Drs. Bruce Samuels, Andrew Sharp and Ehrin Armstrong dive into clinical evidence, imaging techniques for stent sizing and optimization through case-based examples. This insightful panel also discusses the practical application of IVUS in everyday PCI.
Well, welcome, everyone. We are going to have a really great time today. We have three. Well, I won't speak about myself, but we have two other fantastic speakers international speakers here who are really experts in I vis. And we hope to really use this IBIs insights in a way to give you a primer into the use of ivascyn contemporary P. C. I, uh, eso we'll introduce them later. But Andrew Sharp and Aaron Armstrong are fantastic speakers and should really be able to teach you quite a bit about this field. We want to try and keep it a little bit, kind of virtually conversational. So we're going to keep our presentations relatively brief and have some time to discuss in between not only our own talks, but hopefully some of the questions that you can type in and maybe some poll questions as well. So we encourage you to do that. All right, so with that, I'm going to get started here on the very first talk. And here's my disclaimer. Uh, my talk is really centered around. Why use I vis and what is some of the clinical evidence for that? So I'm gonna break my talk into four segments. One is about functional versus anatomical assessment. Were always asked about. When should we use I vis? When should we used physiology? Some historical clinical trial evidence moving on to some of the emerging clinical trial evidence? And then, finally, how I see the role for IBIs in contemporary P. C I So, um, let's start first about functional for San Tom iCal assessment. I think we all understand that physiology has a role to play as well. This comes from the recent Sky Consensus document, looking at the role for physiologic assessment. Primarily, we use physiology and his greatest strength, which is the determination of ischemia. The Differ trial showed how safe it is to differ PC i when physiology is not significant. But physiology can also be used for assessment of cereal stenosis, particularly the resting indices, a zwelling for multi vessel assessment, particularly in non culprit stem e and non culprit, a CS. So physiology has a great role to play in the Kathlyn. But it's primarily, uh, in that landmark analysis of how Doe I decide whether or not to do P. C. I, as well as some of mawr emerging issues related to Syria lesion assessment and multi vessel assessment. But I This, of course, also has a role to play. And from the same consensus document, we know that Ivy's greatest strength is an optimization of stent implantation. So once you made the decision to put that stent in, I've Iskan really help you, uh, to place the stent as well as to optimize the stent deployment. Primarily. We're talking about expansion opposition ruling out edge dissection. These are all things that Andrew is going to go into in the nitty gritty with the how twos and really driving the actual practical utilization. Uh, iw issues can also decrease Mace post PC I. It's not just the guidance that actually can improve outcomes. Of course, we know it can characterize plaque almost better than any other technique out there. And it particularly has you utilization assessment of left main, which we'll talk about coming up. So what are some of these historical clinical trials? These landmark studies that have led to some of the utilization of I vis in the cath lab down the road? Well, early clinical trials focused primarily on complex patient subsets, so we know I this I Zabel's enables us to be able to see inside the artery, be able to see all the different layers of tissue, be able to characterize plaque, etcetera. But for reasons that aren't entirely clear, people really focused on IVs in these very high risk subsets. So we're dealing talking about left main here, diffuse disease, CTO s etcetera. And when you look at left main, there's a wealth of information. This is just one of many, many trials that are out there showing dramatic improvement in patients who had left Main PC I guided by I vis compared to those that were guided by angiography alone. And I think the data is so strong the outcomes were so strong, including mortality, that this got a very high level of evidence in our current guidelines. And people, I would think, don't do left main PC I willy nilly. They always are using I visto help guide. It's a no brainer. We're always using that in the cath lab. But it's true. Also for many other clinical subsets. Here's long lesions. Uh, here c t o s on in each of these various subgroups, and there's many more of them when the risk goes up, when the likelihood of a bad event increases. When you use intra vascular imaging like I visto optimize your PC, I it turns out you can really substantially lower your event rates. Uh, not just with revascularization, but also with death and m I and many of these publications on. Yet when you look at the meta analysis, you see that I've this all the time, is better compared to angiography. Sometimes they reached statistical significance. Uh, sometimes they don't. But when you actually do meta analysis and you combine all these clinical trials, you see reductions and all clinical endpoints, whether it's Mace, death, am I or TVR, and we'll look a little bit later and and try and break that down a little bit more. But in particular, I want to spend a little bit more time talking about some of the emerging clinical trial evidence. I always thought I've got in some ways a little bit of a bad rap over the last several decades for being one of those, um, one of those devices that you pull out when you really are having a tough case or when you're really having trouble understanding exactly what's going on inside the vessel. But I think that the big question is is there clinical trial evidence for the use of ivascyn routine PC? I, you know, a type A lesion, you know or not. Very complex case. Just an ordinary case Is the role for that? And the answer historically was No. There really was not randomized clinical trial data suggesting that I've ISS made improvement in outcomes in routine PC. I not because those trials were done and showed there was no benefit just that those trials were not done. Everybody focused on more high risk situations. Well, adapted es was not a study looking primarily at the use of I, V S and P. C. I was really a trial looking at dual anti platelet therapy, but it was such a large trial and there was a large I've a sub study within it. Over 3000 of the 8500 patients had I've is done and it was pre specified that we would look at those ideas patients and do clinical follow up to see how they did. And as it turned out, uh, as was the case with many of the other historical studies. You could see that if you had, I've is performed. Your sense tended to be a little bit longer, and they tend to be a little bit bigger. This is a This is something that is just a drumbeat that you see over and over in clinical studies. When you do, I vis. Typically, you underestimate the size of your lesion, and you underestimate the length of the stent that you'll need when you don't use I. This when use angiography alone and we all know this when we put in Ivy's Down, we say, Holy cow, I thought that was a three millimeter vessel. It's really a 3.5. This happens all the time, and it was was shown very rigorously in the adapt study with very high statistical significance. And in addition, although it wasn't a randomized study, we saw that with I've issues. Stent thrombosis dramatically declined. Myocardial infarction dramatically declined at the pre specified endpoint, so this was very, very interesting information again, These were routine patients, very ordinary kind of PC here. And in addition, when you looked at how it changed physician behavior, you saw that in general, most docks would say 30% of the time. Wow. I had to put on a larger blue stent than I thought I would, or I had to take a larger previous post still balloon that I thought I would or I used higher pressure. I found out my scent was under expanded, etcetera, etcetera. So about 74% of the time, I was actually changed the decision making during the case, which was really the first time that anybody had looked at that again. Not just about outcomes, but about changing behavior. So So then along comes Ultimate. This was presented a t c T back in 2018. This was a single country study looking at the use again of I V s and a randomized controlled fashion. Finally, in routine P. C. I. And this was an all comers trial. This was really high, high quality angioplasty. As you can see, there was angiography guided PC I group. There was an IBIs guy to PC I group. There was optimization that was required if you were angiography driven. There was also optimization and assessment that was very rigorous in the Ivies guided