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BackTable / VI / Podcast / Transcript #390
Podcast Transcript: Laser Atherectomy: An Overview of the Pathfinder Registry
with Dr. Tony Das
In this episode of the BackTable Podcast, host Dr. Chris Beck discusses atherectomy, laser technologies, and their use in vessel treatment with Dr. Tony Das, an interventional cardiologist practicing in Dallas, TX and one of the founding members of the VIVA Vascular Education Course in Las Vegas. You can read the full transcript below and listen to this episode here on BackTable.com.
Table of Contents
(1) Introduction to Atherectomy: Roles & Applications
(2) Atherectomy in Various Clinical Environments
(3) Mechanisms of Laser Atherectomy: Energy Dynamics & Tissue Interaction
(4) Optimizing Laser Atherectomy: Techniques, Settings & Safety Considerations
(5) Insights from the Pathfinder Registry
(6) Laser Atherectomy & Adjunct Therapies
(7) Laser Atherectomy in Practice: Tips for Starting & Expanding Your Program
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[Dr. Chris Beck]
Ladies and gentlemen, welcome to The BackTable Podcast. If you're a new listener, welcome. For all of our regular listeners, welcome back, and thank you for listening. You can find all previous episodes of the podcast on iTunes, Spotify, or our website which is backtable.com: very easy to remember. Subscribe to the show, leave us a review, or reach out to us on social media.
My name is Chris Beck. I'm going to be your host today. I am a vascular and interventional radiologist based out of New Orleans, Louisiana. We've got an excellent topic lined up for you today. Our topic is going to be in the PAD world. We're going to be discussing atherectomy and specifically, laser atherectomy. To help us with this we have Dr. Tony Das. Tony, I got a little bit off the website, so what I'll summarize is that Tony is an interventional cardiologist and does a lot of peripheral work. Tony, I'll just leave it to you to introduce yourself and tell us a little bit about the practice.
[Dr. Tony Das]
Sure. Thank you very much, Chris. As you said, I am an interventional cardiologist. I've been doing vascular work for over 20 years. I was one of the founding members of the VIVA Vascular Education Course in Las Vegas. We just celebrated our 21st year this year, so that was a great accomplishment.
My background is that I am currently the System Chief of Development and Strategy at the Baylor Heart Hospital. I also run vascular there. My other role is Head of Digital Health and Innovation at that same center. I started a practice called Connected Cardiovascular Care Associates, which is a digital-first practice where we take digital tools and use those to evaluate and assess patients in between their office and their hospital visits. I'm based in Dallas, Texas.
[Dr. Chris Beck]
Hold on, I got to know a little bit more about that. What is that exactly like? How does that play out? I missed it. I was just hearing the regular like, "Hey, this is my practice. I'm at Baylor." Then this sounds very different.
[Dr. Tony Das]
My academic hat is strategy and business development and vascular interventions at Baylor. My practice hat, I'm in a private practice, is to try to take digital tools, whether it be wearables or other types of devices where we can manage patients with heart failure, atrial fibrillation, even vascular conditions, and untether their care. That's been an interest of mine for about a decade, and we've done a bunch of work in the wearable field doing that. This practice was called Connected Cardiovascular Care for that exact reason. Incidentally, I started this particular practice after running my previous practice for over 20 years, in November of 2019, very timely, as you know what happened three months later, which was the need for telemedicine and remote care. It was somewhat fortuitous to start this at that time.
[Dr. Chris Beck]
You were at the right place for a while. You just had to wait for the right time.
[Dr. Tony Das]
Now, I think you're right about that.
(1) Introduction to Atherectomy: Roles & Applications
[Dr. Chris Beck]
Well, that's very cool. We may come back to that because that's a juicy topic in and of itself. Let's jump into it. Without getting too far ahead of ourselves, what I wanted to do is just set the scene. We're going to skip a lot of stuff talking about peripheral arterial disease: how important it is, the prevalence, referral patterns, and all that stuff. We've got a lot of content on that, and I'll add a link to some other episodes where we talk about that.
