My PS recommended a MD to do this for me (a reputable one) but it is only for little areas mainly. I had above my elbows done for the little puff of fat that was still there after my armplasty. It involves loads of injections (like 10 in each arm on each trip and I had to have 5 sessions) it is painful and the area gets purple and swollen for a week or two afterwards and your sessions are supposed to be 2 -3 weeks apart so it can be a long time of puffy bruising. It is also very expensive. It cost me $1k and I don't think that the results were that great. IMHO not worth it and I wouldn't spend any more money on it.
Surgery was less painful, had quicker healing time and was less expensive, inch for inch.
If anyone can learn from my experience..... please do.