Lecture Notes: Full Thickness Skin Grafts (FTSG)






Reconstruction with full thickness skin grafts (FTSG) provides an esthetic advantage for burns of the face and hands. Donor sites used for FTSG are from areas of redundant and pliable skin and include the supraclavicular, groin, lower abdominal, or lateral thoracic skin. STSG from the scalp can be used for resurfacing the face and improves the color match of the skin paddle for patients previously treated with a free flap.

FTSG are reserved for reconstruction of areas of special anatomical and functional importance requiring a more pliable reconstruction than that offered by STSG. This is specifically important in cosmetically sensitive areas such as in the head, eyelids, perioral areas, and neck and extremely important functional areas such as the hands.

Advantages 
In terms of quality, FTSG present obvious advantages by transferring both epidermis and dermis to the burn wound. FTSG provide improved texture, pliability, elasticity, esthetics, and color match and are more resistant to secondary contracture in comparison to split thickness skin grafts. There is also greater patient satisfaction with FTSG for both the recipient site and donor site, which is closed primarily.

Disadvantages 
The major limitations and disadvantages of using FTSG include:
  • Limited availability of high quality donor skin — FTSG donor sites lack the ability to self-regenerate. Reharvesting in the same area is limited by the elasticity of surrounding skin. For example, there is sufficient laxity and pliability of the skin in the supraclavicular and groin areas to permit mobilization of the surrounding tissues and achieve a primary close the donor site. Hence, this site may be harvested a second time. Sites with insufficient laxity cannot be closed primarily. The limited availability of FTSG requires careful decision making to avoid wasting valuable elastic and pliable skin. 
  • Limited vascularity of the burn wound — The graft survival rate is also lower for a FTSG in comparison to a STSG. FTSG have a higher metabolic rate compared with STSG, therefore, their take or survival is compromised in areas of limited vascularity. 
  • Color, texture, and thickness match — Not all areas of the body are suitable as donor sites since a FTSG should ideally match the recipient site for color, skin thickness, and texture. A drawback of applying a FTSG to the face is the potential color mismatch, with results varying from hypopigmentation to hyperpigmentation. 
  • Inability to drain accumulating fluids — Lack of interstices in FTSG makes the grafts more prone to non-take due to hematoma and seroma formation.

Key technical components 
The method of FTSG harvesting differs from that of harvesting a STSG. A FTSG is harvested free-hand, without the use of a dermatome.
  • The burn wound is debrided and must be free of a hematoma, exudate, or infection. 
  • Tumescent infiltration with a local anesthetic and/or epinephrine mixed with saline is performed at the donor and burn wound sites.
  • The donor skin graft is created free-hand using a blade. 
  • All subcutaneous adipose tissue is removed from the dermis of the FTSG. 
  • The donor site is managed by primary closure. 
  • Small incisions are made to perforate the FTSG to facilitate evacuation of blood exudate without compromising graft integrity. 
  • Quilting sutures can be used to fix the graft to the recipient site. Bolstering and tie-over of the grafts may help in protecting the grafted areas, though their usefulness in applying pressure in the interface between recipient and graft area to ensure better take has been questioned.
  • Topical negative wound pressure (TNP) is another fixation option in selected patients.

FTSG survival 
Theoretically, the FTSG survival or take rate should be close to 100 percent in fully debrided recipient burn wound sites. The main factor that prevents a complete take is the lack of initial adhesion to the recipient site due to the presence of a hematoma or seroma that inhibits revascularization. Even small perforations in the FTSG may not be sufficient to drain accumulating fluid. The same local and systemic factors that decrease the survival of STSG also decrease the survival of FTSG.
Local factors of the burn wound that are associated with decreased STSG survival include:
  • Inadequate vascularity, such as exposed unvascularized bone or tendon. 
  • Inadequate hemostasis, such as a hematoma or seroma under the graft. 
  • Excessive mobilization. 
  • Areas of high contact or friction, such as the back, anorectal area, and genitalia. 
  • Local tissue hypoxia caused by smoking or previous radiation.
Systemic factors that may decrease STSG survival include:
  • Advanced patient age.
  • Malnutrition.
  • Comorbidities such as diabetes and immunosuppression.
  • Steroid use.


Reference: UTD
 

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