In this program, Drs. Jon George and Inder Singh discuss how laser atherectomy has broadened their ability to treat difficult and unique complex cases. This presentation includes a concise review of laser physics and howit's mechanisms of action are applicable in a variety of clinical scenarios.
Good evening and welcome to our program tonight. We're really glad that you've joined us. We have a great program tonight addressing the use of alcohol and we're very honored to have two great physicians with us. Um First uh with us is dr endorsing who's the cardiac cath lab director and director of the structural heart program at event is heart and vascular institute in various from California. And we're also joined by dr john George uh practicing interventional cardiology and structural heart at the pennsylvania Hospital, part of the University of pennsylvania Health system in philadelphia pennsylvania. Now as we prepare just to let some logistics, you can use the ask a question feature to ask any questions during this or raise your hand and we can you during that during the program and we'll stop here and there and and allow you to ask questions through those two mechanisms to ask our operators. Um We have doctors seeing with us and I'll get as a presentation ready. But as we do that, there are some poll questions that Dr Singh is gonna help ask the doctor Sing if you're ready to uh come on along and uh join us. We'll have these bold questions. Yeah. Great. Yeah. So here's the first poll question that will you can go ahead and so hello everybody. Good evening. Um uh this is our poll questions just part. So, first of all, as this program begins, would like to know what your use of alka is uh in your pcs and what your comfort level is. So the choices are in front of you very comfortable, use it often somewhat comfortable and use it occasionally, not too comfortable and use it rarely. Or don't really use Alka in my practice dr Georgia if you have, you can uh come along and uh kinda analyse the results. I'll be ending the polling here in a bit and well, see what kind of results. We just let more people vote on that. Yeah, Thanks again, David, thank you uh, phillips for organizing this and for having me and under here as part of this exciting session. Again, this is just a good overview for us to know what your comfort level is. And we see these tickets changing as the voting comes in. But I think We're somewhere in the middle with comfort level with somewhat comfortable being majority and very comfortable being about 30%. So, um, so that's good to hear that a lot of you have experience with Elka and and are fairly comfortable with it and hopefully we have some more to add to your knowledge base today with our discussion. There's your final results and then we have one more question. So, great if there's yeah, just exactly what you said. Very nice. And here's one more question. So go ahead you guys and I can take that as a regarding your use of uh current use of labor laser. Um just a few aspects of how you use it. So I use it in my complex patients. I use it mainly for C. T. O. S. I don't use it in my corner cases. Only peripheral or I don't use currently use laser at all. So if you could look more please. Right, so there's no one that's using it just for purple cases. Uh that's good. So it looks like there's a fair amount of experience within the coronary space. I'd like to introduce dr Singh and allow him to begin our program tonight. And again, you can use the ask a question feature to submit any questions to our panel and we'll try to get those in when we can and will also be time at the end of the program. So family Further do dr Singh? Thank you very much. Yeah. Thank you. Thank you. Dave again. A pleasure to be here. So if you can go to the next life please, These are my disclosures. Next. Perfect. So I think it's a good to start off with some basics about alka. So just as looking looking at you know what what it can do. I think it's important to realize, first of all this excitement asia for coronary extract me that essentially uses ultraviolet light to break up material with it be soft black, whether it be vibe Roddick material or even moderate calcium into the size of red blood cells and the pneumonic that we want. Hopefully for you all to take away from this. Today is I. O. U. Which is basically focused on instant restenosis wire across the conclusions, but then nothing else crosses. So that's religion comes in and then undebatable lesions, uh perhaps were a balloon, balloon won't work, etcetera. So those are the things that we like you to remember as we go through our mechanism of action next. So if you can see the slide, there's a lot on this slide. But essentially what the slide is showing us is how does Elka uh compared to some of the other aspect of the devices that are on on the market and what a lot of you have already alluded to is you use it in I. S. R. Which is great. It's a great use for that. Very indicated device for that. But there's also other indications for use of laser and uh like you talked about some things like total occlusion. Uh Main graphs is a big one, uh filled balloons, osteo lesions along collisions. Those are also indications for uh for laser use. And you can see how it compares to some of the other uh threat commune devices which are mostly folk based on a calcium based developing and on the bottom of the slide, you can kind of see some of the contra indications for alka uh in general and then specifically for the