This is a choice but a lot depends on how big do you want to be and also how much excess fat do you have.Usually when you do fat transfer it may involve more than one session depending how big you want to be.On some of my patients I will place a smaller impalnt and then augment it with their own fat.This is a relatively new procedure.
The best option would be to have the implants removed and replaced with new implants. Fat injections not a good option.
It can be done, with proper technique it may replace a deflated implant.. You must have fat available to harvest, in other words have some fatty body areas to use. There are some new techniques that provide great fat for transfer ( see revolve system by kci ) which allows your plastic surgeon to harvest and transfer good quality fat.
...fat transfers to the breasts, it is frustrating, potentially hazardous, interfers imaging diagnosis in the future and will never achieve any results comparable with breast implants.
I would perform fat injections at the time of implant removal
Fat can be injected into the muscle and just beneath the capsule
Without examining you or at least seeing the photos- it is difficult to answer accurately. However, generally speaking when there is a saline deflation--- the pocket has contracted significantly and will require reopening. I prefer silicone implants over saline for this reason and for others. I am not a proponent of fat transfer- it has not shown to be of permanent value and the volume increase is limited. Seek an in person consultation with an experienced Board Certified PS.
Please consult with a board certified plastic surgeon with experience in the procedure. You are correct, many plastic surgeons have not adopted this technique.
But, this can be a good option for patients that have adequate donor fat and have realistic expectations about what can be achieved in terms of breast size, shape, and the number of procedures required.
The safest option would be to explant with a total capsulectomy then do fat transfer 6 months later. This would return you to your normal anatomy and decrease the risk of complications.