Flap surgery is a technique in plastic, reconstructive surgery where any type of tissue is lifted from a donor site and moved to a recipient site with an intact blood supply to it. This is distinct from a graft, which does not have an intact blood supply and therefore relies on growth of new blood vessels. This is done to fill a defect such as a wound resulting from injury or surgery when the remaining tissue is unable to support a graft, or to rebuild more complex anatomic structures such as breast, jaw etc.
Classification Of Flaps
Based On Complexity
Flaps can be classified according to level of complexity as follows
Local flaps are created by freeing a layer of tissue and then stretching the freed layer to fill a defect.
This is the least complex type of flap and includes advancement flaps, rotation flaps, and transposition flaps, in order from least to most complex. With an advancement flap, incisions are extended out parallel from the wound, creating a rectangle with one edge remaining intact.
This rectangle is freed from the deeper tissues and then stretched (or advanced) forward to cover the wound.
The flap is disconnected from the body except for the uncut edge which contains the blood supply which feeds in horizontally.
A rotation flap is similar except instead of being stretched in a straight line, the flap is stretched in an arc.
The more complex transposition flap involves rotating an adjacent piece of tissue, resulting in the creation of a new defect that must then be closed.
Regional or interpolation flaps are not immediately adjacent to the defect.
Instead, the freed tissue “island” is moved over or underneath normal tissue to reach the defect to be filled, with the blood supply still connected to the donor site via a pedicle.
This pedicle can be removed later on after new blood supply has formed, e.g., PMMC, DP flaps for head and neck defects, TRAM for breast reconstruction.
Distant flaps are used when the donor site is far from the defect.
These are the most complex class of flap. Direct or tubed flaps involve having the flap connected to both the donor and recipient sites simultaneously, forming a bridge.
This allows blood to be supplied by the donor site while a new blood supply from the recipient site is formed.
Once this happens, the
bridgecan be disconnected from the donor site if necessary, completing the transfer.
A free flap has the blood supply cut and then reattached microsurgically to a new blood supply at the recipient site.
Based On Tissue Type
Here are some of the more common classifications by tissue type:
Cutaneous flaps contain the full thickness of the skin and superficial fascia and are used to fill small defects.
Fasciocutaneous flaps add subcutaneous tissue and deep fascia, resulting in a more robust blood supply and ability to fill a larger defect.
Musculocutaneous flaps further add a layer of muscle to provide bulk that can fill a deeper defect.
Muscle flaps can provide bulk or functional muscle. If skin cover is needed, a skin graft can be placed over it.
Bone flaps are used to replace bone, such as in jaw reconstruction.
Based On Vascularity
Classification based on blood supply to the flap:
Axial flaps are supplied by a named artery and vein. This allows for a larger area to be freed from surrounding and underlying tissue, leaving only a small pedicle containing the vessels.
Reverse-flow flaps are a type of axial flap in which the supply artery is cut on one end and blood is supplied by backwards flow from the other direction.
Random flaps are simpler and have no named blood supply. Rather, they are supplied by generic vascular networks.
Pedicled flaps remain attached to the donor site via a pedicle that contains the blood supply, in contrast to a free flap as described under Classification by complexity.
Flap surgery is typically done under local anesthesia, sometimes accompanied by oral anti anxiety medications, alternatively, it may be performed under intravenous conscious sedation.
After anesthesia has taken effect, a small incision is made to separate the gums from the teeth.
The outer gum tissue is gently folded back to give access to the roots and the supporting ligament and bone tissue.
Next, the inflamed gum tissue can be removed, and the tooth roots can be cleaned, if needed, the area may also be treated with antibiotics or other medications.
Bone defects can be repaired with grafting material, and proper regeneration of the periodontal ligament can be encouraged by physical (barrier membranes) and chemical (growth factors) methods.
Finally, the incision is closed, and the procedure is completed.
Performed by an experienced hand, state-of-the-art flap surgery has an excellent track record and offers well established benefits.
It’s often the treatment of choice for relieving periodontal disease and helping to maintain your oral health and preserve your teeth.
Goals Of Flap Surgery
The Goals of Flap Surgery are as follows
One major objective of flap surgery is to eliminate or reduce the pocket itself. To access it, a flap-like incision is made in the gum tissue. This allows diseased tissue to be removed from inside the pocket, and provides access to the teeth’s root surfaces for a thorough cleaning, which helps to eliminate harmful plaque and calculus (tartar). Afterward, the
flapis closed, sealing the area. This begins the healing process, which takes place rapidly.
Another goal is the regeneration of periodontal ligament and bone tissue which may have been lost to the disease. A variety of techniques may be used to accomplish this, including high-tech methods of bone grafting and chemicals referred to as growth factors. These approaches help restore the gums to their normal form and function, and promote the healthy and secure anchoring of teeth.