Interview with John Leonetti M.D.
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Parts 1, 2 and 3: Mastoidectomy, Tympanoplasty and Cholesteatoma for Audiologists
Part One - Tympanoplasty for Audiologists
AO/Beck: Good Morning Dr. Leonetti. Thanks for spending some time with me today and thanks for agreeing to provide this tutorial for audiologists on tympanoplasty, cholesteatoma and mastoidectomy.
Leonetti: Hi Dr. Beck, it's a pleasure to speak with you again and I'm happy to participate.
AO/Beck: Thank you. Probably the best place to start is with a working definition of the word tympanoplasty. I've always thought of it as an operation on the middle ear and/or it's contents? Is that about right?
Leonetti: Yes, that'll work, I like to think of it as the repair of the tympanic membrane and it is characterized by the relationship of the repair of the tympanic membrane to the ossicular chain.
The most basic type of tympanoplasty is a type one repair. The type one repair implies a repair of a perforation only. The repair can be an overlay or an underlay technique and it can be done in the office such as a myringoplasty. In a myringoplasty, we freshen the edges of the perforation and lay a paper patch over it. Using that technique, a dry, small perforation can actually heal and it works fine. However, if there is a larger perforation, and it's not likely to be repaired successfully in the office, then the surgical procedure referred to as a type one repair can be done in the operating room under local or general anesthesia and it takes about 30 minutes. Of course, most small perforations heal on their own, and only a very few need surgical repair.
AO/Beck: Very good. Let me go back to the terms overlay versus underlay please. Does overlay mean placing the graft from the external auditory canal side onto the proximal side of the TM, whereas underlay means placing the graft from the medial side, or from within the middle ear to cover the medial side of the TM?
Leonetti: Yes, that's exactly correct.
AO/Beck: OK, great. Let's move on to a type two tympanoplasty please.
Leonetti: A type two tympanoplasty is essentially a repair of the eardrum, with replacement of the incus. The incus is replaced with either a prosthetic ossicle, or an incus interposition, assuming there is enough incus left to be reshaped and reinserted between the stapes and the malleus.
In the case of a type two tympanoplasty, if the patient does not have enough residual incus for us to use, we may use a TORP (total ossicular replacement prosthetic) or a PORP (partial ossicular replacement prosthetic). As you know Doug, TORPs and PORPs are available from many manufacturers, and they come in all sorts of shapes and sizes. Over the last few years, most middle ear prosthetics have been made from hydroxyapetite with some sort of plastic component. The newer prosthesis are made of titanium, and with rare exception, I use titanium across the board at this time.
AO/Beck: OK, so far I'm still with you. Please describe the type three tympanoplasty.
Leonetti: The type three tympanoplasty implies that the grafted tympanic membrane has been placed directly on the head of the stapes so there is no replacement of the missing incus. A type three would have no man-made prosthesis.
AO/Beck: Dr. Leonetti, what is the most common clinical scenario that would lead to a type three tympanoplasty? Would this result from a long term otitis that was necrotic?
Leonetti: Yes, that's right. These operations typically are the result of long term chronic otitis media with an atelectatic tympanic membrane that has retracted so much that the incus has eroded and the tympanic membrane has attached by itself to the head of the stapes.
AO/Beck: And I believe the final tympanolplasty category is the type four?
Leonetti: Yes, the type four is always associated with a canal wall down (CWD) mastoidectomy. So basically, in the type IV, the mastoid has been very much drilled away to eradicate disease, the tympanic membrane graft has been placed directly on the stapes footplate, and there is no stapes superstructure, and no stapes head. The graft is directly on the footplate.
AO/Beck: So then types I, II and III would repair the middle ear and restore hearing, whereas the type IV tympanoplasty would result in a maximal conductive hearing loss?
Leonetti: Yes, that's true of the type IV, if it's left alone. However, sometimes type IV tympanoplasty will be followed up in 6 to 12 months and if the eustachian tube is functioning well and if it is aerating the middle ear space, then we can go back in, dissect the drum off of the stapes footplate, and place a TORP from the stapes footplate to the underside of the tympanic membrane.
AO/Beck: Excellent discussion Dr. Leonetti. Thank you for your time this morning. In the next interview we'll address cholesteatoma and mastoidectomy.
Leonetti: Thank you Doug. I'll look forward to it.
Part Two - Cholesteatoma for Audiologists.
AO/Beck: Thanks again for joining me Dr. Leonetti. Today we're going discuss cholesteatoma.
Leonetti: Great!
AO/Beck: Let's start with a working definition of cholesteatoma please.
Leonetti: In general, a cholesteatoma is a skin cyst of the ear. There are two broad categories of cholesteatoma, congenital and acquired.