I do want to get into the meat of it. I do want to set the scene as far as just broad strokes atherectomy, Tony. How do you think about it and how does it fit into your practice? By that I mean, who's getting atherectomy versus who's not getting atherectomy? You have a lot of choices with atherectomy. What's your thought process there?
[Dr. Tony Das]
That's a great question. For some people, atherectomy is a little bit more of a religion than a science. You believe in it. There may not be quite as much science as you'd like, but over time, we've continued to develop the science in this space. I think of atherectomy as an adjunctive tool. It rarely is a standalone. I think that there are lesions that really require a change in their overall response to balloon angioplasty or stenting, meaning we want to change their compliance. We use that as a broad term, but calcified lesions, we want to do something to make them less likely to dissect and have complications from balloon angioplasty. More fibrotic lesions or in-stent restenosis, we want to ablate some of that plaque. I think of it as an enabling tool. Depending on the type of lesion we're talking about, different forms of atherectomy seem to make more sense. We can talk a little bit about where we want to use certain types and where other types may be more helpful.
[Dr. Chris Beck]
For sure. One of the things I want to get at is atherectomy as an adjunct. In your practice, there's atherectomy plus. Let's exclude stenting for a second. Is it atherectomy plus POBO or atherectomy plus DCB? It depends on where? It depends on?
[Dr. Tony Das]
Yes. It depends a little bit on where, but I think that the DCB data has gotten so strong, and we finally put to bed the issue of whether there was a mortality signal for DCB. I think that's a topic that really sidetracked us for about two years. Now we understand that this is a safe technology. It's a durable technology. For me, typically, if the balloon sizes exist, especially in the above-the-knee territory, it's atherectomy plus drug-eluting balloon for the majority of the cases.
[Dr. Chris Beck]
I know that people can give whole lectures on this, but if you want to talk about the different choices that we have with atherectomy? Then, we'll zero in on where you like laser, and then for what reasons.
[Dr. Tony Das]
Just to put it in broad terms. Ablative technologies come in a couple of different flavors. There's rotational atherectomy. For those of us that are cardiologists, we used Rotablator even before there was any form of atherectomy for the lower extremity. Those were devices that had a diamond-tipped burr, and we used those to rotate it at 150,000, 160,000 RPMs. We used them for calcified lesions, and usually smaller vessels down into the tibialis, especially. Then came orbital atherectomy, which could give you a much larger lumen because the crown itself was rotating off-center, and so you could get larger lumens. We tend to use those in more calcified plaque as well. When there's more soft plaque, and there's a need for excising or blading, we use laser for in-stent restenosis.
We have proved that in a couple of different trials. Excisional atherectomy with eccentric plaque ablation like SilverHawk and the eccentric plaque, of those types, is how I think about it. Now, you can overlap those in different places. I think there's a need for some of those, but for the most part, if you have something that's fibrotic and soft, you tend not to want to use orbital. If you have things that are more fibrotic and hard, you might want to use that. I use lasers a lot. I use a laser to sort of change the compliance of the vessel, whether it's moderately calcified or fibrotic. In-stent restenosis, I almost exclusively use it there.
[Dr. Chris Beck]
We talked about broad strokes about different atherectomy devices and where and what types of lesions. What we didn't mention though is where you like each one. Maybe you divide it between above the knee and below the knee? This device if we're in smaller vessels, this device for bigger vessels, all things being equal? Is it more hard, soft discussion?
[Dr. Tony Das]
I think for me it's a little bit more above the knee and below the knee. It really does break back into hard and soft. Because if I got calcified, my tendency is to use something that's going to be more ablative, orbital atherectomy or even excisional atherectomy, but soft plaque, you can use pretty much anything there. What we've learned is the higher energies that laser atherectomy can afford us, even calcified plaque can be well suited for that. In the very small, very heavily calcified, we have the ability to use very high energies for laser, and that does change the compliance for those.
