Dr. Brescia discusses various interventions for aortic valve pathology and ascending aortic aneurysms and what the current recommendations are for intervention.
All right, so our next speaker is Alex Brescia, who completed his medical degree at Saint Louis University School of Medicine. He then moved to Ann Arbor, Michigan to complete his masters of Science and Health and healthcare research at Rackham Graduate School. Then his research fellowship in health care policy and innovations, his residency in integrated thoracic surgery, and his fellowship in advanced aortic endovascular surgery, all at University of Michigan. He specializes in adult cardiac surgery, aortic dissection, aortic valve repair and replacement, aortic annular enlargement, aortic repair and replacement, ascending aortic, obviously you do a lot of aortic. Um, aortic arch replacement, aorta aortopathies, complex aortic surgery, coronary artery bypass, grafting, mitral valve repair, and replacement. Transcaheter aortic valve replacement, tricuspid valve repair and replacement, and valvular heart disease. He is currently assistant professor of surgery with the division of cardiothoracic Surgery. In the section of cardiac surgery with WasU medicine and sees patients at the Center for Advanced Medicine at Barnes Jewish Hospital. So, today he is going to talk to us about the role of surgery for severe aortic stenosis and ascending aortic aneurysms in the trans catheter era. So, thank you so much again for your time, we really appreciate it. All right, thanks, Nicole. Let me know if um if you can't hear me very well. Does that sound OK? Yep, sounds great. OK. Great, thanks for that introduction. All right, so there's just a few disclosures, some of these slides are borrowed with permission. So, what I'm planning to talk about today is, is two topics that I think will be relevant to your practices and some of your patients. One is aortic valve pathology, specifically aortic stenosis, and then also ascending aortic aneurysms, and kind of what the current guidelines are, you know, when those changed, and, and how we use them in practice, which should be insightful for some of your patients that you see with these issues. So starting with aortic valve pathology, you know, there will be a little bit of a surgery theme um to this. Aortic insufficiency, you know, we treat a little bit differently. We generally try to repair the valve, if at all possible, um, which is shown here, versus aortic stenosis is always gonna be a valve replacement. As I'm sure everybody's aware, TR trans catheter aortic valve replacement has become the dominant strategy for doing that, and this is a graph from, you know, 2012 to 2023, so the current, you can see the green line there is TAVR, which is, which is far surpassed surgical aortic valve replacement, which in total is in that blue line there, uh, which took a little dip and now is, is kind of steady. So, you know, corresponding to that, surgical explant of TAR valves is actually the fastest growing open cardiac surgery that we do, um, which kind of stands to reason that so many TAVRs are being done, uh, some of those are also explanted. So The question and kind of the topic here is what is the role of surgery for people who still are having surgical aortic valve replacement? And for a historical perspective, kind of how we got here, um, surgeons, we've been placing small valves, and so the normal aortic annulus, just of a, of a human is a 23 and a male and a 21 and In a female, and, and this has been shown through studies and a normal area is about 3 to 4 square centimeters. So some of the, some of the very big, uh, TAVR, and, and I'll say SAR, just means surgical aortic valve replacement. Some of these big trials, you know, the median size that's been placed is a 21, uh, and then more recently in these TAVR trials, in the surgery arm, the median's been a 23. And I think a lot of people, surgeons included, think, you know, well, that matches up with the, the annulus of a, of a normal person. And the, the problem with placing too small of a valve has been demonstrated, you know, first here in 1978, which is that if you have too small of a valve and you develop prosthesis-patient mismatch, uh, that leads to earlier valve failure and is strongly associated with death, among other bad things. So, one of the things that we found is, you know, a 25 bioprosthetic valve is not 25 millimeters, the actual inner diameter is about 2027 is about 22. 