Within congenital cholesteatomas, there are two types; middle ear, and petrous apex.
Middle ear congenital cholesteatomas arise from epithelial rest cells that are inappropriately trapped in the middle ear space during early development. As you may recall from embryology, the normal middle ear space does not have epithelial cells in it. The lateral surface of the tympanic membrane is stratified squamous epithelium, but the middle ear is respiratory mucosa. Therefore, if epithelial cells get trapped in the middle ear space during development for whatever the reason may be, one cell leads to two, then four, then eight, and pretty soon you have a white pearl of skin in the middle ear space and the formation of a congenital cholesteatoma.
AO/Beck: How are these diagnosed?
Leonetti: These are almost always diagnosed during childhood, and the usual presentation is a white mass behind the eardrum, usually visualized with an otoscopic microscope in the office. These are dry middle ears, and they do not involve drainage at all. The problem is that the pediatricians will sometimes see these children for hearing loss associated with the cholesteatoma, which is typically a conductive loss, and then they are likely to diagnose otitis media and will try the child with antibiotics, which will have no impact, and then finally the child is referred to an otolaryngologist who would hopefully notice the white mass behind the intact eardrum.
AO/Beck: Is the treatment for congenital cholesteatoma always surgical removal?
Leonetti: Yes, that's the treatment, unless of course the patient is not a surgical candidate for another reason. Hopefully we see the patients early enough so that the cholesteatoma is small and the ossicular chain is still intact. If we see them later, more damage may have occurred, and in fact the entire middle ear space could be filled with the cholesteatoma. In these late presenting cases the risk of recurrence is higher and the risk of damage to the hearing and related structures is higher. So like everything else, early diagnosis leads to a better outcome with less probability of complications.
AO/Beck: So if the cholesteatoma is diagnosed early enough, can it be removed via a simple type I tympanoplasty?
Leonetti: Yes, that is certainly possible for early diagnosed cases. A 20 to 30 minute procedure where we simply lift the eardrum, remove the cholesteatoma and put the eardrum back in place and that's the end of the problem. By the same token, a late diagnosed case may require a tympanolplasty, an ossiculoplasty and a mastoidectomy, depending on the extent of damage from the cholesteatoma.
AO/Beck: Let's discuss the petrous apex congenital cholesteatoma.
Leonetti: Sure. Usually, the petrous apex congenital cholesteatoma is not diagnosed until the patient is an adult. Interestingly, the hearing loss associated with these is usually sensorineural, not conductive. The reason is that the cyst erodes the anterior wall of the internal auditory canal causing irritation of the auditory nerve and possibly damaging the blood supply to the cochlear nerve. So, as you can imagine, in addition to sensorineural hearing loss, you can have tinnitus too, and if the facial nerve is affected, you can have facial twitching and perhaps in extreme cases facial paralysis too. Additionally, a patient could have headaches due to the expansion and erosion of the petrous bone.
AO/Beck: So the extent of involvement of a petrous apex cholesteatoma can be enormous. How are these diagnosed?
Leonetti: The only way to get an idea of the full involvement preoperatively, is through radiographic techniques such as the CT scan and the MRI.
AO/Beck: Thanks Dr. Leonetti. If you don't mind, let's focus a little on the acquired cholesteatoma please. I believe that is the more common type?
Leonetti: Yes, that's more common. Acquired cholesteatomas are always related to sub-optimal aeration of the middle ear, which is typically associated with a mal-functioning, or non-functioning eustachian tube.
These may present as a pars flacida cholesteatoma, occurring from retraction of the tympanic membrane above the short process of the malleus, and those are also called attic cholesteatomas. These usually present with otorrhea, from the polyp and infection, but they present with normal hearing because the pars flacida is lateral to the ossicular chain. In these situations, regarding surgical treatment, we might perform an atticotomy, which is a limited mastoidectomy, and we would place a ventilation tube
in the eardrum to prevent re-retraction of the pars flacida which often results in normal hearing.
AO/Beck: What about pars tensa cholesteatomas?
Leonetti: The pars tensa cholesteatoma is a posterior-superior retraction cholesteatoma which causes early erosion of the incus and possibly the stapes too, and it also causes otorrhea with an associated conductive hearing loss. The diagnosis is made by microscopic otoscopy and the extent of the cholesteatoma can only be determined by CT. The CT results are then used to determine the surgical treatment plan. So basically, if the cholesteatoma has a limited presentation into the mastoid we might use a canal wall up procedure. However, if the cholesteatoma is extensive, it may require a canal wall down procedure.
AO/Beck: Thanks Dr. Leonetti. The third and final segment of the interview will be next week and that will address mastoidectomy.
