Grafts and Flaps

Skin graft

  • Transfer of skin from one donor site to a recipient site (independent of blood supply)

  1. Graft "takes" by acquiring a blood supply from healthy donor bed
  2. May be partial thickness (epidermis only) or full thickness (entire epidermis with underlying dermis)
    • Dermis does not regenerate
    • Epidermis regenerates from the "adnexal elements of skin" - hair follicles, sebaceous glands, sweat glands

Tissues unsuitable for grafting

  • Unhealthy, necrotic infected tissue
  • Irradiated tissue
  • Exposed cortical bone bone without periosteum
  • Tendon without peritenon
  • Cartilage without perichondrium

Harvesting skin grafts

  • Hand-held skin knives: Watson & Braithwaite modifications of Humby knife, electric or gas-powered dermatomes
  • Donor site usually one that can be easily concealed - inner thigh, buttock, inner arm

Skin Flap

  • Tissue(s) transferred from one site of the body to another
  • Maintains a continous blood supply through a vascular pedicle

Classification

  1. Site
    • Local or distant (aka "free flap")
  2. Contents
    • Omentum
    • Bowel
  3. Random or axial (on a named artery)

Indications for flap reconstructions

  • Situations where grafts will not take
  • When aim is to reconstruct tissue that is "like for like" (bone, joint, tendon, nerve, epithelial lining) to promote optimal structure, function and cosmesis
  • When blood supply to an area is of doubtful viability

Reconstruction Ladder

  1. Healing by secondary intention, then by primary intention
  2. Skin graft
  3. Local flap
  4. Distant flap
  5. Composite flap
  6. Island flaps vs pedicaled flaps
  7. Free flaps
  8. Composite neurovascular free tissue transfer