I think it's a little bit of both of those topics. Above the knee, I like using excisional atherectomy, and I also like to use orbital atherectomy. In the SFA, it can be a combination. Sometimes laser for instant resinosis or fibrotic tissue. Sometimes orbital atherectomy for more calcified but less fibrotic and soft. For in-stent, it is almost always laser. Then below the knee, you can use actually any one of those types. I tend to use a laser below the knee a fair amount because the lesions are pretty fibrotic. They're diffused. They're long. Oftentimes, they're calcified. Oftentimes, the only thing that will go through after a wire goes through is a laser because you don't have to change to a different type of wire. That's one big advantage of using something that doesn't require a unique wire to be able to deploy it.
[Dr. Chris Beck]
I'm going to sidetrack you for a second. When you're above the knee, do you like to use distal protection?
[Dr. Tony Das]
That's a good question. In the laser trials, we've seen that the amount of distal embolization is actually very minimal. We know when you compare all of the different devices, there's about an 11% chance that anything and everything is going to embolize. I think that if I have a lot of debris, that potential, and not just more focal lesions, I will use distal protection, but probably that's only about 15% to 20% of the time. More often than not, I won't use it because we just don't see that much distal embolization, particularly with ablative techniques like laser.
(2) Atherectomy in Various Clinical Environments
[Dr. Chris Beck]
Got it. As a backup, I'm going to ask you about your practice again. Do you have some patients that you see in the hospital and some patients that are in an outpatient-based lab situation, both venues?
[Dr. Tony Das]
I do. I have been part of an outpatient OBL now, a hybrid lab, ASC OBL, since 2011. We've also done plenty of procedures in the hospital outpatient department and inpatients as well. I'd say it's probably about 25% are in the outpatient lab. That's mainly because of our scheduling issues, but a lot of it's our collective outpatients down at the hospital as well.
[Dr. Chris Beck]
The reason I ask is that we have a fair number of viewers who have their own labs or want their own OBLs. I was just going to ask for that particular audience niche, if you had to choose one atherectomy device, two, or what's your recommendation? If you have a lab and there's constraints with money, experience, maybe even storage, how many devices do you recommend having on hand? Or is it just, “get to know one really well and this will serve you?"
[Dr. Tony Das]
Yes, that's a good question, and I think it's one that probably requires an answer that hedges this a little bit. Because I think you need something that really does affect calcium, and then you need something that affects all long ablative. I would use laser, which I use the majority of my atherectomy is with laser, mainly because I think it works in a lot of different areas in the lower extremity. Then, there are times when you just need something that's going to take care of calcium in a more focal lesion. Now the interesting thing is that answer has changed a little bit since we added shockwave to the mix. There are times when we add lithotripsy at common femorals when we previously would have done ablative therapy followed by drug-eluting balloons. That answer may have changed a little bit now.
(3) Mechanisms of Laser Atherectomy: Energy Dynamics & Tissue Interaction
[Dr. Chris Beck]
Can you talk a little bit about the mechanism of action for laser atherectomy? I wouldn't pretend to be proficient, but some of the things that I've seen are photochemical, photothermal, photomechanical, and for me, some of these definitions overlap a little bit. I'd like to hear from your perspective, how does it work, and what's going on behind the scenes of the tech?
[Dr. Tony Das]
Yes, that's a great question. You have to become a little bit of a physics nerd to understand exactly what's happening with laser. I think that the important thing here is to understand that the mechanism really does also beget the technique. Because if you think about what you're doing, you're creating energy. There's several kinds of lasers. We've been used to using the Spectrometric Phillips laser, which is an Excimer laser, also known as Excited Dimer. Two gases that basically interact together and create this energy, and that energy that's created comes at a certain wavelength. Because of that, it has certain interactions with tissue.
The general idea is that you create an energy, it comes out at a certain pulse width, it has a certain repetition, and it's at a certain density, meaning millijoules per millimeter squared. If you take all those things into account, you're basically taking the heat of the laser and its quick dissipation, how it interacts with the tissue, and each of the carbon-carbon bonds of the plaque are being affected by the photomechanical properties of the laser. So, photothermal, photomechanical: we talk about all of those because they are overlapping, but in general what we're doing is we're trying to take plaque and we're trying to change its morphology from a solid surface of maybe a fiber surface into carbon dioxide and water. We vaporize that and basically let that dissipate through the blood. That's the goal for laser atherectomy. Does that make sense?
