The picture on the left is of a large cholesteatoma of ear with exposure of head of malleus.   The picture on the right shows a large attic  cholesteatoma with a granuloma covering an attic retraction pocket.    Click on Pictures to Enlarge

Take a Self Test On Ear Disease and Hearing Loss !!!!

 
The patient's canal wall up mastoidectomy was converted to a canal wall down mastoidectomy.   The canal wall down operation is 95% effective in removing the disease but leaves a larger than normal ear canal opening and creates a large cavity (mastoid bowl) where the ear canal used to be.  This cavity must be cleaned by the doctor every 6 to 12 months.  The chorda tympani, nerve which innervates part of the tongue is sacrificed and some numbness may occur on the lateral tongue surface.   In addition, the patient must not go swimming because water in the ear may cause severe dizziness.  Water in the ear may also cause an infection.   The picture on the right shows a plugged ear tube and a recurrent cholesteatoma (blue arrow) in a patient who had a canal wall down mastoidectomy.
  
 
 

Risks of the surgery are the same as if the cholesteatoma is not removed, but occur less frequently.  Hearing loss and dizziness may occur along with injury to the lining or dura of the brain.  The VII Nerve runs through the center of the middle ear and mastoid cavity and can be injured during surgery.  This may cause a facial paralysis.  However, from the picture on the right, one can see how this nerve can be easily damaged by the cholesteatoma.  Thus, once diagnosed, most cholesteatoma should be surgically removed.  Kos et al. reported on the results for canal wall down mastoidectomies.  He found the average pre-operative hearing loss was 52 dB.  Post-operatively the hearing was unchanged in 41%, improved in 31% and worse in 28%.  Other complications were persistent vertigo and one case of facial paralysis.  View Abstract

A long standing cholesteatoma can erode through the dura and into the brain or into the inner ear.  The horizontal semicircular canal is the inner ear structure most prone to damage.  Below is a link to a CT Scan of a cholesteatoma which produced a fistula of the horizontal semicircular canal.  The patient had a chronic history of hearing loss and ear drainage.  He recently, experienced a severe episode of vertigo from labyrinthitis.  

The picture on the far right shows a patient with a relatively small attic retraction pocket which has formed a cholesteatoma.  At the time of surgery the skin sack of the cholesteatoma had filled the attic and was extending downward.  It had eroded into the facial nerve, which was found to be swollen and dehiscent.  If left untreated this patient would have soon developed a facial paralysis.
 
 
 
 

Click on Pictures to Enlarge

In a canal wall down operation the entire mastoid is exteriorized into the ear canal and the posterior and superior portion of the ear canal is removed down to the region of the facial nerve.  The facial nerve is left intact covered by a ridge of bone called the facial ridge.  This leaves a large cavity called a mastoid bowl which has to be cleaned by the doctor every 3 to 12 months.  In order to clean this cavity, the meatus or the external opening into the ear canal is surgically widened -- see pictures on right.