This is education, not advice
The information here is written for the general reader and does not replace a personal medical consultation. It cannot tell you whether either option is appropriate for your breasts, your health or your circumstances.
No outcome is guaranteed
No treatment can be guaranteed. An implant is not a lifetime device and may need exchange or removal; the proportion of grafted fat that survives cannot be predicted for any individual; and the result of either operation is judged honestly only after six to twelve months.
Scars are permanent
Both operations leave scars, at the breast and, with fat transfer, at the donor site. They mature and soften over a year or more, but they do not disappear, and no surgeon can promise that they will be invisible.
Revision carries added risk
A second operation on a breast that has already been operated on is a harder operation. Revision does not remove the risks of the first operation; it adds to them, which is why this site discusses it before the first operation rather than after.