[Dr. Chris Beck]
Yes, as much as it can for a blockhead like me. I'm hoping it makes more sense for our educated, very intelligent audience out there. With laser, and maybe it depends on the device and certainly most likely depends on the size of the device that you're using, are there laser components with also suction or aspiration? Like it's got an aspiration component to the device?
[Dr. Tony Das]
Yes, so the Auryon laser is a laser that does that. The 2.0 and the 2.3 versions do have the ability for thrombectomy. If you think about one other thing that laser does in addition to changing how the plaque is going to behave, it also vaporizes thrombus, and this is actually a really unique property of laser. Because of the actual wavelength that it sits at, it has a very strong interaction between the thrombus and the device. If you take, for instance, platelets and you put them into a petri dish, and you apply laser to them at higher and higher energies, the ADP aggregation of those platelets will actually decrease, so there's a direct effect on platelet aggregation.
You can imagine if you have a thrombotic lesion and you apply laser energy at a certain wavelength, roughly between 305 to 355 nanometers, you're going to vaporize some of that thrombus. If you have the additional ability to remove that by thrombectomy, which the Auryon laser does, you get the additive benefit, changing the thrombus morphology, vaporizing it, decreasing its likelihood of platelet interaction, and then actually sucking it out. It's worth thinking about that science a little bit when you're doing the procedures, especially because many of these lesions are a combination of occlusive and thrombotic disease, and you really don't know what you're running into until you run a laser through it, what I say, uncover the lesion.
[Dr. Chris Beck]
Just by running the laser through it, you uncover actually what you're dealing with? After you do your next run, you see what really was thrombotic, and actually what was your occlusive disease or your underlying peripheral vascular disease.
[Dr. Tony Das]
That's exactly right. You can have a long SFA occlusion, and after you wire it, instead of just ballooning it blindly, you take a laser through there, and you vaporize as much of the thrombus, and you uncover where the actual lesions are. It really does reduce the amount of adjunctive therapy. Certainly, stenting is reduced by doing that because you can tell there's places that just don't need it at all because they're actually pretty wide open, and the laser uncovered that.
(4) Optimizing Laser Atherectomy: Techniques, Settings & Safety Considerations
[Dr. Chris Beck]
Going back to just the nuts and bolts of actually using laser atherectomy. You can change the scenario if it helps, Tony. You have a lesion. You cross. Do you have to stay intraluminal to be able to run the laser through? Do you have to be intraluminal throughout the entire course of the lesion to run the laser?
[Dr. Tony Das]
Yes, I think it's preferable. We frequently are very close. You may be in and out, in and out, in and out. It's like golf. You want to end up luminally, and you want to start off luminally. In between, you may be off the course a little bit, but you just don't want to be so far off that you can't get back into the segment that you're interested in. For the most part, I don't worry too much about being mildly extraluminal, but certainly you don't want to be very far out. When you do SFA occlusive work, for a long time, you start to get a sense of what you can and can't do. Most of the time, being luminal is the goal.
[Dr. Chris Beck]
Then the platforms available, is it all over an O1-4 system?
[Dr. Tony Das]
No. The O1-4 system for the Auryon laser, yes. Other lasers you can go up to an O3-5 system. Typically, we like to stick with O1-4 because the other ability you have there is to actually inject saline while you're doing it. Back to the science of laser, the interaction between the laser and contrast and the creation of microcavitation bubbles is very different between the interaction of laser and water and the size and the energy that those microcavitation bubbles actually dissipate at. You can reduce dissection and other problems if you have the ability to inject saline at the same time.
[Dr. Chris Beck]
Okay. Is it where you just hook it up to a pressure bag?
[Dr. Tony Das]
Yes, we inject by hand. I have the tech injecting one cc per second at that speed.
