Reconstructing complex wounds is accomplished by shifting or transferring tissues to the wound from a different part of the body. A “skin graft” is the transfer of a portion of skin (without its blood supply) to a wound. A “flap” consists of one or more tissue components, including skin, deeper tissues, muscle, and bone. Flaps are transferred with either their original blood supply (pedicle flap) or with detached blood vessels that are attached at the site of the wound (free flap). Skin grafts survive as oxygen and nutrients diffuse into them from the underlying wound bed. Long-term survival depends on a new blood supply forming from the wound to the graft.
When the wound bed does not have enough oxygen supplied to it, the skin graft will at least partially fail. Common causes for this are continued smoking, previous radiation to the wound area, diabetes mellitus, and certain infections. In these situations, the availability of oxygen in the wound bed can be increased with hyperbaric oxygen therapy in preparation for skin grafting. Additionally, hyperbaric oxygen therapy can be used after skin grafting to increase the amount of the graft that will survive in the compromised settings. Flaps also require oxygen and nutrients to survive. The outer visible portion (usually skin) is furthest from the source of blood supply for the flap. This is the area most likely to be compromised by inadequate oxygen. Factors such as age, nutritional status, smoking, and previous radiation result in an unpredictable pattern of blood flow to the skin.
Hyperbaric Oxygen Therapy for Compromised Skin Grafts and Flaps
If a flap is found to have less than adequate oxygen after it has been transferred, hyperbaric oxygen can help minimize the amount of tissue which does not survive and also reduces the need for repeat flap procedures. If the patient is known to be at high risk for complications, hyperbaric oxygen can help by assisting in the preparation and salvage of skin grafts and compromised flaps before the procedure is done.