Chapters Transcript Aortic Surgery: Personalized Medicine with a Team Approach Dr. Puja Kachroo, MD shares about the evolution of Aortic Surgery including valve sparing procedures and aortic arch procedures. So, our next speaker is Doctor Puja Katr who earned her medical degree at Ross University in Dominica, West Indies. She then completed her general surgery internship and residency at Rutgers Medical School in New York, New Jer or New York. And then her fellowship in the division of cardiac and thoracic surgery and division of pulmonary and critical care medicine at the University of California in Los Angeles. Then she completed her cardiothoracic surgery residency at the Washington University School of Medicine where she is currently an associate professor in the division of cardiac surgery. She sees patients at the Center for Advanced Medicine at Barnes Jewish Hospital for Coronary artery bypass grafting valve replacements, incorporating transcatheter based interventions and surgical treatment of aortic diseases. And I know you do more than that, but that was kind of a summary for you. So, um thank you so much for your time today and I will let you take the floor. Sounds good. Thank you so much for having me. Um So pretty much my passion is actually aortic surgery. I do all the gamut of uh cardiovascular surgery. Um And so today we're gonna just focus on, you know, some of the general concepts of aortic surgery and how really now we're dealing with sort of personalized medicine uh with a multidisciplinary team approach and we kind of go into this. Um So I have no disclosures for this talk, but specifically, we're gonna look at some of the objectives are um to review the anatomy of the aorta in general and to detail sort of how aortic surgery evolved. Um and specifically to dive into the aortic root and some sort of uh some of the available valve sparing procedures we do now that weren't as prevalent before and actually still are not. Um but some of their challenges as well. Um Aortic art surgery is pretty uh uncommonly done around the country. But um there's a lot of new and um upcoming technology here. So I want to discuss like how art surgery evolved. And, and finally, and so I also deal with the thor abdominal aorta with my vascular surgery. Colleagues wanted to just go over some of the types of repairs that are offered for um aneurysmal disease. And I want to focus this topic specifically on aneurysms and not dissections, uh which I'll talk about just very briefly. So as we all know the anatomy, um uh we're gonna start from the aortic root up to the ascending aorta. Both of those can be accessed very easily through a sternotomy in the chest. The proximal aortic arch is also accessed in the chest. Um but the distal aortic arch and the descending thoracic aorta actually runs in the left pleural space. So that's accessed through a thoracotomy on the left side. Um, and then finally the thoral abdominal aorta, I'll show you some pictures of sort of some incisions we make. So when you see patients and, you know, they may be apprehensive about what surgery they're getting and how they're, we're gonna access their aorta. Um, at least you'd be able to sort of tell them what, what to expect. So, aneurysms are pretty rare actually. Um most commonly when they do affect part of the aorta, majority of them affect the ascending aorta or aortic root. About 60% of the time, about 30% are descending and again, rarely the aorta gauge. Um Some of the general risk factors for cardiovascular risk factors are similar to those for aneurysmal disease. There's hypertension, tobacco abuse hyperlipidemia, all of these things that we can actually modify. Um But really, there is also heritable genetic variants that we cannot. Um if you identify a patient with syndromic features, it's um and I'll show you in the next slide about recommendation for testing. Um But those who present, you know, early, less than 60 years of age, those who have a family history or have intracranial aneurysms in a first or second degree relative or anyone who died suddenly in their uh first or second degree relative and for an unknown cause. Um so some of the algorithms available. Um This is for genetic testing. These are from the American Heart Association, American College of Cardiology Guidelines. You see a patient with a syndromic features uh of a connective tissue problem or a family history or they're young. They do recommend genetic testing if it's under 60 years of age and if they have uh a positive result from that genetic testing and there's a number of variant genes, um then you wanna test the relatives as well. However, there's mostly about only 20% of the time. Do you actually identify in these young patient population and identifiable disorder? So, really 80% of the time you don't. Um But you still have to monitor these patients. And that's really once I see a patient for the first time, if they have any sort of aneurysmal disease, I follow them for life until um and, and even sometimes we don't identify some of the causes until later on. Um Just this past week I operated on somebody who initially had had surgery prior for atherosclerosis, we thought. And then on this time around her pathology came back as G cell arthritis. So again, can