[Dr. Chris Beck]
Got it. We've mentioned different wavelengths. Do you have to pick that setting, or is every device that you pull open set to a certain setting? Is there anything that you have to tweak on your end?
[Dr. Tony Das]
Right. There's a couple of settings that you do tweak, but for the most part, there's really one wavelength. Because whatever the device is, say, for instance, if it's an Excimer laser, it's 308 nanometers per second. If it's the Auryon solid-state laser, it's 355 nanometers, because they use different agents to get to that wavelength. That's already set and that's what's going to end up happening.
The changes that you can make are the repetitions per second and the energy density or the millijoules per millimeter squared. I think that those are the two things that you change slightly in these different types of lasers.
[Dr. Chris Beck]
How might you change them to make a difference in what you're trying to achieve as far as the end result?
[Dr. Tony Das]
If you're looking at the repetition rate, the faster the repetition rate, the more energy that you're generating in one-second impulse. The Auryon laser, those are basically in that 40 range. The millijoules per millimeter squared are the energy density. The Auryon laser is 50 or 60.
In the Spectrometric Philips laser, the two things that you change are the repetitions, how quickly it's going to fire every second, and also the energy density or the joules. You can go anywhere from 45 millijoules per millimeter squared to 80 millijoules per millimeter squared, and then up to 25 repetitions per second all the way up to 80 repetitions per second. In the Auryon, you just have two settings, and that's the 50 and the 60. It actually works very nicely because it's set. Because they have different pulse amplitudes.
Not to get too nerdy about this, but the fact is that, if you have the ability to deliver an energy pulse in a very short period of time, you can get a high energy in that second. The more quickly you do it, the more energy is dissipating the plaque and the less energy that's actually acting on the vessel. That's why safety is so important with laser and is so likely to happen is because of the way it gets delivered. The Auryon laser does that very nicely because it's at 40 nanoseconds. It's very quick, high amplitude, and you get the energy to the plaque and not so much energy to the vessel wall. I think that the Pathfinder study basically suggested that that's why safety was so high, over 95% in those patients.
(5) Insights from the Pathfinder Registry
[Dr. Chris Beck]
Actually, this is a perfect shoehorn into talking about the Pathfinder data. Will you talk about the study, what it was set up for? Set the scene for the study, what were the goals, and, ultimately, what were the results?
[Dr. Tony Das]
Sure. It was a prospective study. It was single-armed, multi-center. I think there were 10 centers in total. Open label. It was a registry.
[Dr. Chris Beck]
Were you guys a center?
[Dr. Tony Das]
We were, yes. What we wanted to accomplish is safety and efficacy. Efficacy essentially was the idea that you finish the procedure, including the laser and any adjunctive therapy that you wanted to use with a less than 30% residual. Then, the safety was that you had no major adverse limb events or major adverse events in the actual time frame of the procedure. Death, lower extremity amputation, and all the usual things that you would think about.
102 patients were enrolled. Typical demographics that you would think for vascular patients. 121 lesions were treated. Essentially, the lesions were in that 15-centimeter range, relatively typical, long-length lesions. They were Rutherford categories 2 through 5, excluding the 6s and excluding the 1s. Essentially, it met its endpoints. Safety and efficacy in those patients.
We can go over the numbers in more detail, but essentially, it was to take a look at a laser that was very different from the ones that we're used to. The reason I want to emphasize that is because even though the wavelength was in the same neighborhood, 355 versus 308, this is a solid-state laser, which means it uses not those noble gases like the Excimer laser does, but it uses solid-state crystals. It's a very stable type of device, and it's a simple plug-in, 110-volt plug-in. You don't have to use the more complex equipment. It's a smaller, more nimble, unit because it doesn't have to enclose those gases inside of the actual zamboni, that we call it. I think it's a little bit different than the Excimer laser that we're typically used to. Although we use the word laser generically, there's some specifics. They do work very differently. I think that the idea here was, is this very unique laser science, is it safe and is it efficacious in these patients? It turned out that it really was.
[Dr. Chris Beck]
Let's just start with safety. How safe was it?
