 It's a real privilege and honor to be here talking to this esteemed group about this topic. We've, you know, thinking for, even though we do a lot of transplants and what not, for cardiology grandmothers, thought we would talk about a procedure that we're doing more and more of, essentially, the concept is, you know, how do we select people for certain procedure and how do we give patients what a lot of people are kind of wanting, which is more and more minimally invasive approaches to almost everything we do. Even transplants, there are more and more people trying to ask to see if we can do these minimally invasive and lower stress levels, less blood transfusions and what not. So I thought I'd kind of hone into just one aspect of this whole topic, which has been fairly well characterized historically in the literature and there's a lot of data about it so we could talk about it and that's around the area of aortic valves, so we're approximately sending aortic work and how we view that. So I'll talk a little bit about background operative techniques, benefits, some of the pitfalls which really kind of balances all of our best intentions, is acknowledging what the pitfalls are, preoperative imaging and then how we can branch out to other type procedures. So just honing in here, this is the aortic valve, this is a stenotic aortic valve, many of you have seen these in the OR or pathology slides, this is essentially a transected root and you can see the three commissures, highly calcified valves, typically when we're talking about replacement of a valve like this we have to essentially cut this out along the annulus, remove it and then sew in a brand new valve for when we're looking at doing an aortic valve replacement. So what's the difference in scars or in invasiveness when we're comparing a standard aortic valve approach to a minimally invasive valve approach, at least through a mini sternotomy type approach. So when we look at our standard AVR approach, it's about 11 to 14 centimeter incision and it's, I'll show you some more slides going forward but it gives us the most optimal view for conducting the operation and for protecting the heart and the way that we have to protect the heart in order to do these procedures safely. So when we talk about a minimally invasive one, we're looking really at least a six centimeter type incision or smaller, so six, maybe even six to eight and there are different techniques that we need in order to achieve that. When we look at a standard sternotomy, this is the view, this is what we're talking about and this not only applies to aortic valve, this also applies to coronary bypass, mitral valve. So this is 11 to 14 centimeter skin incision, we split down the sternum in the middle and then you get access to all of these critical structures in the heart. So there's the ascending aorta, there's the right atrium, all of these, these are critical to be able to access because we have to drain the heart and we have to provide anagrid blood flow to the body and to the brain in order to then work within the valve in a bloodless field. So this exposure is absolutely a very nice, safe, full exposure for us to achieve these metrics. Aortic valve replacement, we're all familiar now with TAVR, but just to remind us that aortic valve replacement has very, very long follow-up, 17 year follow-up, even of bovine pericardial bioprostesis shows excellent 15 year results, particularly younger patients with a longer life expectancy. When we look at structural valve degeneration rates, even for bioprostatic valves in patients younger than 60, at 10 years it's still less than expected, this is data from the Cleveland Clinic on 12,569 implants. Clearly TAVR is the ultimate immunally invasive and it is here to stay and we will continue to grow our TAVR practices and compared to standard therapy, TAVR is absolutely phenomenal innovation for medicine. However, clearly there are patients that need these kind of very long-term results, especially the younger patients who are patients needing mechanical valves or various other reasons for aortic valve replacements in a tertiary care center like us, we have to be able to offer open procedures as well as a percutaneous procedures. So I'm going to talk a little bit about the operative technique for aortic valve replacement and try to highlight a lot of the risks involved in it and then kind of hone into how we can make a minimally invasive approach to it safer as we do it. So when, in my experience or in my practice, the MIS, it's an upper, small upper hemi-sternotomy approach that was popularized by Toby Cosgrove and Mark Gilanoff at the Cleveland Clinic which is where I learned it. It's the one that we have data for, a lot of data. It puts the view of the surgeon very similar to a sternotomy if the preoperative imaging suggests that it will be a good view. So that's why I think a lot of folks who do minimally invasive like that approach, it makes it very similar to a sternotomy except it's a very small incision. The incision is positioned just around the angle of the Louis. The actual sternotomy goes from the sternal notch down into the fourth intercostal space jade over to the right. When everything is open and pericardial stay sutures are placed to elevate the pericardium to the surface, you can actually see all of those critical structures that we were talking about before. The aorta, the right atrium, albeit you can see that this is still a pretty limited approach. So this is all that you can see, but I'll talk to you a little bit about how we're able