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Bonebridge Implant

David M. Kaylie, MD, MS1; Cecilia G. Freeman, BSc2; C. Scott Brown, MD1
1 Department of Head and Neck Surgery & Communication Sciences, Duke University
2 Sidney Kimmel Medical College at Thomas Jefferson University

Transcription

CHAPTER 1

So we're going to do a MED-EL Bonebridge today. I'm going to show you the steps in that. Start out with a postauricular incision, standard postauricular incision. And- let's expose the mastoid. It's all the way to the tip. So this woman has single-sided deafness- after a- acoustic neuroma with the- that we were not able to preserve hearing on. And- it was done through a middle fossa approach, so her mastoid is intact. So this would be a good opportunity for a Bonebridge. I'll take a bipolar. The other problem here- not holding the ear- if you can't hold the ear- yeah, if you can, that would be great. So we'll dry it up some. So other opportunities for doing a Bonebridge- it can be done if a mastoidectomy has been done, but then you have to go above the linea temporalis, and it's a little different approach than what we're going to show today. So someone who's never had a mastoidectomy, and has single-sided deafness, the mastoid approach for Bonebridge is- very good- a very good option. Dry up all these little bits here. Okay. I will take a Bovie. Basically just expose the mastoid like we would for a cochlear case or a- a cochlear implant. So I make a T-shaped incision at the linea temporalis, and then bisecting the mastoid- mastoid tip. Alright, can I have a Lempert? Hold the ear. So, I will- use this Lempert elevator. To expose everything up to the ear canal. You see there? And I'll take a Weity. Okay, let me have a- Let's make this incision a little bit more anterior. I'll take a Bovie. So this exposure is very similar to what we would do for a- a mastoidectomy or a cochlear implant. Let me see a Bovie? so like a cochlear implant, I'm event- the- eventually gonna make a pocket underneath the muscle for the receiver stimulator to- package to sit. So, she's had a middle fossa craniotomy, so there's a little bit of scarring up there, but that's okay, we're not going to need to be in that area. Alright, so, at this point, what I want to do is measure for where the implant will go. So see, I have the ear canal right here, all exposed. And this is the middle fossa, linea temporalis here, there's the edge of her craniotomy, right there. So the implant- the device will sit right about here. So here's a measuring stick.

Marking- and I'll need a marking pen to measure out where… And this is 16 mm. And I've measured on her CT scan, preoperative CT scan, where- how much room I have. And she has a very large mastoid. So there's plenty- plenty of room, and depth, and also in- in width- in an anterior/posterior direction.

CHAPTER 2

So what I'll do is I'll start with a 5 diamond, and I'll drill the seat- for the implant. So you're using a 5 cutter to start? This is a 5 cutting- 5 cutting bit. Water down. Up. That'll be good. Can I have the bed towards me some more? Okay, good. That's perfect. Alright. So basically I'm just going to drill a circle. Can I get a face shield? Alright, water on. So basically… You don't want to get through the ear canal. So, the depth of the implant is 9 mm. So, you want it to sit in here 9 mm. And I measured the distance to the- sigmoid in this patient, there should be plenty of room. So, let me measure it. So, I push it in, and there's- I could still go deeper, there's 2 lines there, which tells me it's still 2 mm- I have 2 more millimeters. Now, if this was as far as I could go because of either sigmoid sinus or- if we avoid middle fossa because of the dura, then I would need a 2 mm lift. So the number of lines here tell me how many lifts I need, but if I think I can drill deeper and get- get it fully in, which would then show that I don't need any lifts. So I have- I have more room here. We really just need a couple more milliliters, and it'll be… And that I believe is the sigmoid right there. That might be as far as I can go there. I just want to make sure all ledges are taken down. So we can see there's the sigmoid sinus... the air cells. So that's about as deep as it can go right there. Alright, so let me measure it again. Water off. So now it's in all the way. And the other thing I'm looking for is- are these screws flush with the bone? And what I want to be able to do- is- I should be able to pass- not be able to pass- a Rosen needle underneath it. Can I have a Rosen? So I can feel that's really solid on the bone, but I can't inferiorly, or superiorly. So, this tells me to me that I can go all the way in, see there's no- if as far as I went was like that, that would tell me I need 1, 2, 3, 4 lifts. But this was able to be pushed all the way in with these screw guides flush with the bone. So that tells me that's exactly how I want it. So, I'm not going to need any lifts on this one. So what I need to do now- let me have an irrigation? Is I want to make a pocket for the receiver.

CHAPTER 3

Let's clean it up a little bit. So- let me- yeah, so then- this device hooks onto here, and this tells me the angle that I want. So I want this stimulator… You can take it off the stick if you'd like to, so you can manipulate it a little easier. Press and pull. So you press and then pull it out. And so- I'm going to determine the angle where I want these to sit. So this sits on here- and the device can bend. This plastic one shows you the angles that it can go, so I'm going to want this to sit like that, so that there'll be a little bit of an angle bend at the joint between the receiver and the can. So, that's pretty- not much of a bend will be needed. Alright, so what I need to do now- let me see- is make a pocket for the device. And let me have a- let me have a Bovie? There's a little bit of scarring here. Sarah, can I have you come up here and hold this up like this for me? So, she's had this prior craniotomy, so there's a little bit of a scarring here. Hold that like that. Yeah, lift it up, I want to make a little… Okay, now I'll take a- Lempert. So very similar to a cochlear implant pocket. That should be good. Alright, and then I'll use this. I'll use this tester. I'll slide this under. And see that it'll fit just like that. So the pocket's perfect sized. The bone- this will be flushed with the bone. I don't need any lifts. Okay, you can let go Sarah.

CHAPTER 4

So now, I want to make my pilot holes. So what we use is- there's several ways of doing it, You can use self-drilling screws, or you can use a drill system like the Baha with the drill bit that comes with the- that comes with the- the MED-EL Bonebridge kit. So you open the kit. And- here's the bit. And this fits in. So it's anchored like that. And- just like that. So, what I'll need is this back. There we go. Alright, so now we have our 2 holes drilled. There. There and there. And now we put the device in.

CHAPTER 5

Oh, so that's- okay. Do you have a suction? And do we have the screws handy? So it bends a little bit. So, I'll take my first. Screw. Should I hand it to you like this, or? -No. Pop this part off. Yeah, and then you get the screwdriver. Just screw it with... Yeah, right. We'll put a little bit of a- more of a bend in there. So these are self-drilling, self-tapping screws. Loosen- don't want it- just loosen it just a little bit. Get the other hole lined up. You have the screwdriver, empty screwdriver? That's going to get it. Alright. I'll take the other screw. There we go. Now tighten them up. There we go. Tightened up. Do you want to show the torque wrench for your? Oh yeah, so then we have a torque wrench, so we take this bit. and- oh. You take this into here. Okay. On the inside. In is up. In is- right. This goes in here, and we go to 25? 10 to 20. 10 to 20. There we go. 20. Alright, so... When do you see them back? I will see her back in a couple of weeks. A lot of it depends on, you know, the availability of audiology to do the activation. We'd like to try and do it on the same day. Any time the swelling comes down, correct? Yeah. 2-4 weeks, typically. So as you can see, the hole for the template is bigger than the can. So it's okay for there to be some space around it. It's the anchors of the screw in this bone that is actually doing all the work. It doesn't need to have contact with the bone around it. So that's where all the action happens. Perfect. Alright, so now we close it up.