29, which is the biggest valve that there is, is actually about 23 or 24. And so in general, you know, the inner diameter of valve sizes are actually about 5 to 7 millimeters smaller than the labeled size. And a lot of people don't realize this. And so those trials that we're talking about, um, you know, it's not a 21, it's a 14 for all intents and purposes, a 23 is a 16, and that's why we see about 60% of moderate or severe prosthesis patient mismatch in these, in these most recent trials. So surgeons have, have honestly not done a great job um at doing this. And so, what does this look like? This is a table of, you see the annular area reduction. This quantifies how much you lose by putting a bioprosthetic valve in. So, you know, at 25, which is actually 20, you lose, you lose between 40 and 60% of the actual area of that person's native annulus. And the column on the right shows something we're gonna talk about of doing an annular enlargement, you know, you restore that or in some cases, end up with an even bigger area uh than you started with before surgery. So this is a study that that echoes these findings, and this was carried out by the FDA. And what they did is they did in vitro testing of basically every brand of bioprosthetic valve, and they did that to come up with this new parameter called effective orifice diameter, which is what it sounds like, uh, you know, it's the actual diameter that sees the effective flow that you get after putting a bioprosthetic valve in. And so it's not. You know, it's not the size, it's not label, it's not determined by the company. It's determined by this testing of what the actual blood flow diameter is. And what they found is exactly what we just described. So, this is two examples of the most common valves, magnaese, we've probably seen some patients with those, or inspirus, this is, is a similar valve with different leaflets. Avallis is the Medtronic version of this. You can see the sizes, sort of the labeled sizes on the left, and then you can see what the actual effective orifice diameter is on the right. And it's about 5 to 7 millimeters less uh than the actual labeled diameter. So, just to put that in perspective, you know, if you think you're putting a 23 in, and it's actually a 16 millimeter diameter, you're losing a lot. That's not the whole story, so a lot of times, um. You know, people who are surgeons often who, who put valves in and think, well, this is big enough, uh, you know, they were measuring those gradients under anesthesia, with the patient literally anesthetized under general anesthesia, and Patient's valves and uh the gradients behave extremely differently, whether you're under anesthesia or whether you're, you know, functioning as an active adult. And so I think that makes a big difference. If you have somebody who's very active, that's different than someone who's in a wheelchair and you're doing this as a life saving measure. So, how do we mitigate this through surgery? And this is something I talk about with patients a lot, because we Very commonly, anyone in their 60s, 70s, and even sometimes 80s, if we're talking about whether they should have trans catheter aortic valve replacement, which I also do, I just finished one, or surgical aortic valve replacement, this is one of the considerations. One of the advantages of surgery, uh, obviously the downside is the recovery, but one of the advantages is we control that environment in the aortic root. And one of the ways to do that, if patient has a small annulus, or even a normal annulus, and we wanna set them up for a good long term result, is to do an aortic annular enlargement or root enlargement procedure. So the goals of that, first and foremost, are to avoid prosthesis patient mismatch. So patients with very small annuli should absolutely undergo this if they're having surgery. Patients who have a normal annulus, there's room for debate there for, due to the principles I just discussed, that you actually lose a lot. So you're not going from normal to normal, you're going from normal to small, effectively, if, if you don't do an enlargement. So that's the first goal of this. The second is for lifetime management. So if you have a 65 year old, and we're doing a bioprosthetic aortic valve replacement. As a surgeon, I feel like we have to, we have a commitment to um create an environment where we can do a tavern later. Otherwise, you know, what we're offering them is no better than doing a tavern upfront. Um, and so that would be the second reason is to, we always talk about what is gonna be the pathway to get to the end of life. Is it gonna be two Ts? Is it gonna be a Tver, and then take your chances, meaning surgery later, or is it gonna be surgery upfront and then a tablet? I, I never really promised three valves, you know, I, I, I don't know that we can do. Surgery and then 2 Ts or 3 Ts. Um, and I think it, it's a little bit irresponsible to promise that, and so I, I certainly don't, we don't know yet. But this is the frequent discussion with patients. It's, it's not really just about that treatment and that valve procedure, but what's the next one gonna be? And then the third is, this is just the overarching principle of what we're trying to achieve, and that's to implant a valve where that effective orifice diameter matches the patient's native outflow tract. The basal ring is the very bottom of the aortic root. And that is what the patient's given, and that is their, you know, that is what we wanna match it to. It's not about making that bigger, but just matching it to the patient's normal outflow track. So this is gonna get a little technical, but I think it's important to understand kind of what this means if we're doing this procedure. And there are different types. The next procedure, the Menuian, and then the Y incision is one, that I'm gonna go over