Leonetti: Thank you Dr. Beck
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.
AO/Beck: Good Morning Dr. Leonetti. Thanks for spending some time with me today and thanks for agreeing to provide this tutorial for audiologists on tympanoplasty, cholesteatoma and mastoidectomy.
Leonetti: Hi Dr. Beck, it's a pleasure to speak with you again and I'm happy to participate.
AO/Beck: Thank you. Probably the best place to start is with a working definition of the word tympanoplasty. I've always thought of it as an operation on the middle ear and/or it's contents? Is that about right?
Leonetti: Yes, that'll work, I like to think of it as the repair of the tympanic membrane and it is characterized by the relationship of the repair of the tympanic membrane to the ossicular chain.
The most basic type of tympanoplasty is a type one repair. The type one repair implies a repair of a perforation only. The repair can be an overlay or an underlay technique and it can be done in the office such as a myringoplasty. In a myringoplasty, we freshen the edges of the perforation and lay a paper patch over it. Using that technique, a dry, small perforation can actually heal and it works fine. However, if there is a larger perforation, and it's not likely to be repaired successfully in the office, then the surgical procedure referred to as a type one repair can be done in the operating room under local or general anesthesia and it takes about 30 minutes. Of course, most small perforations heal on their own, and only a very few need surgical repair.
AO/Beck: Very good. Let me go back to the terms overlay versus underlay please. Does overlay mean placing the graft from the external auditory canal side onto the proximal side of the TM, whereas underlay means placing the graft from the medial side, or from within the middle ear to cover the medial side of the TM?
Leonetti: Yes, that's exactly correct.
AO/Beck: OK, great. Let's move on to a type two tympanoplasty please.
Leonetti: A type two tympanoplasty is essentially a repair of the eardrum, with replacement of the incus. The incus is replaced with either a prosthetic ossicle, or an incus interposition, assuming there is enough incus left to be reshaped and reinserted between the stapes and the malleus.
In the case of a type two tympanoplasty, if the patient does not have enough residual incus for us to use, we may use a TORP (total ossicular replacement prosthetic) or a PORP (partial ossicular replacement prosthetic). As you know Doug, TORPs and PORPs are available from many manufacturers, and they come in all sorts of shapes and sizes. Over the last few years, most middle ear prosthetics have been made from hydroxyapetite with some sort of plastic component. The newer prosthesis are made of titanium, and with rare exception, I use titanium across the board at this time.
AO/Beck: OK, so far I'm still with you. Please describe the type three tympanoplasty.
Leonetti: The type three tympanoplasty implies that the grafted tympanic membrane has been placed directly on the head of the stapes so there is no replacement of the missing incus. A type three would have no man-made prosthesis.
AO/Beck: Dr. Leonetti, what is the most common clinical scenario that would lead to a type three tympanoplasty? Would this result from a long term otitis that was necrotic?
Leonetti: Yes, that's right. These operations typically are the result of long term chronic otitis media with an atelectatic tympanic membrane that has retracted so much that the incus has eroded and the tympanic membrane has attached by itself to the head of the stapes.
AO/Beck: And I believe the final tympanolplasty category is the type four?
Leonetti: Yes, the type four is always associated with a canal wall down (CWD) mastoidectomy. So basically, in the type IV, the mastoid has been very much drilled away to eradicate disease, the tympanic membrane graft has been placed directly on the stapes footplate, and there is no stapes superstructure, and no stapes head. The graft is directly on the footplate.
AO/Beck: So then types I, II and III would repair the middle ear and restore hearing, whereas the type IV tympanoplasty would result in a maximal conductive hearing loss?
Leonetti: Yes, that's true of the type IV, if it's left alone. However, sometimes type IV tympanoplasty will be followed up in 6 to 12 months and if the eustachian tube is functioning well and if it is aerating the middle ear space, then we can go back in, dissect the drum off of the stapes footplate, and place a TORP from the stapes footplate to the underside of the tympanic membrane.
AO/Beck: Excellent discussion Dr. Leonetti. Thank you for your time this morning. In the next interview we'll address cholesteatoma and mastoidectomy.
Leonetti: Thank you Doug. I'll look forward to it.
Part Two - Cholesteatoma for Audiologists.
AO/Beck: Thanks again for joining me Dr. Leonetti. Today we're going discuss cholesteatoma.
Leonetti: Great!
AO/Beck: Let's start with a working definition of cholesteatoma please.
Leonetti: In general, a cholesteatoma is a skin cyst of the ear. There are two broad categories of cholesteatoma, congenital and acquired.
Within congenital cholesteatomas, there are two types; middle ear, and petrous apex.
