Tracheobronchomalacia

Podcast Transcript

Raed Dweik, MD:

Hello and welcome to the Respiratory Inspirations podcast. I'm Raed Dweik, MD, Chairman of the Respiratory Institute at the Cleveland Clinic. This podcast series of short digestible episodes is intended for patients and families, and covers topics related to respiratory health and disease. My colleagues and I will be interviewing experts about timely and timeless topics in the areas of pulmonary critical illness, sleep, infectious disease, and related disciplines. We will share with you information that will help you take better care of yourself and your loved ones. I hope you enjoy today's episode.

Daniel Culver, DO:

Welcome to respiratory inspirations. The podcast designed for patients on a variety of topics about pulmonary critical care, allergy immunology and infectious disease issues. My name is Daniel Culver, DO. I'm the Chair of the Department of Pulmonary Medicine at Cleveland Clinic. I have as my guest today, Dr. Thomas Gildea, MD. Dr. Gildea is the Section Head of Interventional Pulmonary and Bronchoscopy. And also, the Institute Lead for Innovations, which has to do with the inventions that come out of our section. Welcome, Tom.

Thomas Gildea, MD:

Thank you, Dan.

Daniel Culver, DO:

Today, we're going to talk about tracheobronchomalacia and excessive dynamic airways collapse. These are long acronyms that basically describe what happens when the large airways closer to the mouth collapse more than they should. Normally, we think about diseases like asthma and emphysema, which cause shortness of breath and coughing and exercise intolerance as being diseases that mostly affect the smaller airways. And if we think about the airways as a tree, an upside down tree with a trunk and then multiple branches, and those branches going out for 26 generations until they get to the leaves where the air sacs are, what we're talking about today is really the trunk and the largest branches of the tree, where the air first enters it, on its way down to the air sacs in the lungs. And recently, we've recognized that these large airways are not just passive conduits, but they also have important functions, and they can get in trouble. And really, that sometimes can cause symptoms, which can be confused for asthma or for emphysema.

So, that's a kind of overview of this thing we're newly recognizing. Tom, tell us a little bit about tracheobronchomalacia and EDAC, and how the large airway works, and what happens when it's not working so well.

Thomas Gildea, MD:

Thank you, Dan. It's kind of a big topic, but we can tear it down into pieces. So, tracheobronchomalacia is a term that describes the destruction or damaging of the cartilages that make up the structural support of the airway.

Daniel Culver, DO:

So, these are the rings that go around three quarters of the airway.

Thomas Gildea, MD:

Right. So, imagine that the rings are really not so much rings, but they are an arcade. A long hallway with an arch.

Daniel Culver, DO:

Like a bunch of horseshoes in a row.

Thomas Gildea, MD:

Exactly right, a bunch of horseshoes in a row. And you're walking underneath them, and the back wall of the airway is the membranous part of the airway. Sort of there and it flexes, and it moves and it helps move secretions around, but the front part of the airway is supposed to be the structure that holds everything up.

In classic tracheobronchomalacia, those cartilages aren't damaged. They're soft, they don't work very well and the airway sort of flattens out. And so, this nice tall open hallway becomes sort of the squished little tunnel through which the air and mucus has to move. And that could be quite challenging for patients to breathe when the support structure, the windpipe are not working.

Daniel Culver, DO:

So, I think about if I were sucking in through a straw, how that straw might collapse, that's the same thing that can happen in the large airways.

Thomas Gildea, MD:

Yeah. It's more on the expiratory side. So, one of the beauties of human physiology is you take a deep breath in, the negative pressure in the chest opens up the airway very nicely. But then, imagine trying to blow out through a sock, so the airway starts to flop, and you can't get the air out very easily and it starts to rumble. And it's that sort of the nature of tracheobronchomalacia. It opens up okay when you breathe in. But when you blow out, that pressure just squashes it down and it makes it hard to move things.

Daniel Culver, DO:

That's quite an image, blowing out through a sock.

