Michael J. Rensink, MD, is a member of ENT Associates of San Diego and has been a practicing ENT specialist for more than 35 years.
When an open ear occurs, audiologists and hearing instrument specialists must understand its pathology and the treatment options they can employ for patients
The patient whose ear is shown has had long-term chronic otitis media and Eustachian tube insufficiency. (Figure 1.) We can see into the middle ear space through the opening to the Eustachian tube. Unfortunately, the ear's condition suggests a long-term lack of adequate ventilation in the middle ear. Frequent infections and long-term instability have resulted in major deterioration of all middle ear structures and functions. Two of the middle ear ossicles (the incus and the stapes) have completely eroded, and the manubrium (long arm) of the malleus is shortened, eroded by chronic infection.
Most of the tympanic membrane is also missing, and the perforation is considered total. Only a small peripheral rim of the eardrum can be observed near the annulus, the outer attachment of the tympanic membrane. When using an otoscope to look in an ear, you typically see an eardrum. In this ear, however, you have to look carefully for remnants of the tympanic membrane because most of it is absent.
Deep in the canal, next to the eardrum, bone has also eroded between the canal and the attic. The space created by this enlargement is difficult to see in the photographs, but is easier to see when viewing the ear with a binocular microscope. The upper portion of this eardrum, the pars flaccida, has retracted and formed what appears to be a cholesteatoma that extends into the attic and the epitympanic space. These areas are not visible through the otoscope because they are behind and superior to the tympanic membrane. This condition will likely require surgery to remove the cholesteatoma to make the ear safe and stable. This pathology has created a severe mixed hearing loss. (Figure 2.)
A patient like this presents a special challenge. All professionals need to work together to sustain health and rehabilitate hearing. An ideal patient would be compliant, relaxed, and cooperative, and he would follow directions and keep appointments. The ENT specialist must see this patient regularly to avoid medical complications.
This type of patient may ask an audiologist or hearing aid specialist for a hearing aid, but under no circumstances should he be fitted without ENT management. If the ear is unstable, the patient should not wear a hearing aid because the risk of medical complications is quite high. If the ear is stable, I would recommend hearing aid use only if the patient keeps his office visits and follows directions.
Audiologists have told me that some of these patients prefer their treatment over an specialists’ ENT, but this is very dangerous. A thin eggshell-like layer of bone lies between the middle ear and the brain. If an infection passes from the middle ear into the cranial cavity, the patient can quickly develop meningitis, become permanently disabled, or even die.
Part of the treatment program for this patient is keeping his ear dry. I recommend custom-made water plugs for patients with open ears. Making the impression for this ear is difficult; traditional ear canal dams will not work because the middle ear is enlarged in the deeper recesses. If the audiologist or hearing instrument specialist has training and competence in this area, he can pack the ear securely with cotton to prevent any leakage of material and then make the impression. If not, an ENT specialist can pack the ear, the audiologist can make (and remove) the impression, and the specialist can remove the packing.
If injection material reaches the middle ear, the consequences may be dire. I have had to remove impression material from deep within the ear in cases where the person making the impression was unable to remove the ear mold. This required painful local anesthesia and long amounts of time to safely remove all of the extra material. We can avoid such dangerous and problematic situations by ensuring the packing used for the impression is absolutely secure.
Anatomy of Open Ear
Read the first part of this series on The Hearing Journal website: http://bit.ly/openear.