Definition and Overview
Mastoidectomy is a surgical procedure that removes mastoid air cells to treat infections in the middle ear or as a part of a cochlear implantation procedure.
Mastoid air cells are found in the mastoid bone that encloses the middle and inner parts of the ear. Due to their proximity to the cavity that is linked to the middle ear, they have the tendency to spread infection to the deeper parts of the ear and into the skull.
The surgery used to be a popular method of treatment, but with the improvement of antibiotics, some of the infectious diseases that affect the ear can already be eliminated without the removal of the mastoid cells.
Who Should Undergo and Expected Results
Mastoidectomy is used to treat infections that occur in or affect the middle ear. These include:
Otitis media – This is a general term that refers to the inflammation or infection of the middle ear, which may result in the buildup of fluid (such as mucus or pus) that prevents the Eustachian tube from functioning properly leading to some degree of hearing loss. There’s no definite cause for otitis media. However, in the majority of cases, it develops when bacteria and viruses travel toward the ear from the nose and throat.
Chronic cases of otitis media require draining the fluid in the middle ear and removing the mastoid cells or even the bone, if necessary, to prevent further infection.
Cholesteatoma - This ear condition is a consequence of chronic otitis media and other ear infections. As the Eustachian tube (the tube that runs from the pharynx to the middle ear cavity that equalizes ear pressure) becomes weak or damaged due to persistent middle ear infection, pouches or sacs can develop in the middle ear. When these grow in size, they tend to press onto the bones of the middle ear, which amplifies the sound waves that reach the inner ear. Other than that, the cyst can also lead to the development of abscess in the brain, facial paralysis, and permanent hearing loss, although this rarely happens.
Mastoidectomy may also be performed as part of a cochlear implant procedure. A cochlear implant is a very small device that is surgically implanted into the middle ear to enhance the hearing of those with severe hearing loss.
By removing the mastoid air cells, chronic infection can be avoided or their recurrence significantly minimised. It can also prevent temporary or permanent hearing loss and more serious complications that can affect the brain.
How Does the Procedure Work?
The procedure is done by an otolaryngologist surgeon, a medical professional who specialises in conditions affecting the ears, nose, and throat. Depending on the patient’s unique circumstances and the severity of the condition, mastoid air cell removal can be performed using different approaches.
It is considered simple if only the diseased cells in the mastoid bone are removed. However, if the canal walls at the back and front are removed and mentoplasty (the widening of the lateral cartilage of the auditory canal of the external ear) has to be performed, it’s called radical mastoidectomy.
In the procedure, the patient is administered with general anaesthesia and he is positioned supine with the affected ear exposed. The surgeon then marks the site of the incision, which is typically at the back of the ear although it can also be done directly into the ears. Antiseptic is then applied to the incision site as a preventative measure to avoid the development of infection.
The surgeon then makes the incision to access the mastoid bone. Using a drill, the bone is sliced open to expose and remove the mastoid air cells while the area is irrigated to ensure there’s no bone dust accumulation. The fluid in the middle ear is also drained. If the infection has already spread to most of the mastoid bone, the bone itself may also be removed.
Once the procedure is done, the incision is sutured, and the area is covered with gauze.
Possible Risks and Complications
After the mastoid air cell removal, the patient may experience pain, discomfort, bleeding, and infection, which can be prevented or controlled with antibiotics. Because the inner ear also governs balance, the patient may also suffer from dizziness or vertigo over a period of days. In rare cases, the nerves in the face can get damaged causing facial paralysis.
Chole RA, Sudhoff HH. Chronic otitis media, mastoiditis, and petrositis. In: Flint PW, Haughey BH, Lund LJ, et al, eds. Cummings Otolaryngology: Head & Neck Surgery. 5th ed. Philadelphia, PA: Elsevier Mosby; 2010:chap 139.
Lambert PR. Mastoidectomy. In: Cummings CW, Flint PW, Haughey BH, et al, eds. Otolaryngology: Head & Neck Surgery. 5th ed. Philadelphia, PA: Elsevier Mosby; 2010:chap 142.