Thomas Gildea, MD:

Sure.

Daniel Culver, DO:

Hopefully, it's a clean sock.

Thomas Gildea, MD:

Yeah, hopefully clean sock. Exactly right. And then, you know, that's just the basket term. There is another term as you mentioned, EDAC or excessive dynamic airway collapse, is a term that describes the floppiness of the back wall, but the airway cartilages are actually still intact. And so, in normal people when you breathe or cough, that posterior airway, it flops a little bit. It moves 50 to 60 percent, up to 70 percent of the time it'll, or 70 percent volume changes because that's how the body works to move things through. But when it goes more than that, when it's more than 70 percent and patients are having symptoms associated with that, it is when we think of it as a disease or as a clinical entity that needs to be manageable. Excessive dynamic airway collapse means that the airways moving more than 50 to 70 percent of what it's supposed to be moving and, and that's where we start thinking about this as a disease or something that could be helped.

Daniel Culver, DO:

So, when those cartilages are damaged, that usually is due to some very specific diseases. When the back wall of the trachea or the large airway is moving too much and pinching off the airway, that's really due, associated with some diseases, but it's not necessarily caused by specific causes. Is that a fair way to think about it? 

Thomas Gildea, MD: 

It is. I mean, there is a spectrum for sure, as the disease progresses or either of those two-process progress. The cartilages of the trachea in the trachea can fail. So, it can happen in both ways. And there is some overlap to that. It's not so clean, but that's a good way of thinking about it. So, the excessive post airway movement is often linked to asthma and COPD and other lung diseases. Whereas, the trachea cartilages can be happening, related to inflammatory diseases primarily of the trachea. Things like lupus and granulomatosis with polyangiitis, great big words, that affect the cartilages, some things you can look up online.

Daniel Culver, DO:

Even somebody who's had a tube in their throat for prolonged period of time, can get damage in those cartilage, can't they?

Thomas Gildea, MD:

You can damage the cartilage in many ways. But yes, endotracheal trauma, having prior tracheostomies, surgeries of the lung, lots of things could damage those airway cartilages that make them structurally not working the way they're supposed to.

Daniel Culver, DO:

So, asthma and emphysema are very common things. A lot of people have those. And they might take inhalers, maybe they take them every day, or maybe they only have to take them as needed, maybe they don't even have to take anything. So, why would somebody start to think about this not just being a disease of the small airways, like asthma and emphysema, but also a problem with the larger airways which then comes into your area?

Thomas Gildea, MD:

So, it turns out there are several different, what we call phenotypes or patient types, so ways that people present with this problem. One kind of phenotype or presentation is a patient who's got a cough that is just not really going away, or it's a very loud rumbly cough, we call it a seal barking cough, where you kind of hear this deep rumble in the chest. That is a good clue that the central airways impacted. Sometimes it's just shortness of breath that seems to be disproportionate. Their lunch function tests are pretty good, or even if they're not very good, they're certainly getting worse.

Daniel Culver, DO:

So, these are their breathing tests, where they have to blow, blow, blow, or go into that telephone booth looking thing, to get measurements of their breathing.

Thomas Gildea, MD:

Yes. So, when people do those breathing tests and they find that they've got some level of abnormality, if the doctor would say to them, "Boy, this number is not that bad, but you really seem very short of breath," sometimes that's a clue to this. Or sometimes we think of patients who just can't clear the secretions, you know, they get a little cold, and it just lingers forever. They can't get it out of their lungs. Sometimes that is chronic bronchitis, but sometimes it's also an airway problem that is contributing to that chronic bronchitis.

Daniel Culver, DO:

So, we talked a little bit about the malacia where the cartilages are damaged, and about how that could be due to a trauma or prolonged tube in your lungs, or perhaps some inflammation. What about just the dynamic collapse of the back of the airway, are there some symptoms or problems that cause that? Why does that happen?

