BackTable / VI / Podcast / Transcript #320

Podcast Transcript: Appropriate Use of IVUS in Lower Extremity Interventions: Expert Consensus

with Dr. Eric Secemsky

In this episode, host Dr. Sabeen Dhand interviews interventional cardiologist Dr. Eric Secemsky about the role of intravascular ultrasound in lower extremity interventions, and how he published a consensus document to standardize its use across specialties and provide a framework for new users. You can read the full transcript below and listen to this episode here on BackTable.com.

(1) Arterial and Venous Application of IVUS

(2) Benefits of IVUS Across Specialties

(3) Barriers to IVUS Implementation

(4) IVUS Consensus Guidelines

(5) Other Imaging Modalities

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[Dr. Sabeen Dhand]
Hello, everyone, and welcome to BackTable, your source for all things endovascular and more. You can find all previous episodes of our podcast on any platform like Spotify, or even our website, backtable.com. You can follow us on Twitter, Instagram, or LinkedIn, keep up with the latest updates, and give us feedback through comments.

[Dr. Sabeen Dhand]
I'm Sabeen as your host today, and I'm so happy to welcome back my talented, prolific, and just straight-up amazing friend, Dr. Eric Secemsky, from Beth Israel Deaconess in Boston. Welcome, Eric.

[Dr. Eric Secemsky]:
Thanks, Sabeen. Awesome to be back on the show.

[Dr. Sabeen Dhand]
Absolutely. Last time we talked, we talked about PE and PE response teams. That was back in episode 120, April of 2021. That was a while ago. Any big changes in your practice over the last two years?

[Dr. Eric Secemsky]
No. It's great to get an opportunity to talk about things I'm passionate about. I would say PE and IVUS are probably in the top three things that I think about on a daily basis. The PE world, as you've watched, has really evolved, and continues to. We've got some big years coming up. While that's been going on, we've really moved into a new phase in endovascular treatment for peripheral disease, with the role of IVUS becoming a real hot topic, and an area that I personally have been really invested in.

BackTable always gets the hottest of things going on, really, the leaders in the field, so it's a privilege to be here and to be speaking about IVUS this time and following up our PE conversation.

(1) Arterial and Venous Application of IVUS

[Dr. Sabeen Dhand]
Let's talk about IVUS. I personally used to use IVUS sporadically when I first started my practice, and about a year and a half ago, we upgraded our system and got a really much more newer generation of IVUS, which has been a lot better. Are you using IVUS for both artery and veins and everything far in between?

[Dr. Eric Secemsky]
Yeah, it's always interesting to talk to an interventional cardiologist about IVUS, because most interventionists in training right now, or in practice, have a specific focus on intravascular imaging during coronary procedures. We use IVUS liberally. I mean I would say in my own practice, 70% to 80% of my coronary interventions are performed by IVUS guidance. In the world of coronary intervention, you're applauded when you use IVUS.

It's something that you wear as a badge of honor, for having taken the extra time to use a device that is making the procedure safer and outcomes better. I spent a lot of time using IVUS in the coronary. When I trained on venous work, we did a lot of IVUS on venous work, and then we had a smattering of IVUS during our peripheral artery interventions. That wasn't as routine back when I was training, years ago now.

But again, as you use this device more and more, you get more comfortable with it, to the point where I don't even feel comfortable doing some procedures without IVUS. It started to become kind of light bulb to say, "I should be thinking about this more in my arterial interventions, doing a little bit more on the venous interventions, exploring where else this device can really help optimize care for patients."

Really, the goal, obviously, is to make our procedures durable, and particularly in the endovascular world, I think this was really a moment for me to say, "I think I can do better with this device as a guidance."

[Dr. Sabeen Dhand]
When you're using it for coronary, I mean what are you looking at in IVUS? Are you just looking at sizing? Tell me, what are the things that are going through your head one, two, three, four, five, when you're looking at an IVUS image?

[Dr. Eric Secemsky]
Yeah, in the coronary space, it's pretty well regimented into how we perform IVUS. On the normal case, you cross the lesion with the wire, and you IVUS. On your IVUS, you get a couple of things. You get lesion length, so you get healthy to healthy reference. You get the vessel diameter so that you can size your pre-do balloon, and then we always stent in the coronary, so our coronary stent. Then you get an understanding of the plaque composition.

