It's not all about valve replacement for patients with aortic valve pathology, some of whom may be good candidates for valve repair or the Ross procedure instead.
In this episode of the AP Cardiology podcast, Andrew Perry, MD, speaks with Chris Burke, MD, of University of Washington, Seattle, about the evaluation of aortic valve disease and the various surgical options that patients may have for their treatment.
A transcript of the podcast follows:
Perry: Hi everyone, Andrew here. My apologies for the delay in posting this episode. I had the opportunity to visit with Dr. Chris Burke from the University of Washington cardiac surgery group to discuss aortic valve repair. You have probably heard of mitral valve repair, but if you are like me 12 months ago, you may not have heard of aortic valve repair. This is an exciting idea with a lot of promise. Dr. Burke will teach about the things to consider when evaluating for aortic valve repair. He is a great teacher, and I think you will learn a lot...
Perry: This is AP Cardiology and this is your host, Andrew Perry. Thank you for meeting with me today, Dr. Burke. Can I have you state your name and your title for our listeners?
Burke: Of course. Thanks for having me. My name is Chris Burke and I'm an assistant professor of cardiac surgery at the University of Washington.
Perry: Beautiful. Thank you. One of your areas of expertise or interest is aorta surgery and aortic valve surgery, and so I'm here to talk to you today about that. To start our discussion, I will present a case briefly.
We are seeing a 40-year-old man with bicuspid aortic valve and he has severe aortic regurgitation with a mildly dilated left ventricle and a mildly depressed left ventricular ejection fraction. To put some numbers on that, the left ventricle dilation has an end systolic diameter of around 47 millimeters and the ejection fraction is around 50%.
He is asymptomatic and reports New York Heart Association Class I symptoms, and he really has no other significant comorbidities with respiratory distress, or diabetes, or kidney problems. He has been followed for aortic regurgitation for about the past 5 years and then recently he's been determined to have severe aortic regurgitation, so he is referred to your clinic to be evaluated for aortic valve surgery.
Now, when these patients are first referred to you, I think most people are thinking, "We're referring this patient to you to have a discussion about aortic valve replacement." But I want to talk to you today about aortic valve repair. Talking about this patient in specific, could we discuss for a moment about how aortic valve replacement may be less desirable for this patient?
Burke: Yeah. I think, Andrew, that's really the fundamental crux and question when you're seeing a patient like this. First of all, the first thing, going over the patient. The patient's relatively asymptomatic, but does have severe aortic regurgitation and is starting to dilate a bit and starting to have depressed ejection fraction. The first thing is I agree with the referral that this patient warrants intervention on the aortic valve, and historically, that would be an aortic valve replacement. There are several considerations for aortic valve replacement, or AVR, in a young patient. We would sort of classically push a patient like this, or at least counsel a patient like this, for a mechanical AVR, which obviously has benefits of durability but has a significant drawback of anticoagulation.
I would just briefly talk about sort of a traditional bioprosthetic AVR in a patient who's 40. It's pretty clear that that's, quite frankly, kind of a bad operation. Even in the world of TAVR and future valve-in-valve TAVR, we have just seen more and more with younger patients, the durability of bioprosthetic valves is very poor and many times less than 10 years, and so that's circumstance where this patient would assuredly need future open heart surgery if he were to elect to get the bioprosthetic AVR.
Perry: It's oftentimes... just to elaborate on that... oftentimes it's hard to convince them to go for a mechanical aortic valve because frequently they view it as like medication, monitoring, and then sometimes like lifestyles have to change as well.
Burke: Sure, and I think mechanical AVR deserves a bit of mention and thought as well. So, #1, you're exactly right. Being on indefinite anticoagulation is less and less acceptable, it seems like, to patients, and I think for good reason. There is certainly lifestyle considerations, and any patient who is taking Coumadin, there's all the dietary and monitoring issues that go with that.
There's also a real risk over a patient's lifetime of having a significant bleeding event. The problem with a mechanical valve is unlike atrial fibrillation or some other indication for anticoagulation, where you can sort of stop and kind of accept the risk of what might happen, you really can't stop anticoagulation with a mechanical valve. If a patient were to develop GI bleeds or something like that, they basically have to have re-operative surgery to take the valve out, so I think that's number one.