[Dr. Tony Das]
95% of the patients had no untoward events after the procedure, and that includes the big things that we talked about: death, lower extremity amputation, et cetera. In that setting, we would think that there would be things like distal embolization requiring a surgery, all those things, but that happened less than 5% of the time in a very broad category of patients. Safety was certainly met.
[Dr. Chris Beck]
I did look over the paper. One thing that did strike me was that, at least for the demographics, it's not like chip shots were chosen. I feel like the demographics were really what you might see in any robust peripheral arterial practice. It wasn't just set up for the short segment, 70% SFA or stenosis. You had long segments. You also had relatively well represented as far as severity of disease. Was that intentional? Is that just what you could enroll and otherwise enrollment would just take too long?
[Dr. Tony Das]
If you think about it, one of the things that's a beauty of registries is that they're real world. Here's a situation in which you can't really cherry-pick the lesions if you want to enroll into the trial. The demographics are essentially what you would expect. Mostly males, I think 70% were males, 40% were females. There was some diversity in this overall population, not as much as we'd like to see, but there definitely was. Then, all the usual comorbidities; people had 50% had coronary disease, hypertension, hyperlipidemia, et cetera. If you look at the Rutherford categories that were 3, 4, and 5, that was 88% of the patients. Very few were Rutherford 2, which was only 5%. Even though they were included, it was a minority of the patients. These patients had pretty significant low-performing, walking questionnaire scores. Less than 39% low-performing patients in the majority of the patients, 82% of them had that.
Pretty important. You were describing the lesions. These lesions were either de novo or restenotic. Most of them were de novo lesions, about 70%, and restenotic lesions about 17%. They were relatively long. These were lesions that were an average of 14 centimeters length and then they went up to 40-centimeters length overall size and length. This was not a cherry-picked type of registry at all, just like you mentioned.
[Dr. Chris Beck]
We talked about safety. Efficacy- How does it do?
[Dr. Tony Das]
In all the subject patients, almost 70% of these patients reached the efficacy of less than 30% at the time of the procedure. That included the adjunctive therapies. What's super interesting is that at the 6-month and 12-month timeframes, it actually remained at that amount of patency as well. That's the part that was interesting to me. If you look at the ABIs at baseline 6-months and 12-months, they improved over time. You look at the ABI and TBIs. If you look at the walking questionnaires, they all tend to stay good over time. In addition to that, the patency rates also stayed quite good. If you look at the initial amount, it was 70%. Then at 6 months and 12 months, the number of patients that were occlusive were in the 10 to 15% range, which means that they actually stayed open over this period of time, which is very unusual for long lesions like this.
(6) Laser Atherectomy & Adjunct Therapies
[Dr. Chris Beck]
One of the things that stuck out to me was the adjunct treatments following atherectomy. You can correct me if I got this wrong, but roughly 25% DCBs afterwards. Does that mirror your practice, that a lot of its POBA follows atherectomy?
[Dr. Tony Das]
I don't know if this was broken down into above-the-knee and below-the-knee. I think that below-the-knee, we don't really have drug-eluting balloons that were available at that time and really don't even now have small drug-eluting balloons. If you look at the majority of these, 70-something-% were SFA and popliteal, and then about 25% or 30% were below the knee. That might have been a reason for some of this drug-eluting balloon use. The other thing that you may have noticed was how few of these patients actually got stents.
[Dr. Chris Beck]
Yes. My thought was that you're dealing with 10 centers, but maybe it was a no metal left behind approach or there was a concerted effort not to drop stents in this. Can you speak a little bit to that and laser's role in reducing barotrauma? I guess you're priming the vessel so that you're set up for less dissections once you actually get into the plasty portion of the procedure.
[Dr. Tony Das]
Yes, for sure. We've had a couple of trials over the years that have suggested that atherectomy in general and laser in specific can change the compliance of a vessel and also reduce the dissections. That's been shown in smaller studies and also over time. This proved that out a little bit in that there is a change to the compliance, probably a reduction in the mean balloon pressure required, the dissection rate, and the need for bailout stenting.
