Free flap

The terms free flap, free autologous tissue transfer and microvascular free tissue transfer are synonymous terms used to describe the "transplantation" of tissue from one site of the body to another, in order to reconstruct an existing defect. "Free" implies that the tissue is completely detached from its blood supply at the original location ("donor site") and then transferred to another location ("recipient site") and the circulation in the tissue re-established by anastomosis of artery(s) and vein(s). This is in contrast to a "pedicled" flap in which the tissue is left partly attached to the donor site ("pedicle") and simply transposed to a new location; keeping the "pedicle" intact as a conduit to supply the tissue with blood.

Various types of tissue may be transferred as a "free flap" including skin and fat, muscle, nerve, bone, cartilage (or any combination of these), lymph nodes and intestinal segments. An example of "free flap" could be a "free toe transfer" in which the great toe or the second toe is transferred to the hand to reconstruct a thumb.

For all "free flaps", the blood supply is reconstituted using microsurgical techniques to reconnect the artery (brings blood into the flap) and vein (allows blood to flow out of the flap).

Free autologous tissue transfer is performed by many surgical specialties.

Free flaps are used to reconstruct tissue defects. Particularly when postoperative radiotherapy is indicated, vascularized free tissue is preferred over non-vascularized free tissue.

Breast reconstruction:

Hand reconstruction:

Head and Neck reconstruction:

When reconstructing complex head and neck defects, the reconstruction often requires bone and soft tissue from a distant donor site to be harvested. Functional reconstruction in the head and neck area often requires reconstruction of the oral cavity, the jawbone and the dental occlusion. Type of defects include:

The most common serious complication of a free flap is loss of the venous outflow (e.g. a clot forms in the vein that drains the blood from the flap). Loss of arterial supply is serious too and both will cause necrosis (death) of the flap. Close monitoring of the flap both by nurses and by the surgeon is mandatory following the completion of the operation. If detected early, loss of either the venous or arterial blood supply may be corrected by operative intervention. Many times an implantable Doppler probe or other devices can be installed during surgery to provide better monitoring in the post-operative period. The Doppler probe can be removed before discharge from the hospital.

Usually the harvest of a "free flap" is performed in such a fashion to cause the least amount of disability. Despite this some disability may occur following removal of this tissue from the "donor site".

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Wikipedia