The second issue with a mechanical valve, just like a bioprosthetic valve, is that its a valve prosthesis. It is prone to things like infection. For a mechanical valve, obviously you can have issues with clotting, pannus formation, and things like that. It's becoming more and more clear that there's probably about a 1%, maybe higher, annual risk of reoperation for patients with a mechanical valve.
Again, you can start to do the arithmetic at 40, and I make this point all the time when I'm sort of giving talks and talking about this, that I never ever tell a patient that if they get a mechanical valve they won't need heart surgery again because that's simply not true, and the data bears that out.
Perry: That's much higher than, I think, I appreciated.
Burke: Sure. I think a mechanical AVR is not a bad choice in a patient like this. Certainly, if you're going to do an AVR, I think if you're forced to do a valve replacement, it's probably the best choice. We should just mention very briefly, I think, to be complete, a Ross procedure, which is seeing a bit of a resurgence in adult cardiac surgery.
A Ross procedure is a much better operation for aortic stenosis. It really needs to be used with caution with aortic regurgitation, especially kind of pure, isolated aortic regurgitation, and you can have late failures with autograft dilation, and that's a major risk factor for Ross failure. I think I would put a Ross in a patient like this a little bit lower down on my list of appropriate operations, so I think you're right. I think mechanical AVR is certainly a reasonable procedure for patient like this, but I can tell you my first step is going to be evaluating this patient for repair, because a 40-year-old with a bicuspid valve and pure aortic regurgitation many times can receive a durable repair.
Perry: Okay. Let's go into, then, talking about how you assess someone for repairability. I think a large part of that relates to the anatomy of the valve, the anatomy of the annulus, and then also the mechanism of aortic regurgitation. Could you just walk me through like what's your initial steps in like reviewing imaging or talking to the patient in proceeding towards that?
Burke: Sure. I think the first step is to even take a step back, and I like to place patients into various groups when it pertains to this, and the first is whether or not there's an aortic root aneurysm that's present. There are patients with severe AR with root aneurysms, patients with severe AR without root aneurysms, and then the third category getting into aortic stenosis, so you start to think about gradients and whether it's a mixed pathology with mixed aortic stenosis, aortic regurgitation. Those three categories all have different treatment choices, so I think that is the first thing that I'm doing, is figuring out under which category does a patient fall because the treatment's very different.
Now, I was being very specific there when I said aortic root aneurysm. I care less about the ascending aorta or aortic arch, or something like that. That's easily treated. But when we think about the valve complex, I'm really concerned about the aortic root or sort of the sinus segment there, so that's really the first thing. That's kind of a CT scan or echo assessment for what's the morphology of the aortic root.
Assuming that this patient doesn't have an aortic root aneurysm, you're exactly right. The next thing is to really focus on the echocardiogram, and I'm looking at several things. I'm first assessing the morphology of the regurgitant jet. In bicuspid AR it's usually eccentric. Sometimes you get a central jet, but it's usually an eccentric jet.
I always make note of the annular dimension, so that's extremely important, to get a sense for how much annular dilation there is, since a mainstay of repair is actually an annuloplasty or a reduction of the size of the aortic annulus. You like to see a nice big aortic annulus, if possible.
Then I want to assess the leaflets. The first thing you're looking at is the degree of calcification. You hope for nice thin leaflets that are mobile, that open fully. For a bicuspid valve, it's going to be kind of that fish mouth appearance, and then --
Perry: Presumably in a younger patient, there should be minimal calcification for the most part.
Burke: Correct. Though sometimes in bicuspid or even unicuspid disease you can see premature calcification, but usually for isolated AR, again, without significant gradients and AS, you see minimal calcification. That's certainly what you want to see. Many times you could see thickening on a raphe for like a Sievers 1, where you have a fused leaflet. Sometimes there's even a little bit of calcification there. That's pretty easy to deal with. You can shave that off.
Perry: Okay. A Sievers 1 is... traditionally it looks very similar to a tricuspid aortic valve, except two of the raphe are essentially fused together, is that correct?
Burke: There's one raphe, so you have...
Perry: Just one raphe?