If you think about the bare metal stent use here, it was about 30%. I think that in general, what we see is that those that are proponents of atherectomy are also proponents against long segment stenting. That's not a hard and fast rule, but we definitely do see that when you use atherectomy, you tend to stent a little bit less. As we've gotten better tools for drug elution, I think that's continued to be probably more so than even in the last decade when we didn't have drug elution.
[Dr. Chris Beck]
With the paper that's been put out now, is there anything that we didn't talk about that I missed or some portion of the paper that we haven't talked about that you think was important to bring up?
[Dr. Tony Das]
I think that in general, the length of the lesions and the all comers really does play into the fact that this device is safe and efficacious for pretty much anything that you want to throw at it. I think that really is hard to tell in some of the studies that we do for specific devices where the inclusion criteria are so specific, you can't really tell whether it's broadly applicable. Which is here, you've got patients that had tibial disease, patients that have SFA disease, you had long lesions, you had all of these different categories of 102 patients, with 120 plus lesions. You could see that it performed across the board. I don't think there's a lot of devices that we see that really can take the information from a trial that has very specific inclusion and exclusion criteria and then broadly apply them. Sometimes I think we need these multicenter or these single-arm perspective registries to be able to tell, what are these devices going to do in the real world? I think this is probably an indication this is a real world device.
[Dr. Chris Beck]
That's cool. Is this the end of the registry in the Pathfinder data? Or is it, "Hey, we're looking at 24, 36--?" Is there anything else playing for this data or just continued ongoing enrollment or anything like that?
[Dr. Tony Das]
No continued ongoing enrollment. I think that the trial was designed and budgeted for a 6 and 12 month timeframe. I think that other adjunctive studies could be done. With this particular data, I think this is the conclusion of what was intended. Is there safety? Is there efficacy? Could it be broadly used for all comers? I think it did prove out those things.
(7) Laser Atherectomy in Practice: Tips for Starting & Expanding Your Program
[Dr. Chris Beck]
All right. Very nice. Let me switch gears a little bit off the data. I just want to ask, if you had to give some advice to someone who's just starting out their practice, whether it's hospital based or OBL based, and they've read the paper or in training, they liked using a couple different atherectomy dice included, which is laser, what advice could you give them about building an atherectomy program around laser? What would you say? "Hey, this is what you need to have. This is the things you need to think about." Just advice you might give like a young colleague.
[Dr. Tony Das]
Sure. It's a good question. I think for the most part, being too prescriptive is a little tricky. On the other hand, you need ablative technology in the OBL and ASC because it's what you have in the hospital outpatient department. You cannot be without. It's nice to have a system that does ablative therapy as well as thrombus removal, like for instance, the Auryon laser does. That is an advantage that I think that I would definitely consider. If I was just counseling somebody on what they should have, they should have a laser and they should have one calcium ablative technology in the outpatient lab. Those two things would get you through 99% of the lesions that you're going to deal with.
[Dr. Chris Beck]
I hope that people heard that because sometimes it's like paralysis analysis. You have so much at your disposal and then each device has its own research associated with it. Sometimes it's nice to know that, breaking the two broad categories, you can have this and you can have that. That's going to get you through greater than 90% of the cases that will come at you.
Another question in that vein. Someone who's a little bit further along and is looking to dig a little bit more into the data behind laser atherectomy. Do you have some recommendations or resources that you could recommend to them? Like, "Hey, look, these are the papers that are going to talk about this stuff, and talk about ways you can counsel your patients or talk about outcomes that you can expect.” Basically, the papers that let if you're on the right track?
[Dr. Tony Das]
I think there's a fair number. If you go back to the Spectrometrics laser data, it started with LACI, which was a laser atherectomy for critical limb ischemia patients. Essentially, in those papers, we were looking at whether patients would benefit from a reduction in amputation. If you look at that, it was a significant benefit for adding laser into those patients.