group is Well, here's what it looked like for the Ivies group. You had to have a good cross sectional area. When you were done, you had to have a very small amount of plaque burden at the edges of your stent. So good PC I that was supposed to be performed. And once again, just like with adapt, you saw that with the I this guy to group you had a little bit of a bigger sent a little bit of a longer stent mawr predilection ation. That was done because of unrecognized animal opposition. And this was the take home message of ultimate again in a randomized fashion. If you did, I this guided PC I Your primary outcome of May set of T V F A 12 months was a dramatically lower than it was with angiography alone and in particular, I love this slide. It shows that if you optimize your PC according to the pre specified optimization criteria, you could drive that mace rate all the way down to 1.6% of 12 months. So the difference between using an angiogram and using an eye this was very dramatic, and the difference between just using an I vis. But using an I vis correctly was all the way down a 1.6% and I sped through some of those optimization criteria. But Andrew is going to share those with you in his slide coming up eso again looking at stent thrombosis, looking at restenosis. Multiple studies now showing, uh that I've ISS can predict this and can help to ameliorate those bad effects. Uh, this was like I promised to show you later showing meta analysis Not only that, we can improve outcomes with high vis, but also it doesn't matter what stent type use. It doesn't matter if it's a C s or its routine, uh, stable angina. It doesn't matter how complex the cases. And in fact, it doesn't even really matter how experienced you are with high vis All the studies show that I've ends up improving all clinical outcomes, irregardless of all these different, uh, different issues. So finally, I'm just gonna wrap up with 30 seconds talking about the improved study. We're very excited. There's gonna be a US based international trial looking at again like ultimate did the random ization of ivy's versus angiography in routine coronary angioplasty. This is run by Ron Waxman out of Washington Hospital Center. Uh, it's gonna be 120 international centers enrolling over 3000 patients. Again, The optimization is something we're going to talk about more with Andrew and how to talk coming next. But basically showing you have a good m s a very little plaque burden, as they did an ultimate. And the primary endpoint is going to be, uh, the Post M s A. That's really the primary imaging endpoint, but the clinical endpoint is gonna be t v f at 12 months and eso we're finishing up here. I'm just going to talk about how I, c i V s and P c I. I think when it comes to functional for San Anatomical assessment, the strength of physiology is to decide on whether or not to do PC I, but I've This helps you to guide, treat and confirm that your result is good. Uh, in the pre PC. When it comes to procedural planning, you want to identify extent of disease, plaque, morphology, calcification and use it for stent sizing. And Andrew's gonna talk all about that. And then Erin's gonna show us many cases. Uh, when it comes to optimization post PC, I You wanna make sure you have good opposition. Good stead expansion. Good. No geographic, miss. And make sure there's no complications. And then finally, what's the critical trial evidence? We know that non randomized trials have shown significant reductions in Mace. But finally, we have a randomized trial showing that ive is guided. Optimization dramatically improves, uh, endpoints in routine PC I and improve a second, large randomized, US based clinical trial should confirm this benefit and hopefully lead to a change in our current guidelines. All right, I'm going to stop there. And David has put up a question here saying, When do you typically do imaging? Why don't you guys go ahead and answer? You can click on that yourselves. Once you answer, you can take that off of your screen. And, uh, while we while you guys were doing that, we give you about a minute to do that. We're gonna turn on the videos here, and Andrew and Aaron, Why don't we have a little brief discussion here about our talks? My talk before we head on to Andrews. Sure. Bruce. Great talk. Thanks. very much. There's a lot of data. I mean, we're talking tens of thousands of patients in either studies going back over 10 years. What do you think is being the barrier to widespread adoption? Well, that's well, how long do we have? Right, Uh, maybe I can throw this one over at Aaron. I would say for me, there's no barrier at all. I think the biggest barrier actually is being set up in your cath lab to do it, to do it rapidly and to do it easily and have a staff that's familiar with it. Have the machine turned on? I always say that's the biggest barrier turning on the machine and entering the patient. Information. There is no greater barrier when you're in the cath lab than saying now I want to do. I've us and somebody has to either turn on the machine, enter the patient information or wheel in the cart. Everybody's eyes start to roll. I think when it becomes part of your workflow, your routine workflow, then it becomes second nature and you're probably going to share with us co registration Co. Registration really is a big barrier breaker because it allows us to see exactly where we are in the vessel. It's always a little, uh, which is always a little bit of, ah, of a drag. Hey, Aaron, what do you think? What do you think? The biggest barrier out there. Yeah, I I couldn't agree more. I think just integrating obvious into the workflow is the single most important aspect of of using. I was on a routine basis. And I think, you know, I think you nicely highlighted as well the multiple ways in which I this makes a difference throughout the procedure. It's interesting here. I think we've got the poll results up is Well, take a look. It appears that the majority of the audience responded to that. These I was after standing to optimize the treatment was the most common response. And then about equally split between before standing, develop a strategy and then threw out the case. So what are your thoughts on that, Bruce? Yes. So I've had an evolution in my own practice. I used to do I vis routinely only after because it was in those early days when we're obsessed with stent opposition. And we really wanted to make sure the stent was in floating in the Lumen, and that seemed like the most important thing it turned out to be by far the least important of all the of all the things. Expansion was dramatically more important than opposition. But it became, uh, how do I put this gently. I just came really stressed. What I would do post anti this. And I would see what a horrible job I did in sizing the stent and I would or missing plaque and having geographic Miss, I don't feel like I'm the worst operator in the world. I just think I'm let's just have an average operator. But if I'm average, then all you guys out there are missing, too. You're all making mistakes. And if you're honest with yourself and you don't do imaging beforehand, then you're going to see those mistakes afterwards. And what that does It cost you time and you end up putting a second stent in getting a larger balloon out. And I realized that I could actually save time by doing the IVs ahead of time, planning the procedure, doing the procedure and then a very quick I. This which I had already paid for was already hooked up just to quickly document that I had good stent expansion without any geographic miss. So I now routinely do it both. Although before many years ago I used to only do it afterwards. It was just after I beat myself up too many times saying what a bad job I did that I started doing it, Uh, routinely, both times. How about you, Andrew? Yeah, I've gone through this similar evolution, so identifying calcified modules is increasingly something that I pay attention to. So I've just come from the cath lab where a colleague were stenting, a vessel that and geographically looked OK, and it had three calcified modules on different sides of the proximal ality on He blew a balloon up that was nicely appropriately sized. And suddenly this contrast on the contrast wasn't in aluminum on it, Really. Waas The calcified nodule is the secret danger of conventional PC I because it's so unpredictable on DSO If I could get a diverse down beforehand on particularly if you've got the plug and play car registration, you're adding about 30 seconds onto your procedure to do a run down as long as it's not a supercritical, calcified tortures vessel you get. You get the IBIs down. You can see how maney arcs of calcium there are, which is frequently not available on angiography. You can see if this calcified modules and therefore know how hard you can push with preparation on pasta Lactation in that segment and you can