Upper Airway Stimulation: An Alternative to PAP Therapy for Sleep Apnea Patients

Podcast Transcript

Introduction: Neuro Pathways, a Cleveland Clinic podcast, exploring the latest research discoveries and clinical advances in the fields of neurology, neurosurgery, neuro rehab and psychiatry.

Glen Stevens, DO, PhD:

Surgical therapy has been part of the comprehensive treatment options for obstructive sleep apnea for over 40 years. In 2014, a new category of surgical therapy became available when the FDA approved the first neuro stimulation device for the treatment of obstructive sleep apnea.

In today's episode, we're discussing neuro stimulators as an alternative for patients who cannot tolerate positive airway pressure therapy. I am your host, Glen Stevens, neurologist/neuro-oncologist in Cleveland Clinic's Neurological Institute. And joining me for today's conversation is Dr. Jessica Rundo. Dr. Rundo is Director of the Sleep Neuromodulation Program in Cleveland Clinic's Sleep Disorder Center. Jessica, welcome to Neuro Pathways.

Jessica Rundo, MD:

Thank you. Thank you very much for having me.

Glen Stevens, DO, PhD:

So let's set the stage before we jump into the topic directly. How prevalent is obstructive sleep apnea? What are we looking at? How many patients aren't we diagnosing? Just set the stage for the scope of the problem.

Jessica Rundo, MD:

Sure. Unfortunately, obstructive sleep apnea is highly underdiagnosed and underrecognized, and there's various studies that will give different ranges of how prevalent it is, but by and large, we'd say 25 to 50% of males have some amount of obstructive sleep apnea and 10 to 25% of females have some amount of obstructive sleep apnea. So we're talking about millions of Americans.

Glen Stevens, DO, PhD:

So let's talk about positive airway pressure as a first line of defense for this medical crisis out there of obstructive sleep apnea. When is it appropriate? When should we treat somebody?

Jessica Rundo, MD:

Yes. I mean, in most cases, we should use positive airway pressure therapy as first line treatment for obstructive sleep apnea. We know that moderate to severe obstructive sleep apnea does increase the of cardiovascular events, so talking about heart attack and stroke, especially with milder obstructive sleep apnea, we may or may not treat that disorder unless someone already has high blood pressure, heart disease, history of stroke, or if they have excessive daytime sleepiness that's interrupting their daytime functioning.

Glen Stevens, DO, PhD:

So Jessica, I am a non-compliant patient that doesn't really want to hear anything about wearing a mask for sleep apnea and I say to you, "Well, can't I just lose some weight?" How much weight do I need to lose? Is this a reasonable direction to go with patients? Or how long do you go down that route before they really need to be treated? Or should they just be treated if they really have moderate sleep apnea?

Jessica Rundo, MD:

Well, generally the more severe the sleep apnea is, the more weight that you would need to lose. And so there's actually an algorithm. And we characterize obstructive sleep apnea based on something called the Apnea Hypopnea Index or the number of times per hour that someone is having a pause in breathing. So say your Apnea Hypopnea Index is 15. If you lost 10% of your body weight, so if you're 200 pounds, you lose 20 pounds, that Apnea Hypopnea Index is going to go down by about 25%, meaning, I'm doing some math here, so meaning it's going to go down to about 11 or 12 on that Apnea Hypopnea Index. Less than five is considered normal.

So it would get you down somewhat, but once again, the more severe the obstructive sleep apnea is, the less likely mild weight loss is going to resolve the sleep apnea itself. It's certainly something, if someone is overweight, it's a good idea to go ahead and use weight loss as one of the strategies, but generally we don't recommend weight loss only. We all know how difficult it is to just lose weight, especially after we reach our 40s and 50s.

Glen Stevens, DO, PhD:

And it sounds like they may need to lose up to 20%, which would be pretty difficult.

Jessica Rundo, MD:

Yes.

Glen Stevens, DO, PhD:

For most patients.

Jessica Rundo, MD:

Yes.

Glen Stevens, DO, PhD:

So let's talk a little bit about airway stimulators. When does it become appropriate? What's the screening criteria? Who's a candidate for it?

