is really going to talk a little bit more and drill down on the importance of procedural and biologic protection, and this is obviously important because we've seen a lot of data in the last couple of days on carotid stenting in comparative studies, and we know that traditionally until very recently we saw that there was maybe more MIs in the CEA group and more small non-disabling strokes in the carotid group, and this has been borne out in a number of different studies. And I think we all know the reason why, and the reason of course is microembolization. So post-stent ballooning is the time where most patients are going to be at risk for having embolization, and unfortunately the video is not playing. So what are the potential mechanisms of why a distal embolic protection device might not provide complete protection? Well, part of it could be that the pore sizes are just too large. It could be that the filter size that you chose was not proper, or especially if you were in a segment of a vessel that was very tortuous, maybe you had lack of acquisition. There are a lot of carotid stent filters that are out there. You don't hear about them, but there are a number that are commercially available through a lot of these industry-sponsored trials that we did a decade or so ago, and they have varying pore sizes. So Ravish Sachar, a good friend of ours from North Carolina, actually designed the Paladin balloon. This is an integrated embolic protection system which combines a filter that has 40 micron pore size, but a filter that can be adjusted in terms of its size with a concomitant post-angioplasty balloon. This was a case from Dr. Kazdov in Macedonia of a very critical subtotal, 99% lesion, that he was able to treat using a dual-lumen mesh-covered stent, and he did this from the radial artery and with that Paladin device in place was able to get a very nice result. We know both endarterectomy and carotid interventions can result in microemboli that can cause defects on diffusion-weighted MRI. The incidence of these new lesions with the Paladin filter is actually on par with what we see in both TCAR and endarterectomy, and in point of fact, 90% of the particles that were captured on this histologic analysis from Ralph Langhoff were less than 100 microns. There's also increasing data that suggests that microembolization may have a negative effect in terms of our patients' cognitive abilities because of microembolization. And again, with diffusion-weighted imaging, we can see that the number of lesions is significantly reduced with this particular embolic protection system, again, on par with TCAR and endarterectomy, and in fact, even better than with dual-layered stent or with proximal protection. But as importantly, I think, is not the number so much as the volume of embolic material, and you can see with this device, it's really quite small. I'm going to show you a case that we did of a very ulcerated, ugly tandem lesion here where the greatest challenge was actually just trying to get a bloody wire because of that entry angle, and we tried a variety of different things, but then again, taking a page from our cardiology playbook, I finally thought, aha, let's try a dual-lumen catheter, and then it became a very pretty easy and routine case. So using that Sasuka catheter, we were able to actually then deliver our bare wire distally, and then we went ahead and delivered the EMBO shield, and then at that point, it became sort of a very routine case, pre-dill with a 4x30. This patient was in performance two, so received the investigational device, and after post-dill, a perfectly lovely result, and the patient did well. The performance one study, zero deaths, zero strokes at one year. Chris already showed you the outstanding data from performance one and performance two, again illustrating the fact that this can be done very safely with an embolic protection system in both symptomatic as well as asymptomatic patients. So embolization is going to occur post-dilatation of all stent types, open cell, closed cell. This was a paper from Poland where they took 25 consecutive symptomatic patients who underwent transradial carotid stenting using the Road Saver Dual Lumen Mesh Stent. They had a 30-day major adverse event rate of 0%, but they did go back and they looked at all of the, and collected, in 22 of those patients, they did histologic analysis, and there was debris 100% of the time, and 75% of those particles were less than 100 microns. So it does suggest that we can do better with smaller pore sizes. Now obviously, that's great for distal embolic protection, but what if the patient's not a good candidate for a traditional distal filter? Well obviously, we have proximal protection. So we have the MOMA device, as well as TCAR, and the advantages of proximal protection are pretty intuitive. You can cross with whatever guide wire you want, and once the device has been delivered, all of the steps are under protection, and you can prevent both micro, as well as macro emboli, and avoid those nasty cases