In particular, for coronary, it's calcium. How much calcium? What's the arc? If it's 360 degrees, we know that we probably have to do something to modify that calcium, to get a stent in. So every coronary intervention that uses IVUS kinda follows that same routine. We're very regimented in the coronary. When you look at coronary cases, you could be across the country, or even the world, we do things almost the same, in Boston as in the Netherlands, or where else.

It's really interesting because in the peripheral, we know that's not the same, and we'll talk a little bit about that later. Then you do your ballooning. Usually, if you feel comfortable with how your balloon looks, you put in your stent, and then you IVUS again. When you IVUS again, you're trying to optimize the stent at position. You want to make sure that there's no malposition, or under-expansion.

Then, for me, you're looking at the edges of the stent and make sure there's no dissection. When I walk away from a coronary procedure with a clear IVUS run, showing a good stent, no problems, I'm sleeping better. I always joke about this to my fellows, because we always get these calls, "Oh, they're having a little bit of chest pain, or their blood pressures--" Listen, I feel very confident based on how I left the lab, that that stent's looking good.

[Dr. Sabeen Dhand]
That stent is perfect, basically.

[Dr. Eric Secemsky]
That stent's per area. Got my stamp on it.

[Dr. Sabeen Dhand]
Now, a little bit of a peculiarity, because now I'm using IVUS almost on every intervention, too. When you're measuring the size in a coronary, or what we're going to extrapolate to peripheral soon, I mean you see the round ring of calcium. Usually, most arteries are calcified, what we're treating. Are you measuring on the outside of the ring, on the inside, in the middle? It makes a difference. I mean, we're talking about 0.5 mm, or a millimeter, which makes a difference in our sizing. So where exactly are you measuring?

[Dr. Eric Secemsky]
Yeah, that’s a continued debate about what's the right way. I think we're both on the same page for arterial sizing. Ideally, you're trying to identify the three layers of the vessel wall. In the coronary, we're really looking to size to that black stripe that happens behind the intima. That's the elastic membrane, and you want to size to that. Now, again, in the corner, though, it's a balloon-mounted stent and you deploy it, that's where you deploy that.

If you're sizing to the elastic membrane, that's fine, but you're doing that differently than when you have an outward force from a self-expanding stent, or if you're not stenting, just ballooning. A lot of times, minus the calcium, if I'm making a measurement of the arterial vessel in the periphery, I'm usually doing a luminal diameter, or extending it maybe a quarter millimeter longer than the luminal diameter of a healthy reference. That's pretty much how I do my measurements.

Keeping in mind that, again, a lot of the self-expanding stents we'll use, but even for one-to-one sizing, or 1.2-to-one sizing for balloon angioplasty.

[Dr. Sabeen Dhand]
Sometimes, I'm a little confused, like, "Oh, should I go--? What part of the vessel should I measure?" Now it's nice, I can measure myself on the system that I have, where I have the tablet in my sterile field. Before, I was using this trackball, and not I was, my techs would use it, and they would measure from the thigh skin to the middle of the vessel. There was no control of it.

[Dr. Eric Secemsky]
It makes a world of difference, how much easier you can do it. Again, I'm a little bit spoiled, because I have a fellow that's usually doing the pullback, and I'm just making bookmarks. I'm telling them to stop, I’ll fluoro-save a healthy reference or section on IVUS. The whole thing goes really quickly when you get used to it. My humble opinion is that I make a smarter device selection after that.

Usually, I don't necessarily dilate anymore. I'm just using one balloon that sized off IVUS. It definitely makes my procedure more efficient.

(2) Benefits of IVUS Across Specialties

[Dr. Sabeen Dhand]
Absolutely. It's been a whole difference to me now, the past year, having this new system, and it's just been tremendously helpful having that fellow or doing it yourself, rather than just relying on nothing. You've released an article last year, about the benefit of IVUS. Tell me how you organized the data, and what it really said. Just give us a little summary first, and we'll dive into it.

[Dr. Eric Secemsky]
Yeah so, I think the big question we ran into is-- We've got a lot of great studies that have come out, supporting IVUS, use is up, in particular, in the venous side, use is very high in the venous side, but we've got many specialties performing procedures in different ways, for different indications. So, this is one of those situations where we step back, and we all love randomized trials. I love randomized trials. This is such a mature field. It's a safe device.