find different things at different stages of their disease process. There's a number of causes for heritable, I'm sorry for aneurysmal disease and there's heritable, there's also congenital. One of the more common things you'll see is by cuspid aortic valve patients, that's about 1% of the US population um Turner syndrome is also rare. Um And, but again, if you see a young Children, um or patients who have had coarctation in the past, you may um you may find that they have aortic aneurysm again, like we talked about hypertension atherosclerosis being some of the most common. Um and rarely, you'll see inflammatory, like I said, g cell arthritis fairly rare. But if you do identify a patient who has some vasculitis ar arthritis and rheumatology, consult um to look for serum inflammatory markers and uh potential treatment with steroid therapy preoperatively, especially if they haven't met any surgical criteria for treatment. Um What we're really trying to pre prevent, sorry uh to when dealing with aneurysm is really wanna avoid these aortic emergencies and, and there's a whole range of different emergencies, um penetrating atherosclerotic ulcer or P A US. As you may see undocumented and scans, it's really just a defect caused by a plaque just like in coronary arteries and cause can cause an internal defect. And if it's large enough can warrant treatment because it can progress to the next dissection or rupture, intramural hematoma, the aortic walls composed of several layers. And so when there's a intramural hematoma, we think it's either there's blood vessels in the advent tissue of the outer layer that have burst or there's some tiny internal defects that can cause bleeding within the wall and this is sort of a precursor to an aortic dissection. So anytime you see an intramural hematoma, a pau um with pain and an aortic dissection that's in medical emergency should be sent immediately to the emergency room. Um, aneurysms are really di diagnosed various different ways. Echocardiography. A lot of people come in, they have um most of it's found really on CT scan for screening for lung cancer. Um those are do generally done with non contrast. So it's really important if you actually notice a dilation to go ahead and get a contrast of CT scan, just makes a referral a little bit easier because sometimes patients are very nervous, they come in and then you're at this borderline phase of maybe you don't have to do anything. Echocardiography is another thing if you hear a murmur, um they may have a dilated aortic root. If they have syndromic features, they may have, they are classically dilated aortic root and Marfan patients or even some patients with lowest deeds have them. And as we know, um the aneurysms follow the law of Laplace, essentially the there's wall tension. So the the larger the radius, the it's proportional to the amount of wall tension. And we, there's been various studies that have documented that the larger um the aorta that the higher the growth rate is. And so they looked at, there's various studies, I picked one of the early ones from Yale because this is um Doctor Lear's group at Yale sort of follows all of their aneurysm patients And now there's various registries available that we also participated in at was u to um specifically in those patients who don't meet the surgical threshold and we sort of follow them for five years and put it in a, in a national registry. But really, they found that aortic dissections tend to occur at higher rates when you have larger aneurysms. Again. And also similarly with rupture. So what's really the hinge point, when do we offer therapy? So again, the study from Yale looked at on the left hand side is the ascending aneurysms. On the right is the descending. And they found that there's on the y axis is a percentage of probability of complications. So the the, the larger the aneurysm in the aorta, um the higher the likelihood of uh complication and that hinge point occurs at somewhere around six centimeters and the descending aorta behaves a little bit differently because it comes from different cells, um tends to, um it tends to cause complications at higher diameters around six, sorry, seven centimeters. And so there was this cut off originally and just sort of an arbitrary cut off of 5.5 centimeters for ascending replacements and 6.5 centimeters for descending replacements. That was the hinge point. And this is all assuming in, in, in patients you don't know that they have a history of connective tissue disorders. But like I said, we're all moving towards personalized medicine a lot of people, especially young patients are getting genetic testing early. So that criteria is sort of shifted down and are um indicate in the guidelines. But again, if you have an aneurysmal patient or syndromic, you should just send a referral uh to an aortic center. Um The guidelines recently were updated from 2022 by the American College of Cardiology and American Heart Association. I'll reference them throughout. But essentially, you know, there's class one indications again for the 5.5 centimeters of the ascending aorta and the aortic group. But there was a two, a guideline that was just changed as in the last up and showed that in those patients who have a maximal diameter, greater