alka X 80. Um and you can see those here essentially lesions where uh their acute bands guide wire won't cross. Uh perhaps some verification lesions and there's some other clinical uh contraindications next place. And that's kind of for those of you who are familiar with using laser. Obviously you've seen this before for those of you who are new to this technology, you'll see essentially the work is done through this laser fiber. You can see the crystals there at the distal tip and then there's the approximate coupler that actually goes into the actual machine uh that generates the power next place. So I think this is sort of where we would like you to really uh hopefully be able to understand how laser actually works. And one of the things it does, as you can see on the video, it kind of when it plays, you can see the actual laser acting. And this is a high speed, high resolution video. But really there's three uh aspects to how the laser works. One is the UV light actually breaking down the molecular bonds. There's the sonic wave that that then cracks the tissue with it, the fiber article moderate calcium. And then there's the capitation bubble that actually uh causes the main debunking of the lesion. And we'll review each of these steps a little bit more in detail. Uh So next please. So if you look at the UV light aspect here, you essentially uh Yeah, thank you. So essentially what you're, what you would see here and this is something we want to make sure that all of you understand is that most of the action that's happening is within 100 microns, microns of the gatherer dip right at the edge of the tip is where all the UV light actually is acting. And then beyond that, that's where the 2nd and 3rd aspects of uh the action take place. So next please. And this is important to understand the concept that there's a whole idea about heat generation and uh concern about how the laser may act at the local, local level. And so what you we want you to understand is that the laser sits somewhere in between the infrared uh spectrum. So, if you go next, Perfect. Thank you. Essentially what's happening is where this laser, Since it's a cool laser that actually is not generating very much heat, there's obviously going to be some key generation. But most of the effect is at the particles that are very close. And then most of the subsequent effect of de bulking and tissue maturation is going to occur in the 2nd and 3rd steps, which will show you an example next this. So here you can see how basically, once the particles uh molecular particles are broken here. The sonic wave that's actually created uh through that motion, then does most of the immediate effect within the near field of the laser itself by breaking down the molecular bonds uh close to the Katherine give. And this is a good representation that you can see. Go next, please. That's a good representation of the sonic wave um of how how it acts and you know the the scope of where it would act in the tissue. Um And you can see here essentially again the idea of being the initial action is very close within 100 micrograms of the laser dip. And then the sonic wave does the rest. So which is which includes cracking the tissue, a fiber optic issue of modern calcium. Next please. And really the major effect then comes from the gravitation bubble. And what is essentially happening as you can see on this on this video that's playing um is when the capitation bubble initially forms once the laser acts, then it actually folds on itself. And the force of that is actually then debunking the rest of the tissue. And so most of the action that happens. Whether it be the maceration of tissue is happening to this micro jet and this is what then causes the uh um no material whether it be soft, black vibrated black et cetera to break up into uh less than red blood cell size. Go next this and so here this kind of summarizes for you all the actions of the lasers that we've kind of gone through essentially looking at the U. V. Light first which breaks the molecular bonds uh of the lesion. Uh This allows these uh particles to absorb a lot of the UV energy initially, then the sonic wave that actually impacts the tissue by by breaking these molecular bonds that have been formed. And then finally the gravitation bubble that actually devotes the lesion or the tissue uh by collapsing into this micro jet at which essentially masters this issue at a high speed next. Please. So we'd like to share a couple of representative cases for to understand the mechanism of action. So this is a case uh I'd like to share with you of a 75 year old gentleman who came to us uh an acute coronary syndrome. And you can see his E. K. G. You can see also that his EF is uh Quiet down and about 25 30% range. Uh interior wall. Am I go next please? So at our institution we follow the N. C. S. I. Algorithm which he fit nicely into both from a human dynamic standpoint and from a clinical standpoint. Um And essentially with the hyper profusion of the organ. So next please. So what we typically do in these patients we'll do envelope BBC which we did. We took his diagnostic pictures which you can see here on the right side. He's got some disease and the distal bl but really all the action is in the lady and the diagonal. And what you can see there's a sort of the area of quite a bit of plaque in approximately lady and then a fair amount of black into the diagonal itself go next place. And essentially so what the concern in these kinds of cases would be that of