Podcast Transcript: Hypoglossal Nerve Stimulation for Adult OSA

[Gopi Shah MD]
All right. So you've seen them, they look like they're healing. Now we're like post-op week four to six. They go back to pulm. And at that point they can then help guide them of starting to turn it on using the mouse, putting it on, the sensor portion or the lead in the chest. and they can start and they just put that on before they go to sleep at night.

[Matthew Hensler MD]
Yeah, and, you just kind of hold it over it, right? Like you just, you hold the device kind of on top of your chest where your processor is and then, and then you take it away. So it doesn't have to stay there all night.

[Gopi Shah MD]
Oh, okay. Okay.

[Matthew Hensler MD]
It is just kind of there to turn it on, to activate it.

[Gopi Shah MD]
And does the sleep pulmonologist then kind of adjust the settings. Are there certain settings or it just automatically kind of goes with your breathing?

[Matthew Hensler MD]
Right, And that gets a little bit out of our wheelhouse a little bit, cause sleep will manage a lot of those settings, but ultimately there are different configurations on the stimulator that they can adjust. So if you're not doing well with a particular pattern, they can change that. And in terms of the intensity or the duration, a lot of that is all modifiable. People often say, am I getting shocked in my base of tongue? It's not a shocking thing. It's more of just a tense kind of tightening sensation that they would feel. So they're able to make those adjustments and the device, about 70% of people, when they go for that initial activation, they're good to go, it works. They're getting a good level of stimulation. It's comfortable and they're sleeping and they're happy, but you do have an important percentage of people who, and that's another thing I try to stress preoperatively is don't think that we just put this in and you turn it on and sleep apnea is gone, you have to maybe work with it and calibrate it kind of when you get glasses for the first time, it's not like it's just easy for everybody. It takes some getting used to, even C-PAP for some people it takes getting used to. So, they'll work with sleep over time to maybe make modifications and rarely would we then see somebody back in the office who, hey, we've tried these different configurations, maybe the sleep study. We're not getting them exactly where we want with AHI. So let's, let's do a scope while they're under, turn on the device and see where our diff different stimulations are happening of the base of tongue. And you can kind of modify it that way too.

[Gopi Shah MD]
I see. Okay. So you put the implant in, then you've turned it on about a month later. When do they get a sleep study again with the device on, is that at that initial turn on or is it a couple of months later?

[Matthew Hensler MD]
They'll do about three months generally, just to make sure that the device is in, subjectively we're getting good improvement. And then you let them use that for a bit before you check the formal sleep study.

[Gopi Shah MD]
So let's say you have the repeat sleep study at three months. What's a good outcome? I mean, you kinda mentioned the AHI range, the indication is 15 to 65 and the higher, I would imagine, you start with, in terms of resolution, the less that's going to be. I mean, it's the same way with OSA in kids, the more severe you start, the harder it is to resolve it or completely “cure it” to an AHI of less than whatever the minimum is. So what's a good outcome or how do you talk to patients about that?

[Matthew Hensler MD]
Yeah. Great question. So there were a lot of studies that have looked at these different registries where they followed a lot of patients to see generally, where are we starting with an AHI, generally though they’ll report median AHIs, and then you see where they wind up afterwards. And so they're still developing a lot of that longer term follow-up, but generally they've brought people from let's go the low mid thirties of an AHI, median AHI, and it brings them down to about six to nine. So just over 90% of people are brought down to no sleep apnea or mild sleep apnea. Right. So that's really good. And again, it's still to tell people, don't think that we're going to put this in and that all snoring is gone and you don't have sleep apnea. It's more, this is your further down the line procedure to consider. So if somebody is not tolerating C-PAP and they're just sitting at home with an AHI of 65 and not doing anything. Yeah. If you can bring them down to mild sleep apnea, that would be awesome. It's really going to improve their long-term health. So I think the education upfront is important with regards to that.

But another parameter they follow is the Epworth sleepiness scale. So the perception by patients is really good. I think it brings them from perceiving daytime sleepiness to a lower number. So you're getting good outcomes with regards to that. And a lot of these devices have a really good patient network that if you have a patient interested in the device, you can set them up with somebody who's already been implanted and they can talk to them and see what it's like. It's kind of like cochlear implants. I feel like that. Or a lot of the other implantable devices, it's important to talk to others who have had it and hear it firsthand from them.

[Gopi Shah MD]
Yeah, that's a good point. I think that's pretty cool that that network and community or support is there for patients and families.