Thomas Gildea, MD:

So, we don't know precisely. There are some theories around, and some pathologic studies we've seen where, when they take those of the lung out and they put them under a microscope, there is a missing component, the elastin. So, the stretchy substance that makes the posterior airway snap back, is destroyed. But there are some theories that perhaps, the inhaled steroids, the medicines that we take to treat some of the diseases may have a direct impact on the airway that can make this disease worse. Not entirely clear, but that can happen. And some people postulate, that just repetitive coughing over, over and over and over again, sort of wears out that structure. All those things are possible reasons that this happens.

Daniel Culver, DO:

And it's important to point out that a lot of people benefit from inhaled steroids. And a lot of people have coughing without ever having this problem. So, we're not recommending to people to stop their inhaled steroids.

Thomas Gildea, MD:

That's right. Absolutely not. In fact, you know, clearly, we're treating something and if it's asthma, I mean, that is the mainstay therapy. It is a mainstay of some kinds of COPD. But certainly, you think about it as a possible adverse event in the context of the right therapy for the right disease.

Daniel Culver, DO:

So, if I'm a patient and I have a lot of shortness of breath, but the doctor finds my X-ray looks pretty good and my breathing tests aren't so bad, and maybe even looking around at the heart, there's not a good explanation for it. You know, what, what should I ask my physician to do if, if we want to think about the large airways a little bit more?

Thomas Gildea, MD:

The quickest thing that you can do in the outpatient setting when you're talking to your doctor is to see if the CAT scan, they show something. And there is a specific CAT scan called a dynamic CT where you do inspiratory images. So, when you take a breath in, they take a picture. That's a normal CAT scan. But you could also repeat that image when you blow out really hard, and then they can do that scan, and they could look at lots of different things in that particular series images. We can look at the airway itself. We could look at the shape of the airway. We could also get a good look at the lungs. See if air is stuck in the lungs, and you can see some other diseases. That's usually the first test that we do that looks at it from a picture standpoint, from an X-ray standpoint.

Sometimes in the breathing tests, there's this thing called the flow volume loop. And its sort of a tracing that we see. The doctors can look at that very carefully and see if it could pick up some abnormalities in that. Those two things alone usually are the first step to try to think about where there might be a problem in the central airway.

Daniel Culver, DO:

Okay. So, if there's a suspicion, really the first step is to talk to your doctor. And then to think about a CAT scan that looks at how the breathing tube changes during the phases of respiration.

Thomas Gildea, MD:

That's correct.

Daniel Culver, DO:

The other thing that we've seen, I think a good bit of the time, is that although many of the people have asthma and/or COPD, there's also a big overlap with weight. What's going on there?

Thomas Gildea, MD:

Well, patients who are significantly overweight often have amounts of fat both inside and outside their chest that puts pressure on the lungs. And not only does it put pressure on the lungs, but it put pressures on all the things around the inside the chest including the windpipe. And so, as a person has to breathe against the pressure of whatever disease is in the lung, if you add a significant amount of fat inside and outside the chest, it can further impinge that central airway. It could, both of those things can increase the closure of that airway related to the excess of weight. 

Daniel Culver, DO:

So, I guess before you get into anything too aggressive here, you're thinking about is the asthma controlled, have I done what I can do with the weight, is there anything else contributing to the cough, like heartburn? And that's probably part of the work up that you do when you see patients.

Thomas Gildea, MD:

Yeah. In fact, reflux disease, heartburn, occurs in almost 50 percent of these patients, as chronic inflammation of the airway, from the gastric contents dripping down into the windpipe can be a part of the problem. Sometimes vocal cord problems are there. People have abnormalities in how the vocal cords work, and sometimes that contributes to it. Looking at other inflammatory disease in their body that they may not know about can sometimes play into this. So, it's a pretty exhaustive evaluation once you start to see these problems because we can find a lot of other potential underlying conditions, including inherited conditions. Something that people may have been born with may be there. And we can find a lot of things, and we start to see these problems linked together.