than five centimeters, it is reasonable with a two a indication to be performed a surgery to be performed by experienced surgeon, a multidisciplinary aortic centers. And that really just means that it was discussed in a team and you have a high volume center and it's not so much the surgeon where you're gonna do an ascending replacement. It's not a technically challenging procedure, but again, it's IC U care. It's high volume. Anyone who's dealt with aortic pathology, when you're dealing with the aortic root, that's a whole different ball game. And I'll kind of show you that in a little bit more detail coming forward. So aortic root specifically is actually very complex. Um and the aortic root really refers to where the heart exits the left ventricle and connects to the aorta. Um and it's defined by this ventricular aortic junction, we refer to as the aortic annulus and it really is comprised of the aortic valve um at the bottom of it. And then you have these sinuses of valsalva. Um And then within each sinus of valsalva are uh the ostium of each of the coronary arteries that supply the heart muscle and then it narrows to this uh area called the sinotubular junction and then continues on to the ascending aorta. So you can imagine doing anything to manipulate the aortic root can change a lot of different structures, especially if you're not replacing the aortic valve, but you could affect the coronary arteries and such. Um so really the arus valves are composed of these leaflets, um mostly are trileaflet. We talked about 1% of the US population has bileaflet pathology and that can be associated with sort of aneurysmal disease as well. Um There's sinuses, they were first described um in the 17th century and really, they have a role in modulating some of the coronary blood flow because they sort of swirl, the blood swirls around the sinuses to allow for uh blood to go within the coronary arteries. But it also seems to have um an effect on the opening of the aortic valve. And so as we age and lose the elasticity in the attic wall, um and even with atherosclerosis, you have um leaflet degeneration. That's potentially could be one reason of why patients who've had either root replacements with bowel sparing procedures or that over time that they can wear out their aortic valve, then you have a numerous amount of structures right underneath the aortic valve. And so this is basically an aortic root, just sort of splayed open. You can see the left ventricle on the left side and the aorta on the right side and you have these leaflets in the middle to find um either we use cusps or leaflets interchangeably. But essentially, there's a membranous septum that sits there that really contains the, the conduction system of the heart, so that can be affected during any root surgery or valve surgery. Um And also, um the mitral valve sits in close continuity. And so if you have destruction of any of these because of infection, um such as endocarditis, you might have conduction abnormalities or it can affect the um mitral valve as well. Um So how did aortic surgery actually even start? So, really, Leonardo Da Vinci, I mean, what an amazing person to even be able to describe, uh he's uh sort of drafted out aortic uh aortic mold, artificial valves and even the sinuses of valsalva went on to describe exactly the cuss and I think he like dissected pigs and had sort of drawn all of this stuff from this. Um But really cardiopulmonary bypass really changed um heart surgery in general, but in 1953. Doctor John Gibbon came up with the heart lung machine. Now, now you could perform procedures where you could still get blood flow to the brain and the rest of the body. So you didn't have to worry about that. Can just focus on the heart. The first described procedure, successful replacement in the AORTA was in 1956 there. Um don't have time to get into the long history of doctor uh Denton Cooley and Doctor Michael DeBakey. But it's really interesting uh feud. So if you get the chance to go it, it's it's a really great story, but essentially they described a patient who came in had some chest pain and they were able to perform this 30 minute replacement on bypass and the patient was able to go home about three weeks later. And I mean, honestly, patients weren't surviving before this without cardiopulmonary bypass. 1964 progressed to now, we could do more than just the ascending aorta. You were able to treat some of the aortic root below the valve, but they still didn't, weren't mobilizing coronary buttons or doing anything at that time. Patient went home successfully here as well. Doctor Myron Wheat. Um and this patient was interestingly after he got a mechanical valve in this and is sending aorta uh replacement and then had a massive automobile accident, found that he made a good recovery, didn't even need. Um didn't have any issues with his valve dislodging. And then about 13 months after his surgery, he was a house painter and climbing stairs and actually not even on anticoagulation, didn't have any thrombosis or dis embolization. So that's kind of remarkable considering these, you know, now we need to anti coagulate for any mechanical valves. Uh The Benal procedure really, um this was treating the whole aortic root. So now you are able