Then, it led to two other sets of papers, including the SFA in-stent restenosis Excimer laser trials. Those showed that laser, in addition to balloon angioplasty, unfortunately, at that time, we didn't have any drug-eluting balloons, did improve. The problem there is that the long-term restenosis rate was still quite high. We did a trial using cryoplasty and laser and showed that in that trial that there was a significant reduction in patients that were diabetic in greater than 20-centimeter long lesions and the restenosis rates were almost halved in the secondary restenosis in the cryoplasty trial.
Then, if you go back even further, if you look at the long laser trials that were done with Giancarlo, Biamino, and some of the real pioneers in that space, those trials suggested that there were so many different adjunctive therapies that you couldn't really tell what the laser really did in those. I said, back to laser has a little bit more religion sometimes than science, but it definitely works. If we go into the physics of it, you can see why I think it does. Certainly, the experience we've had in thousands of laser cases over the years is that it changes the compliance, it reduces the stent use, it decreases the likelihood of distal embolization, and it enhances the thrombus removal and uncovers the lesion. If you want those things in your procedure, you probably want to think about using it.
[Dr. Chris Beck]
All right. That seems like a pretty good note to end on. Tony, I will leave it to you. Final thoughts, anything that I didn't ask that you're like, "Man, this is really something we should have covered?" Did we cover it?
[Dr. Tony Das]
No, I think you nailed it. I think that the science behind laser and also what data that we have, whatever little data sometimes there is, to be able to extrapolate from is always helpful. Maybe we'll come back and talk about what we're doing over here on the digital aspect sometime. That might be a fun one to do as well.
[Dr. Chris Beck]
Man, even when you brought it up at the very beginning of the podcast, I was thinking that would be so cool to talk about. We have BackTable Innovations where we talk about just this kind of stuff. It's not always related to the vascular and interventional space, but a lot of times it is because that's what a lot of the hosts have their background in. That may be like a perfect setting to come and talk about what you guys have going on with that.
[Dr. Tony Das]
That sounds great. We've done a lot of remote monitoring and chronic care management and really have learned a lot. I actually got the highest sensitivity and specificity AFib device through the FDA a couple of years ago that we're using in a trial right now with Pfizer. I think it'd be a fun topic to talk about, especially because there's so much AI being added to it. That term is being overused so much. It's probably worth defining what exactly that means. I'd love to do it if you want to at some point.
[Dr. Chris Beck]
Tony, that would be great. We would love to have you on for that. The Innovation Show- It's also just really cool to talk about- You talked about getting something through FDA approval, like it's just a side of the medicine world that a lot of people don't have any idea about and the amount of gumption and hard work that it takes to bring devices to either market or just through FDA approval, some of those are just incredibly harrowing stories about very dedicated docs like yourself. Thanks for doing that work.
For those of you that would like to support the show, please like, subscribe, or rate the show on Apple iTunes. That helps us. Feel free to go old school, just actually talk to another human and tell a colleague about BackTable. We already mentioned the Innovation Show, but we also have BackTable MSK, BackTable Urology, BackTable ENT, OBGYN. A lot of good stuff. Tell your colleagues about it. We'd love to increase our audience. If you have any ways that you would like us to improve the show, send that to us via social media. We always take that input very seriously. Thank you guys again for listening. Tony, thanks for coming on the show.
[Dr. Tony Das]
Hey, Chris, thank you for having me, appreciate it.
Podcast Contributors
Dr. Tony Das
Dr. Tony Das is an interventional cardiologist and the founder and CEO of Connected Cardiovascular Care Associates in Dallas, Texas.
Dr. Christopher Beck
Dr. Chris Beck is a practicing interventional radiologist with Regional Radiology Group in New Orleans.
Cite This Podcast
BackTable, LLC (Producer). (2023, December 4). Ep. 390 – Laser Atherectomy: An Overview of the Pathfinder Registry [Audio podcast]. Retrieved from https://www.backtable.com
Disclaimer: The Materials available on BackTable.com are for informational and educational purposes only and are not a substitute for the professional judgment of a healthcare professional in diagnosing and treating patients. The opinions expressed by participants of the BackTable Podcast belong solely to the participants, and do not necessarily reflect the views of BackTable.
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