There are several criteria that can make fat grafting to the butt safe and effective:
1) Extraction of the fat under low pressure. We prefer the manual syringe method
2) Processing the fat by centrifugation, which separates the fluids and dead cells from the concentrated fat.
3) Minimal manipulation of the fat and minimal exposure to air
4) injection in very small droplets
We have done well over a hundred of these and are very happy with our results.
Check out the link and video below