Hey there, sorry I can't be there in person, but I'm happy to be able to present to you ultrasound renal denervation procedural strategy technique and show you case example and some other examples as well of this technique. So just to start off with, the device that's approved currently in the United States is the ReCore Paradise system, and this is a balloon-based device, so this is different than the other approved devices that are out there right now, and this is a device that's advanced into the renal artery over a wire and contains a sonicating element using ultrasound-based heating as well as a cooling balloon. The balloon serves first to center the device to allow the ultrasound energy to be actually distributed circumferentially around the artery and equally, but it also serves as a mechanism for cooling because there's a water cooling balloon that prevents the lumen from being overheated. The depth of the ablations is typically going to be one to six millimeters of mercury, so a little bit deeper than other systems that are out there currently, and as I said, the arterial wall is protected. There are actually two to three sonications, each lasting only seven seconds that are delivered to the appropriate size renal arteries, and so that's the premise of this device. Now I think it's important just to sort of think about this device a little bit differently than others that are out there because we do know that we need to ablate a certain number of nerves in order to have efficacy in terms of a reduction in norepinephrine signaling and therefore a reduction in blood pressure. And so the basic premise when we think about these devices is how do we ablate enough nerves in order to affect a good result with blood pressure. One of the things that we didn't actually know about when these therapies were initially introduced back in the simplest hypertension three days was that actually the way the nerves are distributed is that they're further away from the artery the closer they are to the ostium. We in fact thought back in the day that we needed to ablate more at the ostium because we'd get these ganglia, but the reality is that these are further away out here and that's one of the whole premises for going distal with devices that perhaps don't go as deep as this current device that I'm going to show you. But a way around this problem is actually to ablate circumferentially, and if we can truly ablate in a circle around the artery here at a sufficient depth, we can actually effectuate a good ablation of renal nerves so as to reduce norepinephrine signaling. And that's the exact premise of this particular system, which is a circumferential system that's only applied in the main branches for the most part and does not have to go distal in order to get its effect. So this is just an example of what you see in terms of the nerves in cross-section, and with a device if you could only ablate in a quadrant, you could understand how you'd miss these other three quadrants if you were ablating, but if you have a circumferential ablation of sufficient depth, then what you actually get is good ablation of renal nerves and you don't have to actually go distal in order to get that, especially if the depth is from one to six millimeters, which is what it is with this device. So this is just an example of what it looks like in a gel model. As I said, the balloon is there to centralize it or center it within the artery itself, and then this gel turns this color in a donut shape that allows the nerves that are anywhere within this zone here to be ablated. So that's basically what happens. And this is in cross-section, and one of the nice things you can see about this picture is that there is this zone of protection around the balloon itself, and this prevents the lumen from being heated. One of the reasons why other devices were not designed to do circumferential ablations was that there was a concern that you could actually cause a stenosis at that point. So that's why this cooling balloon element is necessary, not only to center it, but also to protect in this way so as to get a good result with denervation, but yet protecting the arterial lumen and making this a safe procedure. So how do we then devise the therapy? And I'll show you this live case in a second, but I think it's important to illustrate these topics first. What we basically want to do is we want to stay away from the renal parenchyma because we don't want to injure it. And so the idea here, in a case where there even is accessory arteries, is that you would get these emissions here and here, and then where this accessory is, you can typically do a single ablation in that zone, and you don't want to be too close because if you were too close here, then this area here in between would potentially be doubly heated, and you don't want to do that. Similarly, for an artery like this, you can basically do two ablations here and an accessory as well. You wouldn't want to be going down here because then if you're off-centered, you can actually potentially hit the renal parenchyma. So key thing is no emissions of the parenchyma, and generally speaking, you do two to three