Chronic Ear Infections
Chronic ear infections often are caused by a perforated eardrum, mucous membrane disease in the middle ear, and cholesteatoma of the middle ear.
These color photographs by Eiji Yanagisawa, MD are reproduced with permission from Hughes GB and Pensak ML: Clinical Otology 3rd Edition, Thieme Medical Publishers, New York, 2006 (in press).
This eardrum has a small perforation without a middle ear infection. When repairing a perforated eardrum and reconstructing hearing bones in one stage, usually cartilage and its attached tissue are removed from the tragus just in front of the canal. An artificial hearing bone implant is positioned in the middle ear, and the perforation is sealed by the cartilage tissues which also stabilize and protect the implant.
The main indications for surgical repair of holes in the eardrums are hearing loss and middle ear infections. Successful repair often helps hearing and reduces the chance of infection by keeping water and other matter out of the middle ear. Surgery can be performed through the ear canal under sedation if the hole is small and favorably located, or through an incision behind the ear asleep under general anesthesia if the hole is larger or associated with infection. At the same time the hearing bone chain is assessed and corrected if diseased. Success rate of 85-95% varies with the size and location of the perforation and associated infection behind the eardrum. Risk of deafness in the operated ear is less than 1%. Temporary change of taste and numbness on the same side of the tongue occurs in 10-20% of patients if the taste nerve cannot be preserved.
Infected Middle Ear Mucosa
Mucosal infection behind the eardrum usually is related to a perforated eardrum and the diseased membranes are removed at the time the eardrum is repaired.
Surgery for this condition also may require removal of middle ear infection from the mastoid bone behind the ear. A clean, dry, safe ear and hearing improvement can be achieved in 80-90% of cases depending on the extent of the middle ear infection.
Risks are similar to eardrum repair, but change of taste occurs more often and weakness of facial muscles can occur in 1% of patients (usually temporary), especially if infection has exposed the facial nerve in the middle ear.
Cholesteatoma is a skin cyst behind the eardrum. The skin is basically the same as skin anywhere else, except it can destroy bone, deafen hearing and cause infection as the cyst grows. Therefore, cholesteatoma should be removed surgically, often in two stages.
At the first operation, cholesteatoma is removed and the eardrum is repaired. At the second operation hearing is restored. The overall success rate for a clean, dry, safe ear is approximately 85% long-term, and the chance for significant hearing improvement is approximately 80%.
Surgical risks are similar to those for chronic ear infections, but are slightly higher during cholesteatoma because of more extensive bone destruction caused by cholesteatoma.