briefly. And so this is, this is a picture of the aortic root, and then on the right is a picture after performing this procedure, and you can see that, you know, it kind of looks like a crown sitting on top of this crown shaped annulus. And, and this demonstrates a 29 bioprosthetic valve, but you can see, you know, it's done to match a 23.7 millimeter left ventricular outflow tract. So again, it's that concept of. You're going to lose space with this prosthetic valve, so by enlarging this area, you will not. So this is a quick. Video of this technique, so this is cutting down the left and non-commissure of the aortic valve, and then it's called a Y incision because you literally cut to the left, and that suction just went in the left main coronary orifice, and then you cut to the right. So again, this is cutting to the left underneath the annulus of the left coronary cusp, and then underneath the non-coronary cusp. And that's the that's the initial incision, and from there, we saw a patch onto that area. So this just depicts that incision and what defines it. It doesn't go on to the mitral valve, but it goes towards the anterior leave of the mitral valve, and then makes those turns in either direction. And this is, this is that anatomy I was talking about, the left coronary, the right, and then um the aorta mitral curtain is what we're actually cutting into. And so then we sew this patch on, and this is what that looks like in practice. And then, um, and then so a number of valve stitches, and then ultimately, this is what the valve looks like once it's in there. And, and this is a aorortotomy closure, which is extremely important, again, in principle to where we're not just enlarging the annulus, but we're enlarging the sinotubular junction in the beginning of the ascending aorta. And the reason that's important, if you think about a Tver valve that's gonna fit inside of the surgical valve. More important than where the coronary artery heights are, is that it's not contacting the aorta, so blood can flow around it. Again, this is all about not only optimizing the hemodynamics of this operation, but making sure that the patient can very easily and successfully get a TAVR later. That's kind of the end product from a surgical view. So, the outcome, the initial experience of this, this was, this technique began at the University of Michigan, and is now done a number of places, including here, but the majority of patients here you can see are 3 and 4 size up. So what that means is. If you measure with a prosthetic valve sizer, it's a 21, 3 sizes up would be a 27, is what actually gets put in there, or 4 sizes would be a 29. Outcomes have been good, um, you know, as expected, patients do better with bigger valves, and so this green line here on the right is for a 29 bioprosthetic valve, and, um, patients do better than that than they do with the 21. So this is, this is sort of a preliminary study, but what, what it shows is comparing to TAVR, and so you can see, uh, towards the right here, the area that you get, the 2.7 is bigger than 1.9, and I, and I always, and then the gradient here at the bottom. And the way I explain it to patients is that, um, you know, with surgery, again, we can control the environment, and we can create a favorable setting. For the valve replacement for now and for the future with Taver, while it is an excellent tool, you have what you, you get what you have, it's sort of. That's what you get, because we're pushing the valve to the side, and so you can't make it bigger, you can't make it more favorable for a future valve intervention. It's just, you get what you get, which in many instances great. As surgeons, if we're not doing this type of procedure, if we're not setting them up for the future, then as I said, it, it really cheapens the value of surgery, and you might as well get a tear. So it's just a quick case example, it's an echo, you can kind of see they have hokum as well, but it's a 54-year-old with a bicuspid aortic valve, and an ascending aortic aneurysm, as well as this asymmetric septal hypertrophy, and she was symptomatic, um, interestingly lost 150 pounds prior to this, normal ejection fraction. And she had a strong preference for a bioprosthetic valve. A 54 year old, um, you know, who really does not want a mechanical valve, in my mind, the discussion for that type of person would be either a bioprosthetic valve with an annular enlargement, um, or a Ross procedure. So she opted for this procedure, uh, and replaced her ascending aorta, and then, and then, you know, she probably most typical is upsizing 3 sizes. So she, you know, measured for a 21 and she upsized to a 27 with an inspired by a prosthetic valve, as well as a septal myectomy. And I think she's, this is a good example of. You know, in a 51 year old, putting a 21 millimeter bioprosthetic valve is really detrimental, and I would even go as far as to say life limiting for someone like this. Like, yes, it would absolutely treat her aortic stenosis, but it's not gonna put her on a good trajectory for lifetime management of this disease. So this is just a depiction of, you know, in this same patient doing the modeling