distal embolization as you can imagine. And uh so what we are strategy for this was to use uh elka. Um And essentially we did that in both the main branch into the lady and also into the diagonal. Uh and then and just sculpted uh the diagnostic um next place. It's going to just highlights those next. And from there on we were able to do facilitated uh PC I using the mini crash technique in uh led diagnosed verification followed by kissing balloon uh and double balloon at the Austrian. Go next please, and this is your final result. So again, the idea being uh we were able to avoid uh distal embolization, uh clear out the diagnosed him as you can see which had a fair amount of black uh building there and uh we're able to get a decent result uh in this patient next please. Uh and this is the cf after a few weeks and had recovered and then we followed it up at some stage PCF the other vessels that were disease. But here the idea being again utilization off laser because this was more a soft black, more acute coronary syndrome type situation, your settings. Then the application of the device will be different than in a ceo situation. And I think john is going to go over some really nice cases to go over utilization in uh some of those different scenarios next place. And this is a case of a patient with the with the C. T. O. That again we'll look at how we apply and this is really a very representative case from a iou standpoint in the morning that we talked about instant restenosis, exclusive vessel or lesion and then undebatable. So this is a lady who had recurrent angina, abnormal stress has failed previous pc. I. For a occluded R. C. R. C. I. S. Are legion that is osteo. And so we brought her back uh and this time we went in with the focus strategy of using more advanced techniques. Go ahead next place. And you can see on these uh pictures essentially our R. C. Is included. Uh and you can see a feeling from the left system next please. You can see sort of a functional CPO with very little flow right at the Austrian. And I don't know if you can tell on this uh angiogram, but there's a stand right at the Osti um uh, that may even be coming out of a millimeter to from the Austrian. So next please. So I can share with you that when this was done uh previously by one of my partners, we were able to get a wire down, but they weren't able to get even the smallest balloon down. And here you can see even a micro catheter is having a hard time going through. So what we did is uh went in with alpha essentially sat at the osmium again, uh john will go over the specifics of the settings, et cetera with you folks. But essentially the idea being in this lesion that was nothing else would cross. We sat without that osmium to be able to help this cross for next place. And here, you can actually see when the alp actually pops through after several minutes of sitting in the SG. Um and just post elka, you can see there's actually established close, it really was just a very tight osteo uh occlusion. Um and once the alcopops to even with that, we establish a fair amount of flow and next please. And then and just go there. Um you can see the post endoscope pictures and go next and I think that would be, yeah, that's our final so that those are final uh, pictures. We were able to get a good result. We have responded, responded Dostie. Um obviously I'm not showing for the case uh, the imaging, but clearly in these kind of cases, imaging is very important to make sure your standards appropriate size. You understand the mechanism of fire star and things like that nature. You go next please. Okay, so just going over those same indications again with everybody just to kind of focus on the pneumonic of I. O. U. Uh Focus being eyes are essentially which just looks like several of your years already. The exclusive disease, whether B. C. T. O. S. Or rain graphs that are exclusive and then undateable lesions or moderately calcified lesions would be another set of indications that would be important to remember for your use next. Okay, this is my contact information. Uh If and if you have any questions uh I think there's gonna allow that, but even afterwards if anybody wants to reach out to happy to happy to engage. Thank you. All right. Thanks so much. Doctor saying that was great. I know we did have one little question maybe that we can pop up and see what you guys think. Um This is for either doctor. What precautions do you take to avoid? No re flow considerations in the R. C. A. Yeah I think that's a good question. I can share with you what I do and then uh perhaps john to share stock. I think it's always good to in these kind of cases whether it be our CIA or even the spg use some uh medical therapy or for mesotherapy. Um Up front if you can if you are concerned about those people have used everything from a nitro door night bride to uh sardine to a dentist in etcetera. So you can use that up front. But of course if you do run into that the best way to go about it that I found is to take a micro Catherine down there and give it into the distal bed. Um If you run into the inspector john, what are your thoughts? Yeah. I mean prevention is key. Right. I mean you want to try to prepare yourself for not having being in that situation if you can. And so exactly as you said basic dilating, corrupting the vessel as best as you can. And then when you're treating it, the key is to go slow, go extremely slow through the legion. Uh And the likelihood of you know mike ramble obviously is