Burke: Yeah. So instead of... there's two true commissures, and instead of your third commissure, you have a fused raphe. That's a Sievers 1. If you had two fused raphe, that would be a Sievers 2 or actually a unicuspid valve.
Perry: Yeah.
Burke: For the Sievers 1, which is the most common type of bicuspid valve, and among that the most common is a right-left fusion -- that's what we see about 70% of the time or so -- so there's one fused raphe there. But I want to make a specific point with bicuspid valves, and especially Sievers 1 bicuspids, and that is this concept of the commissural angle. This is proving to be extremely important.When I'm talking about commissural angle, I'm talking about the angle between the two true commissures. In a perfectly symmetric valve, classically a Sievers 0, that angle is 180, if that makes sense. You've got 180 degrees from commissure to commissure.
Perry: Yes.
Burke: For Sievers 1, you really want that angle as close to 180 as possible, if that makes sense. The more symmetric that valve is, and then you get that kind of perfect fish mouth appearance, that's going to be a valve that's much more amenable to valve repair. As that commissural angle on that fused leaflet gets lower and lower, your odds of repair are going to go down and you're really going to have to do much more kind of extensive and trickier repairs.
Really, once it gets down to about 140 degrees or 130 degrees, getting quite asymmetric -- and like you were suggesting, kind of almost like a three-leaflet valve at that point -- it's really difficult to repair that valve because you run into some leaflet surface issue things. I think that's one of the most important things that I'm looking at on the echos, is I really want to see the valve to be fairly symmetric and then I feel pretty good about repairing that valve.
Perry: Got it. Okay, and that can be done by transthoracic echo or transesophageal?
Burke: It can. I think depending on the windows you get for transthoracic you can see. There are occasions if I'm sort of debating exactly how I want to repair or if something's repairable that I've gotten TEEs preoperatively, but many times in a younger patient who has good windows, one can get it on a surface echo.
Then, Andrew, I should just point out that there's kind of another layer of assessment that happens at the time of surgery. Obviously when we get in surgically, there's some measurements we do on the leaflets to make sure that there's enough leaflet surface area to repair and make sure we're not going to have prolapse afterwards and things like that.
Of course, with these patients, similar to what we do in mitral valve, we always have sort of a backup replacement option because occasionally that does happen, where we get surprised with fenestrations or something like that.
Perry: Got it. Okay, very helpful. Just to kind of recap where we've been, the first thing that we're looking at is the patient, "Do they or do they not have an aortic root aneurysm?" This is at the sinuses of Valsalva, so is their annulus dilated? Then in the patients who specifically don't have an aortic root aneurysm, then we're looking at the morphology of the valve.
We've been talking primarily about bicuspid aortic valves, centered around our patient, and there we're looking for a valve that is, where the commissures are now 180 degrees apart from each other, so I think essentially we're getting like, another way to describe that is two leaflets that are sort of half moon shape, similar to a mitral valve. That would be a valve that's more likely to be repairable. The more we're getting a bicuspid valve or it looks more morphologically, or on echos looking more like a tricuspid valve with different angles between those two true commissures, then we're getting a less repairable valve. Additionally, you're also looking at the calcification on those valves, and I think assuming that that means increased calcification, decreases the likelihood of successful repair.
Burke: Agree, and then don't forget the gradient. The gradient is extremely important. Because we're, again, shrinking the annulus, and many times in a bicuspid valve, again, we're kind of, this concept of the commissural angle, we try to almost make a Sievers 1 into kind of a Sievers 0, and as we'll talk about, some of the annuloplasty devices really force the geometry into 180 degree symmetry.
Your gradients often will go up because of that and so I think you really want to see single digits or very low teens for your mean gradients going in. I think if they're over 20, if a patient kind of has moderate aortic stenosis, that's a big red flag.
You need to have a big red flag about that patient and think about either doing a valve replacement plus or minus a protective Ross or something like that. I think you're kind of in that third category that I introduced before of kind of mixed pathology.
Perry: Gotcha. Okay. Since we had mentioned it, maybe we'll circle back, referring to the patients who have an aortic root aneurysm. How does your approach for repairability then change in those patients? In particular, patients with bicuspid aortic valves frequently have an associated aortic root aneurysm.
