 I would like to thank the Texas Heart Institute and the School of Refusionists for this kind invitation. It's really my great honor to be here today for this 2020 Perfusion Conference. And why this year is very important is because we honor Terry Crane. Terry worked with non-stop with Dr. Denton Cooley for the School of Refusionists and he made a great contribution over the last 40 years. This is my disclosures. Before we proceed, I would like also to thank Scott Weldon for providing these beautiful illustrations that you are going to see over the next few slides. And also I would like to thank the entire team of perfusionists and sociologists as well as the operating room nurses. In addition, I would really like to thank my partner, teacher and mentor, Dr. Coselli with whom I'm working clinically for the last 12 years. So the talk is related to thoracic aortic aneurysm repair a step-by-step approach. And we're going to divide this talk into two parts. The first part we're going to talk for the proximal ascending repair and the arch repair. And the second part we'll talk for the thoracic abdominal aortic repair. So the proximal aorta can come in different configurations as we see. The aneurysm can be only confined into the aortic root or can be in the mid-ascending aorta with the aortic root being normal or can involve the aortic root as well as the ascending aortic aorta or can be a mega aorta, meaning the ascending aorta is dilated, the arch is dilated as well as the entire thoracic abdominal aorta is dilated. These are the different surgical strategies that we have in our armamentarium when we deal with diseases affecting the ascending aorta, the ascending aorta and the aortic arch. This is the classic what we call marfanoid root where the ascending aorta is normal and the root is the one that is dilated. And in this case, the ascending aorta does not need to be replaced but we replace or repair the aortic root. This is another case where hypothermic circulatory arrest is not required but we replace or we repair the aortic root and we replace the ascending aorta. In this case, a cross-clamp can be placed in the ascending aorta and we carry on with the repair. As we see here, the way that we go on cardiopulmonary bypass is the classic way by cannulating the ascending aorta. Then we give cardioplegia and we put a cross-clamp the way that the cardioplegia is actually our strategy to give anti-grade, a retrograde cardioplegia. Anti-grade cardioplegia is being given direct into the aortic root if there's no aortic insufficiency. In case that there is aortic insufficiency then we open the aorta and we give direct into the osteo of the coronary arteries. And then of course, we give a alternate with we give cardioplegia, alternate, retrograde and anti-grade. After the so the cross-clamp is placed, the ascending aorta is open and then we replace it with a darkroom graft. We proceed with the distal anastomosis first and then we proceed with the proximal repair. The proximal repair can involve aortic valve replacement, aortic root repair or aortic root replacement depending on the pathology. In case like this one where the ascending aorta as well as the proximal arch is involved then we have to institute a period of circulatory arrest because cross-clamp cannot be placed in this particular situation. So the way that we proceed is first of all we have to establish an arterial inflow for cardiopulmonary bypass. The way that we establish the arterial inflow is via the axillary cannulation or anominal cannulation with an eighth or a 10 millimeter graft. It is our strategy to always use an eighth or a 10 millimeter graft even though across the country there are tick centers that they actually cannulate direct the axillary artery or the anominal artery. So after we establish the arterial inflow, the patient goes on cardiopulmonary bypass and this is just to mention an algorithm that was published in the general thoracic and cardiovascular surgery two years ago where is an algorithm how we decide to proceed with the axillary cannulation versus the anominal cannulation. In case of free-do sternotomy when the cardiac structures are very close into the chest wall, then axillary cannulation is our preferred strategy. In case it is a primary repair, then we proceed in the elective cases, usually the anominal artery cannulation unless the head vessels are very dilated where axillary cannulation is a choice that we use. So like the case that I showed before where the ascending artery needs to be replaced as well as the artery cart, we'll start with anominal or axillary cannulation. Our mean temperature we cool down to 24 degrees. We use what we call moderate hypothermia. According to the ascension to the anominal artery according to the consensus of experts, moderate hypothermia is defined between 20 degrees Celsius to 28 degrees Celsius. And this is our preference to cool down to approximately 23 to 25 degrees Celsius as a mean temperature. Then when the target temperature is approached then we decrease the flows down to 10 to 15 mL per kilo per minute. And the snare is down as you see on the picture over the anominal artery. And we start what we call the anti-grade cerebral perfusion via the right common carotid artery. At that point also we monitor the nears. Then the artery is open and we proceed by placing the second cannula via the left common carotid artery. The flows, as we said, they're 10 to 15 mL per kilo per minute. The cannula that we place into the left common carotid artery is connected via y connector. As we see, the one y is connected into the anominal or the axillary artery and the other y is via the cannula that is going into the left common carotid artery. The cannula of choices that we like to use is a nine French prui, but lately over the last year we have switched to the cardiophigia cannula that is a little larger diameter so the resistance is a little less when the flow goes through the left common carotid artery. And this is another representation where you can very well see the y connector with the blood going through the right common carotid artery and then via the other cannula into the left common carotid artery. So after the antegrates, a little perfusion is initiated. Then we proceed with the distal repair, the repair closed into the, by replacing the proximal aortic arch. After the replacement is completed, then the snare, we take the snare off and we start going slowly to full flow. At that point, when we go to full flow, a cross-clamp is placed into the distal, into the doctrine graft and we