In simple words: A tissue expander is like a balloon placed under the skin and chest muscle, or over the chest muscle, to stretch the area and make room for a permanent breast implant after a mastectomy.It is filled a little at a time with salt water or air over several weeks until the skin is stretched enough.

This procedure involves inserting a tissue expander beneath the skin and chest muscle, or over the pectoralis muscle, to create space for a future permanent breast implant.The expander is gradually filled with saline or air over several weeks in the office or clinic. This process stretches the skin and tissue, creating a pocket for the implant. The code includes subsequent expansions.

Example 1: A patient undergoes a mastectomy and immediate breast reconstruction using a tissue expander.The expander is placed, and over the next several weeks, it is gradually filled with saline., A patient has delayed breast reconstruction following a previous mastectomy. A tissue expander is inserted, and subsequent expansions are performed over several weeks until the desired size is achieved., A patient with a congenital breast defect undergoes reconstruction using a tissue expander. The expander is placed and gradually filled to create a natural-looking breast mound.

Documentation should include the type of expander used, placement (submuscular or prepectoral), method of expansion (saline or air), frequency of expansions, and any complications encountered.