significantly less cut down the run times. You don't want to run for too long. These elka catheters have automatic um shutdowns and recovery periods which we'll go over uh in just a little bit. So there there are things that you can do technically to ensure that you don't set yourself up for failure and you don't have um no reflex syndromes or significant embolization. So that that would be key and preparing for the lesion. Um David, are there any other questions I'm looking? I don't see any other questions, but again, use the ask a question feature and we will uh insert those. Otherwise. I think dr George can go along with his uh presentation but please submit any questions or raise your hand. We're able to do that and we can try to uh ask those but to ask a question is the best feature. We appreciate any questions. Perfect. Then I'm gonna get started on sharing my screen. Yeah, great. Can you see it in slide share format? Yeah, we do but we do have some questions coming up so we might as well just tackle those while we can. Um So the question is uh when you start, when you stated that the 0.9 fiber pushed through the osteo lesion, how many 12th runs? When you estimate it took dr saying that's a question for you about that case with pushing through that osteo lesion asking how many 12th runs do you think it took to really push through that? Do we lose doctor saying we may have lost him? Okay. Well, we can come back to that question in that particular case and I think I have some osteo lesions as well and I can talk through my case as well when we get to that point. Okay, So I again, thanks again for having me. Thank you all for joining. Uh I'm going to talk about some more of the practical aspects of of doing uh laser a threat to me and the coronaries here. My disclosure, obviously I am a consultant for phillips. Um so optimizing the use of laser is key. And uh we kind of touched on this when we talked about no reef, low and slow flow uh but there are three steps uh that you need to focus on. Step one Catherine advancement, Step two is a power settings. Step three, The frequency uh control. And so these are the three ways that you can control and optimize the use of laser. So let's talk about Katherine advancement. First know that you know as interventional cardiologist. We tend to be impatient and we tend to try to get through fast and treat lesions fast but fast is not necessarily good. Um So allow the laser to work for you. Do it slow. Um And we know that ultraviolet light Penetrates at less than .1 countries less than .1 mm. That's 50- 100 microns. So you need time for these lesions to absorb this light and and display the result that it can allow. So slow, repeated passes is what's best for optimal results. Um So this this little motto here about go slow to finish fast is really key. I mean it it appears that you're taking so much time, but that's what will result in a good optimal finish. So if you look at this table of this, uh this cartoon on the right, you see the difference between the lumen gain from fast advancement versus slow advancement and you see the cross sectional view and the longitudinal view of it. Uh And the reason for this is purely allowing the laser to work. And so if you go slow, you allow that vapor bubble and the laser pulse to penetrate and and create more of a loom in. Then if you go through the legion very fast. Yeah. Step two is the power settings. Um so what we used to objectively control power influence on the laser console. So, fluent is the power or energy of the laser. Uh So first of all, you want to flush out all of the contrast with saline prior to initiating laser a threat to me. Then picking the right size of the laser catheter is critical, so no more than two thirds the vessel size and then the capitation bubble recognized that that bubble that's created as you see in the animation. Um it shows you that it can be 50% larger than the size of the catheter itself, so you need to be aware of that. So the effect that it Stigned that the Catheter allows is much larger than the size of the Catheter itself. And then as you increase that power or increase the influence from 30 fluids to 60 fluent, you'll notice that that bubble is significantly bigger and therefore creating a larger loom in as well. Uh And here's some demonstration of this absorption you see in saline uh there is no ultraviolet light absorption. So all of that power is going right to the plaque or or the uh the lesion itself as opposed to contrast, where the light is completely absorbed by the contrast and therefore this very little. It's creating uh micro bubbles and and uh different from from what its effect would be on the plaque within the vessel lining the vessel as opposed to what it does within the media itself. And so this is why it's important to really flush through the blood and flushed through contrast and just have saline while the lasers operating. Um And then finally three is the frequency control and that's selecting the number of pulses. So you got fluent and then you've got the rate. Uh So this rate really acts on multiple different uh mechanisms of action. Which dr Singh already went over with the ultraviolet light and the sonic wave and the gravitation. But recognize that that's a single laser pulse and you have you could have multiple of these in one second. Uh And so that is what you controlled by frequency or controlling the rate at 25 hertz versus 80 hertz. You have significantly more pulses per second. And so it's a