for, OK, you know, are they, uh, are they a TAVR candidate for the future? She doesn't need a TAVR right now, but you can see the, um, you can see kind of that straight graph there is the ascending aorta replacement, and you can see the struts of the aortic valve, and if you imagine a taver inside of that, you can see that there's no. You know, interference of any of the aortic walls, and that this would, this will, hopefully in 15 or 20 years, be, be very easy for us to do. And this, this attaches some numbers to that. So this is, you know, what we did is we got a, a TAVR CT scan for academic purposes, basically. We get a CT scan afterwards for all of these operations, so it wasn't an unnecessary scan, but we analyzed it as if we were going to do a TAVR. And this, again, the sinotubular junction at the top of the aortic root. Was also enlarged and the sinuses were enlarged by 30%, sinus heights by 100%. And so what this creates is just a ton of room, um, to where it becomes very easy for a future procedure. OK, so that's, that's kind of the first part. Before I go to the second part about ascending the aneurysms, maybe I'll, maybe I'll stop and see if there are any questions about this, uh, or I can keep going. Is this interactive? Can people ask questions or not? Well, they're all on mute, but they can put them in the chat in the Q&A. I don't see any currently either, but. Oh, you do? OK. Oh yeah, sorry. Let's see, I think it's only to hosts and panelists, but I can see it. So from Dorothy Munch, if a patient needs a second taver, how do you remove the first valve? Yeah, that's a good question. So if they, um. If they need a 2nd taver, you don't remove the 1st valve, I guess it's the short answer. So if they get a taver, um, and they're a candidate for a 2nd taver, then we do a valve and valve taver or a redo taver, as it's called. And usually the considerations for that are not only, you know, size is one, but it's kind of only the first consideration. The most common reason someone would not be a candidate for a second TAVR has to do with their coronary artery anatomy. And that is not only the height of them, so the height of the coronary arteries from the annulus is important. But it's also the size of the aorta, and that's why I was stressing the sinotubular junction and above that of making that wide with surgery. You can't do that with TAVR, obviously, the concern is with a second TAVR. Is when you put the 2nd ta in, you pin open the leaflets of the first one. And if those leaflets contact the aortic wall, and they sort of trap, or we call it sequester, the coronary arteries, then you have a problem. And so that's, that's probably the most common anatomical reason why someone would not be a candidate, is coronary sequestration, as we call it, or, or just the coronary heights are so low, um, so. You know, if a patient's not a candidate for a second TAVR, and they've had a TAVR, then they may undergo TA's plan, as I mentioned, which is, which is surgery, and, um, in low-risk people, it's very safe surgery, but it is a little bit more complex than, than just a first time surgical aortic valve replacement, um, just because we have to remove the valve, and if it's been a long time, then it, it kind of grows into the aortic wall, and we have to do it very carefully, but, but we do do those. Um, all right, second question, how does a patient's age affect the decision? Yeah, the age affects it a ton. And as I mentioned, you know, all of these, especially here, we um. We have a really good valve team and so I'm in valve clinic with one of our interventional cardiologists, and they're, they're actually, we have 3 valve clinics where we have, you know, tandems of the two of us, and we're almost always on the same page, and if we're not, then we talk about it and come to a decision, so. What that amounts to age wise is There's almost never a time when we'd choose a primary ta for someone in their 50s or younger. Um, there are exceptions. Uh, the exceptions would be they've had a bunch of surgeries or something that when they were younger, they have a limited life expectancy, or they're severely ill in cardiogenic shock, they're, you know, we're doing something as a bridge to keep them alive and. One of the great things about TAVR is how minimal the impact is to them physically. And so we use it in a lot of different ways. But if it's just a patient coming for a regular evaluation, who's relatively healthy, low, intermediate, even high risk, um, if they're in their 50s, then, then our recommendation is going to be surgery just because of durability, and again, because of that. Um, that trajectory of the lifetime management. People in their 60s is a little more of a middle ground. The young 60s is, is pretty much also always surgery, you know, the American guidelines are, are 65 to 65 to I think 75 or 80 is a shared decision-making zone, and, and everything's shared decision making, but it's generally recommended surgery if they're under 65. And then all this other stuff comes into play. So if there's a, if there's a 70 year old, um, who's bicuspid, who has a calcium score of 10,000, and they have a calcified