emissions at the main artery, and then one emission in accessory or side branch. The arteries that can be treated are three to eight millimeters in diameter, and there's balloon sizing that I'll show you that allows you to do that. Now I do think personally that irrespective of what technology you use, that upfront CT scanning is helpful. Both devices don't require it. One of the reasons for that is obviously these procedures are expensive and you're just adding more time and expense for these cases, but I do think it's often useful, especially in peripheral vascular procedures, to have cross-sectional imaging upfront. It's kind of what we've started doing with carotids. We've joined them in the legs. Same thing is true with the renals, and the reason I think it's helpful is twofold. Number one, obviously this can be done during another CT scan if you're looking for adrenal adenomas or stenosis and that kind of thing, and so many times it's clinically indicated to do it. But number two, it allows you to elucidate are there accessory arteries, because you know that about a third of the time there are always accessories, and so you want to be able to understand that, but it also allows you to pre-procedure plan. So in this particular case, what one can see is the bifurcations here, the bifurcations past here, and the idea here is you really want to stick to these zones here, and in this case you can even map it out and say we're going to do three on this side, two on this side, and be okay. What's the downside of going near the bifurcation here? Well, the downside is that you're kind of close to the parenchyma. So that's what we want to avoid, and that's one of the reasons why I think the CT is somewhat helpful. Now in this particular case, there was a concern for a stenosis at the ostium, and so I'll show you how we dealt with that. So how do you do these procedures? This is just an example in our cath lab, basically standard micropuncture ultrasound access with fluorovag guidance and visualization. As soon as you get in, you advance the micropuncture wire, that's typically done under fluoro. You'll see here with a fluoroscopic check, you notice immediately where the needle is and where the vessel is. And in this particular case, obviously the needle is above the femoral head. So immediately removed, it's just removed. It's not even attempted. You just remove it, hold pressure, and that's the whole advantage of micropuncture. Even with ultrasound, this can happen. And so I think it's really important to emphasize this. Why did I show a high access in our cath lab? Because this does happen, and this is an experienced operator and attending in our lab, and immediately recognized this, took the micropuncture catheter out, held pressure, no issue with that. The idea here is these will eventually be radial. Both systems will eventually be radial, but right now they're not. And for this system, which is the seven French access, you don't want to take the chance of a high stick because just like we saw in the trials, if this is done safely, there are really, really great outcomes that can happen with renal denervation, especially from a safety perspective. Then after that, it's kind of standard renal angiography. I'll let this play again. Sorry about that. So basically what you do is the CT can also be helpful, localizing where the renals are so you're not fishing around too much. In general, if there's not a lot of atherosclerotic disease, I don't favor the no touch technique up front, especially because these are typically okay vessels, but I do target it based upon what I saw on the CT scan. If you don't have a CT scan, you obviously know where this last rib is. You know, it's going to be a little bit lower than that. And then based upon your angulation, you should be able to cannulate the renal successfully. You don't want to have flying it around or anything like that. And that's just an example of a test that we do. We typically do a cine angiogram as well. And that allows us to plan and size as well. You can do QVA. So you can actually measure these things. And for this device, you do need to measure to understand exactly what the size is. QVA works reliably. That's what we use in the trials for the most part. In some cases, we'll use IVUS. I'm actually going to show you an example of IVUS, but it's by no means required to size. And then once you do that, you can put a guide up. Once the guide is up, this is just an O1-4 wire. It's typically a Grand Slam wire in this case, because there's some tortuosity. You might want to use a softer wire, but these are just standard O1-4 type wires that you can use. The reason I use a Grand Slam wire is just because it gives me more support. Here you see the Grand Slams hanging up because it's that transition point, because of it now got to be advanced further. And then you see that loop there is reasonable, but you just want to be careful with that distal wire. I have to say that in the trials, we haven't really seen distal wire perforations or anything like that. I guarantee you in clinical practice, there are going to be groin complications, there are going to be hematoma formations, there