After mastectomy, the surgeon inserts a balloon-like expander beneath the chest muscle. Periodically, over several weeks or months, through a tiny valve-like mechanism buried beneath the skin, a saline solution is injected to slowly fill the expander. When the skin over the expander has stretched enough, in a second operation the expander will be replaced with a new implant.
It should be pointed out that some expanders are designed to be left in place permanently. The nipple and the dark area of skin surrounding the nipple may be reconstructed later. Some women do not require placement of an expander to stretch their skin, so the surgeon can immediately put in the implant.
