SKIN GRAFTS AND COMPROMISED FLAPS
Reconstructing complex wounds is accomplished by transferring tissues to the wound from a different part of the body. A “skin graft” is the transfer of a portion of the skin without its blood supply to a wound. A “flap” consists of skin and deeper tissues including muscle and bone. Flaps are transferred either with their own, original blood supply (pedicle flaps) or with detached blood vessels which are attached at the site of the wound (free flap).
Skin grafts survive as oxygen diffuse into them from the underlying wound bed. Long-term survival depends on a new blood supply forming from the graft to the wound. When the wound bed does not have enough oxygen supplied to it, the skin graft will at least partially fail.
Hyperbaric oxygen treatments can save inadequately perfused or hypoxic grafts by increasing oxygen delivery to the flap and promoting the development of new blood vessels. The elevated pressure within the hyperbaric chamber results in a dramatic increase in plasma oxygen concentration and in oxygen delivery to the tissues from functioning capillaries. Neovascularization represents a delayed response to hyperbaric oxygen treatment. Capillary angiogenesis results in the formation of new blood vessels that improve the oxygenation of the flap and can help it survive.