Anyone know the long term stability of fat transfers?
From my knowledge, fat transfer to any part of the body is open to re-absorption into the bloodstream and could appear like ripples underneath the tissue.
That is not the biology of the process.
The transferred fat - - either is "absorbed" by the body as dead tissue, or the transferred cells interact with the blood supply to secure oxygen and metabolism, in which case they survive and periodically undergo cell division just like they did in their original host site in the body.
The percentage of the fat cells that "take" and then remain and undergo normal cell metabolism at the implanted site depends on the following:
1) How the cells were "handled" and processed when they were harvested;
2) Where they are implanted and the condition of that local blood supply in the new host tissue;
3) The skill & experience of the surgeon doing 1 & 2.
Done right, more than 50% of the implanted cells will typically survive. Maybe 70% at most.
This is no different than transplanting any other human part - - if the transplanted tissue gets a blood supply and is not "rejected" as a foreign body, then it will survive.