to disconnect those coronary buttons in order to re implant um and replace the entire aortic root. So Ben tell refers to replacement of the aortic valve um with uh like sort of a conduit where the valve is sewn at the bottom into uh a Dacron graft and then you reattach the coronary arteries at that time, they weren't really mobilized. Um That was actually done by Doctor Kua I to say that in the next slide. But the next thing at those times, those grafts really actually were porous. So we needed something to, you had to close the aneurysm sac over them. And in order to prevent the blood from pooling up and building in there, there was a procedure to kind of make a hole in fist on to the right atrium to pro this tense hematoma. That was Doctor Cabral as, as a number of other things that he had contributed to aortic root surgery. Doctor Kuki was um credited to mobilize these coronary buttons. So instead of just kind of connecting them to the side of the graft, he actually was dissected them from the the base of the heart and actually was able to manipulate them and kind of free up the indication moving them around. Um And he and he used to work uh at Jewish Hospital here. What about now who is doing these surgeries? So, you know, the long history of this since the 19 fifties, but really out of these 13,000 patients, we queried this our society thoracic surgery or database, uh sorry, database and looked at patients who are underwent root procedures and only about five center center of centers perform more than 16 root surgeries. So really a low volume sort of operation and the median number of root surgeries that are done at these centers are actually only two. Um And, and so when the guidelines came out and you, they say you, you want a experienced aortic surgeon at a multidisciplinary aortic team, but really, that's not the majority of the country. And uh luckily at Washu, we get a lot of aortic pathology, we do a lot of root surgeries, we do a lot of connective tissues. So you have to be sort of careful of just sending to pa to, to um places where there aren't high volume centers. So the guidelines really don't address a number of surgeries required because you realize that root surgery um is really uncommonly performed across the United States. Um And of those, and I'll go into what valve sparing is VSRR as I referred to, about 80% of the surgeries that were performed um for the root rep replacement was done for um aortic insufficiency. And that can be for a number of reasons whether it's endocarditis and you need to replace the valve, but only about 14% are done with a valve sparing. And that's really beneficial if you can spare the valve, that's the best thing to do for a patient because that avoids all the complications of having a bioprosthesis, such as a risk for endocarditis, such as risk for embolization, such as risk for having um being on a blood thinner, um antibiotic, prophylaxis, a number of things that can be avoided and obviously valve degeneration. So, bioprosthetic valves don't last, you know, young, especially in young patients don't last a person's lifetime and aortic valve bearing procedure when done once again, at a high volume aortic experience center um are really performed with very low operative mortality, very low stroke risks and um and various other um comorbidities. Um So, Valspar procedures, what are they? So essentially what it means is there's two types. Um Doctor Magda in 1979 came up with the remodeling. So basically excising just the sinuses and uh sewing it to, to the, to this annulus where you still preserve that um part of the aortic root. Um Generally, this is not reserved for patients with connective tissue disorders, but again, great um success rate. He did perform in a number of Marfan patients where I probably think that some of the failure can be if you don't stabilize the aortic root. Because if you leave part of the root behind, you can still have dilation and further um stretching of the aortic valve if you don't secure that base down. Um So, reimplantation, Doctor Tyrone David credited it for so many operations in cardiac surgery. But 1988 came up with this procedure where he actually excised all of the sinuses, but put this graft around the entire aortic root and sewed it into place. So it's totally secured above and below the aortic annulus and this prevents dilation and that valve just sits in there. Um and um can be um can you can still have the native valve, but again, this is a root operation. So you still need to mobilize the coronary buttons re implant them. So anytime uh coronary artery is manipulated, you still have about anywhere from 1 to 3% chance of just mortality. Um It does triple your risk because you can have just a slight kink can cause a significant problem and dysfunction of the heart. Um And then even when you re implant it within a graft, you still may have what's called prolapse like one of the leaflets doesn't come together normally. So you have to be facile at being able to perform valve repairs. And so these were rarely done before but have now come in a lot of um a lot of the times we sometimes just do isolated cusp repairs or leaflet repairs. Um Sometimes as the aortic valve stretches, you can have a lot of dilation of, of these leaflets