Director of Bronchoscopy, Dr. D. Kyle Hogarth discusses the relationship that pulmonologists and gastroenterologists have when diagnosing certain cancers.
[MUSIC PLAYING] D. KYLE HOGARTH: This is a technology, obviously, that took a little time to make it full blown into the pulmonary world, whereas you all have been blazing ahead within the GI world. But it has definitely come on into prime time, and more and more pulmonary physicians are utilizing it. Depending on where you practice and how you practice, you either have a colleague that is willing to work directly with you and can be very complementary to your efforts in staging the mediastinum, or that's because there's still very much a lag in pulmonary utilizing this procedure, it will be you all potentially utilizing this procedure. It's not all that difficult, I'm happy to say. Just don't tell anybody in pulmonary I said that. And it's something that you could actually, depending on the rules of your hospital and your medical center, utilize in your own practice. So I have no disclosures in regards to the discussions on this topic. So very common clinical scenario that we get involved with on the pulmonary side and where I think EBUS has become much more useful, you've got a standard CAT scan, 65-year-old guy. He's a former smoker. He's got a lung mass. He's got borderline lung disease and otherwise unremarkable. But he's got a clear and obvious lesion that everyone's concerned about. Prior to arriving, he'd also had a PET scan work-up, which showed that the lesion was positive, right here obviously, and that the hyaline lymphadenopathy was also positive on PET scan. And that traditionally was a relatively difficult place to reach with a lot of conventional modalities. Enter, obviously, the EBUS scope, the convex probe. To familiarize yourself, as a guy who does not do EUS but does do radial thin-probe ultrasound within the periphery, the convex probe as a scope has a lot of actually limitations. It's channel's a 2.0 millimeter working channel, and with a needle in it you will essentially have zero suction and zero ability to clear out your airways. But to be honest with you, given even just the 2.0 channel without a needle you'll have next to zero suction. You also have optics that look at 30 degrees oblique, and so you sort of see where you're going as you're passing it and not much else. As an endoscope, it's a pretty awful instrument. But for what it was designed to do, obviously give you a scanning range of roughly 50 degrees within the airways, it's beautiful at what it does and what it's capable of doing. It's also quite a large scope. You can ram it through a 7 and 1/2 ET tube and you'll be very angry about your broken scope. It will be much more easily fit through an 8 or preferably 8 and 1/2 half endotrachial tube. But here are the type of images you'll get. Going after this is a left hyaline lesion. Fellow was having some trouble shoving the needle through, but these should look relatively familiar to everybody other than obviously it's not a radial probe. It is a curvilinear and convex view. And so here's our lymph node here with vasculatures. And needle coming in and out sampling. Sampling, technique-wise is very similar to what you all would be doing. But why do this? The node was PET positive, so it's clearly got to be malignant. Someone had needled the lung mass. Well, here's where EBUS has become sort of front and center and become a very useful modality. And I think worth, as I said earlier, worth potentially being something that you all would be comfortable with or at least be working closely with a pulmonary colleague who is doing it when it comes to the mediastinum. Because for folks who have central tumors or N1 lymph nodes like this person but no obvious distal mets, it is very much recommended that we sample the N2 and N3 lymph nodes within the mediastinum to ensure that there is not further spread and clearly different staging of the malignancy. And obviously the presence of lymph node mets very much changes the stage, and when it comes non small cell lung cancer, dramatically shifts both intervention and also prognosis. And the presence of mediastinal lymph nodes changes you from stage 1 or 2 rather than to 3a or 3b, and very much as 3b is not operable, changes very much who's going to get involved, what type of specialist, what type of intervention. You're familiar with this. I prefer to actually show you this image instead in regards to the general locations where endobronchial ultrasound becomes useful. You'll clearly see there's a lot of overlap in the areas that you all like to reach. And I think that's where we become quite complementary, because lymph nodes that I can't get to you can, and vice versa. There's also clearly some overlap, and so that's where either shared ground or if there's a different procedure that you're doing, why not sample and stage the mediastinum at the same time for us if you're in there already? But if the hyaline's in question, that's an area that is relatively straightforward for us, and depending on its exact location on the lymph node can be almost impossible. I think this summarizes it. What transbronchial needle aspiration through EBUS versus traditionally what EUS versus the prior gold standards before you and I entered this world. There is, and I think probably most importantly, when we look at the two modalities combined, there's really nothing that we can't reach. And most importantly, we can reach places that much more invasive means are unable to reach. And that is reflected, at these for when it comes to EBUS, mediastenoscopy billing rates have dropped by 50% in the last seven years. And endobronchial ultrasound rates have been skyrocketing. And it's actually been skyrocketing-- it's not been a one-for-one swap. Now why, besides sort of this obvious you can't get all the nodes, has Mead been dying off? And why even sample any of it? After all, CT scans and PET scans are good enough, aren't they? So I would always highlight a very great metanalysis that Silvestri put together, published a few years back, looking at multiple CT and PET trials at the sensitivity and specificity for determining that something had spread. Or to put it another way, a loved one of yours has been told don't worry about it. Your PET scan's fine. You've got stage 1a. We'll just go do your thoracotomy. This is not good enough to take one of my loved ones off to a thoracotomy without knowing what the mediatinum shows. So when it comes to clinical staging versus pathologic staging, we see issues of being clinically over-staged. I've lost count how many times we're pulling out