Many people may wonder why someone would want to undergo bilateral mastectomies at this stage of her life while not actually having breast cancer but having a high risk gene. She explains it quite well: she wants to decrease her chances as best as possible, even at the cost of losing her breasts. The complete removal of the breast tissue (mastectomy) early on decreases the chances for breast cancer significantly in the future. In the meantime, she can undergo breast reconstruction which will still allow her to have excellent breast aesthetics. By undergoing prophylactic mastectomy with nipple preservation, she will also avoid any radiation treatment which can severely deform the breasts--radiation has its own set of problems including wound issues, implant infections, contracture, radiation changes to the heart and lung.
The other option that she may have considered is autologous breast reconstruction using her own tissues without an implant. This includes the DIEP breast flaps from her abdomen transplanted to her chest via microsurgical technique which would preserve her “super six pack.” This would allow her to have breast reconstruction at the same time with her own tissues and would get a potential tummy tuck as well. My guess is that Angelina Jolie did not have enough abdominal tissue to undergo bilateral breast reconstruction and that is why she chose tissue expander and implants. She will need to undergo several expander injections and another operation for a final silicone implant.