mm hmm. I'd like to thank the organizers of this meeting for the kind invitation to speak and I appreciate being part of the U. H. T. Car program, which I'd like to share with you. Our story starts in 1980, 1993. Which for some in the audience doesn't seem like so long ago. But it was nearly 30 years. Bill Clinton was inaugurated for the first time in 1993 and later would have to based the crises of a siege at Waco. And the the first attack on the World Trade Center In 1993, Michael Jordan and the Chicago Bulls completed their first three peat three consecutive NBA Championships, which they would then do again a few years later after Michael Jordan's returned from his first retirement, the so called repeat three peat uh popular movies, Jurassic park a long time ago. Schindler's list and in technology. The World Wide Web was born created at Cern in 1993. By year's end there were a whopping 683 websites just for reference. Currently there are upwards of 1.8 billion websites. But also pertinent to our lecture today. In 1993, the first carotid artery stent was performed by Ted Dietrich innovator and leader in cardiovascular surgery. and one would think that with 30 years of innovation, technology and progress that carotid stent placement would have taken over as the standard treatment for carotid artery disease. But that is not correct. The number of carotid artery stents performed in the United States has barely budged Since its introduction. And FADA approval nearly 20 years ago. We're gonna get into the reasons for this. But first let's focus on the problem which is carotid artery plaque at the carotid bifurcation plaque at the crowded modification is a risk for stroke, as the debris from this plaque symbolizes to the brain. And carotid bifurcation disease is the predominant cause of symbolic stroke options for treatment medicines, pills, we can remove the plaque, so called carotid endarterectomy, remove all of the plaque out of the carotid artery or we can trap that plaque with a carotid artery stent. Those are currently the three options for treatment We've known since landmark studies in the 1990s, that medical therapy does not do as well as carotid endarterectomy, especially in patients who are symptomatic with lesions over 50%. In fact, it was shown that carotid endarterectomy is beneficial Over medical therapy alone in treating patients with asymptomatic disease. If the if the stenosis was greater than 60% and those patients who have stenosis is over 80% actually do even better. So this has led carotid endarterectomy to be considered the gold standard in the treatment of carotid bifurcation disease and is a standard by which all other treatments and interventions are judged to this day Now, not all patients are a candidate for standard carotid endarterectomy. Some are too sick from a physiologic standpoint and some have anatomy that is not suitable for endarterectomy. So trans femoral carotid artery stenting was introduced, developed and is still being performed and the procedure itself is conceptually simple. A wire and catheter are placed across the carotid blockage, often with the use of anabolic protection device distal to the lesion to catch any debris. The lesion is ballooned and stunted and the symbolic protection devices removed. The results for transfer Meral carotid artery stenting are not nearly as good as carotid endarterectomy. In trial after trial comparing the two, the risk for stroke, stroke and death. Death alone is typically about two times higher in the carotid artery stent arms of the trials and this has been repeated numerous times. And this is true not just for the study populations where these are done in university settings, where the operators are expert. If you look at the Medicare population overall, the risk of stroke, death, stroke and death all far worse in patients treated with carotid artery stenting versus carotid endarterectomy and the risk of death in these patients is upwards of five times higher than carotid endarterectomy. And interesting if you look at the change over time, carotid endarterectomy has become somewhat safer during the 15 years of this of this Medicare population trial. While carotid artery stenting really has not budged. The reason for this is that to perform a trans femoral carotid artery stent. The wire sheath balloons and devices have to go through a very treacherous path. These patients often have significant disease in the aortic arch and in the super aortic branches and crossing these in unprotected fashion can lead to stroke. And then the carotid lesion itself. The most dangerous part also must be crossed even when using anabolic protection device prior to performing the stent placement. And this leads to distal embolization. In fact, the procedure has such poor outcome that the FDA has only approved its use in patients who are high risk and CMS will only reimburse for these procedures if they are performed in high risk individuals. And by high risk. We mean high risk by uh by physiology either severe cardiopulmonary disease or there are some an atomic high risks uh factors as well, including a cervical lesion. That's too high for standard surgical accessibility patients who have had prior carotid endarterectomy, patients with prior neck radiation and so forth. Trans femoral carotid artery stenting also has the achilles heel of being very difficult to learn. Um It is a technically demanding procedure. It's