start rewarming. In case that the pathology is more extensive, then we need to proceed with the total arch replacement. In these cases, the total arch can be done either as an island, a re-implantation or as a double Y graft. When we do it as an island re-implantation, then while we do the anastomosis, the distal anastomosis as well as the island, when we're cooled down to 20 or 24 degrees Celsius and then after the anastomosis is complete, we proceed like the previous repair where a cross-clamp is placed into the doctrine graft and then we proceed with the rest of the proximal repair that can be a repair of the aortic valve or replacement or just a graft into the proximal aorta. In case that the total arch needs to be replaced by using a trifurcated or bifurcated graft, then the sequence can be a little different because after we place the patient on cardiopulmonary bypass, the anastomosis of the subclavian and the carotid can be performed while we're cooling down and then when we reach the target temperature, 23 or 24 degrees Celsius, then we proceed with the circulatory arrest with anti-grade cerebral perfusion. The distal anastomosis as we see here is performed and after the distal anastomosis is performed, the circular, we go back to full flow, a cross-clamp is placed and slowly we start to rewarming. At that point, we have already a cannula that is connected into the side branch as we see in the image and the rest of the body is perfused at that point. So let's switch gears now into the thoracic abdominal aortic aneurysm repair, the step-by-step approach. Of course, as we mentioned before, the pathology is the one that really determines that would be the approach. And these are the different classifications as are classified by Dr. Crawford. We have the extent one aneurysm that is extended from the subclavian down to the level of the visceral vessels, the extent two from the subclavian artery or the way down to the bifurcation, the extent three mid-desending thoracic aorta down to the bifurcation and then the extent four aneurysm that is extended from the around the visceral vessels to the down to the bifurcation. And of course, the repairs are followed. We have extent one repair from the subclavian artery below the level, the other level of the renails, the extent two replacement from the subclavian artery that we place all the way down to the bifurcation, the extent three replacement where we place the mid-desending aorta down to the bifurcation and then the extent four aneurysm replacement where the repair involves the visceral vessels down to the aortic bifurcation. A lot of times we use the term elephant trunk repair. This is when we have already replaced the proximal aorta and at that point we come back a few months later and we replace the thoracic abdominal aorta by connecting the prior graft that we have from proximal repair into the new graft which is used for the second stage repair. In case that the pathology help us is not very extensive, then the vascular techniques can really help us and the second stage can be done with endovascular renaissance repair. Let's go through the steps of the thoracic abdominal repair. First of all, the reason why we treat the thoracic abdominal aneurysm is to prevent death, secondary to rapture. So the patient is placed with the right side down, left side up. We like to use the thoracic abdominal incision via the sixth intercostal and with the space and the patient is placed on left her bypass. The way that we place the patient left her bypass is that we use as an inflow the left inferior pulmonary vein and then as an outflow, as we'll see on the image, the descending thoracic aorta. After the patient is placed on left her bypass, then a cross-clamp is placed distal to the left subclavian artery or sometimes the cross-clamp is placed between the left common carotid and the left subclavian artery. Then the aorta is opened and we proceed with the proximal anastomosis. This proximal anastomosis is performed with the left heart bypass on. Then after the completion of the proximal anastomosis, the left heart bypass is off and the rest of the aorta is open and we identify the visceral vessels. Depending on the situation, sometimes we do perfuse the visceral vessels. As we see on this image, we use the blood of the pump to perfuse the SMA artery as well as the Celiac artery and then we have the circuit, the cold crystaloid or custodial circuit where we give the cold into a cold solution into the left renal and the right renal artery. So we continue with our repair by proceeding with the intercostal left artery patch and then we'll see here in this image where we have the two catheters into this superior mesentery artery and the Celiac artery as well as the cold solution into the left renal and the right renal artery. After the completion of the intercostal patch, in case that we have to proceed like in this image with what we call the tetrafulcated graft where all the visceral vessels are separated anastomosis to each artery, the second, the next step is to proceed with the distal anastomosis. At this case, as we said, the left heart bypass is off, we just give visceral perfusion we use the blood of the pump to produce the SMA as well as the Celiac artery and we use the cold renal solution to give cold renal into the right and the left renal artery during the distal anastomosis. When the distal anastomosis is completed, then the next step, we concentrate into the visceral vessels. At that point, the sequence, we start with the right renal artery. We continue the perfusion into the SMA and the Celiac artery and we continue the cold renal perfusion into the left renal artery. Then the next artery that we re-implant is the SMA and we continue with the Celiac artery. At that point, the patient continues to get renal perfusion via the left renal artery and the last vessel that we anastomost is the left renal artery and then the repair is completed. As we see here, the repair can be actually performed by two ways or by using a tetra-focated graft as we just depicted or by just using the island technique where all the visceral vessels are re-implanted at once. When we use the patch anastomosis, then the sequence can be a little different because the patch anastomosis we actually is completed after we do the intercostal patch and the distal anastomosis is actually at the end. I would like really to thank you for this great invitation. It's a great privilege to be here today and it is my pleasure throughout the years to work with all of you. Thank you and I hope to see you soon.