choose your stent. Now, we planned on quite quite a thin struck stent for the approximately 80. But with all of these modules, everyone, hey, picked a slightly more sturdy stent. Shall we say, eso All sorts of information was gained from that that I just run before the stent went in on really would have wished would have done it about 10 minutes earlier. Because we have seen those modules and perhaps managing slightly different. I think that's such a good point. You know, calcification, which I know you're going to talk about, is such an important, uh, thing to identify when you're talking about plaque morphology because it really does affect our work flow in the lab and whether or not it improves. Patient outcomes has not been rigorously studied in a clinical study, but I think all of us have shared nightmare stories like you just described. And as we now have more and more options for dealing with calcium, um, you know, whether it's laser, whether it's a direct me a shockwave, Um, you need imaging because angiography alone is terrible at identifying calcium in and of itself. But it's really terrible and identifying extent of calcification. Now that we have algorithms which are very good enough, you're gonna share any of those with us. But it's ah, it's really critical to be able to see that imaging ahead of time. All right, well, maybe I'll introduce Andrew Andrews, consultant Cardiologists, University of Wales. But everybody knows him as the office guru who has taught me personally so much about how to use this in a practical way. So you're really in for a treat. Andrew. Thanks, Bruce. That's extremely kind. Eso that's my disclaimer on. Okay, so what is I vis? It's intravascular ultrasound. So what happens is electricity stimulates a crystal and sound waves are released. So I've This is sound on what happens is the sound hits tissue and is reflected on the nature of that reflection is then collected back by the same the same crystal and it's coded into electric signals and then a computer constructed into an image. So it's not like we're looking through a window here. This is a heavily processed piece of data that you're looking at. There's two ways to look at it. We've got the digital I've us, which from Phillips is the eagle eye. So that's 64 Ultrasound crystals, all arranged accordingly on duh, gives a 20 megahertz grayscale image. You can also get two extra sets of information from the digital I've us. So that's virtual histology on chroma flow. We may come back to those then. The alternative is a rotational office, which from Phillips, is the affinity cap that has taken over from the Revolution catheter. This is a single lives catheter that spins rapidly within a sheath. That's why it needs to be a touch to a motorized sled on. A computer will then build the image in real time, and that gives ah, higher frequency image, which gives better near field resolution. So that's 45 megahertz gray scale. So it's important you understand the difference between the two, because if you use the digital I vis in a very small vessel, say the edge of a 2.25 diagnose stent. In order to get near field resolution, you will get a lower resolution image than if you take the affinity, which is a 45 megahertz, much higher resolution in the near field. Whereas if you're in the led the proximal right, the left main, you're going to get beautifully crisp images with the eagle eye because that image is further away and the lower frequency devices able to resolve that very nicely. And you'll have noticed this how sometimes you get really beautiful images with the eagle eye in the left main on its really well designed for that indication. So in order to understand I was, you have to understand the basic planes. So am I. It's an easy acronym to remember because we use that those three letters all the time. So we need to identify the advent Isha in the media and then the intimate, and that's the order that I do it in. If I'm trying to orient myself, I look for the bright white circle around the vessel, and that's the advent Ishan. It's his vibe, Roddick material. I then step in one and I see a black circle on that is the media. Now, if you're with the riff in ITI, you'll see that lovely and crisp like you're doing here. It'll be a jet black circle, and that's because blood fat and muscle are all black on either because they absorb the ultrasound and they don't reflect it back. If you're with the eagle eye, it's a little less distinct, but the weight or in yourself is you. Look at the vibe Roddick material of the Advent Isha and you take one step in and you'll see that very clear change in demarcation. You then have between the media and the intimate, the intimacy and earthy Liam on the inside that abuts the blood flow. That's what like the skin on the inside of the vessel, it should be microns thick. So if it's thicker, that's because of disease, either because of internal thickening, which is usually a fiber optic process, or because plaque is being laying down between the media and the intimate, and you can see that nicely in this image. Here we have some plaque on, but if you orient yourself in the way that I've described, you've got this bright white circle around you. Take one step inside. You've got the smooth muscle of the media. It's actually a very thin structure, and it's a jet black circle. You should then have the intimate line directly on top of it. In this case, you don't because you have some soft plaque between the intimate and the media, and in this case, it's causing about a 30% plaque burden you then step inside the intimate and you have the blood pool. Now again, you have to know your IV's catheters. If you have a 20 megahertz, Catherine of the blood pool will look very black. So the eagle eye, the blood pool will look very black. The higher frequency you go, the more that the blood, the blood cells in the vessel will start reflecting the diverse. So when you get to 45 megahertz, you start to see this sort of swirling stuff in the Lumen, and that's just the blood cells being reflected, a bit reflecting the ultrasound. If you go up to RCT, you have to get the blood out of the way because the resolution has gone the other way. Eso 20 megahertz, black blood pool 45 megahertz. She got to train yourself to recognize what blood looks like. And what from this? Looks like I'll come back to that. So when you're looking at an I've issue need to be alert identified, non calcified after Roman calcium thrombosis and dissection. So this is an example of internal thickening. Eso weaken. I always start here. This is the 20 megahertz device. So you see how there's a slightly different appearance to it. We have a fiber optic appearance of the Advent Ishan. We step in one and we see the black circle of the media and sometimes we lose that with the 20 megahertz device. So what I normally do then is I trace along the inside of the advantage Shal bright white signal that's always quite clear with the eagle. Er, then we have a bit of plaque and a bit of thickening of the intimate, with the first process of which is a fiber optic one eso it starts to get right away and then we go into the blood poom. We can have concentric plaque all around the vessel, or we may have eccentric plaque which pushes off to one side and therefore we'll eat light the vessel in one plane. That's a very important thing to understand in I've us because what you do not want to do besides your stand on the long axis here from 11 o'clock down to five o'clock. So you're gonna oversize your stent. This vessel was designed for the cross access, not the long axis. And it's just to use Clegg off remodeling to expand and accommodate the plaque that's developed in the early stages of country ethanol. So that would be a landing site. You clearly wouldn't stand that in order to, um, fix a lesion at that point. But at that landing site you size for the Lumen There on, you'll get a nice result. So how do you identify for Bronek material? It's bright white, but it doesn't cause signal dropout behind it. Eso If you see signal behind bright white, you're looking at a fiber optic substance in this case, the advent. Isha, how do you identify calcium with ultrasound? Calcium is reflected, and therefore it can't tell you what's behind that plate of calcium because there's no ultrasound getting there because it's being reflected here. It can't tell you what's happening here because it doesn't reach it. So here we see a calcified nodule on duh. It's causing drop out of an arc of about 90 degrees. So some people refer this to one arc of calcium. Four axes, 361 arc is 92 axes 1 83 axes to 70 when you get above three acts 270 degrees of calcium, the chances of being able to deploy that stent without some preparation at a less than 50%. That was tested back in the early days when we didn't have all this stuff, all this kit for remodeling that we have now. So if you see three acts of