where you have a lot of tortuosity, distal tertiary lesion. We have to, of course, recognize that there are limitations. These are typically requiring larger sheet sizes, and this slide says up to 10% of patients experience intolerance. It's probably more in the sort of 1-5% range, but there is limited applicability if patients have concomitant ECA, in the case of MOMA, or CCA disease in the case of TCAR. So this was a symptomatic patient with a super tight essential string sign that we elected to use with embolic protection, and Chris showed you a couple of very nice examples here. It's really pretty straightforward. After delivering the device, inflating the ECA balloon, and then the CCA balloon, and then very efficiently and quickly going ahead, doing your pre-dill, deploy your stent, post-dilate your stent, and pretty much keep aspirating until your filter is clear, then deflate those balloons and end up with a very nice angiographic result. This is, again, a very similar patient who was symptomatic with a super tight, essentially almost a string sign, that we felt would be better served with a TCAR. And we know from the data that's been presented that TCAR is at least as good as the gold standard of endarterectomy for both high as well as standard surgical risk patients. A question that used to come up more is, well, what's better, proximal or distal? Well, unfortunately, the literature is really kind of all over the map on this. There are more ischemic brain lesions, it seems, with diffusion-weighted imaging on MRI, but from a clinical standpoint, there doesn't really appear to be a significant or dramatic difference in terms of the incidence of strokes. So in summary, I think we all agree that embolic protection is mandatory for coronary re-stenting. Not only is it ethical, it's absolutely important that you do it, because otherwise you will get paid for it. And while proximal protection results in fewer and smaller of these diffusion-weighted imaging defects compared with distal embolic protection, there really has not been a significant difference in terms of stroke rate. I think we all agree that proximal protection is probably favored for patients who are symptomatic, who have adverse arches, string signs, vessel tortuosity, and severe calcification. And I think the NeuroGuard in particular, as an integrated platform, or the Paladin filter as an IEP device by itself, has really demonstrated excellent clinical results with very low stroke rates, fewer and smaller volume lesions on MRI, and does certainly demonstrate parity with both TCAR and endoderectomy here. So I'm going to stop here so that we can have time for some questions and discussion. So this is the end of the didactic portion, so I'd really love for people to shout out if they have any comments or questions, and then we'll have a quick discussion and let you all get out to dinner. So remember, don't hurt my brain. It's my second favorite organ. Thank you. All right, Chris, I know you've got a burning, one or two burning questions here. Go ahead. No, I will probably wrap it up and really prepare for the audience. I'll ask the one thing, I've got to say, I saw your IVL, love it, good cases. I would, I think with today's technology there, you either have a 4 by 12 that's cornered and it's never going to be big enough to do what you need in a carotid, or then you have a 5 by 60, 6 by 60, 7 by 60 IVL, CFT is long. I would, your message to the audience would still be, I would think, until we know further, if there's heavy calcification, it's endoderectomy first unless they're absolutely not a canine. Am I correct there? Yeah, absolutely. If I implied otherwise. No, I don't think you did. I'm just making sure. Yeah. And you know, Mahmoud made that case very elegantly that for the really, really severely calcified patients, typically endoderectomy is probably what we're going to recommend first. But the concept of IVL for those patients who maybe aren't good candidates, and I think that's really where a lot of this is going. I mean, there have been literally now hundreds of patients from around the world that have had IVL used on their carotids. So there are clearly those patients out there who, for whatever reason, are not considered good candidates for endoderectomy. Perhaps maybe they're not a good candidate for TCAR or they're symptomatic or whatever. But we certainly have seen the reduction in acute procedural complications and we've seen much better expansion of stents when IVL has been used for these really densely calcified lesions. So it does make sense that it can work in this vascular bed as well. But I think any studies that are going to be done are going to have to be done obviously very, very carefully with great forethought. And then the question becomes, who's too calcified to even try it on versus are they calcified enough to justify the potential risk of doing this new investigational procedure? Right. And if they're completely asymptomatic, then we really have to ask. It depends on how dense it counts. And we