Fat grafting is a fairly new technique in breast surgery. Fat is liposuctioned from one part of the patient's body, purified and then injected into the breast.
There are several fat grafting techniques that are used by plastic surgeons. There is no "set way" that has been shown to be the best in terms of long-term results. However, studies have shown that regardless of the technique used, the collection, storage, and transplantation of the fat cells (and the fat stem cells) must be optimized to obtain the best long-lasting results.
Studies have also shown that once the injected fat "takes", it can also help improve the thickness and quality of radiation-damaged tissue and skin.
Regardless of technique, some of the injected fat will be reabsorbed over time but this can vary depending on the exact clinical situation. Patients must therefore be prepared to require more than one procedure for the best results. Your surgeon will be able to discuss this further with you during your consultation.
Several independent studies have evaluated breast cancer patients over several years after lipofilling and concluded that fat grafting is safe. However, because the technique is fairly new, no long-term safety data is currently available to prove definitively that it is oncologically safe in lumpectomy patients long term. Unlike mastectomy patients, lumpectomy patients still have significant breast tissue left behind after treatment - there are fears that the fat stem cells may help "stimulate" the development of more cancer cells in the area of the previous cancer. Techniques that concentrate the stem cells in the fat graft are under the most debate because of this concern. While no studies to date have shown this fear to be true, more studies are currently looking at answering this question definitively.
Unfortunately not all insurance companies cover the cost of fat grafting so the procedure can involve out of pocket expenses for some patients.