and can cause what's called fenestrations. They're sometimes common um after or normal for along the areas where called the commissures with the leaflets, um edges come together. But um but sometimes they're pathologic and they need to be close in order to have a successful valve repair. So again, you have to have not just know how to put the graft in, but know how to fix um and align the graft. And so we looked at our experience in this, we published our series a couple of years ago, 100 and 77 patients, young patients, about 40% were Marfan. And we found that the freedom from reintervention in the aortic valve was about 88% of 10 years. So, again, the majority of the patients didn't require a valve replacement um and had a great late survival as expected for such a young cohort of patients. Um But again, we found that we looked at a little bit more closely and but effective height is essentially how well the leaflets come together. So if they co opt well, and there's a certain number that they co opt or millimeters, then the probability of having them stretch out and have recurrent aortic insufficiency um is low. Um I'm gonna just couple slides about the Ross procedure because I consider that part of the aortic root. But the Ross procedure was um first described in 1967 by Doctor Donald Ross. Um It's essentially replacing one's aortic valve with their native pulmonary valve. So cutting out the aortic valve, whatever pathology it is, whether it's aortic insufficiency or aortic regurgita, uh I'm sorry, um uh stenosis and then harvesting that right ven ventricular outflow tract there, that pulmonary valve and putting it into the aortic position and then replacing the pulmonary valve with a homograph. Why in the world would anyone do that? Well, essentially, again, same thing you wanna have this quote living aortic root. So a lot of people have looked at this for young patients, that's kind of where it really started. Um But it sort of fell out of favor. It's a, it's a very technically challenging operation. This carries a significant operative risk. Um And there's, there's a risk that that pulmonary valve um is now put into an area where there's a lot of um pressure from the aorta or the aortic pressures are much higher than on the right sided pressure. So you worry that that autograph that's very thin, that's not used to high pressures, can dilate um and that can require reintervention. So, um so it's really, you know, but the some of the um advantages are you, you avoid any in very young patients, you don't have to have lifelong anticoagulation or this, you know, leaflet thrombosis. Um but it does set up um failure rate. So, um but the reason it's really used is because of this paper, Doctor Alhamzi, um you know, trained with Doctor Magda Yakub, the one who came up with the remodeling procedure and published a series of looking at their experiences with 400 ross. Now, this is done by one surgeon um and very skilled surgeon and that's a high volume surgeon um in 2022 and said, looked at Ross versus the general population survival and is almost matched, you know, relative to mechanical by prosthetic. So here, the Ross came back um and started uh to come back into favor with certain certain Ross centers. Again, we do have a Ross program at wash U but very selective about the type of patients. And they have to know that, you know, there's a potential for reintervention, not only in their aortic valve, but also their pulmonary valve. The tendency in the pulmonary autographs is that they can narrow at the anastomosis and wherever you connect them together. And so they, they may need some stents in that. And luckily, they can be done percutaneously. But again, you need to worry about both sides at that point and need lifelong surveillance. Um There've been various technical modifications to decrease the risk of failure, um especially if you have a dilated aortic annulus. And now Um I think there's, there's been some improving data on better Roth outcomes moving on to the aortic arch. Um It's less common. We talked about less than 10% of the aortic arch. Um uh aneurysms are only in, only involve the arch. Usually it's due to someone who's had an aortic dissection and continues to dilate. Um There's really no large reports of it. It's a very high risk operation to do address the aortic arch. Um And we really are very selective about who we ended up who we end up repairing. So, every one of these patients, especially arch patients, um we'll get discussed at our multidisciplinary aortic conference um because there's probably five or six different ways and I'll go through exactly, you know, some of the various strategies and evolution of aortic heart surgery. So, what are the indications? Well, symptoms, there could be a number of symptoms, you know, they could have hoarseness, they could have compression of their esophagus. It could be Disick because of compression of the trachea. Now again, these are have to be pretty significantly large aneurysms. People come in with horse voices. Again, very rare that probably over, if they're over six centimeters, they're rapidly growing. You have to rule out a connective tissue disorder, probably doing that at a letter lesser um size, but class one indications are for low or