Burke: Again, this is a completely different bucket here. When I'm thinking aortic root aneurysms as it pertains to significant aortic regurgitation, we're really thinking a sinus diameter of 4.5 centimeters or so or greater. Okay?
Perry: Okay.
Burke: And actually, Andrew, I would say for bicuspid valves, actually the most common aortopathy is ascending aortic aneurysms that actually spare the sinus segment. It's really in a Marfan syndrome or a Loeys-Dietz or other sort of genetic aortopathies where you get that annuloaortic ectasia, that kind of old-fashioned term for sort of the Erlenmeyer flask aneurysms at the root.
For bicuspid valves, actually, the most common thing we see is ascending aortic aneurysms with a relatively preserved and intact sinus segment. Now, that's about 70% or aortopathies or so that we see with bicuspid valves. But 15% of the time for patients with bicuspid valves and aortic aneurysms, you get what I'd call kind of a root phenotype.
It looks like what a Marfan patient would look like, with a root aneurysm that may or may not preserve the ascending segment, but the patient has a bicuspid valve and has no features or family history of Marfan syndrome.
Perry: Gotcha.
Burke: And so that's a little... specifically for bicuspid valves, that's a little bit less common, but we do see it. Again, those patients are placed in a completely separate category in that we're not thinking about doing an isolated valve repair. We're thinking now, if the valve is repairable, of doing what's called a valve-sparing root replacement. That comes in sort of two general flavors.
What's called a reimplantation procedure, or more commonly known as a David-V, is sort of one classic version of that procedure. Or what's called a remodeling procedure or the Yacoub, which now in present-day surgical practice will always contain some kind of annular stabilization with either an internal or external ring.
Again, aortic regurgitation, with a repairable valve in an aortic root aneurysm, I'd say defined by over 4.5 centimeters, will put you in the valve-sparing root replacement category if the root can be... if the valves, sorry, could be salvaged, and this is actually a really common thing that we see with trileaflet valves, obviously.
Perry: Sure.
Burke: It's very common for patients with trileaflet valves to come in with root aneurysms and I think you get kind of what I call sort of secondary AR from those patients from dilation of both the aortic annulus and the commissures, which kind of pull the leaflets apart, and then you get a central jet of AR in those patients. Those are very amenable to treatment with the valve-sparing root.
Perry: Gotcha. Okay. Very helpful and very useful discussion there about that story. As you mentioned, a different mechanism, primarily regurgitation from aortic annulus dilation and those repairs hopefully being able to do a valve-sparing aortic root repair.
Kind of circling back, then, to more of the topic that we were on earlier, no aortic root aneurysm, aortic regurgitation, let's take a minute and think about how an aortic valve repair in that situation is performed, and maybe first start with like a compare-contrast with aortic valve repair and then mitral valve repair.
I think a lot of listeners and people are more familiar with mitral valve repair, that being a very common surgery, but aortic valve repair being less common. So what are the similarities and then what are the important differences?
Burke: Sure. Yeah. I think, Andrew, I'd frame that discussion by saying... even taking one step back in saying that the fundamentals of, frankly, both aortic and mitral valve repair, but we're kind of focusing on aortic valve repair, are annuloplasty or reduction of the size of the annulus. That achieves better leaflet coaptation, so that's kind of the first thing. Then, the second thing is any leaflet work that needs to be done, plications, to raise the height of the leaflets because you want your leaflets coapting at the same height to prevent any leaflet prolapse which could result in leaks.
Perry: Okay.
Burke: That's actually fairly similar to the case in mitral valve, although the mitral valve has the sub-valvular apparatus with the cords and things like that, so there is even kind of another layer there. I do think it's useful for us to sort of compare and contrast, as you suggested, since mitral valve repair techniques are so generalizable. This is the absolute gold standard for treatment of mitral regurgitation, and so there are several important differences between the two procedures.
Number one, I think the ability to achieve a reproducible annuloplasty is much more straightforward in the mitral valve situation. The mitral valve annulus is very accessible within the left atrium, so surgically it's fairly straightforward to expose the annulus. The left atrium is a low-pressure environment, as you know, so there's a lot less stress and tension on that as compared to at least an internal aortic annuloplasty ring, which is going to have significant stress sitting within the left ventricular outflow tract, as you can imagine, with every single heartbeat. With those internal rings, there has been issues with dehiscence and things if they're not properly anchored into place.