RA, and we think we are gonna get a bad outcome with TAVR, and this happens a lot actually, cause we see a lot of bicuspids, then we'll recommend surgery. So it's possible that anatomically, it's too dangerous to do TAVR, just because of the mechanism of the procedure. You know, we're opening this basically big stent with a new valve inside of it and implanting it. And so, uh, we actually have a, it's called DAI, we have a, a, um, software now that predicts what will happen with different TR valves at different sizes. And if you have a bicuspid valve with 2 or 3 splits are fused, and you have this big bar of calcium, this big stalactite, you know, when we deploy a taver that has to go somewhere and. Um, that can lead to more commonly paravalgear leak or less commonly, but catastrophic, it would be annular rupture, which knock on wood, I haven't experienced yet. But, um, all of those things come into play. The other scenario where someone may typically get a tavern and doesn't, if they have a really small annulus, and that, that goes to what we've been talking about, um, about lifetime management, uh, to where we would do an annular enlargement. Obviously, if they have a small annulus and you don't do an annular enlargement, what's the point, right? So I think, I think there's a lot of suboptimal surgery done around the country that we can do better at, um, so those are some of the considerations, you know, there are some people even in their 80s, they're, you know, it's not common, but there are people in their 80s that choose surgery, so one example would be bad anatomy. Another one would be, um, I had a patient with severe AS who had just crippling Afib. And he was a lot more interested in a maze procedure than he was in an AVR and so that's why he chose surgery, is to get an AVR plus a maze, instead of a tower. And he did fine, but, um, everybody is different, and so it's an individual decision that we come to as a team. All right. Third question, if a patient's asymptomatic, what degree of aortic stenosis would incite? Yeah, that's a great question. So there have been a few recent studies, um, a couple in with TR and one with SAR. That is studied asymptomatic severe AS. What we do when we see someone with asymptomatic severe AS is, um, obviously, interview them, make sure that they actually have no symptoms. And then we usually get a BMP. If a BNP is elevated, then we're more likely to, to treat them. We almost always get a TAVR CT, uh, and get a calcium score. So I think the things that move the needle for the asymptomatic population are BMP, the calcium score, and if those are kind of unimpressive or normal, then we will also, often get a stress test and, and see if, um, you know, if they respond appropriately to stress. And, and if they don't, then that may also push us to intervene. Um. The studies, you know, the TAVR studies have shown a decrease in heart failure hospitalizations in the group that was treated. The surgical study actually showed a mortality benefit. It was asymptomatic, critical, or extreme AS. I believe it was gradients over 60. And so those are considerations. I, I don't think there's a, there's not a same answer every time, but those are the, um, those are the type of things that we think about. All right. Like that's all the ones for now. OK. So second topic is about ascending aortic aneurysms, which, which I think you see a fair number of, and I'm just basing that off of, I get a fair number of people who are referred from, from their primary care physicians for this, uh, for this condition. So most commonly this is from cystic medial degeneration. Hypertension is chronic hypertension is both the cause of this and also, uh, you know, an exacerbating factor and a risk factor actually for dissection. Bicuspidyaropathy is, is extremely common in our clinic. So we see people with valve pathology who also have aneurysms. Genetic connective tissue disorders, familial aortic disease is this category where they don't have a specific genetic disorder or connective tissue disorder. They don't have Marfan syndrome and Lois Dietz, but you know, um. For example, I have a patient next week I'm operating on whose ascending aorta is only 4.3 centimeters, um, but his mom. Had a 4.3 centimeter a in aorta and had a type A dissection and died. And so, you know, we got genetic testing, he has a variant of unknown significance, but he's in this category where we treat it, you know, a little bit differently, and he's, I don't know if I'd say prophylactic, but we, you know, discussed him as an aortic team, and, and he's not at the traditional 5 centimeter threshold, but. Because of his family history and how um the aortic tissue of, of his, you know, genetic profile, which matches his mom's has behaved, we're gonna replace his ascending aorta due to a valve sprain root and a hemi arch replacement. And then, um, inflammatory vasculitis like giant cell, um, and, and a few others. So, I'm gonna focus mostly on the guidelines. So these are from the 2022 ACC guidelines, which we, uh, which we follow, uh, for the most part, and there, there's a strong involvement in multidisciplinary aortic teams. And we, we