Middle ear congenital cholesteatomas arise from epithelial rest cells that are inappropriately trapped in the middle ear space during early development. As you may recall from embryology, the normal middle ear space does not have epithelial cells in it. The lateral surface of the tympanic membrane is stratified squamous epithelium, but the middle ear is respiratory mucosa. Therefore, if epithelial cells get trapped in the middle ear space during development for whatever the reason may be, one cell leads to two, then four, then eight, and pretty soon you have a white pearl of skin in the middle ear space and the formation of a congenital cholesteatoma.
AO/Beck: How are these diagnosed?
Leonetti: These are almost always diagnosed during childhood, and the usual presentation is a white mass behind the eardrum, usually visualized with an otoscopic microscope in the office. These are dry middle ears, and they do not involve drainage at all. The problem is that the pediatricians will sometimes see these children for hearing loss associated with the cholesteatoma, which is typically a conductive loss, and then they are likely to diagnose otitis media and will try the child with antibiotics, which will have no impact, and then finally the child is referred to an otolaryngologist who would hopefully notice the white mass behind the intact eardrum.
AO/Beck: Is the treatment for congenital cholesteatoma always surgical removal?
Leonetti: Yes, that's the treatment, unless of course the patient is not a surgical candidate for another reason. Hopefully we see the patients early enough so that the cholesteatoma is small and the ossicular chain is still intact. If we see them later, more damage may have occurred, and in fact the entire middle ear space could be filled with the cholesteatoma. In these late presenting cases the risk of recurrence is higher and the risk of damage to the hearing and related structures is higher. So like everything else, early diagnosis leads to a better outcome with less probability of complications.
AO/Beck: So if the cholesteatoma is diagnosed early enough, can it be removed via a simple type I tympanoplasty?
Leonetti: Yes, that is certainly possible for early diagnosed cases. A 20 to 30 minute procedure where we simply lift the eardrum, remove the cholesteatoma and put the eardrum back in place and that's the end of the problem. By the same token, a late diagnosed case may require a tympanolplasty, an ossiculoplasty and a mastoidectomy, depending on the extent of damage from the cholesteatoma.
AO/Beck: Let's discuss the petrous apex congenital cholesteatoma.
Leonetti: Sure. Usually, the petrous apex congenital cholesteatoma is not diagnosed until the patient is an adult. Interestingly, the hearing loss associated with these is usually sensorineural, not conductive. The reason is that the cyst erodes the anterior wall of the internal auditory canal causing irritation of the auditory nerve and possibly damaging the blood supply to the cochlear nerve. So, as you can imagine, in addition to sensorineural hearing loss, you can have tinnitus too, and if the facial nerve is affected, you can have facial twitching and perhaps in extreme cases facial paralysis too. Additionally, a patient could have headaches due to the expansion and erosion of the petrous bone.
AO/Beck: So the extent of involvement of a petrous apex cholesteatoma can be enormous. How are these diagnosed?
Leonetti: The only way to get an idea of the full involvement preoperatively, is through radiographic techniques such as the CT scan and the MRI.
AO/Beck: Thanks Dr. Leonetti. If you don't mind, let's focus a little on the acquired cholesteatoma please. I believe that is the more common type?
Leonetti: Yes, that's more common. Acquired cholesteatomas are always related to sub-optimal aeration of the middle ear, which is typically associated with a mal-functioning, or non-functioning eustachian tube.
These may present as a pars flacida cholesteatoma, occurring from retraction of the tympanic membrane above the short process of the malleus, and those are also called attic cholesteatomas. These usually present with otorrhea, from the polyp and infection, but they present with normal hearing because the pars flacida is lateral to the ossicular chain. In these situations, regarding surgical treatment, we might perform an atticotomy, which is a limited mastoidectomy, and we would place a ventilation tube
in the eardrum to prevent re-retraction of the pars flacida which often results in normal hearing.
AO/Beck: What about pars tensa cholesteatomas?
Leonetti: The pars tensa cholesteatoma is a posterior-superior retraction cholesteatoma which causes early erosion of the incus and possibly the stapes too, and it also causes otorrhea with an associated conductive hearing loss. The diagnosis is made by microscopic otoscopy and the extent of the cholesteatoma can only be determined by CT. The CT results are then used to determine the surgical treatment plan. So basically, if the cholesteatoma has a limited presentation into the mastoid we might use a canal wall up procedure. However, if the cholesteatoma is extensive, it may require a canal wall down procedure.
AO/Beck: Thanks Dr. Leonetti. The third and final segment of the interview will be next week and that will address mastoidectomy.
Leonetti: Thank you Dr. Beck
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.