intermediate operative risk patients. That that's the first one up top. Again, it is not a low risk operation. So, whatever that means, there's quoted risks with aortic art surgery because it requires the use of circulatory rest. Um, the stroke risks are anywhere from 3 to 20% now. I mean, 20 is quite absurd, but I think 3 to 5% is a, is a reasonable risk, especially if you're doing it for patients with atherosclerosis. They probably have microvascular diseases in their disease in their brain. They probably have uh arch, calcium. So these aren't very um well tolerated operations in high risk patients. So, you know, we've kind of defined, ok, if they're 5.5 centimeters and they're relatively low operative risk, it may be reasonable to pursue open surgery. Well, what are the open surgical options? So there's things called he arch where we just replace the whole ascending aorta and part of the aortic arch or extended he arch. These are the typical operations that are done in aortic dissections in order to prevent a catastrophe. And this is just life saving. It's not to fix the whole problem, but just to resect the tear and replace the ac ending. We can do this sort of fell out of favor for connective tissue. I'll show you one patient later um where that island of the whole neck vessels um come off of the graft. Um Now, with the use of circulatory arrest, different various ways to give blood, do blood to the brain during uh circulatory arrest has allowed us to extend the time of doing aar surgery just like bypass uh change thing in the 19 fifties. As soon as we, we got um antegrade cerebral perfusion, retrograde cerebral perfusion, we knew how to cool patients. We've been able to re reduce the stroke risk and organ ischemia and we've been able to extend the various type of operations so we can do this. Um There's also what's called a traditional elephant trunk. If you're treating something that's in the distal arch, like I told you, it's in the left plural space. You can't really get to it while you can hang a little graft inside it and it can be further extended with stents. Um At WASU we have um we're actually writing up this series uh soon. But uh of um looking at um treating distal arch pathology um by just opening the aorta against does require circulatory rest, but didn't need a whole total arch procedure, could just sew a graft um into the descending uh or distal ascending, I'm sorry, distal arch and, and then close up that um put a graft on the ascending and then deploy a stent going forward. As you can see that basically can treat distal aortic arch proximal descending pathology. So that's been uh really good. We treated about 75 patients, most of them were dissection patients that had um that had dilated. But again, you can see the permanent stroke risk um was about 6%. And in hospital mortality, even for that procedure was about 8%. So not low risk at all. What we learned from this operation is not a great operation for dissections. It's a good operation for aneurysms. Luckily. Now, other things have come onto the market. This was approved um in May of 2022. Um And this basically is a single stent that goes into one of the branches of the head vessels. Um And you need a certain amount of what's called a landing zone. So this has to sit in the aortic arch um and can treat distal arch pathology, especially in patients with type B dissections. Um So, again, very limited indication, but um you can, it's usually deployed into the subclavian artery. Um and the left subclan artery and treat the distal aortic arch. We now have this device that's called a thoro lex device. Um It's a multi branch or a single branch device. It's essentially a graft that has all the branches for the head vessels. So you have like these three branches and then it's, there's a stent at the end of. And so you put it inside the aorta, again, requires circulatory rest, you put it inside the aorta, you deploy that stent and then you do your total arch procedure. And again, it treats the whole the whole aorta in the chest, but it can also treat this arch. And the reason this is a little bit better than that little floppy graft is because it's much easier to put a stent inside a stent. They oppose better. Um And so we've done about 25 patients since October of 2022 when it was approved again, right? Like arch um, disease is very rare, but the ones we're treating mostly about 50/50 percent are from chronic dissections. Um, majority were redo operations but we did it with a relatively low um uh uh circulatory rest time. Um with, with um no patients having end stage renal failure at the end or um strokes and had 100% technical success, uh success of deployment so, so far, so good. But again, it's just a matter of time when you're just treating arch pathology, whether you're gonna get a stroke. So now I've come up with, we've described some hybrid techniques. Earlier. This was a case of a patient with a connective tissue disorder. A long time ago, had gotten that little patch where he just had his arch branches um re implanted and now that heart became just gigantic. Um So what we took, we took him to the or, and we basically made some connections from his ascending aorta and connected up to the branch vessels is um these two grafts that you can