have an aortic team here, and we have an aortic center, and we, and, and this consists of cardiac surgeons, vascular surgeons. Uh, we have a cardiology kind of world expert in Doctor Braverman and radiologists too, which, who are extremely important to us. We meet every 3 weeks and we discuss, you know, a lot of cases. We don't discuss every single patient that we see, but, but certainly, uh, complex ones and, and ones that are interesting and ones that we need to come up with a treatment plan for. So in the guidelines, you know, they define this as, because it's, it's kind of a, uh a vague term, you know, experienced surgeons and a multidisciplinary team, but they, they base this on some data that around, you know, 30, 40 annual procedures, aortic surgeries. Uh, puts a hospital in a high value category. We, we are certainly this to give you an idea. So last month I did 10 or 11, and so, you know, as a hospital, we're certainly way over this on an annual basis. So for sporadic aneurysms, which, you know, can be just degenerative aneurysms, basically, any, any that are not specific um bicuspid or genetic connective tissue diseases, um, the, the guideline has always been 5.5, and, and one important change on the most recent is, is again, in these experienced places, it's a 2A indication to have surgery at 5, not 5.5. And um in addition to the 5.5, also, of course, growth of 0 basically 3 millimeters a year for 2 years or 5 millimeters in 1 year. Another part that was introduced with these guidelines is this area to height ratio, which actually I use a fair amount. This is not an absolute indication, it is a class 2A indication, but it's something that we use um as a factor in the picture of how we're going to treat a patient. So, for example, a woman who's 5'2 with a 4.6 centimeter ascending the aorta, and I'm not saying every single person with this profile is gonna have surgery, but if you. You know, if you use this ratio as a guide, their ratio is 10.5, so they're in, they're in that zone, that puts them in the same zone as about 5 to 5 5.5 in, in that zone where it's, it's not unreasonable to watch it, but it's not unreasonable to proceed with surgery either, depending on that shared decision making. If that, if that's a 6 ft man, you know, you're kind of way under the threshold, and so it's a different discussion. And that's what the data has shown is that height is, is a better indicator than weight, um, or other features. You know, size is the most common thing that we use, but what we know from IRAD data for aortic dissections is that 60% of dissections happen. You know, with aortas that are less than 5.5 centimeters, so I also tell patients that this is very imperfect, and it's an evolving field. So there's this category of heritable non-syndromic, so this is where it's not a specific genetic syndrome, but it's, there's clearly family history, and, and this is, this is similar, you know, where you're around 5 or, or even 4.5 if they have one of these features here that are listed where you have growth, or a really strong family history. And then, this, this I found is often a misconception about, uh, especially amongst our fellows, about bicuspid valves. If you look and you, and you really read it through the guidelines, they're essentially the same as a sporadic aneurysm. And so, having an aneurysm associated with a bicuspid aortic valve, I think they're more commonly intervened on because the valves being intervened on. But the aneurysm itself does not have a lower size threshold to um indicate that you should have surgery. It's essentially the same, which I think is important. And then genetic syndromes, Marfan, Lois Dietz, um, a little bit less well described as vascular Eller stanlos, that doesn't have very specific criteria, but, um. Most of these from our family Loy's DETS are around 4.5 or 5 depending on the situation as the threshold for surgery. There's a whole chart in there for Lois's DEETS, you know, the specific genetic variant makes a difference too, and some of them, the threshold is actually 4, and some of them it's 5. And so, you know, genetic testing in these patients is, is essential. Um, when we see these patients in clinic. You know, oftentimes they've already met indications, and so we're not waiting for genetic testing necessarily. They've gotten genetic testing, great, but we usually schedule them for surgery, set them up with Doctor Braverman, and they get genetic testing as an outpatient, you know, because it is important for their family, of course, uh, and for them, but it's usually doesn't move the needle on the indication unless they're really right at that border. All right, then there's an indication when you're doing other types of surgery, and what that means. You know, they, they specified tricuspid valve surgery here, or with bicuspid valves is commonly aortic valve surgery. And in all of these, I think the take-home point is that it's pretty much 4.5 across the board. And so if you're having cardiac surgery, and I follow this, if I'm doing cardiac surgery for something else, there isn't mean, uh, aorta is at least 4.5 centimeters, then, then I will replace