Jessica Rundo, MD:

Currently it is indicated for patients who have moderate to severe obstructive sleep apnea. And once again, we're looking at that number called the Apnea Hypopnea Index or AHI. That number needs to be between 15 and 65. So we're talking moderate to severe patients, but not too severe. So there is an upper limit to the severity of the sleep apnea that would still allow someone to be treated with this type of treatment option.

And then body mass index is still looked at as well, although it is no longer a criteria based on FDA approval. Insurance companies generally will not cover it if the body mass index is greater than 32 in most cases, and in a few insurance companies, body mass index greater than 35, they'll deny it.

So those are some of the two main criteria we look at initially. Also, we're talking about obstructive sleep apnea here, but central sleep apnea can occur as well. And this is not a type of treatment for central sleep apnea. If there's more than 25% events that are central in nature, this will not be a good treatment option for those patients.

Glen Stevens, DO, PhD:

So years ago, it seemed like more patients would get tonsils removed, adenoids removed, soft palates removed, those types of things. Has that kind of gone by the wayside or does that still take place for certain patients?

Jessica Rundo, MD:

It has in many cases. Children, tonsillectomy and adenoidectomy is still first line treatment for obstructive sleep apnea. But once you get over the age of 18, generally, if you have obstructive sleep apnea, it's for other reasons, and so doing that kind of surgery is, in most cases, not going to resolve the sleep apnea unless the patient is of normal weight and they have quite enlarged tonsils.

The other surgeries that can also be done to remove excess tissue in the back of the throat were very popular. Those types of surgeries were very popular 20, 30 years ago, but what we found over the years is that they don't tend to be terribly effective and really are mainly used as rescue therapy now because they only really provide a cure in about 25 to 30% of patients.

Glen Stevens, DO, PhD:

So if I come in to see you, I have clear evidence on my sleep test of obstructive sleep apnea, should I do the mask? Should I do the surgery? What's the order? I tell you I want the surgery, do you tell me everybody should get the mask to start? What do you tell patients?

Jessica Rundo, MD:

Yeah, so generally PAP therapy still is considered first line. The only other time that I will offer another treatment option initially would be if someone has mild obstructive sleep apnea. So mild obstructive sleep apnea is when that AHI, that Apnea Hypopnea Index is between 5 and 14. If that's the case, then an oral appliance or what we call a mandibular advancement device that is specially made to help protrude the lower jaw, the mandible forward, that can also help to open the airway. That type of device could be used and is just as in many cases of mild obstructive sleep apnea.

Glen Stevens, DO, PhD:

So if patients are struggling with their CPAP, how do we help their compliance? "I want to use it, I just, I'm uncomfortable. I don't feel comfortable with it." How can we make them more compliant?

Jessica Rundo, MD:

Well, in general, you have to try to get to the bottom of what is really bothering them most. Are they claustrophobic? Do they not like the way the mask fits? Is the pressure too high or too low? What is prohibiting them from being compliant with PAP therapy?

And here at the Cleveland Clinic, we actually have what we call a Sleep Apnea Management Clinic, where we have nurse practitioners that work with our patients and they do it traditionally in this group visit. With COVID, things have been a little bit different so we do it virtually now, but the bottom line is, is they talk with various patients and see what they're struggling with the most with regards to their PAP therapy. And in some cases, it may be that the pressure's just too high or that needs to be changed, or maybe it's a mask fit. They don't like the full face mask and they want something smaller like a nasal pillow mask.

So if we can make some changes like that, I mean, usually we'll know within a month or two of those patients retrying PAP therapy, whether or no they're going to be able to get compliant with it.

Glen Stevens, DO, PhD:

So you think that I might be a good candidate for one of these devices. I'm your patient. Tell me what you tell the patients in terms of how it works, what the surgeon's going to do to me. Obviously the surgeon will go through all the surgical based risks, but what's the general scenario that you go over with the patients?

Jessica Rundo, MD:

What they do is it's an implantable device. There's a generator that looks like a pacemaker that gets implanted, usually on the right side of the chest. We usually leave the left side of the chest for the heart if you need a pacemaker in the future or a defibrillator. And so it's usually placed under the tissue and in the chest on the right side. And then there's a lead that goes up through the neck. It gets tunneled underneath the skin. It goes around a nerve called the hypoglossal nerve that stimulates the tongue to move forward. There's another lead that goes in between the ribs to detect when you're taking a breath. And what this device does is every time you inhale, every time you take a breath, it stimulates the tongue to move forward to get it out of the back of the throat to help keep the airway open.