calcium, that's a signal to get out some remodeling equipment, whether it's cutting, scoring, whether that Z wrote ablation or the forms of calcium remodeling trump asses a little bit harder to see an ultrasound. Here we have some blood clock down at seven o'clock, and it's like a sort of sponge like material on what you're looking for in a This is a hinge point whereby we have plaque and then we have a clot with mobile material adhering to it. It's typically fresh, and therefore it won't have fibrosis or calcium in it. Red rhombus is what we tend to see an ultrasound on because it's it's only got low density. It's hard to see. White rhombus is not well seen on I this So this is an unexamined I'll just going back and forward a couple of frames within clock, and you can see it's seven o'clock that there's like this finger like material that is, looks a bit like a piece of sponge. And you also, if you look carefully from nine o'clock ground to 12 o'clock, there's a thin black line that appears that is not where the media is. And that's because there's usually a hinge between from bus on the fiber optic material to which it had hearing within the Lumen eso. You're looking for what we call a double layer, the hinge point of from bus to the plaque. You're looking for this oscillation on dure, looking for a relatively consistent appearance. When you go forward and back, the blood pool will continue to swell, and it looks slightly different to this dissections of breaks and into the media that allows blood in you all know what a dissection isn't. It can lever off eso We have a break in the intimate and then we have jet black pool of blood inside the war. Unless that that starts to coalesce. This is the classic thing you see in CTO procedures where the plaque has come off the wall completely. And we have a large, false Lumen present here from seven o'clock toe one o'clock. What happens if that blood starts to congeal? Well, you can start to get intramural hematoma. So this is a still a bit you can see it running in an arc fashion. And if I highlight that now, go back a Z. The blood coalesces. It starts to become mawr ultrasound reflective. And so you start to get this very homogeneous appearance. Eso If you see a 35 year old lady who's come in with chest pain Troponin rice, you're thinking about spontaneous coronary dissection. This is the sort of appearance that you'll typically get by the time they make it to the cath lab. So sizing stents. So I've This isn't magic. The way it makes results better is by making your stands bigger, making your landing zones healthier on helping you to identify dissections at either end of the stent. The ones at the distal end are more important because they don't have a stent to tack them down from running on the ones that the proximal end can retro greatly go back. So you wouldn't want to leave a big one. But they're ones at the distal end of the more clinically important ones. So there's loads of formula, right, and there's been many going back over 20 years. Well, the fact that there are more than 14 of them in that publication tells you something. So what are the principles behind it? Because what this is telling you is, if there's 14 formula, that means we haven't really got it right in one simple slide. Well, when we're selecting stent, we need thio. Put the IBIs down before we put the stent in and assess the need for preparation. I've talked about that one arc with a nodule pressing into the vessel. You might want to think about scoring balloons on door orbital. If there's two acts you can usually get away with just a cutting or a scoring, or maybe even a non compliant is this reacts. You needed to modify that. So I would always use either cooking a scoring or a road ablation type technology. Oh, are now we have Shockwave in Europe have been using that for about four years. Now s a very good technology, but it's not available for a while and it's seriously expensive. You want to pick the largest diameter stent that could be safely deployed on. I'm going to talk to you about how to do that. You need to avoid taking any piece of equipment into the contrary. That's more than one toe, one sized, meaning that if you measure from dear to media sometimes called external asic laminar to external last IQ laminar on from nine o'clock to three o'clock on media to media measurement, the vessel is three millimeters. If you take a 35 balloon. At that point, your risk of rupture increases significantly and it does. So is it goes above 3.0. So what we want to do is avoid going above 1 to 1 sizing, and that's how priest and I vis can help us. We want to pick a step with mechanical properties that match the vessel and pick the right length. So ultimate has helped us with us, they said. They've guided us to say What is the minimum stent area you must achieve? These aren't picked out of the air. These air, based on trials going back 20 years so we want more than five millimeters squared is the smallest bit of our stand. All right, so that's just a straight cut off now in the proxy ality. That's not gonna work. You need it much bigger than that. You need at least above eight. But that's a minimum across most stenting areas, or it needs to be more than 80% of the distal reference area, so that helps you accommodate the proximity to some degree. You want to avoid landing in plaque of more than 50%. Avoid the thing swinging in the Lumen, which is arbitrarily defined us a 500.4 millimeters, and you need to correct edge dissections when they involve the media on a more than three millimeters in length. So this is just a cartoon to tell you what to do. So this is a cartoon of a vessel three millimeters approximately 2.5 millimeters distantly with nice, healthy landing songs. So we size for the distal end 2.51 to 1. And then we gradually smooth it up with an NC balloons to get this stent nicely deployed and maximally expanded. Looking for a minimum stand area of greater than five millimeters squared Onda, a minimum stent area that's more than 90% if possible. Or if you're in a small vessel, 90% of the distal reference area we want to avoid stand swinging, like on the left, and we want to avoid those sections, like on the right. So here we have a long stent along vessel. How would we deal with this one? How would I vis help us up front? Well, we've got a three millimeter healthy landing zone distantly on. We've got a long, complex lesion. That's 4.25 approximately so approx led type thing we've got. Healthy edge is defined as less than 50% plaque burden. We've got a need for the stent to go up to 4.25 so we can either pick a single three millimeter stent or two states. So how do we know of three millimeters stem will do it Well, A J courtin A from New York look has managed to produce this nice chap that summarizes nickel finds work where he tells us which stents could go aware. So this shows that the synergy will nicely go from 3 to 4.25 on, then weaken smooth that by sizing it for three distantly and then expanding approximately with noncompliant balloons. Five millimeters squared is a minimum, but more than 90% of distal reference a Zanon alternative criteria. But in a big, long stand like that, I usually size it in two halfs on I take them the reference for the approx half of the expenses for the second half. So in summary, aim for more than five millimeters squared is you minimum stand area or more than 90% the distal reference. If you got really long stents, segment them in two and apply the results of the rules to each segment. Avoid landing in more than 50% plaque. Correct significant mile opposition on dissections involving the media. So can we make it easier? Well, yes, we can call register them s O. This is the sort of thing that you can store from the sink vision system from Philips. This is what you get when you take it off on a pen. This isn't what you get on the screen in real time, but it just illustrates how the white marker here is tracking the lady and given lovely, crisp images of where the stent is, where it's expanded, under expanded their on. Then it's nicely expanded here, and as we're coming back up, we got an eccentric nodule of calcium here. Circumferential calcium here that's going to need some work if you're going to stand there on all sorts of different tissue characteristics as we come back into this disease, left main on back to the Austin and this is the output you get. It allows you to measure length, diameter, click on the angiogram, see what I've us you're seeing. It makes it a lot easier toe handle a lot easier to process, and it really accelerates your learning curve, so I would recommend it. If you have this system available to you, that this will really accelerate you up your learning curve on here. We've got a question. What is the main objective of political question you're looking for when you can use Eidos, I'll call back in. Aaron and Bruce on have a little chat whilst you guys on ladies, Answer that, Bruce. I've had to do a little whistle. Stop to the accelerating Towards the end. I hope I didn't overrun on time too much. You can see it's got dark here. I've talked for so long. Eso Are you comfortable that the ultimate criteria are doing everything you need when it comes Thio selecting and optimizing stents. Are you varying from it at any point? How do you handle it? Well, you know, I think I just have to comment that that was hilarious. I'm not sure, but I think he just gave us a primer on all things in ivascyn. 