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Stapedotomy (Endaural)

David M. Kaylie, MD, MS; C. Scott Brown, MD
Duke University Medical Center

Transcription

CHAPTER 1

So we are going to do an endaural stapedotomy on this patient's left ear and start with the injection.

Let me have suction first. 40. Prepped. Alright, can I have the bed towards me, please? Other way. There we go. Alright, that's good. And I'll take injection. So we'll infiltrate the ear canal with 1% Lidocaine with 1:100,000 epinephrine. And prior to starting, I injected the intertragal notch to get- the area where I'm going to get- make the endaural incisions. So one of the benefits of an endaural approach for stapedotomy is, get a lot of exposure. For patients who have narrow ear canals, it really gives you an advantage over a transcanal approach. Let me have suction. And it's a very commonly-used approach for any middle ear work, commonly used throughout the world. Less so in the United States, but it's - something that really does have a lot of advantages. So- the incisions will be - uh, let me have a Gimmick?

And could I have the bed away a little bit, please? Alright, that's good. I am- focusing on the drum now. So here's our malleus at 12 o'clock. And so we'll have an incision that'll come up here, up the ear canal and into the intertragal notch. And then there'll be a second incision, which will be along posteriorly here, and we'll raise a flap that'll get us into the middle ear. So- what I'll start with is- the external incision. Let me have a knife? So, the intertragal notch- the incision will go right between- I'm sorry, not the intertragal notch, the tragus and the helical root, and right where that crease is, that incision will go there, and when it heals it'll be nicely hidden. A 15 blade? So, start in the ear canal. Get this incision down to the bone. Let me have a- let me have a sponge. Get this dried up. Great. Let me have a Weitie. So start by just kind of getting some exposure here. Do you have a suction? And a Bovie? Get the exposure down to the bone. Here. And let me have the Lempert. Okay, that should actually give the exposure we need up here. So- actually, I'm going to go back to microscope. Alright. So now I want to continue this incision. Let me have a straight Beaver. So this incision goes right to 12 o'clock, right at the top of the malleus. Let me have a round Beaver. And then this incision goes from the top- midway up the bony-cartilaginous junction. Alright, let me have a Freer. So now we elevate this soft tissue up.

CHAPTER 2

This posterior soft tissue. Let me see the scissors. Alright. Let me see the Freer again? Okay, now I'm going to re-place this retractor. And, suction? And a Freer? So here's the lateral bone in the ear canal, and there's my flap. Can we have a pickup? So they make special retractors that are smaller- for- transcanal incision - for endaural incisions like this. Suction? Which would be helpful to have. Alright. Freer? So you see, now we get back and get exposure this way all the way to the mastoid, and so, technically you could do a mastoidectomy through this approach. It'll be a little difficult, but that's certainly done. Alright, I'll take the bed away, please. So now we're going to focus on the eardrum. I'll take a 20 suction. And you see here's our flap. And we can elevate this- inferiorly and get into the middle ear space. So we'll take a #2. As we elevate this. Let me see the scissors. Get rid of these straggly- bits, these can- become problematic later, you know- if it doesn't lay flat, you can get a canal cholesteatoma. Alright, number- #2? I like this instrument because you can use the point to dig things out and then the flat side to push. It's called a House Lancet. Commonly we just call it a #2, where a sickle knife is a #1. It's just a convention we have, but it's technically called a House Lancet instrument. So we're getting up near the annulus. Just want to be very careful because it's very fragile. This canal skin is very thin. Digging out the annulus right there. I'm getting into the middle ear space. It's very fragile here. There's our chorda tympani. Scissors. Okay, and we see in the dep - uh, let me have a Gimmick.

CHAPTER 3

A House annulus elevator. Can I see the scissors again? Let me see the Gimmick again. So here we have exposure. There's the round window. This is chorda tympani. Here's stapes. And so when I'm moving the undersurface of the malleus right here- let me get a better view of that- so here's the malleus, and when I move that, I see that the incus moves, but the stapes does not. Let me have a Rosen. Can I have the bed towards me, please? Alright. So here's the incus, and there's the stapes, and there's a fairly large scutum here that we're going to have to remove to get a little better view of it. But what I can feel is- when I press on this incus, the incus moves, but the stapes does not. And you want to press- you want to press in an in-and-out motion, not side-to-side, because even on a fixed stapes, you can rock it side-to-side, but it's really the motion- that way, and you see the joint moving- let me zoom in on that. Bed away just a little bit. Alright. So when I- press there, the joint moves, but the stapes does not. So, what I would like is a curette.

CHAPTER 4

This is a bone curette. And this can be done… So what I want to do is be able to mobilize the- chorda without evulsing it, and in a right-handed surgeon, in a left ear this can be very difficult because your natural curetting motion is right to left, and in a right ear that means you're curetting towards the- chorda. So you want to be very careful curetting around it. But by doing that, you'll get a lot better exposure. So what I want - what I'm looking for is exposure- of the- stapes, the facial nerve, and the round window. Let me have a Rosen. So you see here, there's- so mobilize the- chorda some, but there's this bone here, so I can move the chorda out of the way- and let me have a curette- and remove this ledge of bone, which will help me have better exposure. That was very soft. That's helpful. And now I can see the stapedius tendon and move the chorda. Okay. Curette a little more superiorly. And now I can see- the facial nerve. Let me have a Rosen. Right down in there, that's the facial nerve. And I see the stapedius tendon there, and the posterior crus, and the oval window. Let me see a curette again. And I can see the pyramidal eminence down here. Which is where the stapedius tendon comes out. So- At this point we get our laser ready. So, I've- let me have a Gimmick again. So at this point I have all the exposure I need and I know that I can proceed safely. I see that the whole stapes- the stapes is not moving. There's a better view of it now. I see the facial nerve and I have a good view of the round window. So I know that there's enough room that the facial nerve is not prolapsed over the rou- oval window- I'm sorry, I should say oval window- it's not prolapsed over that, preventing- safe placement of a prosthesis. So what I do is, I will laser the stapes footplate- first I would like the measuring stick. 4.5 mm, yeah.