see. These two tubes are going up into the anomic artery and sub claiming on the left and then the left common carotid artery. And then um one of our vascular surgeons. He basically took a picture on the left hand side. You can see that there's some connections, there's tubes going up to the, to the arch vessels, the grafts. And then there's this giant sack, which is what his aneurysm was. And then this could be easily treated with a stent device done through the groin. And this avoided an open giant arch operation. This was just done on the heart lung machine. We are participating in a number of clinical trials as well. Um This is a uh again, um this, this was a, we we were part of the feasibility trial um in two branches into the anominous artery and the common carotid artery. It did require some sort of reconstruction to the left of plavi because you can't, you have, you, you try not to cover the left of plavi artery if you can help it. Um You do reduce the risk of paralysis um in those cases and arm ischemia. So you wanna um do a reconstruction between the subclavian artery um and the common carotid artery and then put this device into two branches. But again, pretty extensive operation. It required bilateral carotid, cut downs giant, you know, sheets in the groin, this big, you know, graft coming up. But so again, they're being fine tuned. Um This was another device we're actually participating in this clinical trial. It's a single branch, but again, requires reconstruction of the rest of the head vessel. So you have to do a carotid carotid ala and then uh sorry, carotid carotid bypass and carotid ala bypass. So that way all of the top vessels get perfused. You put one branch into the nominate artery and then deploy a stent graft to complete treatment of the entire aortic arch. So still employ uh uh still enrolling for this triumph. Um Mainly looking at patients who have aortic dissections that have grown over time. Um This one's coming out, um which is basically, you have, we have a lot of uh arch, uh I'm sorry, ascending pathology also. And now trying to see if there's ways that we can treat the ascending aorta. The limitations in the ascending aorta are that the aortic root where the sinuses um are that hold the coronary arteries, that sort of limit how much, how long stents we can put in. So we can't put these, you know, 10 centimeter long stents a lot of the times um or these 15 that we can treat the descending because we're gonna be co potentially covering a coronary artery. We can be impinging on the valve leaflets. Um We can be covering up to the anomic arteries. So you need a certain amount of length. But again, and they've made shorter graphs and if you don't put it long enough and you don't match the curve, then they can leak and you really haven't fixed the problem. So, um and they also require you to go inside the aortic valve. And that can be limited by somebody who has um a mechanical aortic valve in the past, like those patients who are byus, the patients who've gotten valve replacements and now need their ascending aorta done. Um So really, um there's a number of different devices available for um art pathology. Some are approved um and are open and some are endovascular, but again, some, they're not suitable for everyone. Um There's a lot of planning that goes into all of them. What are their landing zones? How long the aorta can be what we're covering? Um And really, we don't have long term data on these. So these are really reserved for patients who are higher risks. Um not patients who have connective tissue disorders. Um We try to do these in patients who have had prior heart surgery. A lot of these patients have had multiple operations for dissections and you're going back into their chest two or three times. Those are the ones we start screening for trials like this, especially until we get long, long term results from them. Moving on to the final topic of thor abdominal aneurysms. And this is just kind of an overview if really what does it entail patients with aneurysmal disease also can have um their entire thoral abdominal aorta. Now, there's various extents, this is called the craw for classification of thoral abdominal aneurysms, really sort of divided by distal to the subclavian artery and how far it extends past the visceral vessels or to the uh iliac bifurcation. So, um the most extensive one is this type two, which is really contained from the top all the way down to the aortic uh uh bifurcation. Um And we do, you know, we try in those cases to sort of split the operation up because if you do that, that has the highest risk of spinal um spinal cord ischemia and can lead to long term paralysis. So there's a lot of limitations for these procedures. It's an all day surgery. Um It's really reserved for patients who have good pulmonary reserve because you're gonna um you support them with the heart and lung machine partially, but you wanna, you have to drop the lung in order to expose the aorta. So they have to have good pulmonary reserve. Um They have to have relatively decent hearts. We do get stress tests on these patients uh to make sure they can tolerate a big operation. Um And what really they undergo is this, they get placed on their side. Um There's a graft that's