repetitive action of all of those steps. Um And then there is um uh sorry? Uh We have a lot of data over the utility of uh laser in the coronary. So there's been multiple studies that are done granted Now these are not necessarily current studies but there we've had years of data uh including ones that cross into the recent era. And so these are a variety of different studies that look at various uh numbers of patients across multiple centers. But you'll see the common theme are those last two columns of effectiveness and safety. Now that the effectiveness is, you know, approaching 90% or greater. Uh and the safety margins it's very safe across the board with very low perforation or dissection or embolization. Um And so that is key. And you utilizing an a thoracotomy system for your your cases. So now we'll get into case applications and have a variety of cases depending on the amount of time that we have. Um uh So here's uh first case um that I'd like to demonstrate a case of stent under expansion. No, we have uh this is again a position you don't want to be in, but nonetheless, we've all been called in or have had our own cases where you had stent regret where you placed a stent and it doesn't expand to what you thought it would expand to and now you're stuck because you placed a stent there. Um This was a case that I was called into a patient that had prior stents in the L. A. D. And you'll see already before the contrast goes through the vessel that there is under expansion of a previously placed them there. Although the lumina graham looks okay, you can you recognize that there are significant restenosis in the expanded part going into that under expanded segment. And so the lumen looks okay. But you know that there is disease and under expansion. This was treated appropriately with the noncompliant balloon. So it was recognized by the operator. But again, it sometimes becomes hard to see if you have adequate sent expansion or not. Um and uh so you'll see as we go to the next image. Uh This is a larger balloon that is being expanded within that stent. Again, I think you see a little neck where there is under expansion. Um and and the last thing you want to do at this point is to add more metal to an under expanded segment. But unfortunately, that's what was done here. Um There was another long stent place to cover the gap between the two stents, but also overlapping that area of under expansion. And now that under expansion becomes amplified and you see it so much greater. Uh And this is where I got called in because as soon as that was recognized, subsequent noncompliant balloons uh would not extend within that segment. What you see here again, is an area of under expansion to the point where noncompliant balloons are dog boning at the lesion, Um And this is what you're stuck with. Uh And so the question is, do you leave that alone, which is not appropriate in this? Uh Come back with restenosis at best and at worst and thrombosis right at that site. Um And so this is where I got called in for laser. Uh and uh you know, we went through utilizing a laser and I'll tell you that in in my cases such as this, I tend to use the laser catheter based on intravascular imaging and sizing of the vessel. Um So if the vessel is three millimeters or larger, I tend to use at least 14 or 17 laser catheter, uh um And then also depends on the size of your guiding catheter. So in this particular case, I used to 14 laser, I had it sitting right at the proximal edge of that under expanded segment. Um and I allowed the vapor bubble from that laser catheter to work directly at the site of the under expansion. And this is very different ascent under expansion. Especially a focal under expansion is very different from a typical laser, a threat to me case where you're trying to do bulk plaque here, You're trying to work on a restrictive lesion outside of the stent and so you're not really moving the catheter as much as opposed to letting it sit and letting the laser do its work. So in this particular case, it was multiple runs of a larger laser catheter um uh to allow it to take effect. And in between pulling the catheter out and using a noncompliant balloon to see if if you've had adequate effect outside the stent. And that's what we achieved. What you'll see is in a non compliant balloon that expands much better. And here's the final result. That looks significantly better than what we started with again, Not perfect, but much better than what we could have left behind If we had not used laser a threat to me in this case. Um So that's a very nice application in my mind of utilizing um uh laser a threat to me uh in an under expanded stent. I want to bring up vein grafts because these are unique cases as well where you can be overwhelmed with uh symbolic and probiotic debris. And this uh brings to light again the question that was asked earlier about uh slow flow or no re flow. This was a case that we published in catholic digest. Uh It's a unique case where we this patient was just had a catherization Uh two or 3 weeks prior to this presentation And we knew that this vein graft was open and this patient came in with an n steamy uh And on this admission on repeat and geography, this vein graft was included. Uh And so we knew that it was a sub acute occlusion at best. Uh And this patient had significant mitral regurgitation as well from the territory that the supplied and uh due to papillary muscle dysfunction. Uh And so the decision was made to try to intervene on this