Fat transfer survival - what type of things cause fat cell death?

After a second BBL, it's important to protect the newly transferred fat—especially in the first 2–3 weeks, which is the most critical period for fat survival.
* Excessive bending, pressure, or bumping into objects can reduce fat survival, especially on the hips and buttocks where grafted fat is still establishing blood supply.
* Sexual activity that puts pressure on the buttocks or hips can also be risky early on.
To protect your results, Avoid direct pressure on grafted areas for at least 3 weeks, Sleep on your stomach or sides, Delay intercourse involving hip or glute pressure for 2–3 weeks, or until your surgeon clears you.
Gentle movement is okay, but anything that causes pressure, friction, or trauma should be minimized during early healing.
Erman AK, MD. Plastic Reconstructive & Aesthetic Surgeon.

There are a number of variables that determine how well a fat transfer procedure is going to work.
In my opinion, the two most important variables are how much tissue with the patient has to graft into.
It’s not so much how much fat is grafted as how much tissue there is to support the grafted tissue.
I referred to this as hosted tissue.
The host tissue has the support the grafted fat until the graft establishes its own blood supply.
Areas they’re very thin will not do well regardless of how much fat is grafted.
The second variable is using good technique.
This basically means Layering the fat in many layers from different angles.
Placing too much fat in a single area will increase the rate of fat necrosis.
Different doctors have different opinions in regards to the impact of movement after surgery.
In our office, we usually recommend patients minimize movement for the first three weeks, then start gradually.
I don’t think things like pressure, movement using or not using compression environments really make much of a difference.
I do encourage my patience to minimize excessive movement at first, but in comparison to patient candidacy and provider selection these are fairly minor variables.
Best,
Mats Hagstrom MD