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Interview with John Leonetti MD, Professor of Otolaryngology, Loyola University Medial Center, Chicago, Illinois

John P. Leonetti, MD

February 4, 2002
Part Three - Mastoidectomy for Audiologists
Part Three - Mastoidectomy for Audiologists.

AO/Beck: Dr. Leonetti, I want to again thank you for your time and enthusiasm for this project. I am very grateful to you and I know the professional readers will be getting a tremendous benefit from this three part series.

Leonetti: Thanks Doug, I'm happy to help, and it's really been an enjoyable experience for me too.

AO/Beck: OK, then let's move into the discussion of mastoidectomy please. My understanding is tat there are essentially two general categories of mastoidectomies, is that correct?

Leonetti: Yes. We discuss mastoidectomies as either canal wall up (CWU) or canal wall down (CWD).

AO/Beck: Aren't those also referred to as a simple versus a radical mastoidectomy?

Leonetti: Yes, the canal wall up is also referred to as a simple mastoidectomy. The canal wall down is referred to as a modified radical mastoidectomy.

The canal wall up is performed when the patient had chronic otitis media with a sclerotic (hardened, solid) mastoid bone. It's important to understand that for a patient with a chronic perforation, if you simply repair the perforation, it will likely fail. The etiology is not enough air, a non-functioning eustachian tube and the fact that all of the air cells in the mastoid over the many years have dried up. The mastoid bones serves as a safety valve for the middle ear, in the event that the eustachian tube shuts down. So in essence, we core out the mastoid bone, via drilling, to provide a reservoir of air for the middle ear, leaving the ear canal intact, and leaving two separate chambers. So, we have the external ear canal and the mastoid cavity, and to insure air flow, not only do we open the mastoid antrum (air space), which is the natural path for air between the mastoid and the middle ear, but sometimes we also open the facial recess approach too, which is a surgically made air passage between the two.

AO/Beck: Then, if you were to summarize the different surgical techniques (canal wall up, versus canal wall down) based on the status of the ossicular chain, how would that work?

Leonetti: If you have an intact ossicular chain and chronic ear drainage, a canal wall up mastoidectomy with tympanoplasty is the standard treatment. If we have a patient with chronic otitis media and with ossicular erosion, we'll often times stage the procedures. So the first round is a canal wall up mastoidectomy with a facial recess approach and tympanoplasty and then 6 months to a year later, go back to the operating room and reconstruct the ossicular chain in a separate procedure.

AO/Beck: And is reason you wait for the 6 to 12 month period of time is to watch for regrowth of cholesteatoma and to see if the ear is aerating?

Leonetti: Yes, that's correct. If the ear had a cholesteatoma and that was the primary reason we did the surgery, we go back to look for recurrence, and we also give the eardrum a chance to heal in a lateral position, so that when we go back and do the ossiculoplasty, we don't have to worry about retraction of the tympanic membrane.

AO/Beck: And finally, Dr. Leonetti, can you please speak about the indications for a canal wall down procedure? My understanding of the canal wall down is that is the most dramatic of the mastoidectomies, and that it removes the bony structure of the ear canal via the drill, hence the name (canal wall down) and that does impact the anatomical structure and the function of the ear canal, but the CWD is done primarily to eradicate disease, rather than to preserve or restore hearing.

Leonetti: Yes. The indications for a canal wall down procedure would be a large cholesteatoma involving the mastoid cavity, or, a patient with chronic otitis media who has already failed a canal wall up procedure.

There is a category of canal wall down procedures based on intracranial complications of chronic otitis media, due to cholesteatoma. For example brain abscess or meningitis from ear disease, or even a sigmoid sinus thrombosis from ear disease, these would merit a canal wall down procedure.

The final category we'll talk about for CWD procedures would be when you have patients who are not likely to follow-up for the second procedure. Sometimes we might do a modified radical right off the bat for patients who are indigent, perhaps handicapped mentally or physically and not likely to be able to have a second procedure, or people who are just not likely to follow-up. We know that if we give them a CWD, or basically an open mastoid cavity, the cholesteatoma is not going to reoccur and sometimes, based on the socioeconomic status, that's the safest way to go for their benefit.

AO/Beck: What about long term maintenance for the CWD post-op care?

Leonetti: That's a good point. For most patients with a CWD, they'll need to have a physician clean the cavity once a year or so. If the CWD procedure heals well with no problems, most of those patients can even go swimming if they so desire.

AO/Beck: And of course the caution there is that only the surgeon should clean out the mastoid cavity and only the surgeon should make the determination about swimming and related ongoing care issues.

Leonetti: Exactly right.

AO/Beck: OK, Dr. Leonetti, it has indeed been a pleasure to spend so much time with you and to pick your brain on these issues. Perhaps we can do a follow-up next year on a few more related topics?

Leonetti: That would be great Doug. Thanks to you too for your time and preparation.

CLICK HERE TO REVIEW Part One - Tympanoplasty

CLICK HERE TO REVIEW Part Two - Cholesteatoma