Daniel Culver, DO:

So, really, you're talking about all the disciplinary assessments. You're talking about familiarity. And you're talking about expertise when you're thinking about both making the right diagnosis, and then how you're going to deal with it. And that brings us into what you spend a lot of your time doing, which is really looking in the airways with a light and a camera using a bronchoscope.

So, tell me a little bit about how the bronchoscope plays into this, on the diagnosis side, and then even on the therapy side.

Thomas Gildea, MD:

Sure. So, bronchoscopy as a procedure is a medical procedure where we give patients sedation. And we take this very thin scope, it's a flexible tube that has a camera on the end and a light source. We either go down through the mouth or nose, and we numb things up as we go. And once we look inside the vocal cords and go down into the windpipe, we ask the patient to try to do exhalation maneuvers. Take a breath in, and then they blow it out. And if we see the airway moving much more than it's supposed to, that is sort of the disease. That is exactly what we're looking for.

And we can take pictures and videos. And we can try to figure out if we can assess and measure exactly how much the airway collapses. And if it starts to go more than 70 percent, I think that's where we start to see the mild disease. But if the airway closes more than 90 percent or completely collapses, that's when we know we have a severe problem. And we can actually grade that and measure it, about how far it goes into lungs. And that's sort of how we come down to making that diagnosis for sure, is just seeing it with our own eyes.

While we're in there, we can get some biopsies of the airways. We can get some cultures to see if there's some smoldering infections. But really, at the end of the day, looking at the airway as you're doing these maneuvers is how the diagnosis is made.

Daniel Culver, DO:

So, that's great to be able to, to tell somebody, "Hey, here's what's going on. Here's why you feel like this." But what can you do about it? What's the point of making the diagnosis?

Thomas Gildea, MD:

It's a great question. So, once we have the diagnosis while we're in the room, if we identify this as a problem, we can then put a CPAP machine or a CPAP mask on and have the anesthesia team help us dial in some pressures and see if a little bit of pressure that we can add into the airway holds it open.

Daniel Culver, DO:

This is just like what you use to treat sleep apnea?

Thomas Gildea, MD:

Exactly the same device. And the idea here is to pneumatically splinter. You use air pressure to hold open the airway, so that the airways are not collapsing so much that causes the symptoms. It's not a perfect fix. It doesn't hold it open all the time. And certainly, you're not gonna wear it all the time around the clock. But in times when it's being a challenge, you can put this on, give the airways some support, so it takes some of the pressure off the windpipe a little bit as it were, keep the airways from bumping into each other and causing inflammation. And for most patients, for a lot of patients, it actually is a very good therapy for the mild to moderate conditions.

However, when it's way over 90 percent is when we start thinking about advance interventions and surgeries and then stenting maneuvers. Because once it's that bad it's so difficult to manage just with CPAP alone. 

Daniel Culver, DO:

So, it always strikes me that you can use CPAP at night while you're sleeping, or a BiPAP which is really a different level of pressure during breathing in, versus, breathing out. And then that has some residual benefit from during the day. What's the all about?

Thomas Gildea, MD:

Well, just the idea that when the airways are collapsing so much the mucus is getting stuck or the airways are really bumping into each other, the inflammation and irritation that that causes can be an ameliorated or made better by periods of time when it's not suffering. Also, these patients, you could wear it during the daytime. So, if they're having symptoms and they're feeling like they can't clear the secretions or having problems with some shortness of breath, they could just put the CPAP machine on and give that airway a rest, give their body a rest. And give a chance for them to recover, sort of get some good airflow, get the secretions out. Just enough to, to really sort of settle things down, so they feel more comfortable.

Daniel Culver, DO:

And then they tend to feel more functional and less short of breath during the times they're not using the mask.