Again, as you even speak about in your own experience, once you start using it, you see the benefit of it, was-- How do we harmonize this across specialties, across arterial and venous beds? Harmonize the data, harmonize expert opinion, and create a little bit of a guide for new users to follow, and feel that they are doing things in line with more experienced users. I think that was really the origin of how we put together this consensus document.

[Dr. Sabeen Dhand]
Exactly, how many people did you have? Tell me about your data.

[Dr. Eric Secemsky]
Yeah. Most important thing was, it had to be representative of all specialties practicing in our field and that was the number one key for this. It had to be completely independent of any external industry relationships. How this started was a conversation, honestly, with Phillips in Boston, about how do we create a better template, a better format for incorporating IVUS, and the appropriateness of IVUS in lower extremity interventions.

Myself, Sahil Parikh at Columbia, Ken Rosenfield at Mass General, created a 12-person steering committee. This is all on the JACC Interventions publication that, hopefully, we'll be able to link to the podcast, but we had 12 members who were a mix of vascular surgeons, interventional cardiologists, interventional radiologists, and vascular medicine specialists, from both the US and abroad. We really had a well-rounded group of experts who were really experienced users, but also balanced, in terms of their perspective.

Some people felt like IVUS is important, but not for every case. Some people were more like me, where I felt like IVUS, if I could, I'd use it in every case. We tried to get a number of opinions, a number of backgrounds represented, and we dove in. Again, when someone says to you, "You should do a consensus document," I'm one of those headfirst people. I'm like, "We're doing it, I'm in," I get home and I'm smiling, I'm like, "We're doing this consensus document," I sit down on my computer, I'm like, "How do we do this?"

We went back to other consensus documents that were done. In the cardiology side, we had the American College of Cardiology, that has done several AUC, and then a society called Sky, as well. We looked at how they did that. Again, we set up some basic rules. We had to set up the framework for how the survey would be put together, and we had to create criteria, including that anybody on the writing committee can't vote. On the voting committee, no one could be, obviously, reimbursed, no one could know each other.

I had to go through several rounds to meet consensus. Then, it came down to-- How do you structure an appropriate use criteria for IVUS? And then I can probably pull 10 people in a room and say how to use IVUS, and everybody uses IVUS differently. So, one of the secret sauces in the whole project was creating three phases where we were like, "Let's focus on three important procedural parts of your intervention, where IVUS is utilized, could be utilized, or should be utilized, and we'll use it as a framework.

That was probably what I was most proud of out of this, because we created this pre-intervention phase, which was a step through on the corner side, you get the wire crossed, and then you IVUS, and now, you're evaluating again, where's a healthy reference vessel, what's the diameter? Is there a clot in the mixed plaque? That's a pre-intervention phase. We have the procedural phase, which was-- Okay, I'm going to balloon, and if it doesn't yield, I'm going to IVUS, see what I want to do next, if I want to stent.

If I debulked with atherectomy, I may go back in and make sure I did a sufficient job. Then, the post-procedural optimization phase is-- I put a stent in, let's just make sure that stent's well opposed, no complications. I've got a small dissection, let's just take a look at it, make sure it's not extending back into the media or adventitia, that I feel like I need to cover. That was probably the breakthrough with the whole document. That is probably the most under-recognized out of the whole thing.

[Dr. Sabeen Dhand]
Is that format, or that form-- You can say, is that available to other people? Could I go in my practice and have a little regimented way of how I use IVUS? You're right, all eight IRS in my practice, either some of them don't use IVUS, some of them do, and then there's some, like me, who use it all the time, but variable, even within myself.

[Dr. Eric Secemsky]
Yes, absolutely. I mean, if I could say I have one career goal, is to get all of us, me, you, all of our colleagues, vascular surgery, vascular medicine, to do superficial anything that we do in the peripheral vascular space, to get it to be done a little bit more consistently in the more standardized approach. One of the table in there, in the consensus document, walks through these three phases, and it talks about different clinical scenarios that you're looking for in each phase.