pain graph. The problem, however, is you can't visualize the extent of the robotic debris in a vein graft that's completely occluded and you can't see the distal vessel. So you have no idea where to put in a um a filter. And so we had to obviously got a wire across reasonably easily but it was very difficult to get equipment across. Uh And so we actually had to do a very gentle dilation pre dilation with a small balloon gingerly so as not to um mm belies distantly. And then we did laser a threat to me. And this was a perfect scenario for laser a threat to me because again we still have no idea there's no integrate flow, we still have no idea where we can place a filter and so we perform laser a threat to me through the entire graft. Uh and this way and here we just utilized a .9 elka and we're able to treat through that entire segment with multiple runs. You'll see in that figure and figure five. That we did use uh black of protein to be three inhibitor as well because we expected the amount of debris from a degenerated vein graft to be significantly high. And once we did that we had enough visualization to at least see the distal end of the graft and be able to place a filter on top of it. So then we place a distal filter uh and was able to adequately treat this vessel. And you see that we've got a fantastic result. But the reason why I like to show this case is because despite all of that we took a lot of precaution. We used laser attracted me upfront. We used this symbolic protection device. We did all the ballooning and stenting with the filter in place and the final angiogram looks great with brisk tv three flow into both om branches. Uh This vein grafts apply except upon completion of this angiogram, we retrieve the filter and literally the next picture after retrieving the filter showed that we lost one of the om branches. And this shows again the capacity of uh what a vein graft could hold. And and you know, you can overwhelm the filters within a vein graft and you're treating an entire band graph. And so it's just again, just to throw they throw in the importance of being able to treat and pre treat these lesions adequately. Uh and uh in this particular case, despite laser, despite using a filter, we still had embolization into the distal vessel. So you can only imagine what would have happened if he hadn't utilized laser at the beginning anyway. Uh And so this was easily thankfully recovered by wiring with the second wire into that own branch and then ballooning. And we were able to successfully retreat that branch and still at 23 flow. So it was a successful save but lessons learned about embolization. Uh This is a case of uh chronic total occlusion. Um This I I like to demonstrate because again, you can get fooled so easily when you've done a bunch of these cases. This was one of those cases where I got fooled. Uh and what you'll see here in the initial angiogram is this is a chronic total occlusion within a previously stent, ID R. C. A. Uh so you have overlapping stands throughout the entire R. C. A. Uh with reconstitution of the just a vessel from left to right collaterals. And what I assumed uh inappropriately so, uh is that this would be a very easy cto to fix. The reason why for those of us that have done C. T. O. S. We know that once you have a stent protection and a guide to really uh advance the wire and the catheter, you have essentially aluminum marked out for you. Uh Yeah, this turned out to be one of my most challenging cto cases and I'll show you why. Here's again the vessel that do aluminum, dual catheter injections of the left and right systems demonstrating reconstitution of that distal Arcia. It reconstitutes justice Still to the stents. I thought this was gonna be easy. I have a support catheter coming through with a wire. Uh, and you'll see in the next images how it's easier said than done. And the reason why is that? You'll notice here that even the support Catherine weir tended to go outside the stents. It was so fi Bratt IQ and included within the segment in the mid R. C. A. Uh, that nothing could cross. It took the path of least resistance. So anytime I advanced, even a way to tip wire, it was going out of the stent struts and around now you could argue that you could come around it and re enter and as long as you go through the true, you could crush these stents and still resend the whole thing. But it's not, it's not attractive. You obviously like to go through the center lumet. Uh So I tried a variety of different techniques. I tried uh laser a threat to me here, integrate, we use this in the periphery of the step by step technique, but um utilizing this here, trying to soften that proximal fiber Roddick cap within that mid RC inclusion. Um was the attempt here. However, despite trying to do that with laser without wire crossing, was not successful. And you'll see here in subsequent images at the same problem occurred that the wire and Catherine were still exiting the vessel. So, no problem. After spending a lot of time I decided to come retrograde, coming back through the L. A. D. Settles. We were able to wire and bringing support catheter retrograde around the septal collaterals into the disk Garcia. We're now at the distal cap and we think we're home free now we're back at the stent will be able to cross this pretty quickly. But what do you see here in this video image? You'll see that that retrograde wire is crossing nicely so much easier through the stent. But don't be fooled. Check out this segment here. You'll