Glen Stevens, DO, PhD:

So do I notice any electrical motor movement or sensory change when it stimulates, or not necessarily? It just moves forward and I don't?

Jessica Rundo, MD:

The tongue moves forward involuntarily. I mean, it's being stimulated, so it may feel a little strange. It shouldn't be uncomfortable. It shouldn't feel like you're getting shocked. It is strange initially for patients to feel that stimulation and it is something that they sometimes have to get acclimated to, but it shouldn't be painful.

Glen Stevens, DO, PhD:

And I understand when these devices initially came out, they did three incisions and now they're just doing two incisions.

Jessica Rundo, MD:

Correct. So originally there was an incision between the seventh and eighth rib in the chest. What they later realized is that in women, that's exactly where the bra line is. And so it's a bit more uncomfortable and it's usually just the more uncomfortable of the incisions in general for men as well.

What they have been able to do is they can just use the incision where they put the generator that's in the upper right chest and that's where they can put the lead now. The lead goes into the area between the second and the third rib instead.

Glen Stevens, DO, PhD:

How long does the battery last?

Jessica Rundo, MD:

11 years.

Glen Stevens, DO, PhD:

So then 11 years later, I'd have to have another surgery to replace the battery?

Jessica Rundo, MD:

Yeah. They would just replace the battery though. They wouldn't need to replace the leads.

Glen Stevens, DO, PhD:

And in terms of patient populations that are out there, are there some underserved populations? Are we not treating all groups equally in terms of the devices or even the CPAP?

Jessica Rundo, MD:

Well, I think our Medicaid patients are the ones that are going to be limited more with this device because currently it is not a covered treatment option for them. So that tends to be one of the bigger issues for patients that have Medicaid insurance.

Glen Stevens, DO, PhD:

Would you recommend anybody that's thinking about this see a sleep specialist or can they go to their general neurologist for this?

Jessica Rundo, MD:

I think it usually is most helpful if they can be referred to a sleep specialist, just to discuss in more detail what their issues are with PAP therapy, what other potential options there might be in addition to hypoglossal nerve stimulation.

Also, we see a number of patients that are intolerant to PAP therapy or just struggle with whatever their treatment option is for sleep apnea, struggle in general also because they have other sleep disorders like insomnia, restless leg syndrome, circadian rhythm disorders. And so going to a sleep specialist, they would be able to assist in determining if there are other sleep disorders that are contributing to their difficulties with being compliant with their treatment options.

Glen Stevens, DO, PhD:

And are these stimulators all one setting or you can adjust a setting?

Jessica Rundo, MD:

We do extensive adjustments. That's really where I come in. I don't actually do the surgery. It's one of our sleep surgeons that does it. We have an ENT doctor that does it and we have a plastic surgeon that's actually trained to do it at as well.

But what I do is I do a lot of the programming. So I get to turn the device on for the first time for the patient. They get to feel the stimulation. And then based on where we see good tongue movement, we'll start to make some adjustments on voltage settings where they can start to gradually go up to different levels and do slightly higher voltage settings over time as they get acclimated to it.

Glen Stevens, DO, PhD:

And do you have to repeat their sleep study once you get them in the sweet spot-

Jessica Rundo, MD:

Yes.

Glen Stevens, DO, PhD:

Or does the partner just say they're not snoring anymore?

Jessica Rundo, MD:

No. No. We have to confirm everything. So we want to make sure that we're definitely treating their sleep apnea. So we do bring them in for an in-lab sleep study and we test different voltage settings to make sure that we're optimizing their treatment.

Glen Stevens, DO, PhD:

And how's the outcome. The index that you talked about earlier, how do patients do with this versus CPAP?

Jessica Rundo, MD:

So we get good control of someone's sleep apnea. We get that AHI normalized below five or very close to five in probably 70 to 80% of patients initially. So it's the extra 20 to 30% of patients that we struggle a bit more with, but if we're given enough time and they're diligent enough for us to work with them on this, we can also get them well-controlled as well.

What I've learned over the past five or six years of doing this is that we really need to take extra time sometimes with patients just getting acclimated to the device. So it's not an immediate you turn it on the first time and your sleep apnea is completely controlled.