Honestly, out of all, you can cite the appropriateness, and we'll get into that in a minute, but if anything, if you're a new user, just following that first part is really helpful to standardize how you use it. Again, that's how I use almost every one of my IVUS cases now. There's always somewhere-- something happens, and I vary from it, but I would say 80%, 90% of the time, I'm doing the pre-intervention run, I'm doing the middle run, I'm doing my post and that's how I use IVUS. I think everyone in that committee agreed on it.

(3) Barriers to IVUS Implementation

[Dr. Sabeen Dhand]
That's three times you're pulling up the IVUS catheter. How much time is that adding to your intervention now? You said you have a well-oiled machine, I realize that some people don't have that. What would you say is the average time you're adding to an intervention?

[Dr. Eric Secemsky]
Yes, it's a really important question. There's a couple we recognize as barriers to implementation costs. We're lucky in the US, our reimbursement's pretty good for these devices. It's not, outside the US, and that's big trouble. Then it's the, "How do I learn how to use IVUS?" That's a big one. I got lucky because that was part of my coronary training. In peripheral, we don't really have a lot of peripheral tracks for intravascular imaging, which, hopefully, will be available in the near future.

Then the third is, "God, I have eight cases booked, and you want me to pull out IVUS three times?"

[Dr. Sabeen Dhand]
Per case, that's 24 times, we put in that rapid exchange catheter on.

[Dr. Eric Secemsky]
We did this study on the coronary side, where we have a similar technology called OCT, Optical Coherence Tomography. We did this study with Abbott, called the Light Lab, where you started to ease and increase their use of OCT to guide your coronary intervention. Then they checked metrics, how much time it took to take that, you would do one or two runs, how many devices, radiation, contrast, exposure. Everything about your procedure became more efficient when you were using intravascular imaging, compared to before.

Again, it's back to-- I only pulled one balloon, I didn't take that extra shot at contrast, because I had that great run there, and I didn't need another image. Going back to the peripheral, I can't say that it's completely time neutral, but it's in the order of minutes. I spend more time sometimes just sitting there, asking my techs to run upstairs and try to find another balloon that wasn't on my shelf or something than I'd do doing three IVUS runs.

If you're counting minutes like that, I would say this is minutes well spent because, again, you can cut down device utilization, you can cut down contrast, cut down radiation, do something better for the patient, and, potentially, improve their outcomes. I would say maybe 8 to 10 minutes I could add, if I'm doing three IVUS runs, at most.

[Dr. Sabeen Dhand]
Yes. I agree. Again, too, when I upgraded my system-- Before, it used to be a 20-minute fiasco of trying to get this, or measure, and now it's just-- It's a streamlined machine, where I think it adds a couple minutes, but I do less runs. It's so fast, and I get so much more information. I'm literally probably opening IVUS for every single PAD case I do now. Whereas before, it was probably less than 10%. It was a big change in my practice, and I love it so far.

[Dr. Eric Secemsky]
It's really remarkable. Again, the things that you stumble across, also, where you're like, "Wow, I would normally guess there." [laughs] You know what I mean? Something like-- You got a prosthetic in the way, or it's just some weird angle, and you're like, "I'm just going to look on IVUS, it's not going to lie to me."

[Dr. Sabeen Dhand]
It's positive feedback. You're like, "Oh man, I thought that was like a five-vessel, and this is like eight. What the hell?"

[Dr. Eric Secemsky]
Oh, yes. That's the best.

[Dr. Sabeen Dhand]
Oh, man. I'll be honest, I've been getting-- I know I'm focusing on PAD, because that's a part of my practice, but I've been getting more palpable pulses now. I was getting them before, but now it's just much more often. I'm just using bigger devices, and doing better treatment.

[Dr. Eric Secemsky]
I think that the long-term durability of our procedures are based on the sizes, the diameter, that we get a vessel, and that's the same idea in the corner. If we're getting better luminal gain at the end, like you said, you're going to get a bigger bounding pulse, but hopefully, a better, long-term durability.

(4) IVUS Consensus Guidelines

[Dr. Sabeen Dhand]
What are the take-home points of your consensus guideline, then? Tell me what are the major things that you guys found.