are going to be distal wire perforations, irrespective of whatever device you use, just because that happens in the real world. And so that's why good technique is so important. Watch where the wire is, know what it's like on the co-registered angiogram, which you can freeze and put on the right of your screen, and just be careful. And I think those are the ways that we can maximize safety with these procedures. So that's basically what you do with this wire, this is a 7 French guide. In general, you're going to be using either IMA guides or RDC guides, you need to get a short one, that's totally reasonable. You can actually use a short wire, you don't even have to use a long wire with this device, even though it's an over the wire device. So let's talk a little bit about sizing now. So in this case, the reason I did IVUS was because there was disease at the ostium. I want to show you though, the IVUS to show you that basically the artery remains relatively the same size throughout, and there is some plaque at the ostium, which is why I wanted to avoid it. So why am I avoiding plaque at the ostium? And this is true, irrespective of device, there is a theoretical risk that if you apply energy at an area where there's plaque, you can make the plaque more active and you can get a stenosis. It's theoretical, it's not something that has a lot of study associated with it, but we tend to avoid this. And so that's the reason why I did it in this case, but the areas are basically very similar. And you can see, if you go back here, that basically it's under six millimeters and is above five millimeters. So that tells me with this specific device that I need a six millimeter balloon, and I'll show you the chart in a second. How does the device work? It's an over the wire system. Here's the transducer, here's the balloon. And essentially through the balloon, there's sterile water that goes through there. And that's acts as the cooling mechanism. The transducer is an ultrasound based transducer. It works similar to like Haifu technology. And basically that just hits the areas that are needed. How does it work? Well, there's a generator. So the generator is connected to the back of the device. The generator basically, it recognizes the size of the balloon and automatically programs itself to deliver the appropriate energy to get that one to six millimeter depth with ultrasound. That's basically how it works. The generator also has a system associated with it that allows it to circulate that cooling water. It's sterile water, not saline. And the other thing that it does is it allows the balloon to inflate and deflate. These are super low pressure inflations. So contrary to what you might hear, this is not something we're inflating in the renal artery and also they're short inflations. So the patient is not getting ischemic for more than seven seconds at a time. And that's kind of important as a whole during the sonication time. Here is the balloon sizing matrix. Basically what you see here is that you're kind of going a size down. So if you're five to six, which is our case here, you're going to take a six millimeter balloon. If it's six to seven, you're going to take a seven millimeter balloon. Now what you will see here is the fact though, that there are multiple sizes of balloons. Fortunately, the way this is stocked is that the price is going to be the same irrespective of however many balloons you use, but you do have to stock more balloons. So that's important. The second thing about this is to note that you may have to use multiple balloons in a case. And that adds a little bit of time, but not a lot of time, fortunately, because the sonications are slow. So here's how the setup works. And what you'll see here is you hit next here. So basically it's, once you plug in the balloon, you basically are testing this out. There's a remote control that allows you to do this with the remote. You can hit the green, you can do it on the screen as well. It just makes sure that the cartridge is inserted. The coolant is set up and that's just basically a saline bag that your techs will put there. And then it detects the catheter. Once that's done, then you prep the catheter. Now this whole procedure, this is actually an interesting picture. This is actually a slide directly from the record people. They're very honest. And so they say, what do you, what else do you want to discuss within the physician during this time? Because you need to be prepared for the one to three millimeter elevator pitch, because this probably is the most painfully slow part of the procedure. It does take three minutes and 10 seconds to get that first balloon ready. Fortunately, if you switch a balloon out, it's only a minute and 30 seconds, but this is really to set up the system and to make sure that everything is working fine. What is it basically doing? It's circulating the saline, it's getting rid of the air bubbles, et cetera. And inflating and deflating the balloon to make sure that works. These are important ways of testing the system outside the body. So you're not using a catheter in the body that you don't essentially need. So I thought it was interesting