I'm considering fat injections around my lips and have heard from various sources that a) the fat can be frozen after removal to be used for subsequent injections as needed over the following months, or b) the fat cannot be frozen and remain useful, and only fresh cells used immediately are worth injecting. There is a substantial difference in cost and discomfort between these two methods, but, most importantly, I would like to know which statement is, in fact, true. Are frozen fat cells useful or not? If they are, is there any benefit at all to repeating the procedure each time to withdraw fresh cells?

To my knowledge, the scientific facts surrounding this question have not been definitively answered. Theoretically, it may be true that preserved fat cells remain viable; however, it is likely that time diminishes their efficacy. From a practical standpoint, I doubt that there is much

difference in the cost of the surgery using freshly harvested fat versus stored fat, because of the added cost of providing fat storage under temperature-controlled conditions. Most patients could not tolerate the procedure of replanting the fat cells into the face without some type of anesthetic, so the issue of discomfort is really moot.

Stored or frozen fat may or may not be safe. But, it is certainly not viable for lasting results.

Fat grafting has been performed by plastic surgeons for decades. There is no question that fat is the ideal material for soft tissue augmentation, and that the results obtained with fat grafting are the most natural-appearing. However, one problem with this procedure in years past has been resorption (breakdown) of the grafted fat, so that the resulting improvement is not permanent. The grafted fat must gain its own blood supply in its new location in order to persist long-term, and this generally is not possible when large amounts are injected at once and when specialized instrumentation and techniques are not employed.

In order for fat to persist, small amounts (less than 0.1 cc at a time) of fat are carefully microinjected in a series of discrete layers to gradually 'build' new soft tissue structure. As there is space between each microinjection, new blood vessels are able to grow into the grafted fat, allowing it to persist. If this process of blood vessel ingrowth (neovascularization) does not occur, then the injected tissue cannot truly be considered a 'graft' and is instead just another 'soft tissue filler' of limited duration.