Perry: Okay.
Burke: The other thing I would say there's a much more delicate balance between regurgitation and stenosis in the case of the aortic valve. There are lots of things we can do to the mitral valve. I think the most impressive thing is an Alfieri or kind of MitraClip, another way to think about it. You could literally sew the middle of the mitral valve leaflets shut and you, frankly, very rarely induce mitral stenosis.
Perry: Yeah.
Burke: Complete opposite situation, obviously, on the aortic side. I mean, you're constantly... with each manipulation you do of the valve leaflets, especially in the case of a bicuspid valve, you are walking a balance between regurgitation and gradients. The more that you do and the more plications you do to raise the leaflet heights and get the leaflets to coapt more in the aortic position, the higher your post-operative gradients are going to be, and so there's a delicate balance there.
Perry: It's less forgiving for the postoperative stenosis than the mitral valve?
Burke: In terms of gradients, yes, I would say that that's true. The next thing that I would mention is in the case of a trileaflet valve, there are three lines of coaptation, and obviously in a mitral valve there's one, given that there's two leaflets. For a trileaflet valve repair, which, by the way, many times are actually more challenging than bicuspid repairs, again, because you have three lines of coaptation between the three leaflets, and so it's much more sort of three- dimensional, and it's a little trickier to assess your valve repair in the operating room prior to closing everything up and looking at the echo, but to sit there and just assess it while you're repairing it. It's a little easier to do that in the mitral position than it is in the aortic, so there is a little bit of pattern recognition for the aortic valve repair to figure out if you've done enough, if you should do another plication, are the heights okay, etc.
Perry: Okay.
Burke: The last thing I would say is for the external annuloplasty rings for aortic valve repair, that's a dissection, again, that most surgeons don't perform very often. Unless you're doing a lot of aortic root surgery and have a practice that's similar to mine where you're very much focused in the aortic surgery, that is an area of cardiac anatomy getting way down into the subannular space around the aortic root that just most surgeons don't do very often. That's completely different, again, than just opening up the left atrium, which is very standard.
I think there's some technical challenges and differences as well, just in that this is sort of... many times this involves a dissection that, for many surgeons, is just not performed very often.
Perry: Sure. In fact, I think aortic valve repair surgery is also not very common, but maybe we could just... since we had brought it up and I'm thinking about it now, maybe we could talk about like how is that surgery increasing in frequency or is it increasing in frequency like on a national scale?
Burke: Yeah. That's a good point, Andrew. I think this is again where separating those different patient cohorts is really important. I think for patients with aortic regurgitation and root aneurysms it is very much accepted that the standard therapy, in my opinion, for those patients is a valve-sparing root replacement, and...
Perry: The David-V.
Burke: David-V or, to be fair... I mean, I'm biased. That's what I do... or remodeling with some sort of annuloplasty, which is...
Perry: Okay.
Burke: That's kind of... I would call that a modified Yacoub, but the differences there probably aren't terribly important right now. That's a great operation. It's a reproducible operation. It is a fairly common operation. That's an operation that is not just performed at very high volume centers, but reasonably experienced cardiac surgeons who are comfortable with it can perform that operation, and it's fairly reproducible.
In my opinion, and especially for patients with root aneurysms who have more of the kind of moderate or even mild degrees of AR, you really shouldn't be cutting out those valves, especially in younger patients. I think most of those valves can be spared because there's usually not an issue with the valve. Sometimes you get into fenestration. If you get a huge root aneurysm and there's been chronic AR that just hasn't been addressed for a long time, sometimes the leaflets are kind of destroyed and can't be spared, but most of the time... if you have a 25 year-old Marfan syndrome patient, that valve is probably pristine, and if it's leaking, it's just pulled away because of the aneurysm.
Isolated valve repairs is much less common. By far in a way the most common therapy for these patients is some sort of valve replacement. Now, I think there is more and more interest in this area. I can't quote you numbers for how much it's increasing. It is still the vast minority of cases being performed, being repairs.