to slow this slide because they're honest in terms of the pitch that's there. So this is how the prepping goes. And this is just an example of waiting for Godot. It takes three minutes and 10 seconds for that to occur. So typically what I tend to do is once I've sized it, By the way, this is the other reason the CT can be helpful is that you can then sort of allow this to occur while you're doing other things. But for the most cases, what you're going to do is you're going to take the Angio. As soon as you take the measurements, then you start prepping the balloon and knowing, and then by that time the guides up and the wires in. Now you can see here, this is bubbles in the balloon. This is why you need to prep because as you do it, these bubbles kind of wash out because the cooling is circulating through there. And then ultimately there's no real bubbles at the end of that. So that's the reason why this was sped up a little bit. As I said, real time, it's three minutes and 10 seconds. And so that's kind of how that works. Once it's clear and everything's fine, then there's a really cool step, which is actually testing the procedural elements outside the body as well. So that's what this looks like here. And basically in this procedure, what you basically see is that the way this works is that once you go into the vessel, you verify apposition. And so then that will inflate the balloon. I actually did misspeak earlier. The ischemic time is probably, it's not seven seconds. The sonication is seven seconds. The ischemic time is probably a little bit longer that probably about 20 seconds because you are verifying apposition and then testing it out and then applying the energy and then deflating. So basically what you do is you hit the button, you verify apposition. So it inflates the balloon. And then if you were in the body, you do a gentle contrast test. And I'm going to show you that to make sure that you're opposed because there's no dye going past it. And then once that's done, what ends up happening is it counts down and then we'll apply the sonication. So in this particular case, it's pre-cooling the balloon. And then all of a sudden, when it gets to that 12 o'clock position here, now this is sonication. And you see this wave here that shows you that the element is actually working and there's sonication. I had one case at one point where that wave did not occur. And we ended up switching out the catheter because we knew that there wasn't actually anything working there. And that was during a research case. In commercial use, I haven't had that happen yet. So again, this is what it looks like. You see, there's no waves here at all. Once it goes in, the sonication goes on. Wait for it. Wait for it. There. It's on. The wave shows. And that's what happens. Now, the other thing that's important is that the wave actually goes away really quickly. And the reason for that is the sonication is seven seconds. And if I can't have you remember one thing more from this talk, the key thing is this is a seven second device. And for patients, that makes a huge difference. Obviously, our patients are sedated, et cetera. But the truth of the matter is that they feel it and they typically feel it at about two seconds in. So sonication on, six, they feel it about now. And what I tend to tell the patient is five, four, three, two, one, done. And they don't feel it anymore. And that's really important because I'm telling you these cases, especially in the U.S. where we do them under conscious sedation, this is a real element to the case. So anyway, this is what it looks like in real life. So we've advanced the catheter in. And what we do is we test with contrast to be sure that we're opposed. So we'll hit the button and it'll inflate the balloon lightly. And then you're basically doing this test to make sure that you're truly opposed. You can see the balloon tracks pretty easily over the wire here. It's over the wire system. And so here's just an example. You see, there's no flow. So clearly we're opposed at that point. And then what we would do is we'd basically do that sequence. So we hit inflate. It then does the pre-cooling mechanism. And then as it does the denervation, you basically have seven, six, then the patient starts feeling it a little. Typically there's a little bit of movement of the toes. And then I obviously count down to the patient. Now, in this particular case, we're avoiding that osteo area where there was actually plaque, but we typically would have done an ablation here, bring it back 10 centimeters or 10 millimeters, do another one, and then come back and do a third. And these are just gentle manipulations with the hand. You see the guide is very stable. It's not jumping around or moving in or anything like that. This is how it's coming back. I'm making sure it's coming back. And so in this case, actually I did come back and do it near where the osteum is. And then you'll see the repeat the process again. So it's really quick. You basically are just up for seven, you're down, you bring it back, you then basically go up again. Now you see there's no flow there. And here he'll be another ablation that happens