A mastoidectomy is an operation that is aimed to remove any pocket of dead skin and infection in your ear and mastoid bone (ear bone) and thus stop ear discharge. This type of infection is often associated with a hole in your eardrum and/or erosion of the hearing bones in your ear. If so, the operation is combined with a tympanoplasty, which will close the hole in the eardrum and if possible repair the hearing bones (called an ossiculoplasty).