to conduct the procedure safely by just seeing those structures. Obviously another option is to write lateral thoracotomy and here we're doing so much minimally invasive that that's another approach that we're doing a lot of here at the Texas Heart. These are the different cannulas that we think of that we have to have for these procedures. We have to have drainage in the atrium with the cannula and the inferior vena cava, sometimes in the superior vena cava. We have to have an aorta cannula and the aorta. We have to have an anagrade cardioplasia line to deliver cardioplasia to the aortic root. And then sometimes you need to have a cannula in the retrograde coronary sinus to deliver cardioplasia retrograde. And finally a vent that is placed in the right superior pulmonary vein that helps to decompress the left ventricle and improve your exposure. So this is a lot of gear and whenever we modify our technique to make it a very small incision we have to say well how can we safely still achieve all those components through a small procedure and is it right for this particular patient. This is the full cardiopulmonary bypass circuit what it looks like. This is outflow going into the reservoir. This then gets filtered, air bubbles in particulates gets filtered. It gets pumped into an oxygenator and then gets pumped back into the aorta. The aorta goes here into the aortic root. Cardioplasia is one is absolutely probably the most important elements of an aortic valve replacement. A lot of these patients have hypertrophy ventricles and making sure that they get a really good myocardial arrest is critical. If not no matter what we do they can end up with some degree of heart failure afterwards after the procedure. And I will say that's probably, this is probably one of the, a little bit of Achilles heel about minimizing the exposure is how do you protect the heart still. The most ideal way to protect the heart is retrograde and anograde. Retrograde is highly unpredictable through a minimally invasive approach. So delnito is actually a solution that we use a lot here and that's kind of circumvented this issue a lot and has revolutionized our ability to do these procedures. It's a single dose it's just one shot you give as opposed to having to give retrograde and anograde. You need one cannula and in fact you can even remove it when you're done. So one dose arrests the heart completely for about an hour and a half allows you to do the procedure. You don't have to worry about the retrograde cannula being in place or not so it starts to take away some gear while maintaining safety. This data here from the Cleveland Clinic showed it was extremely safe to use. We're currently looking at our cabbage data is one of the biggest series actually here out of the Texas Heart with Dr. Ott looking at all of the cabbage cases that have been done with and without delnito preliminary results show it's identical even from multi vessel coronary disease. So this is a great advancement for minimally invasive procedures. After you protect the heart you go on bypassing or decompress next thing is to actually do the case do the actual procedure. So typically there's a longitudinal incision just above about two centimeters above the right coronary artery and that lets us see the disease the aortic valve. We start resecting it along the plane of the annulus and then often times you still have some debris and some calcium still hung over along the annulus so we take a second pass with this rondeur to take off any particulate matter that was left behind. Once it's nice and clear we've irrigated and flushed everything through we place several interrupted pericardial sutures usually about 12 to 15 of them then we pass them through the sewing ring seat the valve tie the valve down and then close this air autonomy. So what are the potential benefits when we think about making a relatively complex procedure even more complex by by kind of you know sort of seeing less of the field hopefully there's going to be some benefit to it and so there's on the minimally invasive upper hemisternatomy there's a lot of data looking at this actually this 11-year experience by Dr. Rocky and colleagues group looked at a thousand five patients 13% of them are re-operations that's a little unique to do these for re-operations is a is a different topic 18% of the patients were older than 80 which is obviously a very old group operative mortality even in patients older than 80 was very low was 1.8% so that's that's very encouraging it tells us there's there is some data suggesting you can keep that low STS mortality rate that we need even by offering a small incision small sternotomy bleeding rates were very and infection rates MI rates were all 1 to 2% which is what we would expect for standard sternotomy so that's that's very good news when we look at the Cleveland Clinic data which probably has the most mini sternotomy approaches in their latest update that was published in 2013 about 10% of all the aortic valves was done through a mini upper hemisternatomy this includes all of the valves that were done in 2013 they have they reviewed that data but you can still see 32% of them are still done open 27% were done partial half of these were for aortic valves so it shows you that even in a high volume center there's still we have to kind of select which ones go where survival was identical out to 10 years from less invasive and full sternotomy that's encouraging pain scores were superior for less invasive than full sternotomy although not by a ton but they but it was