So, we're going to very quickly talk about the role of intravascular imaging in peripheral arterial disease. I think this is a slide I borrowed from Hiram Bezerro and my partners when I was in Cleveland on how we might look at really all interventional therapies and guidance with physiology or imaging. You could substitute coronary for peripheral vascular here. But specifically for peripheral intervention, imaging is helpful in the diagnostic imaging prior to intervention, then planning your intervention, and then making sure that your interventional result is optimized, very much similar to coronary. A lot of this has been codified in a paper that several of us participated in and is in your intervention. So, for those that want an atlas of images of peripheral arterial ivis, there's an appropriate reference. Eric has really done the lion's share of the work in this space and, along with his team, has done a lot of interesting research and survey of the landscape. And really, what's clear is that there's a host of studies that are out there that use ivis for peripheral intervention with all different sort of approaches, but the level of evidence, at least until now, has been relatively poor. We really get a level 2B rating if you were to sort of very carefully look at the literature. The past year or two has really heralded a sea change in how ivis is used. This is a vascular surgical group in Australia, not necessarily the surgical community, not necessarily known for using lots of ivis, but this is infemeric popliteal intervention in all comers and successive patients in 150 patients in a row, where they looked at the use of ivis plus angio versus angiolone to see if there was an impact on freedom from resynosis. And you can see in the red curve that the use of ivis substantially improved the freedom from resynosis in a large elastic arterial circulation, specifically the SFA. Some of the predictors were, as I think we've seen in other vascular territories, that about three-quarters of the time the use of ivis changed the interventional plan. And this was particularly true when looking at the reference vessel diameter or the lesion length or whether after intervention there was a dissection that needed treatment. Eric and his team have looked in the big data of the Medicare database to see what sort of penetration there was for ivis, and interestingly, about 12 percent of procedures in the Medicare database from 2016 to 2019 incorporated ivis, and this is, of course, in places where ivis is incentivized via reimbursement, and you can see in a variety of different sort of populations. You can have reductions of major adverse limb events, subsequent acute limb ischemia, and major amputation—all very important endpoints that we care about in vascular intervention. So with this in mind and with the support of Philips and Boston Scientific, a series of us got together to put together what we thought was a consensus in the absence of guideline-based recommendations. And so we sort of took on an iterative writing process where scenarios were organized based on procedural phase—either pre-, intra-, or post-intervention—with respect to these parameters—occlusion, etc.—to see when it would be appropriate in the estimation of an expert panel to use intravascular imaging. This was also done for Venus, and the survey was written by a couple of us, one sitting to my left, and it included questions for 15 members, and these were the types of questions we asked. You can see a man with new claudication for a week with tolerance of less than 50 meters and an ABI that's low. Angiography demonstrates diffused calcium with a tapering distal vessel. The lesions crossed, and there's dog boning of the balloon catheter. Would this be an appropriate time to use IVAS? So these kinds of scenarios, some of which seems, you know, sort of relatively mundane and some of which were more nuanced, were posed to this expert panel of a multidisciplinary group of operators from around the world, and not surprisingly, for most interventional areas in the diagnostic phase—let's say in the iliac artery—it was felt to be either maybe appropriate or appropriate to use IVAS during the procedure, and then certainly for post-procedure optimization, similar. The further down we go, in other words, from larger to smaller vessels—this is now the femoripopliteal segment—it was more and more likely to be agreed upon by the group that IVAS would be helpful in virtually every situation, and you can see below the knee where we have the poorest outcomes for interventional therapies, IVAS is thought to be appropriate in virtually every scenario. You always learn something, and it always helps you do a better job. So these data were published in Jack Interventions last year and made a little bit of news in a space that's otherwise been bereft of any real recommendations, and so to summarize these data and then get to some cases that June's going to show, I would say, as with coronary intervention, angiography is limited. We can get invasive hemodynamics, but they're not particularly commonly used in peripheral intervention in contradistinction to coronary intervention, and so IVAS has been shown to lower amputation, improve patency, and we recommend that clinicians that are doing peripheral intervention—and not just ICs, but obviously IRs and vascular surgeons—should be familiar with the techniques and the basic image interpretation, and use of IVAS is strongly supported in our consensus document, as I just showed you, and so we're now focusing really on implementation into practice and streamlining the procedural workflow. Curiously, and I will just editorially comment, that we don't have an MLDmax paradigm as yet or an IVAS 1-2-3 paradigm as yet, because sizing of intervention therapies for peripheral intervention depends on whether we're using balloon expandable stents or self-expanding stents, and so that's something we can talk about in the cases, but certainly we're a lot further along than we were three years ago, and it's great to see all of you here entrapped with us to talk about it. Thanks very much.

intravascular imaging

peripheral arterial disease

intervention planning

positive outcomes

procedural workflow