Definition of Cortical Mastoidectomy
Cortical mastoidectomy is a surgical procedure that involves drilling out the air cells of the mastoid bone while preserving key anatomical structures, specifically staying lateral to the antrum and not entering the middle ear space or exposing the facial nerve. 1
Anatomical Boundaries and Surgical Landmarks
The procedure is defined by strict anatomical boundaries that must be respected to prevent complications:
Superior boundary: The tegmen mastoideum (floor of the middle cranial fossa) forms the roof and must be preserved to prevent CSF leak or intracranial complications 1
Posterior boundary: The sigmoid sinus defines the posterior limit and must be carefully identified and preserved during drilling 1
Medial boundary: The horizontal semicircular canal serves as a key medial landmark 1
Facial nerve: While the facial nerve's course must be respected, it is not routinely exposed in simple cortical mastoidectomy procedures 1
Surgical Extent and Technique
Cortical mastoidectomy involves removal of the mastoid cortex and exenteration of the mastoid air cells while maintaining the integrity of the posterior canal wall. 2, 3 This distinguishes it from more extensive procedures like radical or modified radical mastoidectomy, which involve removal of the posterior canal wall and creation of a common cavity.
Clinical Context and Indications
The procedure is primarily indicated for:
Acute mastoiditis with complications: Cases presenting with subperiosteal abscess, post-auricular fistula, or intracranial complications require cortical mastoidectomy 4, 3
Non-cholesteatomatous disease: In patients with intracranial complications from non-cholesteatomatous otitis media, cortical mastoidectomy is appropriate, whereas radical mastoidectomy is reserved for cholesteatomatous disease 2
Failed conservative management: When intravenous antibiotics and myringotomy fail to resolve acute mastoiditis after 48 hours 5, 3
Important caveat: The presence of cholesteatoma fundamentally changes the surgical approach, necessitating more extensive mastoidectomy rather than simple cortical mastoidectomy. 4, 2