• Free soft tissue graft is not vascularized
  • 1-3 days: plasmatic imbibition
  • 2-3 days: inosculation

 

  • Unlike flaps, grafts are dependent on nutrition from the recipient bed (plasmatic circulation or imbibition) for 48-72 hours; beyond that, neovascularization and inosculation take over
  • Split thickness skin graft:  include the epidermis and portion of dermis; usually 0.3-0.45mm (0.012-0.015in) thick; heals primarily by epithelial migration from adnexal structures
    • Advantages: less primary contracture; ability to cover larger areas; higher successes with graft take
    • Disadvantages: less esthetic; more susceptible to contracture
  • Full thickness skin graft: include entire dermis; contract 15-20%
    • Advantages: more primary contracture but less late wound contracture; better esthetic result; more resistant to trauma
    • Disadvantage: need to close donor site; increased risk of partial or complete graft failure
    • *primary contracture refers to the immediate shrinkage that occurs when a soft tissue graft is harvested

 

  • When harvesting a split thickness skin graft the ideal thickness should be 0.012 to 0.015 inches. This allows the graft to contain both epidermis and the superficial dermis. Allowing early revascularization.
  • The main advantages of a full thickness skin graft over a split thickness skin graft for facial reconstructive surgery include less contracture of the healing graft, and less labor regarding the donor site’s postoperative management. This is owing to the ability to primarily close the donor site of a full thickness skin graft, while the donor site of a split thickness skin graft must heal by tertiary intention. During this time, the split thickness skin graft donor site must be dressed with an occlusive dressing such as Opsite or Tegaderm. With this in mind, the potential for postoperative infection is such that the closed wound may develop infection, while the defect pertaining to the split thickness skin graft is open, and therefore less likely to become infected postoperatively.

Full thickness skin grafts can be expected to contract 15 -20% and should be harvested with that in mind. Healing of the donor site in split thickness skin grafting is similar to burns, and occurs primarily from the contribution of adnexal skin structures. Therefore, “b” is the best choice. Survival of skin grafts in the initial 48-72 hours is dependent upon  plasmatic circulation or imbibition. Beyond that, neovascularization and inosculation take over.