see that the wire has exited out of the stent and gotten back in again. Even coming retrograde through the distal cap, it still caused the same problem. The lesion was just so vibe, Roddick, we couldn't get through. Uh and so we had to again, uh do a variety of different techniques and we were able to um thankfully use awaited tip wire retrograde to cross through the central lumen of that stent and externalize the wire. Uh And to make a long story short, uh This was retrieved, successfully snared externalized uh to create a nice um left to right loop that you then have the railing to be able to treat however you want it. And so with that railing, knowing exactly how high broderick and annville able that lesion was, uh we decided to do laser a threat to me through that entire segment. And this time around you're able to pass the laser because of the railing, the wire across it and the support that you had from both sides. And we were able to laser through uh the entire R. C. A. All the way to the distal stent that we couldn't initially uh and got a great results with just laser and balloon angioplasty. We put one stent the osmium and flared that with the flash balloon to make it accessible in the future. And this is the final result uh that I don't think we could have achieved without all of those techniques that were described. And also using laser after up to me to to adequately treat that entire mint to distal stent segment because it was very um uh fiber optic and resistance. And again, I I also want to reemphasize the need for intravascular imaging in some of these complex cases. And I tend to routinely use it in most of my appendectomy cases, especially in a recent erratic and included case where you want to know the path of physiology of what occurred. And also to make sure that you get adequate stint expansion. Because in my mind this the reason why it was so high broderick and the wire kept exiting is because the natural vessel, the vessel architecture is significantly bigger. Uh And so I was still within the lumen of the vessel. Uh but outside the stent every time it exited. Uh And so the vessel was just so much so much bigger. And the stent initially that was placed was so undersized, which was appropriately treated afterwards with imaging. So I think we should probably stop there. I have many more cases, but I definitely want to leave time for discussion. Uh We do have some great questions that I think you can answer about um your cases and and and dr seeing too if you want to address these. So we do have a couple questions. Um One was basically about yourself in this vein case um about sizing. Should the sizing be the same for Elka with native coronary artery. Or how do you size with bypass graft? Your your fiber versus your vessel? Yeah, That's a great question. And I I tend to use the 17 in a big vein graft. If it's a vein graft obviously if it's a lima or radial artery conduit that smaller, I used a smaller catheter. But you know I I tend to use the 17 in the vein grafts just to get the maximum opposition of the vapor bubble to the vessel wall. Uh and to make sure that I can do bulk as much of that plaque as possible and reduce the symbolic debris. But again it's about sizing it appropriately for the size of that bank graph and also doing it slow and methodically advancing it through the through those lesions because there is a lot of debris in a degenerated being graft. So just be wary of it. And we also have a question about techniques with double wires. What technique to use in a modification if you want to uh do you lose access on both arteries? But want to do elka on either one of those are both of them? How do you do that? Having two wires? Uh India are you still on? Do you do you want to take that or do you want me to go forward? Sure. I'm happy to. Uh Yeah, that's a very good question. I you know, for me in my practice, I think that's really one of the niche uh indications for this because you don't have to actually lose your wire on in the in your side branch. And it really helps in patients who basically have a true uh medina 111 lesion or something of that nature. And you want to treat that while maintaining your wire. Um I think it's one of the niche indications obviously as you know, and most of the other uh a threat to me, you cannot really have a second wire down uh, do a threat to me next to it. So I think it's very doable. Um it actually saves many cases. Uh my experience. Yeah, I agree. I think, I think it's it's one of the advantages of using laser attractive is the only after actively device that you can use, protecting both branches in a verification. And so you could have wires across the whole time. You never have to worry about losing one of your branches or compromising one of your branches and be able to laser as many times across both the parent and the side branch or the two side branches. Or however, the anatomy maybe even left main into cirque and an L. A D. Um, and so it's the versatility of using laser cataract. I mean, those qualifications, The one thing I would add is if you are going to be doing a verification lesion for folks who are starting to do this uh, in their practice, um you want to make sure the the uh wire that either of the wires, but specifically if it's on a side branch is not a hydrophobic coated wire because if you're lazing across it and uh in the parent vessel or in the hydro wires entirely hydrophobic, there is some potential risk there. So if you're going to do a verification