Surgeons' Thoughts: Aorta Surgery

Podcast Transcript

Announcer:

Welcome to Love Your Heart, brought to you by Cleveland Clinic's Sydell and Arnold Miller Family Heart, Vascular, and Thoracic Institute. These podcasts will help you learn more about your heart, thoracic, and vascular systems, ways to stay healthy, and information about diseases and treatment options. Enjoy.

Lars Svensson, MD, PhD:

Hello. I'm Lars Svensson, I'm Chairman of the Heart, Vascular and Thoracic Institute here at the Cleveland Clinic. With me is Marijan Koprivanac. He's one of our great and outstanding surgeons. He spent a lot of time with us doing research and then did his general surgery training here at the Cleveland Clinic and then went to one of the leading institutions in Pennsylvania for further training. We brought him back here and he's doing just a great job and taking over a lot of the practice in aortic surgery and aortic valve surgery as we transition a lot of care to our younger and outstanding surgeons. So, let me start off, Marijan, and ask you, when it comes to your interest in aortic valve and aorta, how did that start out?

Marijan Koprivanac, MD:

Thank you for having me here. But it started basically from the beginning, when I started my research here, as looking at how many of the surgeons, especially you, operate and how much skill and technique is required to complete these advanced procedures for the betterment of the patient, to increase the quality of their life, to save the valve, is just impressing and it was fascinating. It was something that I wanted to do and challenging.

Lars Svensson, MD, PhD:

Good. So, let's ask you a bit about preserving the valves. Let's start off with the re-implantation operation. What are your insights into keeping the valve in re-implantation?

Marijan Koprivanac, MD:

Well, re-implantation is, as we would call it, one of the more favorite surgeries we like to do in aortic surgery because it requires a fair amount of skill and understanding of the valve. The benefits for the patients are great because the alternative, if you cannot try to save the valve or repair it you would need to replace it, which would mean either anticoagulation with mechanical valve or a biologic valve that can entail another surgery down the line. So, saving a valve really means a lot to the patient and that could potentially aim to be a lifelong surgery and preserve his natural valve for a long time. There are many technical considerations in the aortic valve repair surgery and that really depends on the morphology of the valve, whether it's a bicuspid valve, whether it's a tricuspid valve, and then what's the pathology of the valve itself, is it leaking and how and why is it leaking and how we can repair it based on that.

Lars Svensson, MD, PhD:

Yes, the re-implantation operation is a very good operation as we've proven with our study of our patients. We certainly, well over 1200 patients with re-implantation operations, we're probably up to about 1,300 now and the results, we analyzed that fairly recently in subgroups. So, for 214 patients with connective tissue disorders, mainly Marfan's but also Loeys-Dietz, the freedom from re-operation at 10 years in that series is 97 percent, incredibly good. And so, that means that out of 100 patients we've operated on, 97 percent still have their own valves functioning well 10 years after surgery and, at 20 years, my guess is it's going to be still in the 93 - 95 percent will have their own valves. Essentially, we will have repaired the valve, kept that mechanism intact for patients, and I would expect that will be a lifetime solution for them.

I'd like to say that it comes with a hundred-thousand-mile guarantee for the repair and, in the non-connected tissue disorder patients, the freedom from re-operation was 93 percent, also very good results. There are some reasons for those slight differences but, essentially, the re-implantation operation solves the long-term problem of requiring otherwise a mechanical valve in patients who have enlarged roots and leaking aortic valves. For the bicuspid valves, the results aren't quite as good but run in the 90, 91 percent freedom from re-operation at 10 years. All right, do you want to talk a bit about bicuspid valves? You've seen now a lot of bicuspid valve repairs, and your insights from that?

Marijan Koprivanac, MD:

Regarding the difference between the, what we call a standard tricuspid and bicuspid valve repairs is the bicuspid valve functions differently. While in tricuspid valve, technically you want to have nice line between those three leaflets and a bit of a redundancy between them, in the bicuspid valve we really want more tension actually between those two leaflets. Whether you can do bicuspid valve repair without necessarily doing a re-implantation or a root procedure or just you can do a repair itself within the native root if it's not dilated, those principles stay the same.

