A tympanomastoidectomy is a surgical procedure addressing issues within the mastoid bone behind the ear and the middle ear. The middle ear is the space behind the eardrum containing the small bones responsible for hearing. This operation combines a mastoidectomy, the removal of diseased portions of the mastoid bone, with a tympanoplasty, the reconstruction of the eardrum. The objective is to create a safe and healthy ear, free from chronic infection or other progressive conditions.
Reasons for a Tympanomastoidectomy
A primary reason for a tympanomastoidectomy is to treat a cholesteatoma, a noncancerous skin cyst in the middle ear. It is often caused by poor eustachian tube function and repeated ear infections. Instead of shedding normally from the ear canal, skin cells become trapped and accumulate behind the eardrum, forming the cyst.
As the cholesteatoma expands, it can erode the fragile bones of the middle ear, the ossicles, leading to hearing loss. If untreated, the cyst’s growth can damage surrounding structures like the inner ear bone that controls balance and the facial nerve, causing dizziness or facial weakness. In rare instances, it can extend toward the brain and risk serious complications like meningitis.
Another reason for this surgery is chronic suppurative otitis media, a persistent middle ear infection causing ongoing drainage. This condition occurs when a hole in the eardrum fails to heal, allowing bacteria to repeatedly infect the middle ear. When antibiotics fail, surgery is necessary to remove the infected tissue and repair the eardrum.
An infection can also spread to the mastoid bone, a condition known as mastoiditis. This infection of the mastoid’s air cells causes pain and swelling behind the ear and can lead to widespread complications if not addressed. Surgical removal of the infected mastoid tissue is required to control the infection.
The Surgical Procedure
A tympanomastoidectomy is performed in a hospital setting with the patient under general anesthesia. The procedure begins with an incision behind the ear, which allows the surgeon a clear view of the surgical area without leaving a visible scar.
Using a high-powered operating microscope, the surgeon can see the minute structures within the ear. The first step is the mastoidectomy, where a specialized drill is used to open the mastoid bone. This allows for the removal of the infected bone cells or the cholesteatoma cyst.
After the disease is cleared, the surgeon proceeds to the reconstructive part of the operation, the tympanoplasty. If the eardrum is perforated, it is repaired using a graft of tissue taken from the patient’s own cartilage or muscle lining. Damaged ossicles may be repaired or replaced with a tiny prosthesis to help restore hearing.
Surgeons choose between two techniques based on the disease’s extent. The canal wall up procedure preserves the back wall of the ear canal, but has a higher risk of cholesteatoma recurrence, sometimes requiring a second surgery. The canal wall down procedure removes the back wall of the ear canal, creating a single cavity called a mastoid bowl. This technique reduces the chance of recurrence but requires regular, lifelong cleaning by a specialist.
The Recovery Process
After surgery, patients have a protective dressing over the ear and packing inside the ear canal to hold the eardrum graft in place. During the first few days, it is common to experience some dizziness, nausea, or a stuffy feeling in the ear. Pain is manageable with prescribed medication.
The initial recovery period at home lasts one to two weeks and involves restrictions. Patients should avoid strenuous activities, heavy lifting, and forceful nose blowing. If you must sneeze, do so with your mouth open to prevent pressure from displacing the new eardrum graft. Keeping the ear dry for several weeks is also required; a cotton ball coated in petroleum jelly can be placed in the outer ear during showers.
Follow-up appointments are necessary for recovery. The surgeon removes external sutures about a week after the operation and gradually takes out the internal packing over several weeks. Hearing will be muffled initially due to swelling and packing. It can take several months for swelling to resolve and hearing to stabilize, with the final outcome unknown until the ear is fully healed.
Potential Risks and Complications
A tympanomastoidectomy has potential risks. A primary consideration is a change in hearing, which may be a secondary goal of the surgery. Hearing can sometimes remain unchanged, worsen, or in rare instances, be completely lost in the operated ear.
Dizziness or vertigo is common for a few days after surgery, but balance issues can persist for some individuals. Tinnitus, a ringing or buzzing sound in the ear, may develop or become more noticeable after the operation. Another potential side effect is an altered sense of taste, as the nerve for taste sensation, the chorda tympani, runs through the middle ear and may be stretched or injured, leading to a temporary or permanent metallic taste.
A rare but serious complication is injury to the facial nerve, which controls the muscles on one side of the face. This nerve passes through the mastoid bone, and damage can result in weakness or paralysis of the facial muscles. Other rare complications include infection, bleeding, and failure of the eardrum graft to heal.