better what was interesting was that in patients with pulmonary disease who had already had some low FEV ones you the track these FEV one scores patients between 40 and 50 that's a really low FEV one they in particular had a benefit with a with a mini sternotomy compared to the full sternotomy different study looking at 500 patients by back years in Kali group out of Europe showed they really ventilation ICU stay was about the same hospital stay was the one thing that was significant by about a day or two so not a huge difference but some benefit here in hospital resource for for a length of stay in this meta analysis perioperative deaths were lower with the minimally invasive approaches it was interesting compared to full sternotomy 1.9% versus 3.3% but it was not significant there were no difference in the neurologic events there was less renal failure no difference in pulmonary failure no difference in cardiac events there were lower transfusion requirements this does seem to be consistent with a lot of data about one or two units less of blood transfused and then less pain requirements other potential benefits are with the mini upper strum you have so you have approach you have access for TAVR when you need it suture list valves can be deployed through that that exposure as well and in the future reoperations may be a lot easier this this patient Jeff green when I was training at Cleveland Clinic he came in for a mini sternotomy made a lot of sense for him he had to he's a point guard for the Celtics yet to go back out get back out on the field you know for in the court pretty quickly so it made a lot of sense for him he's young though so he had a biologic valve because he couldn't be on kumitan playing you know playing in the NBA but he will probably almost certainly you know five year five ten years from now need to be back for another valve replacement or possibly a valve and valve TAVR so the the reops are certainly easier when a prior previous mini sternotomy was used now how about some of the pitfalls though so the benefit is there I think the psychological benefit is there there there are resource resource benefits as well but what are the pitfalls what is the trade-off what are the things that we got to think about when we're minimizing our exposure or offering a minimally invasive procedure conversions to a standard full sternotomy are not uncommon they when we look at a global kind of full country experience one to 8% of cases you have a conversion when you do have a conversion your mortality rate goes up so it which kind of makes some sense if you have to convert if it's an emergency it's it can be associated with up to a third mortality the order cannulation sites may be a little bit far hard to reach might be calcified the also the atrial cannulation sites may also be hard to reach the annulus itself may be far from the operator might be hard to truly get a good full debridement you may have some greater slightly greater leak rates coronary occlusion rates and there are there's been reported a six percent revision rate so these are all kind of important points to think about so this brings us to a concept that I that I like a lot which is the preoperative imaging so how can we level the playing field how can we make this kind of relatively complex concept a little more user-friendly for almost anyone that goes into approach it this is where preoperative imaging comes into play to plan the procedure and select the procedure for the right patient so ideally you want number one visualization and access to the distally sending Eorta and the right atrium for central cannulation should be ideal so if you're looking at doing a mini sternotomy and the anatomy is not gonna is not going to be ideal for that if the order in the atrium is gonna be far away you should change your approach or you should do it slightly differently because you need to have safe cannulation as that's critical you need to be able to visualize and access the aortic annulus after you clamp and arrest the benefits of ideal exposure are shown here so there is significant variability in patient anatomy I'm going to show you a couple of case case reports of this but essentially if you have the right exposure a mini AVR proceeds honestly like a standard and full sternotomy AVR very very little difference to the operator looks the same if you have the wrong exposure if you you chose one particular decision for a different patient and their annulus and measurements are different than what you would expect it's a very difficult operation and that's where I mean thankfully obviously there are some very seasoned surgeons that can get around that kind of stuff but for the average practitioner in the US doing minimally invasive you want to try to pick the right exposure for the right patient when you can the options for exposure or upper hemistronotomy as I mentioned these this for me was the most popular from from training in Cleveland extended upper hemistronomies when it comes down into the fifth interspace it's still a very small incision six centimeters lower hemistronomy you can use the very bottom of the sternum right lateral thoracotomy which is very popular here mini skin with a full sternotomy is also another option or finally conventional sternotomy these are the different things we have to think about when we look at the particular patient so this is a study that did with dr. Roselli a Cleveland clinic 2013 that got me on this mindset of tailoring the procedure to the patient's anatomy and I use this for everything for transplant