Thomas Gildea, MD:

They can derive some benefit in the long run. So again, if it's used to reduce some of the inflammation, reduce the infections, help to clear the secretions out, then they do feel better during the daytime. And we, again, add this to other things. We add this to the normal inhalation of therapies. We do this to breathing techniques in rehab. We do it to add-on to their, any other medicines or therapies they need for their other disease or other problems to help sort of basically just calm the airway down, and then help them breathe better.

Daniel Culver, DO:

So, I remember when we were first starting out, the surgery for dealing with this was a really tough one. And there was excitement about it at first. And then we noticed that it was a very hard surgery for patients to go through. It seems like maybe there's a much better approach now. And that involves the use of robotics. So, tell me about how surgery fits in and who could qualify for that.

Thomas Gildea, MD:

So, for patients with very severe disease, who have over 90 percent occlusion of their airway or collapse of their airway who continually be persistently symptomatic despite our best therapies, there is a surgery called a tracheobronchoplasty, which is a procedure where the surgeon will sew a mesh to sort of pull the airway together and staple down or tack down that floppiness in the airway. That mesh would extend the entire airway as high up as the surgeons could reach from inside the chest, as down to the main left bronchus and the right bronchus, as far down as they can reach, and sort of stitch that all down.

It used to be done with a thoracotomy, which is a large incision in the chest. And they would put their whole hands in there to do this. And that procedure was pretty complicated. It was done well. But surgery of that size in patients with significant lung disease can be a challenge. They have pain. They can have surgical complications. They can end up in the hospital for more than a week. It was a difficult procedure. For the right patient, it was a good procedure, but a lot of patients just couldn't tolerate it.

There's a new technique that's done robotically. So, very, very tiny incisions, just some small ports. And the surgeon can go in through the right side and do the exact same thing with a tiny incision or a tiny series of incisions and achieve the same results of tacking down the airway as I described. But hospitalization is a series of three days, and without as much complications. Patients are out of the hospital very quickly and it's much better tolerated and a better procedure.

It takes some skill to learn. Not a lot of people do it just yet. Quite a few in the center, just a few centers in the country. But people who do that procedure seem to have better outcomes.

Daniel Culver, DO:

What the image I can't get out of my head is, putting a corset on the airway. Is that about, right?

Thomas Gildea, MD:

It's kind of like that. It's just putting a piece of mesh on the back wall. So, just imagine that you have something very soft and floppy, and you want to put a stiff piece on the back, and you just staple it on there. So, it just keeps that back wall from moving as much, kind of locks it in.

Daniel Culver, DO:

Gotcha. So, if the surgery is not an option, or somebody doesn't want to pursue a surgery, can you put a stent in? And maybe you could just start by even defining what is a stent.

Thomas Gildea, MD:

So, a stent is a tube-like structure that we can put in the airway to hold it open. Most people are familiar with say, cardiac stents. It's a stent that would go into the artery or the vessel to hold it open, or a stent that someone would put into a vessel in their leg or their neck. Something to hold open a vessel. We have similar stents in the airway. GI guys have it for the esophagus. It's basically just a vice that goes inside the structure to hold it open.

When considering the surgical options, sometimes we put a stent in just to see if the patients are gonna feel better. So again, you mentioned that there's other diseases playing a role here, and we don't know all the time if the airway is the problem. So, occasionally in patients with severe disease, we'll put in a stent just to prove the point, you know, are they gonna feel better if we stabilize this airway, is this really gonna solve the problem, and so, we can put in this device.

We typically use something called a Y-stent. And so, it's shaped much like the airway. And the goal here is to put it in there for a short period of time, and then see if the patients feel better.

Daniel Culver, DO:

So, that gets the trunk and the two main branches.

Thomas Gildea, MD:

That's correct. And we can design a stent to fit exactly that area. And we custom make it, and we put it in. And if the patients feel better, then we take the stent out, and we send them onto surgical evaluation and see if they might want to have surgery. But 60 to 80 percent of patients do feel better with the stent. Some don't. We measure, you know, how far they can walk, what their breathing tests look like, and really do they feel better. We can do some quality-of-life questionnaires to see if they feel better. And if they do feel better, then we push them down the line to see if they might want to have surgery.