CHAPTER 5

And what I do is I measure- from the footplate- So I'm touching the footplate, and that goes to the top of the incus. And that's 4.5 mm. So the stapes prostheses are measured from the undersurface of the incus, so if this is 4.5 mm, what I'll need is a 4.25 mm prosthesis, which is pretty much what I use standard. Because I do a stapedotomy, and that's generally about the distance that I find most of these end up being, to give the proper- proper length of prosthesis. Alright, so next we're going to get the laser.

So I set- I use a CO2 laser with a- Waveguide fiber. And I set it at- it's at 4 watts? Yes. So it's at- yeah, 4 watts is a pretty low power setting for a 100 ms pulse duration. I do not use continuous pulses because that could really cause damage. But CO2 laser is very effective for stapes because the energy of a CO2 laser is absorbed very quickly by water, so if you were to get through the- through the footplate into the vestibule, you won't damage the underlying structures, whereas other laser- shorter wavelength lasers could damage the underlying structures. Alright, so- hold the chorda out of the way and laser on. Alright, so I cut the tendon. And there's a lot of vessels right here over the joint, which'll bleed, so I just kind of diffusely- get those, which will help prevent bleeding. Alright, standby. Now before I- laser the posterior crus, I like to separate the joint. So I'll take a joint knife. So this is a very small, round knife. And I just separate that. Alright. I'll take the laser.

So now I'm going to laser the posterior crus. Laser on. So for proper laser safety, everyone has goggles that are appropriate for this laser wavelength. And the laser operator knows that- does nothing unless I say "laser on" and "standby." So we have a good system here, so we have good laser safety. There we go. So, I'll take a Rosen. Standby. So now the posterior crura is- or crus. Well, the posterior limb is- crus is singular. Alright. So there- see, it's separated here. And I just downfracture that. And that removes. And I'll take an Alligator. That's right, crura is plural, crus is singular. So, now we're looking right down at the footplate.

Let me have a Gimmick. Actually, no, I'm good. Yeah, that's fine. Alright. So now we have the incus floating there. So now I switch to the small drill. We'll take the 0.6 mm drill bit. So the- I use a DragonFly drill for the- to make the stapedotomy, and the- the stapes prosthesis has a 0.5 mm diameter, so I use a 0.6 mm burr to make a perfectly-sized hole that the prosthesis will then go into. And you can open up the prosthesis, as well. The one that we preselected. I'll take the drill. So I want to center the hole where I'm going to make the stapedotomy directly under the incus. And I'm trying to position my hand so I'm not blocking my vision. There we go. There's the hole. Alright, I'll take the prosthesis.

CHAPTER 6

Alright. Let me have a- Let me have a crimper. So what I'll do is I'll crimp it into place on the incus. Let me have a Rosen. Okay. Crimper. Rosen. Crimper. There we go. Right into place. So, let me have a Rosen. So now we need to take the- suction. Take this fascia. And place this down in the oval window to seal it around the prosthesis to prevent CSF leak- I mean, sorry, purulent fistula. And that is how you do it.

CHAPTER 7

Alright, so this is how you close this incision. Make- get some deep bites here to reapproximate the muscle and the soft tissue. And then- See, that brings that- nicely reapproximates that. We'll reapproximate this tissue. I see them back 3-weeks postop. And I- generally like to get a hearing test then. And I- can I have a- a lot that I counsel the patients about.

This is very safe procedure, but there are risks to it, and one of the risks is loss of hearing. And so, that's something I want to know about right away. So I tell the patients that when they get home, they should- their hearing's not going to be quite as good because of all the ointment and surgical healing it needs to do, but I want them to get a sense of where their hearing is when they first get home. And if their hearing should drop, if they feel like their hearing gets worse, particularly if they start getting really dizzy when they weren't dizzy, that can be a sign of a reparative granuloma. And that's something that needs to be treated right away. Okay, I'll take a 4-0. And so- you can come out with that. So I tell them I- if that happens, I want them to call, even if it's the middle of the night. And we'll start them on Prednisone and antibiotic - oral antibiotics, and they should be on their- already on their drops. They should already have the drops. And then they need to come in right away for a hearing test. So if they live far away, they need to have one locally and sent to us. So they need to do it that day, or, if it's the middle of the night, the next day. And if there's a sensorineural loss, we need to evaluate them. So these incisions heal very nicely and they're all hidden in the natural skin crease between the helical root and the tragus. And now I'll take the 5-0 fast. I'm going to do- just a skin suture here. Some interrupteds. With a 5-0 fast absorbing gut suture. Put a little tail on those, because those will come unraveled. One more ought to do it.