

Another common indication for the use of a FTSG is when a multistaged procedure is inappropriate for the patient. Other indications for the use of FTSG include punch grafting for hair transplantation and minigrafting (punch grafting) for the surgical correction of depigmenting conditions.

Contraindications for the use of STSGs and FTSGs are described in Contraindications.

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Relevant Anatomy

By necessity, the harvested skin graft is completely separated from its vascular supply prior to its transplantation in the recipient site. The graft proceeds through several physiologic stages before the newly transplanted tissue is assimilated (ie, "takes").

The initial stage of graft healing, termed plasmatic imbibition, occurs within the first 24-48 hours after the placement of the graft on the recipient bed. During this process, the donor tissues receive their nutrition through the absorption of plasma from the recipient wound bed via capillary action. In this phase of healing, the graft is white and may appear somewhat edematous. Furthermore, because nutrients can be absorbed more effectively over shorter distances, thinner grafts tend to survive better in this stage of graft healing. In addition, during this phase of healing, a fibrin network is created between the graft and the recipient bed. The recipient bed then generates vascular buds that grow into the fibrin network.

After imbibition is the phase of graft healing termed inosculation. This phase starts 48-72 hours after grafting and may continue for as long as 1 week after grafting. During this time, the aforementioned vascular buds anastomose with both preexisting and newly formed vessels. This revascularization of the skin graft, which occurs more rapidly in an STSG than in an FTSG, is initially accompanied by a mottled appearance and then a vascular erythematous blush or, occasionally, a slightly cyanotic appearance. In most recipient areas, revascularization occurs from both the base and the periphery of the recipient bed during this process.

Lymphatics develop in the graft tissue at approximately 1 week after transplantation, and reinnervation of the graft may begin as early as the first few weeks, although many grafts may have some degree of permanent anesthesia. A unique phenomenon of vascular bridging has been described to account for revascularization in relatively avascular recipient beds. In this phenomenon, vascular ingrowth occurs from the relatively highly vascularized lateral aspects of the recipient bed and bridges across the avascular base of the recipient bed. However, for vascular bridging to occur, the recipient area must remain small, and the area that immediately surrounds the graft must be highly vascularized.

Many variables can affect proper wound healing and, thus, the overall success of skin grafts. These variables are discussed in Complications.

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Contraindications

Contraindications to the use of STSGs include the need to place the graft in areas where good cosmesis or durability is essential or where significant wound contraction could compromise function. A poor color and texture match, as well as the lack of pilar and eccrine adnexal structures, contributes to the more pronounced patchwork appearance with an STSG than with an FTSG.

In the planning of any surgical reconstruction, all options for repair should be considered, with their inherent strengths and weaknesses. Often, second-intention healing may produce results better than those with a STSG if the original defect to be corrected is small. Furthermore, second-intention healing can also be combined with an STSG to correct significant discrepancies in the depth of the surgical defect and surrounding unaffected skin surface.

The use of FTSGs is contraindicated when the recipient bed, due to lack of reasonable vascular supply, cannot sustain the graft. Using an FTSG on avascular tissues, such as exposed bone or cartilage, most often leads to graft necrosis unless the area is small (and allows the bridging phenomenon to occur).

Uncontrolled bleeding in the recipient bed is another contraindication to the placement of an FTSG because hematoma and/or seroma formation under the graft compromises graft survival.

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