Body fat makes excellent soft tissue filler material. Fat injection (also called analogous fat transplantation) transfers fat from one part of the body to another to recon tour the face; diminish frown lines, crow’s feet and provide definition to areas like the cheeks and chin. It can also be used to fill out depressed scarred areas on any part of the body. Fat injection is not permanent, and may require an effective maintenance program.
Technique:

The donor site (for example, abdomen, buttocks or thighs) and the treatment site are injected with local anesthetic. Intravenous (IV) fluids also are injected into the donor site to facilitate fat collection. Fat cells are extracted through a small needle attached to a syringe. The fat is then processed to remove excess fluids and rejected with another needle in multiple thin strands in the desired area. "Overfilling" is a necessary corrective due to fat absorption in the weeks after treatment. Fat also can be harvested during a liposuction procedure in one area of the body, and then rejected in another. For longest-lasting effect, patients generally receive 3 to 4 treatments over a six-month period.
Benefits:

    Natural, non-allergenic. Outpatient procedure that generally takes under an hour.
    Injections may last from several months to permanently.
    Little or no downtime.
    Minimal discomfort, which can be controlled with medication.
    Because fat is from the patient’s own body, no pr-testing is required and the fat cannot be rejected.
    Good alternative if the patient is allergic to bovine collagen.
    Cost effective if combined with another procedure like  (liposuction).

Other Considerations:

    Longevity of results can vary significantly from patient to patient.
    Some swelling, bruising—usually about 48 hours. Patient should avoid the sun until the condition subsides.
    Not every area is appropriate for fat injection. Injecting fat into the breast, for example, makes cancer detection via mammography more difficult and is strongly discouraged (see ASAP Position Statement, "Fat Injection for Breast Enlargement).
    Lasts longest when rejected in relatively stationary areas (such as the cheeks).

ABOUT ASAP

The American Society for Aesthetic Plastic Surgery (ASAP), is recognized as the world's leading organization devoted entirely to aesthetic plastic surgery and cosmetic medicine of the face and body. ASAP is comprised of over 2,600 Plastic Surgeons; Active Members are certified by the American Board of Plastic Surgery (USA) or by the Royal College of Physicians and Surgeons of Canada and have extensive training in the complete spectrum of surgical and nonsurgical aesthetic procedures. International Active Members are certified by equivalent boards of their respective countries. All members worldwide adhere to a strict Code of Ethics and must meet stringent membership requirements.