[Dr. Eric Secemsky]
After we created those phases, we had to write the whole survey. We tried to really take clinical scenarios that we encounter in our daily practice. We focused on Iliofemoral obstructive, venous obstructive disease, and then we broke up lower extremity arterial disease by iliac, fem pop, and tibial, just because they have three different-- Those are all different procedural, in the approaches. We created this really robust survey that was originally about 180 questions, for the arterial side, so 60 per vascular bed.

Then we took the survey and it took three and a half hours. Then we were like, "No one's going to do this," so we randomly picked two questions out of-- We wrote five for each scenario, so two questions. It was about a four to five minutes arterial survey, and about a little over 40 questions on the venous side, it was a little bit shorter for that one. Then we voted and nominated, and identified 15 arterial experts, who did not know each other, or at least did not know they were all participating, and then 15 venous experts.

No overlap. None of them were on the writing committee, and we sent them the survey.

[Dr. Sabeen Dhand]
That's awesome.

[Dr. Eric Secemsky]
We sent them the survey and what we get back-- I remember when we unveiled, it was September of 2021, right before we were planning to have a meeting on this, at VIVA. It was like-- Wow, everybody on this survey-- Again, we didn't know how people's IVUS experience necessarily were. We were just looking for representation from different specialties, different countries, whatnot. It was really remarkable how much people were on the same page about using IVUS, and in particular for tibial intervention.

If you look at the tables that go through the appropriateness, it is kind of green, yellow, red, appropriate, may be appropriate, not appropriate. Pretty much the whole survey is green and yellow. There's really no red, and it's all green for tibial. Everybody there who did extensive or advanced tibial work felt like IVUS was a necessary tool to get a good outcome. On the iliac side, a lot of people looked at IVUS as important for later in the procedural, so those optimization phases.

Again, I get that, there's a little bit more standardized sizing on iliacs. A lot of people use CT scans to size.

[Dr. Sabeen Dhand]
You have a CT. Yes. Exactly.

[Dr. Eric Secemsky]
Exactly. It makes more sense that it would be more of a post-procedure thing. The fem pop, it was more consistently appropriate throughout the procedure scenarios, a touch less on the pre-procedure side, where a few scenarios were maybe appropriate, but really, the take-home on this was-- Each photo contributes to score, then we take the median of all the scores. Could be seven to nine to be appropriate, all them, the medians, were eight or nine.

Just showing you that people really felt passionately about where IVUS should be used. I think we came out of it with two things. One is really a consensus, probably the first time, by multiple specialty, multiple providers, that IVUS is a mainstay in peripheral intervention now. Then the second thing was-- It did give you some granularity about where IVUS is particularly helpful, where you really should be honing in if you're a new user, or you're dabbling a little bit, where this should be the right first space to move into.

If you're doing tibial, grab the coronary IVUS from their partners in the cath lab, stick it down there, see what we've been talking about on this podcast for the last half hour, and you'll really see the value.

[Dr. Sabeen Dhand]
Yes. Exactly. I'm sure in venous, where was the most appropriate-- Probably iliofemoral, probably iliac. I mean, that one is a little different, right? I think everyone says you got to IVUS the common iliac vein.

[Dr. Eric Secemsky]
Yes. We came off at the right time with the survey, because we had the stent recall in one of the newer stents that were on the market. I had actually looked at this in Medicaid data, we were looking at deep venous stenting with IVUS, and it was like 70% of deep venous stents placed in the US for Medicaid patients, older patients had IVUS use. We focused only really on the iliofemoral disease, both nerval and thrombotic.

It was unanimous, the IVUS was an integral part of any venous intervention. I know you feel strongly, I feel strongly, that is the appropriate way to do venous work. That was less unexpected, and again, very consistent, in terms of the recommendation.

[Dr. Sabeen Dhand]
Yes, no, it's great work. It's a very good article. We will link to it in our podcast now. I don't think it's available for free. I don't know. I actually tried searching it, and I think it's on EuroInterventions, but I think they should just have this posted and available. It'd be awesome.

(5) Other Imaging Modalities

[Dr. Sabeen Dhand]
What else is in the future of imaging guidance? You mentioned OCT, is that ever something we're going to see outside the coronary space? It looks cool. The images are orange, and I don't know, there's some cool stuff to that, but is it valuable?

