During a mastoidectomy, what structure is primarily removed?

In a mastoidectomy, the primary structure removed is the mastoid air cells. These are small, pneumatic spaces located within the mastoid process of the temporal bone, which lie behind the ear. The procedure is typically performed to treat conditions such as chronic otitis media or cholesteatoma, wherein there is infection or inflammation that can cause damage to the surrounding tissues.

By removing the mastoid air cells, the surgeon alleviates the infection and prevents further complications. This helps to clear the area of any infected tissue and creates a path for drainage, which is crucial for healing. The mastoid process is important for proper ear function and is also closely connected to the middle ear and tympanic membrane, but the focus of the mastoidectomy is specifically on addressing issues within the mastoid air cells.