15 minutes. That was it was actually quite entertaining to watch you try and get through what should be a probably one day simple e. That's that's getting close to T c t level where we have to give our talks in five minutes. That's next. Next the next tour. Well, I I think that no trial is perfect. Of course, all clinical studies used these criteria to try and standardize everything. Right? That's the downside of randomized clinical studies is that they do things in a certain way to standardize everything so that the outcomes can be felt to be verifiable if you use those same techniques, but not everybody can can really take one of those techniques and apply it to their own clinical practice. And so I think it gets very difficult. As you said when you have long lesions, diffuse disease, really no specific spot tow land your scent on when we're dealing with a lot of edge disease and we're dealing with a long tapering vessel. Ah, lot of these sort of go through the window and you end up winging it a little bit more. I've done a lot of what you've done in my own practice. When you have these long lesions, I've started dividing up the stent in my mind to two portions. Even if I'm using a long 38 millimeter sent, which as long as we have in the US I know you have 48 in in the UK, don't you? Uh, it really is silly to talk about one m s A, um um when you're dealing with the stent that long so I do think it's helpful on aluminum was the first trial that really sort of talked about doing this is in a formal way, breaking the stent into two into two pieces and really using the proximal or the distal reference segments is a way of making sure that our expansion is adequate. How about you learn what? What do you What do you think? Yeah, I mean, I I completely agree to the extent that we have to have, you know, a set of criteria when looking at things systematically, uh, in any kind of trial, I think that those are reasonable criteria. The fact is that in real world practice, we end up tailoring the optimization to the sizing the patient. Specifically, I think long lesions are great examples of where that matters, especially as we increasingly see people with more complex coronary disease. So I thought I thought that was a really nice example. You showed Andrew of kind of the relative sizing. When you're treating a really long lesion where sometimes as you pointed out, you have differences in diameters that that can span a millimeter or more. So yeah, Paul stands do that. Do they I mean, do you have that sort of chart on your wall? Because some of the stents won't go up from 3 to 4.25 And if they do, they start to lose their characteristics. S o. Do you have that on your walkers? I find them very useful. Yeah, we absolutely do. And I think you know, many of my colleagues I know sort of have a stent favorite sort of their go to stent. If that's the case, that's I guess, all right. As long as you really know the parameters of what that sent Could Dio. And if that stand can't go above a certain size and you know that you have a longer lesion to treat, that's tapering by a dramatic amount that you're gonna have to use a second step approximately, right? That's bigger. Eso you really just have toe have to know those sizes. Nobody can keep all four straight in their minds, so you have to have a chart. If you're going to be able Thio, be flexible, use different companies products. What do you think about the answers here? I think this is actually a terrific that the group here is talking about using IV's. Primarily it looks like for stent sizing and for optimization that makes me feel good. I think it should make all of us feel good that people are using I vis both before and after for its really greatest strengths. Um, a little less about morphology, assessment and landing zone Clarification. What do you think about that injury? Yeah, I mean, that's good. That's probably the balance of where you get it from. Because the most powerful predictor of stent failure is the final minimum stent area. That's the most powerful s. So if in doubt, you just make sure that at the end you take a balloon that's half a millimeter smaller than the media to media after the stents gone in half a millimeter smaller than that at each point. It's a powerful message because people still so I still find no matter how long this field has been around, how much data has come out people are still so obsessed with, Is it round? Is it pushed up against the plaque? And that's really so much less important than is it large as it needs to be? Yeah, All right, well, I think? I think we're probably honing in now on air in stock. Do you mind if we cut this off and turn it over? So I think I think we should turn over to Aaron. Aaron is rock star over there in the Rocky Mountain region. Oh, I'm so good. I came up with that. I love the fact that that Aaron is a Stanford cardinal just like me. So go, Cardinal. But anyway, hey is doing unbelievable stuff with high vis, um, over there in his lab. And And we asked him, uh, to really show us some great cases. Eso We could bring some of these beautiful things that Andrew showed you and put them into practice. So and why don't you take it away, Give us 15 minutes here some cool cases, and then we'll we'll wrap up the end. Sounds great. Yeah, thanks. So for the next 15 minutes or so, I wanted to just show some real world case examples of utilizing I vis. I've got three different cases that I thought I'd talk through. And one of my goals with this was really to just emphasize the utility of IBIs Throughout the case, both for the initial sizing of the vessel. The decision for potential adjunctive therapy as well as maximizing the M s. A. So this first case is an interesting one. Is a 75 year old man with a history of a prior cabbage with Lehman led vein grafts to die again? P. D a. He presented with exertion all angina on mental exertion and he had evidence of anti are in a pickle ischemia, a non invasive stress imaging on diagnostic angiography. He had a heavily calcified long segment led CTO, so it appeared there was no native option in his led. He unfortunately also had a tragic Lima to his lab and included vein graft, the P d. A. So as a result, the flow to the native led was primarily via Arcia collaterals. So you can see here this is ah, baseline and geography of the R. C. A. Clearly there's some disease that it visually appears significant in the proximal r c a. There's Cem mid disease, potentially as well near the take off of this marginal and some potentially moderate disease distantly and then it, if usually diseased, vessel down in the distal p. D. A. M. P l. And then importantly, you can see some of these collaterals coming up fed from the distal Arcia and pl collaterals to the patient's native led, which was the site of the ischemia scene on the stress imaging. This is just a Norio projection of that where I think you can appreciate that collateral ization better to the patient's native led, which, based on the stress imaging, was not in farted, it just had severe ischemia. Leads the patient's chest pain. So here's an I V s pull back in the RC A. So this is the distal Arcia you could see. Actually, there's a fairly heavy plaque burden in the mid two distal R c A. Perhaps more than you would have imagine. Based on the angiography, here is the area of the mid R C A. Where you can see there's some calcium in the least an arc on, then the Maura proximal vessel, which is larger but then has a proximal toe austral disease that extends with some moderate calcification throughout as well. So I'm just gonna finish this pullback here on this I vis to that more proximal vessel, which you can appreciate right before pulling into the guide. Here's some still images where I actually captured on scene A, um because this is kind of a manual co registration where I took the catheter. You can see this picture of the catheter here which corresponds to this area of the distal R C A and just some baseline measurements you can appreciate. This is actually a pretty large vessel. Um, it's a 3.8 and 4.1 in these two measurements, I think a little bit larger than you might have visually thought looking at it and actually the minimal luminaria down in this area. The segment was 4.0 millimeters squared. Interestingly, in the more mid Arcia near that marginal takeoff, there was