One thing we should mention is there's now a commercially-available internal annuloplasty ring here in the United States that's called the HAART ring, H-A-A-R-T. That's really the first commercially-available ring that has a fairly standardized sizing algorithm, implantation technique, etc., and so I think with the advent of that technology, there are more and more surgeons doing this.
With regard to the external annuloplasty rings that sit on the outside of the aorta, if that makes sense, and get sutured subannular space on the outside of the aorta, there is no commercially-available rings for those yet in the United States. There are rings available in Europe. They have not made it over to the U.S. quite yet, so surgeons will improvise and use Dacron Rings. You can actually use a mitral annuloplasty band and turn it into a ring, but as you can imagine, that's a much less standardized type of procedure.
Perry: Sure.
Burke: That's much more sort of surgeon experience and refining their own technique. We're still very much on the learning curve of these technologies and of these repairs.
Perry: Okay. Very interesting.
Burke: We've been focusing on root aneurysms, but for ascending aneurysms that's no problem. We can fix those and repair a valve, leaving the root intact. That's very easy. That's a very standardized type of thing, so it's all about that root segment when you're thinking about valve repair.
Perry: Most of what I read about involving aortic valve repair is in the setting of chronic aortic regurgitation. Obviously, acute aortic regurgitation would be a separate topic, but I was interested in the thoughts about aortic valve repair for aortic stenosis. When might that be a useful or an applicable surgical technique?
Burke: Most valves with significant aortic stenosis are not amenable to repair, or at least with any sort of generalized valve repair techniques. There are certainly described things, like the Ozaki technique of basically using fixed pericardium to kind of remake an aortic valve. There's a lot of controversy whether or not those do well long-term. I think for me, again, if a valve has a significant degree of stenosis, I consider it not repairable at that point.
However, I think there is still an option for a living tissue valve in those patients, in the name of a Ross procedure. That, I think, is where we're, again, in younger patients, leaning more heavily on a Ross procedure for patients with either pure aortic stenosis or even in mixed-picture in appropriately selected patients.
Perry: Okay. Just because I don't know that we stated it clearly before, a Ross procedure, this is where we're taking the pulmonic valve and inserting it into the aortic position.
Burke: Right.
Perry: That's our "Valve replacement," is the pulmonic valve being moved to the aortic position.
Burke: Exactly, and then we reconstruct the pulmonic valve with what's called a homograft or a cadaver pulmonary valve. The first question you should ask yourself is, "Well, why not just replace the aortic valve with an aortic homograft which exists?" Which, again, is a cadaver aortic root. The problem with that is that they calcify. They tend to have the same durability as a bioprosthetic valve. In fact, they could be a little bit problematic because the entire root complex can then calcify and degenerate, and they can form pseudoaneurysms, and it could be a little bit of a mess, so an aortic homograft is a good operation for complex endocarditis.
We don't tend to use it very often for sort of run-of-the-mill aortic stenosis, so a Ross procedure -- again, moving the pulmonary valve over to the aortic position -- is much more durable, and the pulmonic valve works wonderfully as a neoaortic valve. It's a semilunar valve. It's the patient's own tissues. There's low endocarditis risk.
There are several technical points we do to limit dilation of the autograft, which tends to be one of the main modes of failure. Imagine, the pulmonary artery system is used to a lower pressure environment, and actually, avoidance of hypertension for about a year after surgery is critically important in these patients. That's been found to be a risk factor.
Then, again, we really get nervous, if a patient has a big dilated annulus, about doing a Ross. You don't want to see a big mismatch between the aortic annulus size and the pulmonic annulus size, because then you can have dilation of that neoaortic valve annulus on the autograft, and that can cause regurgitation as well.
Perry: Yeah. Okay, understood. What are the current gaps in knowledge or surgical techniques regarding aortic valve repair?
Burke: Number one, we are certainly refining and reinventing these techniques as time goes on. I think we are learning the advantages and disadvantages of the internal aortic annuloplasty rings that sit in the left ventricular outflow tract versus the external rings.
I think the technology for both of those rings will continue to improve over time, and I think definitely for the internal rings, having -- which, by the way, are available in a trileaflet and a bicuspid configuration -- I think having those as low profile as possible because they're taking up some space in the left ventricular outflow tract. I think it will take time to see how durable these repairs are over time, and that gets into the issue of gradients, so what does it mean if a young bicuspid patient gets a valve repair and has a postoperative mean gradient of 18. What will that do over time?