Glen Stevens, DO, PhD:

And does it wane over time? You have to turn up the juice?

Jessica Rundo, MD:

You shouldn't need to turn up the juice unless there is weight gain or something that would cause their sleep apnea to become more severe. In fact, over time, we can see a need for decreased voltage settings in some patients.

Glen Stevens, DO, PhD:

Any negatives other than the obvious surgical related complications?

Jessica Rundo, MD:

For the most part, no. There may be some tongue soreness, and that's where we have to work a little bit more with patients and try to find more comfortable settings for them sometimes. So sometimes we'll find a good voltage setting that really controls their sleep apnea well, but they're just not able to tolerate it or it's causing some tongue soreness just from the continuous stimulation. And so we need to make adjustments.

I'm going to give you some physics here really quickly. Basically there's different configurations we can do with the cuff that goes around the hypoglossal nerve. And so when we make changes to the electrode configurations, we can enlarge or concentrate the voltage field and that can make different changes to how we stimulate the nerve.

Glen Stevens, DO, PhD:

So if I remember my anatomy correctly, if I stimulate the right 12th cranial nerve, it will push the tongue. Is the voltage not strong enough that it actually deviates the tongue? It just pushes it out, or how does that work?

Jessica Rundo, MD:

No, it usually does push it to the left somewhat, but there seems to be some bilateral stimulation even though we're only stimulating a single nerve on the right side.

Glen Stevens, DO, PhD:

Are there other devices available on the market or anything coming to market?

Jessica Rundo, MD:

Nothing available on the market now, but there are several devices that are being studied. Currently there is a bilateral hypoglossal nerve stimulator. It's in trials right now. It's being studied. And it's a little less invasive from a surgical standpoint. There's a single incision that would go basically above the genioglossus muscle, so kind of under the mandible. And it lays across both hypoglossal nerves. And then there's a device that you would place externally underneath the chin to turn it on at night. And so that's a device that's being studied right now.

There's also another transcutaneous electrical stimulator that's being looked at in Europe. And finally, there is yet a third device that's not really doing anything from a stimulation of the hypoglossal nerve standpoint. It's giving some continuous negative expiratory pressure. So it looks like a neck brace that you basically wear and it helps to give this negative pressure to help open the airway that way.

Glen Stevens, DO, PhD:

And I'm just kind of curious, numbers-wise if you look at your patient population with obstructive sleep apnea, what percent are treated with this type of stimulation device?

Jessica Rundo, MD:

Currently I would say probably about 1%. It's a small percentage that we have right now that are being treated with this type of device at our sleep center. It's still fairly new and it does take a bit of a process because once you finally get to the surgeon, they also have to ensure that your airway is compatible with what would need to be done.

Glen Stevens, DO, PhD:

So Jessica, anything that we've missed that you think is important for our audience to know?

Jessica Rundo, MD:

One of my biggest points that I like to make with is really just getting the patients to see one of the sleep specialists first. We find that there are a number of other sleep conditions that seem to make tolerance to PAP therapy or any kind of therapy easy for these patients. And so we will get some patients that have this hypoglossal nerve stimulator implanted and then they start getting nervous about the fact that it's going to turn on, and so they almost anticipate that this device is going to start stimulating. Even though it's not painful or uncomfortable for them, it's almost this hypoglossal nerve stimulation induced insomnia that they anticipate the device turning on. So that's something that we like to try to address up front and take care of in the beginning before they even get implanted.

Glen Stevens, DO, PhD:

Well, Jessica, I'm happy to say that I don't snore, so I don't think I have obstructive sleep apnea, but I know you would like to see the electrical tracings to document that to know for sure, but I'd really like to thank you for joining me today. It's been very educational and we look forward to continued advances in your field.

Jessica Rundo, MD:

Thank you. Thank you very much.

Conclusion: This concludes this episode of Neuro Pathways. You can find additional podcast episodes on our website, clevelandclinic.org/neuropodcast, or subscribe to the podcast on iTunes, Google Play, Spotify, or wherever you get your podcasts. And don't forget, you can access real-time updates from experts in Cleveland Clinic's Neurological Institute on our Consult QD website. That's consultqd.clevelandclinic.org/neuro, or follow us on Twitter @CleClinicMD, all one word. And thank you for listening.