some moderate plaque throughout, but the minimal luminaria was 4.8 millimeters squared eso actually less severe in the mid segment. And then in the proximal segment, you can see here this e centric calcification with what appears to be a nodule from noon to about four o'clock on, then a pretty large vessel about four millimeters in diameter. So I thought this was helpful and, uh, somewhat unexpected in the sense that the extent of the disease in this more distal Arcia down here was actually more than you'd anticipate on angiography. The disease in the mid segment appeared only mild to moderate. And then, of course, there was some Maura proximal disease as well. So using the obvious here, I think, really helped identify which areas needed to be treated in order to optimize subsequent results of flow to these distant collaterals. So, as a result, I placed a stent in the distal Arcia and more proximal r c a, then did not stand the mid R c A. And then this is just post dilation of the stents to 20 atmospheres with a 35 balloon and final I vis demonstrating the stent implantation landing. Um, and with really good expansion distantly and what is, I think, a larger vessel than you might have appreciated otherwise. Some remaining moderate plaque in the mid R c a. But again, the minimal luminary here have been 4.8 millimeters squared. And then the Maura proximal stent well expanded and opposed approximately throughout this area of scattered calcification. And this is what that final result look like And you can see here. I think more robust collateral ization across the distal pl on P D A. To the L. A. As well. And this actually improved the patient's angina significantly. And he's continued on other medical therapy as well, uh, to minimize his angina. So with regards to a second case, I thought that this was an interesting example of the use utility of IBIs in instant restenosis. This is a 73 year old man with a history of a prior L. A D p C I. In 2000 and 19. At that time, he had presented with a non S T elevation of my and was noted tohave Timmy to flow in the l e d. Hey had a PC. I performed the mid led at an outside hospital with a 2.5 by 20 millimeter drug eluting stent, reportedly deployed a 2.8 millimeters, but it was unclear whether was actually post dilated in the report, and the patient actually had initially done well, but he presented with extra accelerating angina just recently. Here's baseline angiography where I think you can appreciate, uh, in this r e o view that it appears there's ah significant area of focus stenosis within the midst and of the L E D, which you can see a little bit better here in the more cranial angle ations. There's basically this, uh, extremely tight waste of the mid stand area. We didn't have films of what this looks like. Post intervention, presumably it it looked better than this. Initially on Bond, the patient had evidence of aggressive restenosis and stent under expansion. So here's itis of the lady. You can see that the distal stand edge was relatively well opposed. But then there is a mid segment that looked significantly under expanded, where the stand had land in some severe plaque, and it's apparent that there's calcification throughout this area. And there was likely a 360 degree ring of calcium that had been underappreciated on the initial angiography, which then led to the stent implantation that had an area of focal severe under expansion. So, just for reference, you can see here the distal reference vessel was about 3.4 millimeters. The distal stent edge was well opposed into the area of plaque with relatively good expansion. But in that mid stents segment, you can see here that the minimal. Lumen diameter of the stent was 1.7 millimeters in what really is a 3.5 millimeter vessel. Eso pretty significant stand under expansion that had led to this, uh, re presentation with accelerating angina. So in this case, I opted to perform excimer laser, uh, a threat to me. Uh, laser, I think, has a lot of utility in the in the treatment of instant restenosis, both in de bulking the new, intimate and potentially creating acoustic waves that will decrease Theo extent of the calcified ring around an area like this. And then I subsequently used in Anja scope scoring balloon. This was a three or by 10 millimeter balloon that I inflated. And then you can see here the result of that by really getting much better expansion, that mid stent you could still see, I think a slight nodule of the stent on the left side of the image your But it appears that the expansion of the stent is much better and that this is what the final result looks like. Where you can see that the stent eyes well opposed distantly, it's got a good overall cross sectional area and on still, imaging the final diameter was still not perfect. I achieved a cross sectional diameter of 2.5 millimeters And this, uh, correlated to an M s A of 5.1 millimeters squared. And I felt based on the visual appearance of this, as well as the fact that this required both a laser at threat to be in very high pressure balloon inflation that this was at least an adequate result. And the patient has actually done very well without recurrent angina. And then the final case that I wanted to show is a case of adjunctive use of a threat to me. Based on the office imaging, this is an 83 year old man with a history of prior peripheral artery disease and endovascular intervention to his bilateral s a phase. And as with many of these patients with purple heart disease, they have a very high prevalence of corner disease. He presented with new onset Anjanette rest the had dynamic deep anterior T wave inversions and his proponent with borderline elevated. Here's the baseline angiography. In this case, you can appreciate that the patient has a moderate sized circum flex that appears mildly diseased it appears that there's a sub total inclusion of the lady, which is then more apparent on these initial injections here with more cranial angle ation. You can see that there's about Timmy to flow through what appears to be a very tight osteo led that then sub tends this area coming down here on the angiogram. So in this case, you can see here I think a little bit better with the guide catheter, and it appears there's a sub total occlusion of the osteo led just before the take off of the first large diagonal and probably Timmy wanted to me to flow down the ongoing led. So after wiring this lesion, I did go in with the obvious catheter. This was a sub total occlusion. So the Ivies Catherine was not able Thio go all the way across the lesion. But what I did want toe to show here and emphasize is that there was clearly ah, very severe ring of calcification that near 360 degrees. And although the lesion looked somewhat calcified on angiography, this the obvious here I think, really convinced me that some type of adjunctive a threat to me it would be necessary to optimize the subsequent balloon angioplasty and stent implantation. So therefore, opted to perform orbital at threat to me of the proximate led, this was with two passes on low and interestingly after the atthe rectum e And prior to any adjunctive blue an angioplasty, you could see there was already significantly improved flow down The ongoing led This also allowed me to perform I vis of the the vessel after performing the A threat to me. And so this is in the mawr mid led segment. You can see it's about a 2.5 million vessel coming up from the diagonal. Um, you can see that the vessel has s centric calcification still in the right up to the Aussie lady. But importantly, this ring of calcium was now fractured and was therefore dilate herbal with subsequent balloon angioplasty. Therefore, used a 2.5 millimeter Angie sculpt extended the osteo led lining that up right here in the Aussie, Um on. Then, after stent employment, you can see the and geographic results that this is actually a pretty large caliber led that had Timmy wanted to flow down it post dilation to 20 atmospheres with a three millimeter balloon. And then this is the final result of that. After the stent deployment again, you can see here the more approximately good stand opposition overall on, uh, expansion across that calcification which I think arguably would probably result in an under expanded stent even at high atmospheric pressures, if the Ivies had not identified the extent of the calcification therefore leading to use of adjunctive or were last threat to me. And this is just what those final angiograms looked like here. You can see this pretty large caliber led coursing down that had been so totally included. So that's what I had for the cases that I wanted to highlight. I hope that's helpful to demonstrate the utility of IBIs both in the initial sizing as well as the decision for adjunctive a threat to me. We have a panel question that we wanted to ask, and that is that following this program, what do you think your likelihood