granulomas from lymph nodes that was someone ready to call the guy stage 4 cancer from whatever primary they had. 20% are clinically under-staged. And then obviously when you have clinical N2 disease versus pathologic with N0 versus N1 versus some that were N3. So it is, you know the old rule, until you look, everyone's N0, right? And so part of the various-- and actually all of the large governing bodies, at least over the pulmonary world, as I'm sure it is within your neck of the woods-- you want sample. Tissue's the issue. So mediastenoscopy used to be the gold standard, but when you actually look at it in a critical way, it wasn't so gold. It has a significant false negative rate, and if you've ever watched a mediastenoscopy, it turns out that it doesn't look like a Netter diagram. There's a lot of material inside the mediastinum that mistakenly looks like a lymph node, is resected, pulled out, and the pathologist tells them they got a great fat biopsy and no lymph node whatsoever. And one kind of hopes that that means there was no cancer, but no one does not know. And because, as we talked about, can't reach it, it's also obviously much more invasive. And though it's very safe, it's not 100%, and it's definitely got a higher complication rate than our combined procedures. The other thing, of course, why do we do it, though? Why do we sample? And this is what sort of led-- this was the one bar we needed to reach for sampling the mediastinum-- was the fact that in people who clinically had early stage disease, up to 10% will have positive nodes. But then the other thing about mediastenoscopy that sort of opened the whole role for you and I is the fact that within non-high volume thoracic surgery centers, the problem is that only roughly 10% of thoracic surgeries are done by people who only do thoracic surgery, and then another 20% are done or 30% are done by cardiothoracic surgeons. But 50% percent or more of thoracotomies in this country are done by general surgeons who don't do mediastinal staging. And if you look, only 27% patients undergoing lung cancer surgery had mediastinal staging prior. That's unacceptable. So the evidence for EBUS-TBNA is actually quite excellent for multiple different studies that its ability to pick up nodal mets from non-pulmonary tumors is quite high. And when you look at for lung cancer, it's quite high. In higher, actually, than CT and PET. Actually higher than what we see in mediastenoscopy. One of the best studies ever done was done by a thoracic surgeon, Doctor Yasafuku, in Toronto, and but used to be at Shiva University and probably is the world's premier EBUS physician. He's also one heck of a thoracic surgeon. So he looked at CTs and PETs on all his patients and then did EBUS-TBNA and then took them for surgical staging so that he could have definitive proof of what he got. And you'll notice, of course, how much superior EBUS is to just taking imaging modalities. The list goes on and on. Felix Herth in Germany also sampled multiple nodes, had some are non-diagnostic, so they do miss some, but this was ultimately the sensitivity and specificity as well as the positive predictive value. But in the total radiologically normal mediastinum, if you remember we talked about that mediastenoscopy in the past had proven that in that scroop you could still find cancer. The mean lymph node diameter was eight, so this is, of course something of that by CT criteria is not cancer. They did two aspirates per node. They saw cancer in 19 of the 100 patients. They missed it in two. These were later confirmed with Mead. And notice the definitive changing of the stage. And they avoided surgery-- actually, they did surgery on these folks in the study, but 17% of the patients could have avoided an unnecessary surgery for having been upstaged. And same with the PET negative mediastinum. So the same with this crossover study. You will notice, last, for certain nodes, and especially station seven, EBUS is way better. Obviously it's quite an easy location for EUS to hit as well. And though I will plead my complete ignorance of the US literature, if this study hasn't been done, I think it's not a major leap to say that if EBUS can hit seven better than the Mead, EUS can hit seven better than Mead. I think that's a safe assumption on my part. But what about other things? Because of course, it's not just lung cancer, though that clearly and especially lung cancer screening coming online and just being approved through CMS we're going to see more and more of this. But for lymphoma you can actually make this diagnosis. And you can gather material with an RPMI. We're also able to remove big enough cores that you can look at core nodal tissue. Sarcoid, for sarcoid now we've gotten moved away from doing transbronchial biopsies of the lung if there's lymphatanopathy, because transbronchial biopsies of the lung actually has a slightly higher complication rate than we would like. But EBUS has an almost nonexistent complication rate. [INAUDIBLE] the granular randomized clinical trials. We also have the nice-- it's not like we're using EBUS to go find PEs. Please use the CT, et cetera. But while you're in there, it's pretty shocking what you find. This was a case we did just not that long ago with someone with high prob lung cancer. And while we were busy looking, we found this nice clot. She had no symptoms and had no prior formal diagnosis of PE. She does now, though, so-- And that's all I have to add. There's a lot of more than what's going on the bronch world. But I think from an EBUS perspective, if it is something that, again, within your center that it's something you could, with the limitations and the rules of your medical center, something you could easily do, and you say well how do I learn this quickly if I already have EUS skills? There are multiple workshops. The American College of Chest Physicians puts a workshop on almost every other weekend and with high-fidelity models there are wonderful ways to learn the technique. And I think it becomes very complementary. If you have, obviously, a pulmonary colleague who has this skill set, then I think between the two of you can easily be actively involved. And if you're not currently involved with the thoracic oncology tumor board at your institution, I would strongly advise coming to those meetings, because there are plenty of people that are still going for either transthoracic approaches or surgical approaches that the people in that group that come at it from a thoracic approach do not realize how many other things can be obtained via the esophagus and the stomach, a la, you guys. That's all I have. Thanks so much.
