Does freezing fat cells kill or preserve them?

CoolSculpting has FDA approval for fat reduction since 2010. CoolSculpting freezes the fat cells. Fat cells are more susceptible to damage by freezing than the other cells, (nerve, vessel, bone, etc.), around them. The fat cells die via a process called apoptosis, (programmed cell death). The number of fat cells are therefore reduced. This happens over a period of time, so the body is not overwhelmed with dead fat cells. The body will take these cells up, process them and excrete them, just as any other cell. The remnants are filtered through the liver, and then excreted eventually via stool. CoolSculpting now has an applicator for thighs.  CoolSculpting had been used in this area with good results. See an experienced CoolSculpting practice, they will determine if you are a candidate.  Best to see a Board Certified Plastic Surgeon.  They will be able to tell you of the different options, (CoolSculpting, Liposuction, Direct excision, etc.).           

Freezing the fat cells essentially kills them.  The research has shown that the fat cells die off in a process termed apoptosis. 

Coolsculpting is a safe and effective procedure that safely delivers precisely controlled cooling to gently and effectively target the fat cells underneath the skin. The treated fat cells are crystallized (frozen), and then die. Over time, your body naturally processes the fat and dispenses these dead cells, leaving a more sculpted you. I recommend going to a consultation to see if you are specifically a good candidate and how many treatments you would need.

Coolsculpting uses a scientific process called cryolipolysis to have a systematic elimination of the fat cells (apoptosis).

This is an interesting question. First off, CoolSculpt uses a process called cryolipolysis to kill fat cells. It doesn't kill all of the fat cells, and the temperature is low enough to damage fat cells but not the overlying skin (i.e. no frostbite). Approximately 15-20% of the fat cells are killed or injured in one CoolSculpt treatment. The remnants of these cells are carried away by cells in the body and excreted naturally. So, CoolSculpt damages or kills a percentage of the fat cells in the area being treated.In fat that is harvested and stored in a freezer to be used for injection later it is possible that some of those fat cells are damaged or killed when they are harvested or in the freezing process (probably not nearly as much as the CoolSculpt procedure). However, the majority of those cells are preserved and may survive after thawed and injected at a later date. The difference may be in the temperature and the fact that in CoolSculpt the fat cells are still in the body. The freezing causes apoptosis or programmed cell death. Also, when the injured fat cells thaw in the body they may cause damage to other nearby fat cells, thus increasing the effect of CoolSculpt.