placed in the femoral artery for arterial perfusion. And then one of various different strategies, this is called left heart bypass circuit. Essentially, it's basically takes the blood from the left atrium of the heart that's already oxygenated and recirculates it back. And this provides partial support. The advantages of this are you don't need to um to thin out the blood or have a high AC T level in these patients, like you do for cardiopulmonary bypass, cardiopulmonary bypass requires an AC T level, activated clotting time level ac T greater than 480 seconds. That's really, um that's, you know, causes um a lot of bleeding in these very large incisions. Um So to limit this, we see a couple of things that patients get spinal drains to reduce the risk of spinal um ischemia. Um they go on the heart lung machine to protect their organs. Um and to also perfuse um the kidneys during this uh during this procedure. And then essentially the aneurysm is cut out and replaced and with various different types. So on an extent to the most extensive one, the whole graft and we re implant the celiac artery, the S MA and the left and right renal arteries. Um And you know, you can see there's like one other area in the thoracic area where anywhere from T eight to t 12, we think are some arteries that perfuse or big branches to the spine. So, if we see large arteries that are supplying um the spine, we think, um then we try to re implant them. But again, really, you don't know, especially in dissection patients, it can be a mass, you can be looking at two or three different movements, you know. Um so you have to be, these are especially the dissections of the highest risk. But for straightforward aneurysm, these are well tolerated operations, but again, carry a lot of morbidity and it's not a small incision. This is one from the operating room. On the left hand side, you can see there's an aneurysm, um where the blue hand is, uh, my hand is essentially holding of the abdominal organs back. There's a lung to the left and then right above here is the aneurysm in the chest and it continues down below where that white um the white glove is and continues underneath them. And then at the end, um you can see the this Dacron graft that has all these branches and that goes to the various two renal arteries, celiac and S ma. Um and then it takes like half a day to close this incision as well. So, um but you know, patients still spend about a week to 10 days in the hospital after this surgery. Biggest thing, we keep them in the IC U for spinal precautions, spinal drain, they can have delayed um paralysis after this operation even several weeks out. So it's really important to do strict blood pressure management while they're in the hospital and to minimize the risks. Um So to conclude, um really, there's just so many techniques to address aortic pathology. And now it's the trend is towards personalizing surgery to the pathology. So, if it's, we're talking about a connective tissue disorder patient, they have a different treatment pathway. They have genetic testing. Um uh And if you have patients that are just atherosclerotic, you have to treat the underlying disease. But once they reach the surgical thresholds, then we offer them surgeries and then you risk assess them. Are we trying to talk, are we talking about patients who are low risk that can tolerate any open operation or they are the higher risk that we have to think about a hybrid approach. Um at centers of uh for multidisciplinary aortic teams and aortic surgeons, the new guidelines have lowered the risk um or the threshold from 5.5 c centimeters to five centimeters for this is the ascending aorta and the aortic route. Um And really, you need an aortic team and it's essential to providing, you know, care for complex disease because you really need, there's like 10 different ways to do every type of operation. And so this is my little plug for our team. Um I have the privilege to work with Doctor Sanchez from vascular surgery is my co-director for aortic center. Um who really specialized in we do thor abdominal procedures together, all of the stent stent. Um stenting is done by the vascular surgeons. Um Doctor Alan Braverman is a a ory specialist, so especially all the connective tissues, every single um patient is seen by him and then all of the films reviewed by either Doctor Sanji Bala and Doctor Costa RTI is another dedicated chess radiologist and this, we have this multidisciplinary team twice a month. We look at every imaging in detail and can come up with various plans and then have a nice discussion with the patient of how we should proceed. So, thank you so much for your time and I'm happy to there's my cell phone number on there and also my email free. Feel free to contact me if there's any questions or if you just wanna run a patient by and happy to hear about anything. Thank you so much. If you all have any questions. Yeah, feel free you can email doctor Kater or you can email myself. Um but thanks again, Doctor K, that was wonderful information. So I appreciate your time. Thank you so much. Have a good day. Bye bye. Created by Presenters Puja Kachroo, MD Surgical Director, Center for Diseases of the Thoracic Aorta (CDTA), Associate Professor, Surgery View full profile
