Medical Definition of Mastoidectomy


Mastoidectomy is surgical removal of the mastoid cells or of the mastoid process of the temporal bone.

A simple mastoidectomy consists of opening the mastoid cortex and identifying the aditus ad antrum. A complete or canal wall up mastoidectomy necessitates removal of all of the mastoid air cells along the tegmen, sigmoid sinus, presigmoid dural plate, and posterior wall of the external auditory canal. The posterior wall of the external auditory canal is preserved.

Types of mastoid surgeries:

1. Cortical mastoidectomy
2. Modified radical mastoidectomy
3. Radical mastoidectomy

Successful and safe mastoid surgery requires routine identification of key anatomic structures including but not limited to the tegmen (middle fossa floor), sigmoid sinus, external auditory canal, lateral semicircular canal, and facial nerve.