Sleep position post explant and fat transfer operation.

After
breast implant revision or removal surgery, I advise the patients to take one
week off from work. We do not use bras for one full month after surgery.
At that point we take out their stitches and drains. The patients may
return to work, but may not engage in any strenuous activity. At one month, the
patients start to wear a soft cup bra with no underwire and can start low
impact cardio. This is when it is safe to sleep on your side or belly. At two
months they can wear an underwire bra and engage in more strenuous physical
activity.

This question is best answered by your surgeon as opinions may vary. Typically you want to keep pressure off of the breasts for the initial recovery. Sitting in a semireclined position may be more comfortable if you place pillows beneath your knees.

I would ask your PS his/her advice regarding the aftercare for you breasts / garments / sleeping. It is best not to put pressure on the areas that have been fat grafted wherever possible. 

I tell my patients to avoid sleeping positions that would place pressure on your breasts. You probably can sleep flat on your back or minimally on your sides. I would suggest asking your surgeon any specific questions. For the liposuction areas, sleep how it is comfortable. Your sleeping restrictions are for your breasts.