here. And it's just seven seconds, the pre-cooling and then seven seconds. And then basically that's the end of that. What we then do is we tend to bring this device out. And then I do take a final picture. I just want to make sure there's no distal wire perf. I want to make sure there's no big dissections or anything else like that. And once you do that, you can then ascertain that everything is fine with that nephrogram on that side. So here's, here's, it basically is coming. It's going to come out in a second. And once that happens, there will be an angiogram that's taken. There it comes out. Even though we're interventionists, I tried not to fast forward or speed anything up. So you could see that's the picture. You don't see a great picture. So I probably will put the guide and take another picture or just be happy with it or satisfied. And then once the wire comes out, you can take a final picture if you'd like. You don't actually need to do it. I have to be honest with you. I've done minimal contrast versions of these procedures as well in patients with CKD that we were able to get approved. So there we go. I know myself, I knew I would have had to take another picture to be satisfied with it. And so then ultimately this will come out. And if the balloon is the same on the other side, you can just leave the balloon in this position and then turn the catheter to the other side, wire the other side and leave it. If that's not the case and you need to swap the balloon for a different size, then what you end up doing in those particular cases is obviously taking it out all the way. And then, you know, moving the guide to the other side, wiring the other side, and then going from there, this is, you can see it's a short guide here and it was a short wire. So I didn't need to, you know, I walked it out myself and that was fine. So now I'm going to go to the other side and then we'll do the ablation on the other side. So I'm not going to show you that because that takes some time, but I will show you some other cases that are interesting. And it's again, just one other thing to show you what happens with the ablation. This is just basically it. You're basically putting it in verifying out position. It's doing the pre-cool there. Then here's a sonication, six, five, four, three, two, one, done. And the balloon comes down. So then there's a deflation sequence. You do have to wait for it to deflate before you're moving it and adjusting it. So then you wait for it to deflate, do that, and then go from there. This is another case. This is the case. This is an example of why I say CTs are good. I don't know if you saw it there, but there's two renals on each side. So you let it play again. It's not rolling. So let me just scroll you through it if I can. So one, two, one, two on each side. And so with selectives here are DSA images. There you go. Two on the left. Here you go. Two on the right. Didn't matter if I use DSA or not. There's two on the left, two on the right. And so in this case, fortunately, the sizes were very similar. And so actually, even though there were four arteries, I actually did multiple ablations. And because there were two, I didn't treat them as accessories. So I actually did one, two on this left renal number one. I did one, two on left renal number two. On right renal number one, one, two, three, and then one because there was a bifurcation and there was a vessel coming here. So I just did it proximal to this part. So just for strategy purposes, I'll show you what I did again and why. So here's the left renal. These are the two different versions. So clearly you can do one, two here. This one, this is a tiny branch, doesn't really matter. So you could do kind of one, two there. This is the right renal. You could do this one, two, three like that. But this one, because of this branch here, you're pretty much left with just one over there. So that's kind of how you do it. You get the hang of this pretty quickly after some time. So that's kind of that. Now, in terms of the last thing I'll show you is there's always questions about, you know, does this thing track because it's an over the wire balloon and it's Southern French, et cetera. So I say, this is hopefully not your first renal denervation case, because this was a patient who had spinal rods. It was impossible to get a good view and had this tortuosity and everything. And I was of course saying, I wish this was a radial device. So in this particular case, I didn't think a Grand Slam was going to free wire down this. So what I used as a buddy system. So I used a BMW Ocean Blue, and then I was able to get the Grand Slam down. But I actually got it with a micro catheter. So I used coronary techniques to do this because yes, I, now I remember I had repressed that part. Basically the Grand Slam was not going to advance in this way. So what I did is I took the, the micro catheter down and then got a Grand Slam to go this way. You can see how everything straightens out at that point. Obviously you have to do this carefully. I do CTOs. I use, I do this for complex PCI. So you can see how everything's kicking out at this point, but as soon as it gets past