it. Um, there are exceptions with that, as with everything, but that's the general guideline that I follow. And then switching gears a little bit, um, and I think, you know, judging from the questions we've got, and you might get questions about this in your clinic. If you see a patient with an ascending aneurysm, and then they say, well, I don't wanna have heart surgery, what are the other, and nobody wants to have heart surgery, so what are the other options? And stent grafts or TBARs. You know, it's an area of research that we're actively involved in. For somebody with a sporadic ascending aortic aneurysm or fusiform aneurysm as we call it, which is the typical aneurysm where it's very gradual. They're not really candidates for any of these. And the reason is because there's not a proximal and distal area to seal, um, to seal off that aneurysm. A saccular aneurysm where it appears like a mushroom is kind of the perfect configuration for this type of um of intervention, and then chronic aortic dissections are another uh kind of ideal population that we use these in. So this started really a decade ago, uh, with a feasibility study for acute type A dissections, and this was, you know, about 30-40 patients, and it, it was a feasibility study. This is an ongoing study that we use to treat chronic pathology. Again, it's most commonly penetrating ulcers, pseudoaneurysms, saccular aneurysms, and it's a combination of these devices, you know, the novel device that's being studied is, is for the ascending aorta, and the ascending aorta behaves differently. And some of that is the anatomy, and some of that is the flow dynamics of, of just um what that area of the aorta is seeing rather than the descending. And so, this technology, that's why it's evolving. The outcomes have not been as good as the descending aorta, where if you have a type B dissection or a descending aneurysm, it's actually the standard of care to do a a uh stent graft rather than open surgery. So this is, you know, another study that we're. Involved in. This is a similar concept, different company, and a, and a different configuration, but this is again to treat either aortic arch or ascending aorta pathology. The study ended and it's in continued access right now. This is what that consists of. It's a separate component for the ace inning, but it locks into this, this branch component. And these are a few other options, um. We use branched devices regularly. We're doing one of those on Friday. Uh, there's, we just started Arrise 3, which is another study for acute type A dissections for people who are at prohibitive risk for surgery. And just a couple of things for that, I think, you know, you obviously sense the theme of multidisciplinary team is essential to this, and I think that's the biggest strength of our hospital, is that. We are the only area in about a 200 mile radius that has all of these clinical trials and has a, a true aortic team. Um, there are a number of hospitals that have excellent aortic surgeons, but not really, uh, a team the same way we do, where you have vascular surgery, cardiac surgery, ptho or I mean, the radiology. And cardiology. OK, so wrapping up, conclusion, patients with severe AS should be evaluated by a multidisciplinary valve team, and that's for all the reasons I listed. Um, it's, it's very nuanced at this point in contemporary care in terms of deciding if a patient should get a taver or a saber. It's not really about that decision. It's about the rest, it's about from that point until they die, till when we think they're gonna die. How are we going to put them on a correct path to, I usually tell people, I want them to either have 0 or 1 open heart surgery. You know, how can we achieve that? And that takes a team, um, a team to figure that out. Second, for patients who are undergoing surgery, um, they should, you know, be considered for an annular root enlargement, and that's essential to optimize this lifetime management of aortic valve disease, and I really think that's important, and obviously, I'm, this isn't a surgical audience, but I think as, you know, referring physicians, you should. Um, advocate for that for your patients. It's, it's really, especially in the current era where, where TAVR outcomes are quite good, you know, if, if a patient's not getting an annual enlargement, if they're not getting something with the future in mind, then, um, then of course they should get a TAVR. Um, every patient is going to want a TAVR, and that's understandable, because who wants to go through open heart surgery if they don't have to. Which is why if someone does need to go through open heart surgery, or if that's deemed to be, you know, the most durable outcome for them, then we, the surgeons need to, need to do it right. And then lastly, aortic aneurysms, you know, should be considered by, again, in the setting of this multidisciplinary aortic team. If it's at a place like this, where you have this team, I think the numbers to remember are are 5 or greater than 10 for that index, and then 4.5 for these genetic syndromes, or if they're having a concomitant cardiac surgery. All right, that's all I got. Thank you.