will be to use? I was in the lab and the options are very likely. Somewhat likely no change from current use or not very likely. Well, thanks, Erin. That was fantastic. You know, we really, um see what you what you've done here. You've really driven home the critical points, I think, and summarized in a way, by showing us cases, you really summarized what Andrew and I have been trying to beat everybody over the head with, which is that I've iss is so important, Uh, in planning your procedure because if you don't use it, you're going to get surprised, and you're gonna end up paying for it on the back end, with sweat and with nervousness and with a lot of time. If you don't characterize the plaque, don't see the calcium, and you go ahead and you make your those decisions based on, you know, just uneducated. Guess of what the angiogram is showing. There will be times it won't be every time, but there will be times you'll be sorry. And on the back end, of course, even when you do those planning with the best of intentions on you, choose your scent size in what you think is going to be correct. And you've you know, you've you've prepared your lesion as best you can. You still need to document that that optimization of your scent eso that you know you're going to get the best possible outcome for your patient. Um, Andrew, uh, tell me what you thought looking at these, uh, look at these cases. Yeah, I thought they were great. Case is really representative of where I've just makes you money, both figuratively and probably literally, because on the on the right coronary, we have lots of plaque that we found it difficult to appreciate on the angiogram on this is not uncommon where we say, Where's the culprit? Here, you put ice down expecting to find a little ring of ruptured plaque, and there's a huge plaque burden. And you think, My goodness, where was that in the interim on then you size for maybe half a millimeter below that plaque size you make you make your post allocation balloons. If it's media to media after the stents going in before you take a 35 you get it nicely expanded at high pressure on. Therefore, you're not taking your balloons beyond one toe. One. You're getting the stents large safely. And it looked beautiful at the end, and it always does. You know, I ever see, you know, you know, you take you down Off. You think? Yes, it looks good on then. The second case, you've got stent failure. Why is the stent failure? Because there's a poor final minimum stent area. It was too small. There was a sheet of calcium that was worst in the the lower half of the stent size that has prevented expansion on. Maybe they've only been looking at the stents going up in one view. So they it looked like it's gone up in one view, but it hasn't on the other. His identified the problem. You use the laser beautifully to fix. It s oh, we fixed stand failure by making the minimum stand area bigger by identifying the problem which was calcification restricting expansion. And then in the final one, we've identified circumferential calcium, so there's no signal out beyond this near field. So all we get is the ripple of echoes. We don't see texture. So we've got this bright white circle and nothing behind it on. If you put a stent in that, you're nuts. So you've gotta fix it so beautifully done orbital or road ablation or whatever to fracture that calcium. Then you use a balloon to expand be a little conservative in those segments that 3 60 for the size of your balloon, Andi. Then you get the stent in, and then you optimize as we've seen. And again, you've got what looks like a gloriously large vessel that you could do safely Once you know that you're a little bit below that media to media dammit Toe Once the stent is, um and it will still look huge. You don't have to go for glory. You don't have to say, Oh, it's 4.5. At that point, I'm gonna take a 4.5 and go crazy. You're just You're gonna look beautiful if you go half a millimeter below media to media after the stents gone in on, just take it to nicely high pressures, errands done. 20 there. I think that's a very good place to pause on. See how your stent is. Gonna Some people still feel that's high pressure. I do not. If you sized on I this you're safe. Uh, he that's a critical thing. It just gives you that confidence. Yeah, I have to say that's with using I vis. That's one thing that has changed my practice to because I am confident of the size. Then I routinely go up to 20 atmospheres for my postal blue because I know what size I'm treating it. That that's a safe size to do. I want to pick up on something Andrew said, which is that that last case I was so critical that you have imaging because you're right near the left main. You want to make sure this is not gonna be a left main PC? I What's going on? Is your calcium, etcetera. Everybody would use imaging on a case like that. I love that first case where you've got that distal right disease. You break out the Ivies Thio to characterize that, and then all of a sudden, it's Whoa, I didn't expect that proximal disease. You know, nobody would have seen that, and geographically, or at least nobody would have thought that was significant enough to fix it. Turns out that's dramatically more, you know, important than what was going on. Distantly, you know, you leave that proximity is that progress is that could, you know, really injure the patient that's going to drive Mace that's going to drive outcomes. That distal stuff is gonna look nice. Andi vis does that all the time. And which is why I think you know the theme of this show today is really routine. PC I you've got to break out the office because you will be not only relieved to save time, Do better procedural planning. Characterize your plaque, etcetera. But you will be surprised how much you miss just by doing the angiogram, making sure that you're really taking care of all the critical areas in the vessel. Not just the ones that you can see on angiography. Really Great illustration of that very, very important point way. Have some great questions. Yeah, we have some questions from the audience, and a lot pertain to those cases. So maybe this one on those cases that you just presented Dr Armstrong. Um, with that last one, with all the calcium I have a question about, uh if any of you comment whether orbital road of later would be better. Um, about that if any. Yeah. I mean, I think they're both excellent adjunctive treatments for severe calcification. And I think that the live it comes down Thio. What you're familiar with is an operator I personally tend to use more orbital a threat to me because I think the ease of use and the fact that it cuts coming backwards has some safety benefits. But I think the key issue is identifying that calcium and then choosing a treatment in order to make sure that you're not trying to implanted. Understand it's 10 alright injury if you have strong feelings about that. But that's that's my approach. Well, I do, because I'd have to get on a plane and go to America to get the orbital so we don't have it in the UK So I have wrote ablation and I have read ablation. So yeah, we dio. But but without 3 60 that's a really crucial part of Iris, because I would think about Angie sculpt if it was to 70 degrees, because it's not circumferential. Now I know it's 3 60. I wouldn't go for a balloon. I would go for a drill. Basically, eso I think that's a really key part. If I see that it's 1 82 to 70. That's where the cutting sculpting scoring balloons really can make a difference on. It can save you time and money once you've identified that eso Bruce, There's some more questions here, Coleridge. Yeah, we want to talk about that. Yeah, the first case that Dr Anderson presented the question is, was there a role for physiology as well as I vis or instead of IBIs on that first r C? A case? Yeah, that's a great question. I mean, I think you know, we had we had objective evidence of ischemia from stress imaging. But I think another great approach to that case would be to really demonstrate the utility of using FFR or in fr fr pull back in order to identify stepwise the areas that were associated with ischemia, in this case, you know, utilized I vis throughout the vessel and identified what looked like physiologically significant lesions. But I think that's the real power to integrate I vis with fr. For example, to then identify the races to treat and then use I visto optimize the standing plantation. Great. Um, going back, we had an earlier question that I think you all only touched on core registration a bit. And the question was about each of you has experience with registration. Um, what do you think leads to or what have you seen with failures. And I have a school registration. One of the reasons for failure of a courage. And how do you get around that? Have you solved that problem? You know, Bruce, what do you think? Well, I'm not really sure. I understand