Lars Svensson, MD, PhD:

Principles of repair with a bicuspid valve versus a three-leaflet valve are very different. With a three leaflet valve the leaflets are separated and they leak and so the re-implantation operation is very effective in bringing those together. With a bicuspid valve, the mechanism of competence is very different, so you have two leaflets and the way you make them competent is to stretch them rather than bring them together, and so you've seen now lots of repairs. You've seen how those principles apply to bicuspid valves and the stitches we put in, including what we call a figure of eight hitch up stitch. This is a stitch on the commissures that we use to hitch up the leaflets to a higher level. Long-term results are better with hitching up the leaflets for bicuspid valves.

Marijan Koprivanac, MD:

We try to put the biggest graft as possible for those leaflets to stretch them. Quite often those leaflets are still redundant and then we put those figures of eight stitches. We actually call them also Svensson sutures, just so you know.

Lars Svensson, MD, PhD:

All right. Let's talk a bit about the aortic arch. You've been doing a lot of cases now. You have to do the acute dissections and see a lot of arch operations. You want to talk a bit about what you've learned from aortic arch surgery?

Marijan Koprivanac, MD:

Well, absolutely. I mean, there are many ways that we can do arch surgery now and we have a lot of tools to do it. One of those is where we do use stents in these open arch cases trying to eliminate any subsequent surgeries down the line, but the point of the whole arch surgery is addressing the aneurysm or dissection. You do have to be fairly expeditious and efficient because time on the circulatory arrest is important as our outcomes as we know. The key is to have a good plan before the surgery and have all of the tools available and effectively and quickly address the problem of the arch. One of the also key points once the arch is addressed, whether it's with what is popular now here that we do a lot to be safer technique or the standard Zone One or Zone Two or total arch replacements with the graft is also making sure during the circulatory arrest time you have fairly good perfusion or protection of the brain and as well as you're coming out of the circulatory arrest is actually the airing and cleaning all debridement from the arch so you minimize embolic event.

The whole arch surgery, in my prospects, most important part is prevention of the stroke. Minimize that as much as possible. I always tell our patients if we have bleeding, if we have issues with the heart, we can fix those things. But stroke, once it happens, we can't do really much about it except give it as much time as possible to recover from itself. With the whole arch surgery, we are pretty good technically at addressing all of it and fixing it, but it's actually to minimize this one complication that is most significant and that's a stroke.

Lars Svensson, MD, PhD:

Yeah, so that's an important point. Many years ago, I did a study on patients with aortic arch surgery, some 600 patients, and looked to see if we could improve outcomes. We learned a lot from that. The gold standard using what was called the elephant trunk procedure, something that we spent a lot of time developing over the years, and we've done multiple papers on this too showing how one can improve the results with a total aortic arch replacement. And then, the second stage operation after the so-called elephant trunk procedure when we leave an elephant trunk, which is a tube, in the aorta beyond the artery to the left arm for the next operation and patients have big aneurysms in the descending aorta or what we call a thoracoabdominal aorta. You want to make some comments about using stent grafts now for second stage operations or replacement of the descending or thoracoabdominal aorta, whether you use endovascular, which is going through the groin with a stent graft or an open operation?

Marijan Koprivanac, MD:

Absolutely. I mean, this is where the aortic surgery started to go further where advances kind of led us, and this is that we cannot just think acutely, let's say in dissection situations or in aneurysms, and just address potentially the aneurysm that's present at that time and let's say Zone One or Zone two arch but we also have to think what can happen down the line and afterwards and if there is already some aneurysmal dilation on the remaining aorta. In this case we have to think about, what we call quite frequently now, a second stage so what's going to happen with the patient in future and what should we do, what's best for the patient, try to minimize operations for the patient. So, what we did in the arch surgery, as you said, we perfected this elephant trunk procedure. We have kind of a mobile elephant trunk, which is the first as we did where we push a graft into the descending aorta.

Now more recently we started doing frozen elephant trunk where we don't put a graft to kind of float in the aorta, where we actually deploy a stent into the aorta that is a little bit more fixed. What that provides us, when the patient has aneurysmal dilation in the rest of the aorta in the lower chest and the abdomen, is that we don't necessarily have to right away, if there is aneurysmal dilation in the area, go and do another open-heart surgery or open chest surgery. What that stent provides us, that elephant trunk provides us is a good landing zone for us to actually deploy endovascularly a stent within that previous either stent or graft, and then lay a series of stents down all the way to the abdomen, excluding the aneurysmal dilations within the thoracic aorta.