difficult and this is some early data when folks were learning how to do uh trans femoral carotid artery stenting and the stroke rate is incredibly high. As operators learn to do the procedure, It took on average, 72 cases for an operator to achieve the benchmark of stroke and death under 3%. Which we use for carotid endarterectomy. Now, this would have been the end of the story. Except there's a new kid on the block. And this is the T car procedure. Trans carotid artery revascularization, partially pioneered here at university hospitals and studied by dr. Cash Up, who was the national CO. P. I. For the Roadster To trial. The procedure is a carotid stent but it's performed differently rather than accessing the carotid through the groin, the carotid arteries accessed through a small incision at the base of the neck. Where an arterial sheath is placed, The sheath is then connected via some flow regulating tubing to the femoral vein in the groin and during the carotid stenting portion of the procedure. The common carotid artery is clamped proximal to the sheath, causing an arterial venous fistula by pressure so the blood is flowing in reverse fashion from the carotid into the femoral vein. Thus the entire procedure can be performed under reversal of flow such that the arch and the superheroic branches are not crossed unprotected and the carotid lesions not crossed in unprotected fashion. The results for this procedure. The T. Car procedure were studied in a premarket FDA approval study, Roadster one and also were evaluated further in a post market analysis, Roadster two. Both trials conducted also at CMC. So Roadster one had 203 patients, Roadster to 692 patients. All of these patients were high risk either from a physiologic standpoint or an an atomic standpoint and sometimes both. They were either symptomatic with lesions over 50% or asymptomatic with lesions over 80% and roughly a quarter of these patients were symptomatic primary endpoints of the standard endpoints used for carotid interventions which is stroke death and myocardial infarction. The results were quite good In Roadster one, the stroke rate was half a percent, Roadster 2.6%. And as you can see the combined stroke and death rate well under the 3% benchmark we were talking about earlier. In fact, if you compare the Roadster one and Roadster to trial results together and compare them to the largest modern carotid endarterectomy and carotid artery stent trial performed, which is crest. You see that the roaster data is better than even the carotid endarterectomy arm from the crest trial and the crest trial by the way reported. The best carotid endarterectomy results ever reported. And you can see that the complications from T. Carr in this trial were about a quarter of what was seen in the carotid artery stenting arm. In standard risk patients. And keep in mind the Roadster patients were all high risk. In fact, the car has shown the best data for any carotid intervention ever reported, including carotid endarterectomy. Now keep in mind that these patients were carefully selected. They had to meet inclusion criteria for the trial. And so not all patients would qualify anatomically or physiologically for inclusion. Not a car and see a have never been compared in a head to head fashion. But there are a couple of retrospective reviews looking at carotid endarterectomy versus T. Carr in the vascular quality initiative project. And they have shown very similar results and that is that the T. Car patients generally have more comorbidities and they are more often symptomatic but the rate of stroke, stroke and death and stroke death and am I are all equivalent. It's just the patients who had two cars stayed in the hospital for a shorter length of stay and had less cranial nerve damage. Leading some to suggest that perhaps T carr could be used in standard risk patients as an alternative to carotid endarterectomy. So how hard is to car to learn? I'll tell you it's not very hard at all. Um Many of our trainees have done procedures with us and have taken it to their home institutions and started this program. And if you look at the Roadster to trial, nearly um two thirds of the patients who were treated in the rosary to trial were treated by new operators. And so these excellent results. We're we're um were performed by relatively inexperienced surgeons. We looked at this ourselves when we did a multi institutional analysis And then this data was also repeated in A. v. Q. I study. We found that the learning curve was about 10 cases to achieve proficiency and most importantly in distinction to trans femoral carotid artery stenting the risk of stroke and stroke and death was not higher In an operator's 1st 10 cases versus later cases. Whereas in trans femoral carotid artery stenting patients really pay a price for an inexperienced operator. So to conclude, T carR has the lowest reported rates of stroke, stroke and death, or stroke death, and myocardial infarction ever reported. For any carrots intervention. The chief limitation for T. Car is going to be patient anatomy. They have to meet the an atomic eligibility T. Carr is a fairly simple procedure to learn and master. We found that roughly 10 to 15 cases required for um proficiency and individuals can master T. Car faster than either carotid endarterectomy or transferable carotid artery stenting. Okay, thank you, mm hmm.
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