That's a great question! Just like in most of plastic surgery, there are many different techniques that we use. So first and foremost, when considering a fat grafting procedure, make sure your surgeon is board certified in plastic surgery and that he or she performs buttock augmentation regularly. Personally, I think buttock augmentation with fat grafting is a great procedure. Once fat is harvested (with liposuction), it is prepared on the back sterile table in the OR. The majority of oils, dead fat cells, serum and blood is removed gently, leaving behind healthy fat and fat stem cells. This fat is then grafted (injected) into the buttocks. For the fat to survice, it must be grafted with a meticulous technique to maximize survival. Some of the fat will not survive, but the presence of the stem cells will cause new fat to grow, enhancing the grafting success. There us no exact percentage of fat survival, but it likely around 70 - 80%. Fat that survives within the first 3-6 months will likely be permanent. Thanks!