Obviously, the issue of valve-in-valve TAVR becomes a big issue and that is a big question, especially with these internal rings, and one thing that makes folks a little bit nervous.
Then what are the reoperations like, because even in sort of the best of circumstance, we are going to be re-operating on these patients.
I think for all of these things, internal rings, external rings, valve-sparing roots, Ross's, anything we do, there is a chance we're going to have to go back in surgically for whatever reason, and I think learning how to safely do those operations and sort of what are the implications, and if there are things we can do on the front end to facilitate those reoperations and make them safer, I think, are going to be really important.
That, I think, Andrew, is the fun in a lot of this, is that we are very much, I think, on sort of the front wave of all of these things and it's extremely exciting. I think it's great for patients, and I think it offers a lot of promise, but this is by no means sort of a done deal, or that we've figured it out. We're still refining mitral valve repair --
Perry: Sure.
Burke: Thirty years later, and so this will be something that I will get better and more experienced throughout my entire career. I think all of this stuff will continue to evolve in the same fashion.
Perry: Cool. That's awesome. No, I appreciate your expertise, your advice, and you're really helpful with a number of our patients that we see in clinic in consultation, and... yeah. I think I agree with you. I think it's an exciting area and fields. I think when I first heard of that concept and idea of aortic valve repair, I was like a little surprised because I hadn't heard of it before. So just like the promise that that holds, particularly for a lot of patients, the ability to maintain their native tissue valve and the potential benefits from there, I think that's really exciting. I hope that things move forward, that it's able to be refined and improved, and applicability can expand in some respects.
Burke: Yeah. I think, Andrew, I would just add to that. What I think is important from my end is it's important that patients at least understand that they have some options. Repair may not be a great option for every patient, because there is not a 30-year track record for this stuff, and there are some patients who just say, "Look, I don't care about Coumadin. I don't care about the valve ticking, whatever. I'll take a mechanical valve. That's fine." And that's okay. There's nothing, I think, wrong with that. Just as in for a patient with aortic stenosis, not every patient is a good Ross patient, and there are some patients, for either preference reasons or for anatomic reasons, that should get a valve replacement.
But I think being able to honestly assess these choices and at least counsel patients on the relative pros and cons is extremely important, because personally, I think if you have a patient less than 55 or 60 years old who's got valvular pathology and isn't hearing about either a repair option or, in the case of stenosis, a Ross, my personal opinion is that patient's getting a bit of an incomplete picture of what their choices might be.
Of all the conversations I have in clinic, which can range from very complex, older patients with aneurysms that we end up not fixing and we're talking about end-of-life stuff, whatever it may be, this tends to be the longest conversation that I have in clinic.
Perry: Really?
Burke: Trying to induct some of the higher-level concepts that we just went over into somebody who's maybe like your patient you presented, 40 years old, has valvular pathology, trying to talk about repairs, and this, and that, and then you get into the Ross and all the pros and cons and, "What does life look like in 10, 20 years?" Etc. It's easy to spend over an hour, which for a surgeon is like an eternity in the clinic, going over this stuff. Many times, I'll encourage patients, "Go home and think about it and talk to people, do research, and call me or email me." And we continue the dialogue because it's a big decision, the decision to forego a mechanical valve and attempt a repair, or vice versa.
Once the valve comes out, it can never go back in. That is a life-changing decision for these patients, and so it's exciting in that regard. But I think it's also our responsibility to completely understand the implications for all these things, including valve replacement, and counsel patients appropriately.
Perry: Cool. Well, I was going to close by asking you about what excites you most about your job, but I think we've gotten a little bit of that taste. I can definitely sense the excitement about that, so I appreciate that and appreciate your enthusiasm.
Burke: Absolutely, Andrew. I could talk about this stuff all day.
Perry: Cool. Well, with that, I know you have a busy schedule, so I thank you for your time and I will let you go.
Burke: Absolutely. Thank you Andrew. It's been a lot of fun.
, is a cardiology fellow at the University of Washington Medical Center in Seattle.