Curious about side effects of female breast fat grafting

Generally, breast surgery is said to be divided into two main methods: implant insertion and breast fat grafting.

Among these, breast fat grafting is a method performed when there is a rejection of implants or a relatively large scar, or when the patient also wishes to remove unnecessary fat from the abdomen or thighs.

Since the surgery is performed using one's own tissue, it has the advantage of fewer rejection or hypersensitivity reactions and fewer side effects such as contracture, but I am still curious if there might be some issues.