If for some reason, they can't have surgery and there's no way, that the surgical risk is too high, or they've had other diseases that would preclude surgery, sometimes we can put a stent in with the intent of it being the destination therapy, you know, this is what they're gonna have. We don't like to do that. Stents as a long-term option for the long are difficult. They can have granulation tissue. You could have scar tissue build up in the lung. They can have problems with mucus getting stuck inside the stent. They could have a cough that won't go away because of the stent. So, we only use the stent if we absolutely, absolutely have to, and there's really no other options.

And then the patients have to know that once the stent is in there, we got to take care of it. They got to come back every couple of months to have it cleaned up or changed in maybe more than once a year. And so, it's a big commitment to do that. So, we only do it in patients who are really absolutely necessary and really have to be dealing with complications of stenting.

Daniel Culver, DO:

So, it sounds like in both the diagnosis and the therapy, there's a lot of complex decision-making there, there's some need for experience, and there's also a real requirement to have several different specialties talking closely with each other.

Tell me a little bit about what kinds of settings, what kinds of practices are usually able to handle these problems? What should patients look for in terms of a referral?

Thomas Gildea, MD:

So, we have a multidisciplinary group that meets and sees these patients. We have sort of a protocol where we sit down and go through all the testing and all the evaluations to be done. And then once we feel like we have a good sense of what's going on with the patient, we meet as a team. There's a bunch of pulmonologists, interventional pulmonologists, nursing teams, and also, thoracic surgery. And we get in a room and actually it's a virtual room these days. But we get in front of our computer screens, and we pull up all the data, and we go through each case individually, and we try to come up with a plan.

Occasionally we will find that we have to reach out to other members of our team. We may reach out to the asthma team. We may reach out to the bronchiectasis team. We may reach out to the ENT doctors or the GI doctors. We reach out to lots of different doctors, including obesity specialists, to find ways, to make sure that we've done everything we can to make this patient better before we commit to a surgery or a major intervention.

Daniel Culver, DO:

So, that's a really comprehensive approach. And I think that's probably a good place to wrap up today. We've learned that many people with unexplained shortness of breath or severe cough, have not a problem only of the small airways, but also of the large airways. And that that can really take two main flavors, which overlap. It can be damage to the cartilage. But even more commonly, it can be too much movement of the floppy part of the airway.

But now that we know about these things, and we recognize them, which was not the case really just a few years ago, we can think about ways to, to intervene and to improve people's lives.

So, I want to thank you, Tom, for educating us today, and for what you're doing to help patients in this area.

Thomas Gildea, MD:

So, thank you, Dan. I like to thank you for the opportunity to talk, I just want to give a shout-out. There are resources available on the internet for patients to look this up, not just the Cleveland Clinic website, of course. But there is something called the Tracheobronchomalacia Foundation, the TBM Foundation. It's founded by a woman named, Jennifer Champy. When we started this program, the first speaker I had was the founder of this program, to talk about this from a patient's perspective.

This is a very difficult, it's a challenging and confusing thing for a lot of people. And that website, the TBM Foundation, is a great place to look for patients. They have resources and information about this condition if it seems to be something that they may be thinking about or concerned about.

Daniel Culver, DO:

So, that's T as in Thomas, B as in bravo, M as in Mary, Foundation.

Thomas Gildea, MD:

That's correct.

Daniel Culver, DO:

Well, thank you again, Tom, for joining us. And thank you to all of you for joining us for this episode of Respiratory Inspirations. I'm Daniel Culver, DO, Chair of the Department of Pulmonary Medicine at the Respiratory Institute at Cleveland Clinic. Have a good day.

Raed Dweik, MD:

Thank you for listening to this episode of the Respiratory Inspirations podcast. For more stories and information from the Cleveland Clinic Respiratory Institute, you can follow me on Twitter @raeddweikmd.