I use it for for coronary work for almost anything in this particular case series we were looking at the effects of preoperative imaging and how that could make the operation comfortable or not comfortable this is the type of view that we can plan out preoperatively using Aquarius 3d off offline processing of a cta that was done with contrast and thin slices we can look at many different angles I'm sure a lot of you have seen this for tavern planning or for stent graft planning you can look at the at the heart from many different directions to try to plan what things are going to look like when you're already in the operating room in this particular case so this is a 58-year-old gentleman who had severe valve stenosis norm actually not not hemodynamically significant coronary vessels came in requesting a million base of AVR the preoperative imaging suggested that when this part of the sternum is now it's not it's not removed it's just this is the part that's separated down into the fourth intercostal space we would have access in fact to everything we were talking about we have access to the aortic annulus we have access to the ascending aorta beautifully here to cannulae we got access to the right atrium it's real nice for draining the heart so this this preoperative view tells us that this particular exposure is going to be perfect for this for this gentleman and in fact it was a very easy to conduct the procedure this patient a different patient 68-year-old female with a bicuspid aortic valve and they send any aneurysm her aortic annulus is was far below the fourth interspace actually if you draw a line to it which I don't have here it shows the degree the angle is actually greater than 30 degrees to the aortic valve so in this particular case doing it through a fourth interspace incision that kind of standard the very classic cost growth type mini AVR would make it a very difficult operation instead we're using this imaging we were able to extend the sternotomy down to the fifth intercostal space still keep the incision about 7 centimeters and then have complete access to all these structures this is a different case this is a 7-year-old patient female with tricuspid valve aortic valve stenosis whose anatomy is very unusual so she has ascending aneurysm but the aortic valve is down below the xyphoid so this is a very very low-lying aortic valve if we had done this through a standard sternotomy the chances of converting we're gonna be very high and kind of obviated the potential benefit by doing the preoperative imaging and cutting away the slab of bone on the CT scan ahead of time and just getting a sense of what things would look like we could tell that an inverted sternotomy incision would be ideal so this was ended up being small incision almost looks like a pericardial window type incision about the level of the xyphoid and we did an inverted sternotomy into the fourth interspace in this case gave excellent access to the aorta the valve and the right atrium for cannulating this is a mini right lateral thoracotomy incision which I think which we may have heard about already previously and this particular patient the anatomy was such that the aortic valve was beautifully positioned on the second interspace towards the right of the sternum so this was really a very ideal view for this particular annulus some considerations for CTA so a lot of people say well why do do I have to get a CT for every scan every patient I think if if it depends on the surgeon depends on your preference but you do have to be careful about the timing of the diet administration you do it right before bypassing might be a slightly greater risk of renal insufficiency for that patient insurance doesn't cover all CTA so you have to have a kind of a reason for having forgetting it cardiac MRI is an option non-contrast CT scans probably okay for looking at the dimension but it's not as ideal and it's obviously anybody who's a re-op a CT scan is going to be mandatory always going to be covered anyways echo there's a lot that we use the echo for so I'm not going to belabor that here but you certainly want to rule out things that will make the minimally invasive approach very difficult such as subvalvular hypertrophy other valves that you have to approach when you go in they just want to be sure you're going in for specifically what you want what you want to do and that you can get in and out pretty quickly and safely transesophageal echo is sometimes used to guide the retrograde cardioplecia cannula but as I said with del nido now giving one dose of del nido anigrate kind of gives you a great arrest and you almost don't need retrograde anymore so branching out a little bit just in terms of this concept of looking at the preoperative imaging and how that can clear up the field for what you have to do and make the operation similar to what you're used to going to show you how we can use this approach for a variety of additional surgeries you can use it's a plan almost anything a mitral valve aneurysm repairs circulatory arrest valve repairs ascending aneurysm replacements you name it so let me see if this if this video plays here this is a similar concept I'm going to kind of just take you into the cockpit a little bit of being in the operating room what you see and how how the structures that you have to cannulate and the structure that you have to deal with can make or break your procedure so this particular patient 27 year old male young guy 3 plus AI has a 5 centimeter ascending aneurysm a lot of tattoos really no other past medical