[Matthew Hensler MD]
Oh yeah. Yeah, it's really hard to see your long-term results. And that's what's been cool to work with sleep medicine and have now a coordinator. We're following our own patients long-term and seeing our outcomes, which are the same as what you're getting on a national level. And it's pretty cool too, because when you operate on somebody and you don't see them back, it's generally because they're better, but you never get to see your patients that are doing better back, it's if you have issues. So it is nice to get some of that feedback and follow up.

[Gopi Shah MD]
One other question, or actually in terms of a candidacy, do you feel that the patients that do have lingual tonsils, for example, or maybe have a slight maybe some sort of elongation of the soft palate or do you have to do those surgeries first and then consider staging, or at that point, if you're thinking about putting a stimulator in you've already bypassed all that. Are there certain patients you're like, your lingual tonsils are huge, we just need to get those out.

[Matthew Hensler MD]
Yeah. Yeah. This actually just yeah, this happened pretty recently. I had a patient who they're on kind of this track to consider the implant and you do your DISE. And truly during this DISE, the tonsils, the amount of collapse that was just lateral wall collapse and purely tonsil and everyone else looks fine. You're kind of like, look, you don't fit the mold for needing a tonsillectomy. I totally get it. But, if you're younger or if maybe their AHI is 16, and you're just creeping into candidacy. If I was young, and that was me, I would say, okay, well then let's try the tonsillectomy or the lingual tonsillectomy. So I think you'll pick up on that with the dice to make sure that there isn't a very exaggerated contribution to their sleep apnea or if it's just the normal, multilevel collapse and you go about it that way.

[Gopi Shah MD]
So I think that's a great point because in kids, tonsil size, always, isn't a predictor. You'll see kids in clinic with two, four, plus kissing tonsils, abnormal sleep studies or kids with one plus two plus that you don't think much is there and you might get a sleep study and be like, oh, okay. And then you take the tonsils out and they actually get a little bit better. And I always tell families, they’re kind of like belly buttons, I think when they sleep, they'll fall out, like fall into the pharynx when, when sometimes they're asleep and maybe we just don't always appreciate it.

One other question for you is, right now in kids, I think, we do the TNA, they might still have residual, moderate to severe OSA. They might need C-PAP, maybe they can't tolerate it for like six months. Maybe you do a DISE or a cine MRI, depending on where you practice and what you prefer. We will do, I feel like, because it's not approved obviously, and under 18 yet, tongue based surgery or lingual tonsillectomy, if that tissue is there. In terms of adult basic tongue surgery, is the stimulator replacing that then like a posterior midline glossectomy or tongue-based reduction. Is this in lieu of that?

[Matthew Hensler MD]
I would say, I don't do a lot of lingual tonsillectomies. And it's not because I'm biased towards doing the implant. I think there are patients where I'll say, look, there's hyoid suspension, you can do these procedures to tighten up the pharynx in various ways or reduce the base of tongue. And I think they're all things to consider doing. And you kind of walk them through. And I've even referred people to other physicians that do those procedures to say, why don't you talk to them about it, before you get this implant, because I still put the implant as being far enough down the line right now that we want to make sure that it's either a specific area that you can't control, like tonsils or their palate or the base of tongue, or make sure you know of all of the other non implantable procedures you could do, look at their outcomes and, and make that decision sometimes for yourself. But, yeah. I think if again, if somebody's got exaggerated lingual tonsils, and that's what's collapsing on their DISE, it's totally worth trying to do that rather than, if there's somebody that can go through it medically based on their medical history or their age. Yeah. I think that's still something important to remember that this hasn’t just gone from C-PAP to nerve stimulator.

[Gopi Shah MD]
Yeah. Yeah. Yeah. And I think the questions I keep asking is because I still find it so hard to identify the level of obstruction. Right. It's multilevel, and it's hard to know exactly where, and then what procedures going to help.

[Matthew Hensler MD]
Well, yeah. And that's an important point that you bring up because on the DISE, really, the main thing we're looking for for the nerve stimulator is that they don't have lateral wall collapse. Because if you think, if you're going to stimulate your base of tongue to go forward and they're primarily getting a concentric or lateral collapse, you're not helping that with the device. So the DISE is sometimes more important from an exclusion perspective, as opposed to, oh, this is your level. So we should do this procedure.

[Gopi Shah MD]
Right.

[Matthew Hensler MD]
So that's an important point.