[Dr. Eric Secemsky]
Yes. OCT, the thing about current OCT devices is that you have to clear blood to get an image, and you clear blood by giving contrast. There's two components to it that are important. One is how much contrast are you willing to spend on getting an intervascular image? If they're normal renal function, that's not the most complex case, that might be fine, but that's not our average case, as you know. Then the second thing is, the larger the vessel, it's harder to opacify the vessel with contrast.

Then you get blood swirling, and not a great image. There's still some kinks to work out in the periphery. The cool thing that you can see coming through, in a couple different companies right now, in devices, is mixed IVUS and OCT images. One catheter does both, and that could be really cool, where there are some areas where you get drop off or whatever on an IVUS, and you get a better resolution image on OCT, but you're using only one catheter, so no extra cost or anything.

There's also a study that my good friend Junlee and colleagues are doing at CASE looking at OCT imaging and the tibials, which are a little easier to opacify. We might get a little bit more data on that. It's going to be later to the game. I think IVUS really is the right tool right now, for intravascular imaging in the periphery, but the goal is to make this a bigger field, to make these devices more practical for use in the periphery, and then also try and really to focus on getting better outcomes for our patients.

[Dr. Sabeen Dhand]
Do you find you're doing less pressure measurements now that you have IVUS, or are you still doing pressures as often?

[Dr. Eric Secemsky]
That's a really timely question. I was doing a bilateral iliac, and then a left SFA, all in the same patient, the other day, and I kept dragging pressure. In whole catheters, I'll pull back if I don't have two pressure lines matched. I'm doing IVUS and I'm like, "Let's just pull back a pressure gradient." It was completely correlative, where if I saw an IVUS image that was severe, the pressure gradient was significant. Again, the pressure gradient didn't tell me anything about-- Is it calcified, what's the right diameter, or anything.

It just told me, "Fix this area of the iliac." I was just joking with my fellow at the time, that this was informative in the sense that I probably couldn't stop wasting time doing that, and I'll just focus on my IVUS image. I'll do all of them. I think it's important. I like to document the appropriateness of everything I do, but when I save IVUS images, I feel like that's good data, as well.

[Dr. Sabeen Dhand]
Totally. Yes, man. Well, thanks. I love what you're doing, Eric. I think you're a boss in all fields, so thanks for contributing, this article is done in such a great way, including all practices, taking out as much bias as you can. I can't wait to see what else you're going to come out with in the next decade, man. Thank you so much.

[Dr. Eric Secemsky]
Well, I'll give you one plug, just before we wrap up. We did a multi-societal round table in February, we had SIR, SVAs, ABF, ABLs, SVM, and SCAI was the leading society to sponsor it. Everybody who's anybody in the endovascular space, in particular using endovascular imaging, participated. The proceedings of that are coming out later this year. Hopefully, we'll have some good conversations. Again, the goal is-- This is a team sport.

I want to do this with all my friends and colleagues, like you and others, throughout the vascular space. Hopefully, we put some good messaging out there, and again, keep growing this field.

[Dr. Sabeen Dhand]
Absolutely. Well, Eric, thanks again for your time. This is really informative, and like I said, you're really contributing a lot to the entire endovascular field and more, so keep doing what you're doing, man, and I'll be excited to see you at Western Angio too.

[Dr. Eric Secemsky]
Thanks, Sabeen. Same here, buddy. Appreciate the time.

[Dr. Sabeen Dhand]
Of course. Thanks to the BackTable team. Thanks, Nick, for making us sound good on this episode. Yes, man, Eric, I'm excited to have you back again for something else.

[Dr. Eric Secemsky]
Perfect. Looking forward to it.

Podcast Contributors

Dr. Eric Secemsky

Dr. Eric A. Secemsky, MD, MSc, RPVI, FACC, FSCAI, FSVM is the Director of Vascular Intervention and an Interventional Cardiologist within the CardioVascular Institute at Beth Israel Deaconess Medical Center (BIDMC).

Dr. Sabeen Dhand

Dr. Sabeen Dhand is a practicing interventional radiologist with PIH Health in Los Angeles.

Cite This Podcast

BackTable, LLC (Producer). (2023, May 8). Ep. 320 – Appropriate Use of IVUS in Lower Extremity Interventions: Expert Consensus [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.