Tissue expander breast reconstruction is commonly used when a patient does not have enough skin to create a new breast at the same time as a mastectomy. It can be used as part of a two stage reconstruction, being replaced with an implant at a later stage, or it can be kept permanently.
During the first stage, a partially filled tissue expander is placed either above or below the chest muscle. This can be performed at the same time as the mastectomy or any time after. In the several weeks following surgery, the expanders are gradually filled in a hospital setting until the desired breast size is achieved.
After the tissue expanders are filled, a second procedure may be performed. During the second surgery, the expanders are removed and a permanent breast implant (either saline or silicone) is placed.
Some women chose to keep their expanders rather than exchange for implants, either for aesthetic reasons or because they do not wish to go through further surgery.