history so he wants a minimally invasive approach through which we can offer through a mini upper hemisternatomy potentially so it's a lot of work that we have to do so we plan this look at looked at this with the CT scan we see is a dilated ascending aorta right a nice cuff here at the proximal arch the measurements were such that the root would was above the fourth interspace so this does seem to see be like one that would be approachable very easily through an upper sternum we'd be able to see the structures we need to cannulate to protect and to repair the valve so this would be the approach here small upper hemisternatomy into the fourth intercostal space and what up in a few seconds what you'll see is what this looks like so I think you'll agree once you see it it's almost indistinguishable between full sternotomy in terms of what we need to do so you see all these cannulas that I was talking about this was the cannula into the right atrium to drain the heart this is the anagrid cardioplasia line to give cardioplasia to the root this is SVC line going into the superior vena cava the we're already on bypass cooling the patient because we need to replace part of the arch in in this particular case you notice that the incision is not very big the incision is from here to here it's about seven centimeters at the most it's about this big and only about half of the sternum is divided here we have room to cross clamp the ascending aorta opening up the the aortic valve like we normally would to expose the aortic valve this is a remnant of the ascending aorta I'm just kind of getting as much tissue as possible out of there and now you can see the bicuspid aortic valve in this case and the pathology the view is very good there's the annulus is right in the operative field the heart is arrested nicely the flows both forward aortic flows and aortic drainage is good so even though it's through a small limited exposure the preoperative imaging suggested that this was going to be very much like conducting it through standards or not I mean it was so here we're able to breed this leaflet back and and do the repair which is a different concept but essentially just lining up the length of the of the diseased bicuspid valve leaflet to to be the same length as the normal healthy leaflet now the the heart in this particular case is starting to fibrillate so we start preparing the graph that we're going to use to sew to the arch and I'm going to stop the circulation now completely to do circulatory arrest and replace the proximal the proximal arch so right now the circulation is stopped completely and believe it or not this facilitates the the minimally invasive approach because we can take the clamp out of the way so the circulation is completely stopped we're giving support through the SBC cannula that's delivering protection to the head the patient's 18 degrees right now and we're sewing this standard graft gel we've grafted with a piece of bovine pericardium along the underside of the hemi arch just being very meticulous and careful about each each bite I mean one of the things that definitely minimizing your exposure does is it doesn't give you much room for error so almost everything that you do has to be actually slowed down a little bit it has to be verified before you move on to the next step because it is hard to go back to it without you know completely increasing your exposure so now that the graft has been sewn in now we're going to resume systemic circulation again through this side graft and we've de-air it and now we've just clamped this graft and are resuming circulation to the rest of the body just getting a little bit of hemostasis here of the suture line to make sure everything is very perfectly dry before we proceed with the aortic valve part of this procedure so just tying this down and in fixing these these small leaks and then moving to the next spot now we're going to size the graft to the proximal aorta and then in a second we'll go back to the aortic valve and again just to illustrate that because of the imaging predicting what this exposure was going to be like this really is carried out in very little difference than a standard synodomy would be here we're able to plicaid this valve leaflet after having debrided it we'll suture it down with a double-layer running suture to reinforce that tissue and and we'll sew it down and make it a better co-aptation line with the healthy leaflet and this is what it looks like when that is done now we're just completing it removing our cannulas removing the anigrate cardioplegia line and slowly weaning off a cardiopulmonary bypass follow-up echo shows no aneurysm no aortic valve leak CT scan postoperatively was good patient was discharged home in a few days and is doing well but this could have been very different had his anatomy been different would not have been able to offer it through that through that approach so in conclusion many AVR particularly many upper synodomy may offer some advantage over conventional approaches the benefits are most pronounced in small series with very experienced surgeons preoperative CT imaging provides important details that can level the playing field for cannulating and for your working areas it I believe it should be required for patients undergoing many AVR depending on your level of experience and the expense should be weighed against the potential benefits and clinical outcomes and resource utilization so with that I'll take any questions that you guys have thanks a lot for allowing me to chat with you guys this morning