 Following your surgery, the tissue expander is gradually filled with salt water over a period of months. Once the expander is filled to the size of your new breast, a second operation is performed. At this time, the tissue expander is removed and a permanent breast implant is placed. This is a standard procedure. We are interested in learning about the use of AlloDerm in breast reconstruction. AlloDerm can be used instead of some of your own chest muscles, in order to cover and protect a tissue expander. We want to know if the use of AlloDerm can decrease your pain or discomfort after surgery and after the filling of your tissue expander. 