that phase, then it goes down, it ends up prolapsing and being fine. And then I'm very happy with how that, how that all works out that way. So with that in mind, though, this is actually the device. This is the picture. Are you making sure that it's not a ton of tortuosity and everything else like that? And obviously, you know, you don't want to go into the parenchyma. So you like to go through these segments. It's tortuous. Is this going to cross or is it not going to cross? It's actually going to cross. This was an IVAS catheter I was using for demonstration purposes, but this is the actual device itself coming up and around. And basically you see, it goes, you see the guy's not kicking out. The wire's not coming back. It actually has a pretty reasonable profile. So with that in mind, that's what I did. And I treated that side, same thing over here. There's some proximal tortuosity. You see this bend here. This is the device coming up and around through that bend. No issues. I didn't need to use a micro catheter on this side in terms of doing it. So to summarize, what have I shown you today? Well, I think hopefully I've shown you that this can be a pretty straightforward procedure to do. If you have basic skills, it's seven French femoral, it's conscious sedation. I don't view this as sort of your standard cath sedation. I view it kind of more as almost type, almost colonoscopy type sedation, because even though it's a seven second ablation, patients feel it. And I've done this procedure with four different devices now through, through research studies, et cetera. And it hurts. It, there's no question about it. I have to say it's a good thing in some respects that you, you, you, the patients feel something because there's no other procedural feedback that we have, but it hurts. And therefore I personally feel the less ablations and the faster you can do it, it's a much, much more straightforward procedure for you and everybody in the lab. There's nothing worse for the nursing team. And for you as a person who's taking care of a patient in front of you, I kind of sound like that line from like Notting Hill, like I'm a person or someone looking, I'm just a girl looking, asking a boy, just a patient asking the physician to be sort of sensitive to their pain during the procedure. You know, it's important. And so I think the key thing is, is you want to make sure that that these procedures have the appropriate sedation that having been said, it's a much straight, more straightforward procedure when it's only a seven second ablation and you only are doing two to three on each side. But be generous with those things. It's a standard deliverable over the wire balloon catheter system, treats vessels and accessories from three to eight millimeters. Balloons are sized to vessel. They may need more than one balloon if they're size discrepancies. As I said, the prep time in the beginning was the main sticking point, three minutes and 10 seconds. If you swap for another catheter, it's another minute and a half after that. Those are probably the worst parts of the procedure for me besides the pain that the patients experience. And hopefully you can get ahead of that with sedation. I find though, I'm not using like five of Versed and 400 of Fentanyl. It's more like three or four of Versed and probably about 200 of Fentanyl. That's kind of the cases that I've been doing. And maybe that's because the ablations are a little bit shorter. The external generator inflates the balloon, introduces cooling of the lumen, delivers a seven seconds on occasions. You have to have good technique. You want to make sure you're doing it in the right way. You want to avoid plaque, et cetera. I think CT scanning is helpful upfront. I don't think it's necessary. I think I have this because in our lab, we do it all the time. It's reasonable, but you don't have to use it. Obviously it adds expense. And so the QVA approach works very well too. It's conventional arterial closure, good access. There's a reason I showed you that. Good access is really key to avoiding complications. Conventional closure, same day procedures, patients go home. Many times they don't recognize what we did during the procedure because of the Versed that we've given them. Other times they do. That's why I typically do talk to them up in advance about what they're going to experience during the procedure as well. As far as the blood pressure reduction, you're typically going to leave patients on their meds. They're not going to stop them because usually the blood pressure effects take about two weeks or so or more to have to occur. And I would also encourage you all to do this as a procedure where you're seeing the patients before, during, and after. Don't just do this as a proceduralist. It's really important to get the feedback and understand what patients feel afterwards, what they are thinking about going in. Be a good doctor and hope this was helpful to you. I'm happy to take any questions via email or otherwise. I'm sorry I can't be there.

ultrasound renal denervation

ReCore Paradise system

circumferential ablations

renal artery procedure

conscious sedation

patient safety