really have to ask. First, I would ask a surgeon their opinion whether they're high risk for surgery. We can always imply that if I don't ask, you may say, hey, buddy, I could have done that just fine. But I wouldn't know that if I didn't ask you. And I'm a little skeptical right now. I'm not skeptical. I know it's been done by 200, but they're all individually reported. Your cases were awesome. But I'm just concerned. And I think the company is working for more carotid specific devices, which will help a lot. That will make a difference if you have a five by 20, a five five by 20, something like that. Then maybe we're there. What do you think? Yeah, I agree with you. I think if you think about what you do in your standard carotid stenting, you're never putting a six centimeter long. Right. And when you look at the carotid intraoperatively, the distal part of the carotid that is beyond the lesion, it's really paper thin artery, very fragile artery. And to me, the problem that I'm having with this is you're ballooning part of the carotid that is not doesn't have really a lesion. And yes, I think it does have a role like any new technology. We don't want to just right away say, no, no, no, it's not going to work. I think we should investigate it, study it. Well, I love the fact that they're making balloon specific to the carotid, meaning not that long. Right. And not necessarily that large, because you don't every single time go in and put a seven millimeter balloon in a standard transfemoral. There's a bigger problem here. Apart from the fact it's taken us 25 years to get the complication rate down to one percent now, we're going to start monkeying around with IVL and other things. The bigger problem is, and having tried this many times with many different devices many years ago, is that when the calcification is really severe, it's difficult, and you wire it, you're difficult to get a filter in, let alone get a balloon through that will allow you to, particularly a six millimeter or seven millimeter balloon. In addition to the length issue, and what we've learned most importantly about carotid stenting is, minimize the manipulation if you want to have a stroke-free procedure. And what we're doing here is we're maximizing manipulation. When there are alternative procedures, medical therapy if they're asymptomatic, for sure, and endarterectomy if they're symptomatic, and most vascular surgeons that I've spoken to will tell you, look, there's no such thing as high risk. I can operate on anyone and get them through. So I think we just need to be cautious, and I welcome the opportunity to see specifically low profile five millimeter balloons, which we can slide across. I would almost prefer to do something minimalistic, then put a micro-mesh stent in, and then get it dilated, then go in with your shockwave balloon and optimize the result. So we've got a long way to go. It's critically important, though, that any balloon that you're going to design for carotid, I'm asked about shockwave, and I've spoken about shockwave a lot, and I'm very fond of saying that shockwave is a device by which sonic waves are delivered to the target lesion. It's not meant to be a workhorse balloon. It's not meant to go to high pressure. So when we do shockwave, and especially if you're going to consider doing a shockwave in a carotid artery, I mean, you're going to be at like two, three, four atmospheres, absolutely the max, just enough so that you can be in contact with the vessel. While we're not looking to do an angioplasty here, we're looking to just modify the calcium. And I think that's going to be critically important if a study does get off the ground, that the operators realize that you are just using it as a means by which to deliver therapy to modify the calcium. We're not looking for it to be a workhorse angioplasty balloon. I can share with you very briefly. There's a colleague of mine who used them with TCAR from University of California in Davis, and she actually presented the data in one of our societal meetings, and the event rate with TCAR, this is flow reversal, with shockwaves was about 8 percent compared to, you know, the standard TCAR, like if you look at muscle stroke rate, 1.7 percent to 2 percent, depending on what study you're looking at. So it's impressive, the data that you showed, and, you know, maybe there is technical issues or whatnot, but to me it's like I'm still not a big believer, not saying absolutely not, but just like Gary said, maybe to kind of think about these patients, maybe better off medical management or CEA, because with CEA you're just kind of removing the whole thing completely. Right. All right. Well, I really want to appreciate everybody coming and sticking it out all the way to the end here. So I want to thank our esteemed panel for their wonderful presentations, and thanks to the companies for sponsoring our session, and please enjoy the rest of your evening. Thanks very much. Thank you.

carotid stenting

embolic protection

microemboli

TCAR

intravascular lithotripsy