In case you were curious…
Monday, February 27th, 2006Here’s a bit about me. Surgery’s on May 11. Everybody throw down!
Background: Cholesteatoma is a destructive wound of the middle ear and/or mastoid, a process that produces complications by erosion of the temporal bone. The clinical hallmarks of cholesteatomas, namely: invasion, migration, uncoordinated proliferation, altered differentiation, aggressiveness and recidivism, are traits typically associated with the neoplastic cell.
A cholesteatoma can form in the middle ear by means of an improperly functioning eustachian tube. The eustachian tube is a canal which connects the middle ear to the back of the nose. It is responsible for equilibrating middle ear pressure to the pressure in the external environment. This tube is normally collapsed in its resting state and when we swallow or yawn, the muscles around the tube contract and cause the tube to open allowing the influx of air into the middle ear space. When this tube does not work appropriately, a relative negative middle ear pressure is generated and maintained. Over time the intact eardrum begins to retract back toward the inner ear. Eventually a skin-lined sac forms which continues to grow and cause infection and bony destruction.
Erosion of the ossicles or bones behind the eardrum can lead to a conductive hearing loss. The bone over the facial nerve can also be destroyed and a facial paralysis can result. The inner ear is composed of a bony labyrinth which can also be partially destroyed. This can lead to a sensorineural hearing loss and dizziness. The infection can also spread into the veins carrying blood from the brain to the heart. This large vein called the lateral venous sinus can obstruct and cause excessive fluid to accumulate within and around the brain leading to a condition called hydrocephalus. The infection can also spread to the covering of the brain and cause meningitis. In rare circumstances, a brain abscess can result.
Frequently the mastoid bone located behind the ear must be explored to remove any cholesteatoma that may have spread there through the middle ear. Another reason to perform a mastoidectomy is to improve ventilation of the middle ear. Whether the bony partition between the external ear canal and mastoid is removed or not depends on the extent of disease. Canal-wall-down refers to the removal of this bony partition. Canal-wall-up refers to keeping this bony partition intact. The term modified radical mastoidectomy refers to an operation where this bony partition is removed and the eardrum and ossicles are reconstructed. A radical mastoidectomy is an operation where this bony partition is removed and the eardrum, malleus and incus bones are permanently removed so that the inner lining of the large cholesteatoma sac can be safely cleaned in the office. This operation is done when an extensive cholesteatoma is encountered or one that is adherent to the inner ear or facial nerve.