the the the text of the question there when you talk about failure, do you talking about mechanical failure of the courage system or in what areas? Does it not really work all that well, Probably that, yeah, I think like, where do you find like, it's What do you need to really do to make sure you get a successful one steps. So again, I come back toe workflow. You know, for those of you who have a Coleridge system in your accounts and are using it, um, I find that it's incredibly seductive. And it's one of those things where once you've used it a few times, you start to realize how you ever did angioplasty without it, because it's all this wonderful book of information that's right in front of you, and you just don't have it unless you have that co registration. So with physiology, it's a no brainer when you do a pullback and you can see exactly where the pressure losses in the article in the in the artery. Then you really can understand where you have to fix how long of a segment that you have to fix. And you could really do procedural planning. That way, when it comes toe IBIs, similarly, you do a pull back. You can really map out exactly what you want to fix, and you can measure length very accurately, Which is something. Of course you could never do on an angiogram or you could never do on a non co registered I This pullback were always guessing at length. Of course, we always have those dots on the I've a catheter so we can measure if we give a scoop of die there down the artery. But but, honestly, once you start to do coke registration and you do a pull back and you can accurately measure, um, length measurements and of course, it doesn't matter if you're coming back quickly. If you're coming back slowly, if you go forward backwards forwards backwards, the slower the better. So the better quality of the information is, but, uh, the computer is incredibly smart about this, and the length measurements are very good. At the geographic, Miss Likelihood goes way down. The failure with IV's is not from co registration. The failure is I this without co registration because we're missing all the time. It's the geographic myths that the co registration really enables you to avoid. And no matter how good you are, a tie this, you know, even if you're a good as Aaron is, even if you're smart, is Andrew is There are times when you know the length of you know what you want to do, you know where you wanna put it. But if you don't have co registration, you're still going to be guessing at those landmarks approximately distantly. And there are times that you will fail and you'll have to go back and fix that up. Um, you know, when you do co registration and you really can do procedural planning, uh, to that level of detail again, you sort of at the end realized why did I ever do this? I'm not sure I answered the question. I think the question was about when does consideration not work, but I think it's more important not toe focus on the failures, potential failures or downsides of concentration. Really focus on the upside. Maybe I'm being too optimistic. What do you think, Andrew? Why don't you answer that question? I'll add a couple of comments that so there's two scenarios. There are really critical optimizing courage. First is you have to be able to get the divers down. So if you've got some sort of totally included tortuous non engineer Ian Calcified Nightmare, and you're going to need to prepare that vessel to get anything done, you know there's no I've this that's going to get down. The second thing is you need a nice opened our image. So if you're core registering in the lady, I tend to do it in the aerial cranial because it's nice and opened out. There's no foreshortening. And so the machine could beautifully tracked the diverse along the angiogram, and it always gets it right on. De so otherwise, as Bruce is, is a way around. It's so easy. It's just a manual pullback. Roughly a millimeter a second on. Then the machine will do it all for you when you click about yeah, we really didn't go into great detail about what co registration is, or, you know, if you don't have it, it might be a brand new concept for you, but there is no difference in workflow at all. Except that you have to step on Flora while you're doing the pullback. That's the only difference. Yeah, the computer does the rest and lays everything out for you in the way that you saw in Andrew's case. Very, very helpful. In a question I think you guys can easily clarify. Maybe Dr Sharp, when you say optimal for stent is 90% of the distal reference, Do you mean vessel size or loom in size? Yeah. So in many ways, the distal reference will hopefully be both eso when you're sizing for the distal reference. What that means is, what what size is The area of the vessel on door? Lumen. Additionally, if it's completely healthy, the vessel in the Lumen size will be the same. If you've got disease, then you sign eyes for the Lumen, uh, distantly eso when you're sizing your stent, you're sizing at the vessel distantly, okay, and you'll hopefully have landed in a healthy bit. So you measure your healthy bit just that the edge of the stent afterwards and it's six millimeters squared. So what you need to do is get 90% of that, which will be roughly and in all, 5.7 or something A Z. The smallest bit of your stent is you're going back now. That works really well. If it's a short 50 millimeter, if it's 40 millimeters, that's different because the disloyal lady might only be 4.8 millimeters squared. Clearly, you're gonna need a big approximately. So that's when we start segmenting things. So let's let's make it more complicated. What if as you showed us your land to get in plaque Yeah, and your loom in is not the same as your vessel distal reference when you are shooting for 90% of the M s. A. I'm sorry if you're shooting for the M s A. Being 90% of the distal I think the question was is a distal bloomin or distal vessel? Yeah, so it depends. Eso investors like that. You get a lot of positive remodeling and negative remodeling, so you have to take that into account. But if you can't find a landing zone you can still make your stent, Uh, 90% of the distal vessel size. Okay, so if the vessel is three millimeters of the landings on, But you've had two landed 2.5. Because this plan, then you saw down the three millimeter, not the 2.5. You started your stent size for the Lumen, but you do your optimization to the vessel. That's how I do it. What do you do? A lot of people have suggested you could stand it for the vessel size. I'm sorry, the Luminal size and you can add half a millimeter recorder millimeter to your sense size. Yeah. I mean, I actually have another three cartoons that I normally do. And when we're doing our courses that go through all of this, uh, clearly, you can't. If you Londoners still stent in Lumen, you can't then make that stent the size of the vessel. That's why you don't. So these air complex situations usually you consent normal to normal, so find normal, find normal stent normal to normal, and then get 90% of the distal vessel. There we go. Um, question came up. Well, Dr Sharp, you mentioned about calcium Nah, jewels. And how important they are to identify. How do you treat calcium modules? Yeah, I mean, in many ways, Erin's already alluded to the right answer. I'll ask him to come off, Mutant. Just tell us because this is where I want orbital. Is that what you are doing, Erin? Yeah. I think that is potentially one area where or will a threat to me has a benefit because of its ah, orbital motion. The fact that it can actually modify and treat specifically areas of nodule er, calcification. While you know, avoiding injury to the more normal tissue. I think that is a potential advantage because, of course, compared to rotational a threat to me where you're treating mawr the middle section of the loom in you can mawr specifically bite into for lack of a better phrase thes calcified modules. Yeah, and I don't have it. So if I'm using road ablation and it's biasing physically away, even though this differential cutting the throat ablation if it's physically on the other side of the Lumen to this lump is not going to do anything, So that's when I use a sort of half millimeter downsize scoring or cutting balloon. But I find that an unsatisfactory solution to modules they remain the hardest problem in angioplasty. In my view, there you go. It's complex, so Well, I think we've gotten our questions, and I think we've gone over our time a bit, which was okay, because it was a great presentation. I can't thank you all enough of each of our presenters for their great time and expertise. And we hope that this was very informative and helpful in the world of IBIs. And we hope to continue to have these, uh, types of programs going on in 2021. All right, take care, everybody. Thank you all, Doctor. Thank everybody. Appreciated by now. Everyone, everybody just