specifically, you want to make sure that the wire that's in uh there the part that you're doing lazing on is not a hydrophobic park. So just something to be careful about their great, yeah. We have some other questions that we can do after the poll. We can probably have an old Q. and a at the end. Dr c uh George, did you want to present any of your cases? Are you good? And we can go to do the polls and then we'll have a whole Q and a session with the end. Are you okay with that? Yeah, I'm okay with whichever way you want to proceed cases if you need to or we can do the polls, we have a whole bunch of Q and A. That will do at the very end. So I just want to uh as we kind of went through your presentations. Right, Well, we can ask some of these other um holes if I can get to them. No, we already did that one. Sorry about that. So here's another one. Yeah. That you can ask dr George. All right. So, so now now that you've heard a few of these discussions and and seeing a few of these cases uh, following the information you receive during this program. How do you feel your comfort level and understanding of alka uses compared to before the program? Uh So where do you stand now? I mean, a lot of you were somewhat comfortable too, very comfortable to begin with. So we had already a seasoned audience. But how do you feel to be help? Uh did it uh improve your understanding and comfort level? Good. Well, let a few more people answer that question. We appreciate your feedback. Um, We like hearing about that. Oh, create folks and we'll show you the final results. Okay, That's good. We uh this is this is a pat on our backs I guess. Uh you feel like uh most of you feel like, yeah, you had some improvement in comfort level and and more likely to use it based on what you heard. So Oh actually the speeds well into one of the, one of the questions we got was for each of you, for both of our speakers is how many cases do you think it really takes to feel comfortable with using laser? What would you put in your estimate of how many cases you think did it take? Um So I can I can start with that. You know, I think when you ask that question, you kind of have to figure out what part of uh laser are you trying to get comfortable with? Right. I think just doing, You know, 10 cases you'll be very comfortable with the laser operation. Uh so just you know, as far as fluent and rate and understanding how to advance the catheter, how to set it up, those kinds of things. I don't think it takes long to learn that. I think the longer time that I think I'm still learning as we do more complex lesions. Doing bifurcation is doing C. T. O. S. Applications and annville edible lesions. That's where you know, doing more and more improves your um your comfort level and your expertise within that segment. So I think there's a lot to be learned till you've done, even if you've done um you know 25 30 DeNoble lesions, it's going to be different when you're doing a vein graft case for the first time or a C. T. O. Case for the first time. So those don't necessarily translate because the techniques are slightly different or an under expanded stent where the technique is slightly different. And so You know, I think within each subset, if you get about 5-10 cases you should be very comfortable and there you have more dad um and uh I agree with you, I think just from an operational standpoint, I think 10 cases is a good number to get comfortable with it, but I agree with you, I'm I'm still learning in my practice and getting comfortable as I do more and more. So it just, it just depends what you, what you end up tackling uh on routine for folks who are doing cTO work routinely. Uh and if they are looking to add laser uh into their toolbox, uh you know, it's a different scenario than folks who are trying to start CTO work and lasers is sort of one of the first devices that are attracting me that using. So it's a little different scenario, but I think the idea is you do want to, as, as john said, get comfortable with the operations first one simple. The noble cases because there are some subtleties and technique uh, in how you use the laser in what circumstances, undeliverable regions etcetera. That as you gain more experience you'll get comfortable. And I think this is where these kind of interactions help uh, when you talk to folks who have had some experience uh reach out to some of your partners or people in your communities who perhaps uh for us for that matter of uh use laser for a while. I think it helps to kind of uh engage from them what they're using and what are the settings they're using. I think that really helps for the experience to right? And we do have one more polling question that just helps us from phillips to understand the needs of our customers. So um, if you want to go ahead and fill that out for all of our physicians out there, um it's letting us know if you want more additional information from phillips and we'll work hopefully with your local reps or your market reps wherever you are in the world because we do have a global audience tonight. So hopefully we can try to help connect you with your local rep and let you have more resources to continue your learning for laser. So we appreciate that. Great. So we'll try to gather that information and we appreciate it. So with that I do want to say thank you. We are going to continue the uh the Q. And A. So please remain on the line for that. But we're going to end that part of the program and continue with Q. And A. Uh huh.