This way patient pretty much comes to the hospital a day before and leaves from the hospital in two, three days without any major incisions, just a groin, little prick or, as you would say, needle stick from what we use as an access to deploy all the stents. That's a kind of attractive way of dealing with these aneurysms nowadays. Before, we had to do everything open and you know that very well as you are the leader in that area and you were doing both of these approaches where you had to be pretty much address any of these problems, make a huge thoracoabdominal incision that would go pretty much from the scapula, behind your back, all the way down to the abdomen, to the groin.

Lars Svensson, MD, PhD:

Yep. So Marijan touched on a few important points in what he commented on there. One of the big problems with descending and thoracoabdominal aneurysm repairs is the risk of paralysis afterwards. We did a lot of research on trying to reduce that risk and we were able, with the methods we use here, particularly with spinal fluid drainage so it's called CSF, and drainage of the spinal fluid during the operation and the part of the stay in ICU and using a drug to put that into the spinal space and then improve blood flow to the spinal cord during the operation and after the operation. We've been able to significantly reduce the risk of paralysis after those type of operations, which obviously is a dreadful complication, and we've shown that that effectively reduces the risk.

At the American Association of Thoracic Surgery, I was asked to talk about our experience, and we had about two and a half thousand patients who had descending or thoracoabdominal operations. In the patients who had open procedures, we had a very low risk of paralysis using the techniques we've described. Let me go back to something that you touched on, which is an enlarged aorta and another operation or, for that matter, the first operation. So how do you decide when a patient needs the ascending aorta, the aortic root, to be operated on, replaced? What do you use as numbers or guides for that?

Marijan Koprivanac, MD:

When we have these aneurysmal dilations and patients come to us with different sizes, primarily one of the first important things to mention is that the sizing of the aorta was best and the gold standard for that is the CT scan. Quite often we get these measurements based on the ultrasound of the heart, which are not as reliable and sometimes can confuse patients if they have different methods of measuring that show different numbers, which is not unusual. But the CT scan is the one that we looked at and made it a gold standard for sizing the aorta. Now, in terms of sizes, you already touched a little bit on it. This is already about 4.5 centimeters in specific cases of connective tissue disorders we start looking at those patients as they might need to have their root or aorta replaced because already at 4.5 in patients like Marfan's population, they already start to have pretty significant risk of a dissection rupturing of the aorta, which is a life-threatening situation that everybody wants to avoid.

While in the normal population, the number around five centimeters and higher is the number that we start looking in the root and the ascending aorta that will indicate us for going to replace at that time point. Also, there are other factors that we need to look at, it's patient age. If we are kind of a borderline aortic size, let's say 4.8 but the patient is very young and we do expect of course that aneurysm to grow as patient ages, so we might pull the trigger a little bit sooner. Same as if the patient is physically active and also doesn't want to limit his physical activity due to those things. Second, or actually we are now on third and fourth, I guess, factors are also the size of the patient, and this is where you describe your index if you want to tell us a little bit about it.

Lars Svensson, MD, PhD:

Yes. As Marijan pointed out, in patients with connective tissue disorders above 4.5 centimeters we start asking questions and doing genetic analysis too. In patients who have Loeys-Dietz, we would certainly look at those patients from the point of view of surgery after 4.5 centimeters and bigger for someone of, let's say, average size. And for patients with Marfan's, who have got a family history of aortic dissection 4.5 centimeters and larger, we usually recommend surgery. If there is not a family history of dissection and Marfan's, usually about five centimeters, but we do take into account a patient's height. We have this formula that we use so it's the cross-sectional area and square centimeters divided by that patient's height in meters. If that ratio is above 10, then we recommend surgery and we apply that also for patients, for example, with bicuspid valves and root aneurysms or ascending aortic aneurysms.

We know patients who have enlarged roots, which is where the aortic valve sits, part of the root. In those patients, they have a higher risk of developing complications and dissection. And so, that is another measure that we then look at. In patients who have had previous heart surgery, it depends on a patient's age but, for example, in a patient who's had previous heart surgery and young, we'd look at re-operating for about 5.2, 5.3 centimeters. Part of the reason for that is they have scar tissue from previous surgery, which somewhat protects them from rupture of the aorta. So, yes, as Marijan said, we do factor other things into deciding when to operate on a patient and that's why it's always good to get an opinion from a surgeon. Thank you for joining us, I hope you've found this discussion useful for you.

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