Mastoidectomy

Definition
Purpose
Demographics
Description
Diagnosis/Preparation
Aftercare
Risks
Normal results
Morbidity and mortality rates
Alternatives

Definition

A mastoidectomy is a surgical procedure that removes an infected portion of the mastoid bone when medicinal treatment is not effective.

Purpose

A mastoidectomy is performed to remove infected mastoid air cells resulting from ear infections, such as mastoiditis or chronic otitis, or by inflammatory disease of the middle ear (cholesteatoma). The mastoid air cells are open spaces containing air that are located throughout the mastoid bone, the prominent bone located behind the ear that projects from the temporal bone of the skull. The air cells are connected to a cavity

in the upper part of the bone, which is in turn connected to the middle ear. Aggressive infections in the middle ear can thus sometimes spread through the mastoid bone. When antibiotics can’t clear this infection, it may be necessary to remove the infected area by surgery. The primary goal of the surgery is to completely remove infection so as to produce an infection-free ear. Mastoidectomies are also performed sometimes to repair paralyzed facial nerves.

Demographics

According to the American Society for Microbiology, middle ear infections increased in the United States from approximately 3 million cases in 1975 to over 9 million in 1997. Middle ear infections are now the second leading cause of office visits to physicians, and this diagnosis accounts for over 40% of all outpatient antibiotic use. Ear infections are also very common in children between the ages of six months and two years. Most children have at least one ear infection before their eighth birthday.

Description

A mastoidectomy is performed with the patient fully asleep under general anesthesia. There are several different types of mastoidectomy procedures, depending on the amount of infection present:

• Simple (or closed) mastoidectomy. The operation is performed through the ear or through a cut (incision) behind the ear. The surgeon opens the mastoid bone and removes the infected air cells. The eardrum is incised to drain the middle ear. Topical antibiotics are then placed in the ear.
• Radical mastoidectomy. The procedure removes the most bone and is usually performed for extensive spread of a cholesteatoma. The eardrum and middle ear structures may be completely removed. Usually the stapes, the “stirrup” shaped bone, is spared if possible to help preserve some hearing.
• Modified radical mastoidectomy. In this procedure, some middle ear bones are left in place and the eardrum is rebuilt by tympanoplasty.

After surgery, the wound is stitched up around a drainage tube and a dressing is applied.

Diagnosis/Preparation

The treating physician gives the patient a thorough ear, nose, and throat examination and uses detailed diagnostic tests, including an audiogram and

KEY TERMS

Audiogram— A test of hearing at a range of sound frequencies.

Mastoid air cells— Numerous small intercommunicating cavities in the mastoid process of the temporal bone that empty into the mastoid antrum.

Mastoid antrum— A cavity in the temporal bone of the skull, communicating with the mastoid cells and with the middle ear.

Mastoid bone— The prominent bone behind the ear that projects from the temporal bone of the skull.

Mastoiditis— An inflammation of the bone behind the ear (the mastoid bone) caused by an infection spreading from the middle ear to the cavity in the mastoid bone.

Otitis— Inflammation of the ear, which may be marked by pain, fever, abnormalities of hearing, hearing loss, tinnitus and vertigo.

Tympanoplasty— Procedure to reconstruct the tympanic membrane (eardrum) and/or middle ear bone as the result of infection or trauma.

imaging studies of the mastoid bone using x rays or CT scans to evaluate the patient for surgery.

The patient is prepared for surgery by shaving the hair behind the ear on the mastoid bone. Mild soap and a water solution are commonly used to cleanse the outer ear and surrounding skin.

Aftercare

The drainage tube inserted during surgery is typically removed a day or two later.

Painkillers are usually needed for the first day or two after the operation. The patient should drink fluids freely. After the stitches are removed, the bulky mastoid dressing can be replaced with a smaller dressing if the ear is still draining. The patient is given antibiotics for several days.

The patient should inform the physician if any of the following symptoms occur:

• bright red blood on the dressing
• stiff neck or disorientation (These may be signs of meningitis.)
• facial paralysis, drooping mouth, or problems swallowing

WHO PERFORMS THE PROCEDURE AND WHERE IS IT PERFORMED?

An mastoidectomy is performed in a hospital by surgeons specialized in otolaryngology, the branch of medicine concerned with the diagnosis and treatment of disorders and diseases of the ears, nose and throat. The procedure usually takes between two and three hours. It is occasionally performed on an outpatient basis in adults but usually involves hospitalization.

Risks

Complications do not often occur, but they may include:

• persistent ear discharge
• infections, including meningitis or brain abscesses
• hearing loss
• facial nerve injury (This is a rare complication.)
• temporary dizziness
• temporary loss of taste on the side of the tongue

Normal results

The outcome of a mastoidectomy is a clean, healthy ear without infection. However, both a modified radical and a radical mastoidectomy usually result in less than normal hearing. After surgery, a hearing aid may be considered if the patient so chooses.

Morbidity and mortality rates

In the United States, death from intracranial complications of cholesteatoma is uncommon due to earlier recognition, timely surgical intervention, and supportive antibiotic therapy. Cholesteatoma remains a relatively common cause of permanent, moderate, and conductive hearing loss.

Alternatives

Alternatives to mastoidectomy include the use of medications and delaying surgery. However, these alternative methods carry their own risk of complications and a varying degree of success. Thus, most physicians are of the opinion that patients for whom mastoidectomy is indicated should best undergo the operation, as it provides the patient with the best chance of successful treatment and the lowest risk of complications.

QUESTIONS TO ASK THE DOCTOR

• What are the alternatives to mastoidectomy?
• What are the risks associated with the surgery?
• How will the surgery affect hearing?
• What are the possible alternative treatments?
• How long will it take to recover from the surgery?
• How many mastoidectomies do you perform each year?

Resources

BOOKS

Fisch, H. and J. May. Tympanoplasty, Mastoidectomy, and Stapes Surgery. New York: Thieme Medical Pub., 1994.

PERIODICALS

Cristobal, F., Gomez-Ullate, R., Cristobal, I., Arcocha, A., and R. Arroyo. “Hearing results in the second stage of open mastoidectomy: A comparison of the different techniques.” Otolaryngology - Head and Neck Surgery 122 (May 2000): 350–351.

Garap, J. P., and S. P. Dubey. “Canal-down mastoidectomy: experience in 81 cases.” Otology & Neurotology 22 (July 2001): 451–456.

Jang, C. H. “Changes in external ear resonance after mas-toidectomy: open cavity mastoid versus obliterated mastoid cavity.” Clinical Otolaryngology 27 (December 2002): 509–511.

Kronenberg, J., and L. Migirov. “The role of mastoidectomy in cochlear implant surgery.” Acta Otolaryngologica 123 (January 2003): 219–222.

ORGANIZATIONS

American Academy of Otolaryngology-Head and Neck Surgery, Inc. One Prince St., Alexandria VA 22314-3357. (703) 836-4444. http://www.entnet.org.

American Hearing Research Foundation. 55 E. Washington St., Suite 2022, Chicago, IL 60602. (312) 726-9670. http://www.american-hearing.org/.

Better Hearing Institute. 515 King Street, Suite 420, Alexandria, VA 22314. (703) 684-3391.

OTHER

“Mastoidectomy series.” MedlinePlus.www.nlm.nih.gov/medlineplus/ency/presentations/100032_1.htm.

Carol A. Turkington

Monique Laberge, Ph.D.