greetings everybody we're going to talk here about carotid artery disease so carotid artery disease is simply atherosclerosis of the carotid arteries so it's the same thing as coronary artery disease except this is happening in the carotid arteries instead of the coronary arteries the risk factors are just the risk factors for atherosclerosis so diabetes mellitus hyperlipidemia particularly an LDL to HDL ratio of greater than three to one smoking and then some of the non-modifiable risk factors such as male sex advanced age and genetic predisposition all of those work into a patient susceptibility to atherosclerosis and therefore for carotid artery disease to develop plaques in the carotid arteries carotid artery disease is the most common underlying cause of stroke so when you look at your causes of stroke about 85 to 90% are thrombosis which means a blockage and about 15 10 to 15% are hemorrhage which means a spill of blood from the arteries so in this case when we're talking about cerebrovascular disease cryo artery disease we're talking about thrombosis we're talking about mostly here embolization which would be either a thrombus from the from the heart or carotid artery debris which can be sent up to the higher arteries or primary vascular occlusion which would just be a atherosclerosis that's built to the point of 100% occlusion and then I just want to point out here embolization is also the cause of TIAA and a neurosis fugax in addition to stroke all right so the manifestations of carotid artery disease as I mentioned our transit ischemic attack and this is a a stroke so what that is is simply stroke symptoms that come on quickly and usually they last for about 15 minutes or less I think it lasts up to a day so this is what's referred to as a mini stroke because the symptoms are transient amaurosis fugax is a form of TIAA in which you've got a you've got an emboli that's sent to the retinal arteries and it causes monocular transient monocular blindness so blindness in one eye which ultimately also goes away and then the big one is cerebrovascular accident which is the big stroke and this causes long term symptoms longer than a day so these are all the manifestations of carotid artery disease and of course you can also have carotid artery disease it's just an asymptomatic patient long term medical management includes modifying risk factors so the risk factors diabetes mellitus of course you want to have that under control hyperlipidemia statins are useful and then stop smoking and then if that's not enough than antiplatelet drugs or anticoagulation can be useful as well the surgical management for carotid artery disease which is going to be the focus of this talk is carotid endarterectomy now there are there are surgeons who are using carotid stenting now and that's fine but I don't suspect that that's going to come up in the USMLE carotid endarterectomy is the traditional gold standard surgical treatment for carotid artery disease it's the one that you'll be asked about on the test so as I mentioned here's the causes of stroke we're primarily here concerned about embolization particularly embolization of carotid artery debris so you develop you develop a you develop a plaque on the carotid artery and after from that then you can get debris smaller pieces from that plaque embolizing off and causing a blockage in a smaller artery so this is your carotid circulation you're kind of looking here from the right kind of an angled look here so your arch of your aorta would be down here you can't see it so you have your inanimate artery on the right which comes off you're the arch of your aorta it's gives off the subclavian artery which ultimately goes to the arm and then also gives off your right common carotid which will then give off external and internal carotid arteries on the left your carotid artery common carotid artery comes directly off of the arch of the aorta and there's a separate branch off the arch of the aorta for the subclavian and then the internal carotid artery is what ultimately is going to communicate with the Circle of Willis so this is all communicating circulation so the manifestations of carotid artery disease kind of refer to this a little bit earlier probably the most common would be asymptomatic most patients who are older have a certain degree of carotid artery plaque whether you'd be able to hear it on physical examination as a bruit or not depends on how severe it is but most patients with carotid artery disease are asymptomatic now the ones who have symptoms they usually have to have either a TI a the amaurosis fugax or have had a stroke so it's difficult to to see patients who just come into the clinic with this this is usually a patient that's going to come into the II D so the transit ischemic attack as mentioned is like a mini stroke it's an acute focal neurologic symptoms so basically the way to think about this is just a stroke but it has a rapid onset and a quick resolution and usually it resolves within 15 minutes but it can by definition go up to 24 hours what this is is a schema of the brain tissue so the brain tissue is not working properly and that's kind of like if the brain tissue were dead where it's not working at all so you're having stroke like symptoms but it reverses it the the capabilities come back the neurologic symptoms go away now I want to contrast that with the cerebral vascular accident CVA or stroke that is where the symptoms have lasted longer than 24 hours by definition this is necrosis of the brain tissue and in most cases there are going to be irreversible symptoms now when we're working up a dia or a stroke it's going to be a little different than when we're just working out plain old carotid artery disease and I'll refer to that a little bit and then amaurosis fugax is kind of like I mentioned a specific type of T ia where you get this transient blindness in one eye and that's caused from an embolism to the retinal artery now there's a lot of different things that can cause amaurosis fugax not just embolism so some of the things that can also cause it would be in addition to embolism from the carotid artery you can have an embolism from the directly from the heart from the left ventricle you can have giant cell arteritis lupus can cause it as well as some of the vascular duties like polyarteritis nodosa usin it you'll send a fillip vasculitis and I think as I mentioned lupus can cause it as well so there's lots of things that can cause this it's not just emboli but this is a manifestation of carotid artery disease that's worth knowing and on often logic exam it may be brought up that you can note in the retinal artery you can see a plaque on the ophthalmologic exam I don't expect that you'd ever be able to see this with your ophthalmoscope this would be more of a formal optimal object exam with a better piece of equipment that a ophthalmologist would do but again another thing worth noting because the test likes to bring up these these words okay so the history patients with carotid artery disease as I mentioned usually this is a pretty dramatic presentation so the patient with carotid artery disease often has a previous or possible previous stroke TIAA or amaurosis fugax also in their history they're going to usually have risk factors for atherosclerosis so they're older there's a tendency towards males maybe they're smokers they've got diabetes those things symptoms there's very few symptomatic manifestations besides the neurologic symptoms themselves unphysical exam really really important to associate with carotid artery disease the carotid artery bruty and why do you have a bruit because you are going through a narrower space so you have your carotid artery which is getting narrowed by the plaque and now you're going through a narrow workspace and it's causing that turbulence which causes a bruit it's it's just like the turbulence that you would get if say you had a or text enosis you got a smaller space and so now you're gonna have more turbulence and it makes a louder noise so the carotid artery bruit is usually going to be heard right around the angle of the jaw right around where you can palpate the pulse of the carotid artery and that's right about where the common carotid artery splits into internal and external carotid and that's just because that's the most common place for people to get plaques developing in the carotid artery it can be confused with a transmitted heart murmur so the best way to differentiate the two is that the carotid artery bruit would get quieter as you move down the neck and also a heart murmur you should be able to hear it on both sides whereas the carotid artery bruit you'll probably only hear it on one side or the other more on one side than the other so a carotid artery bruit is much more asymmetric in appearance if you will the carotid artery bruit is an alert not just for carotid artery disease but for other atherosclerosis carotid artery brewing are actually more associated with heart attack than with stroke and that's just because it takes a lot less atherosclerosis to get a heart attack than it does to get a stroke so certainly any patient who has a carotid artery bruit should be worked up for all kinds of manifestations of atherosclerosis so certainly an EKG would be something you'd want to get on these patients a carotid artery oscillation is an important part of a physical exam just a normal physical exam for any older patient or patient with risk factors for carotid artery disease so for diagnosis if a patient has an asymptomatic bruit the best initial diagnostic test is going to be a duplex ultrasound of the carotid artery and that's just what it sounds like it's an ultrasound of the carotid artery and you're able to see what direction the blood is flowing and from there then you can see if where the plaque is and how much how much occlusion you've got an EKG is also good to get on these patients just because you're also working them up for other atherosclerosis so you want to see if maybe they've had any any silent MI but the best initial diagnostic test with a patient with an asymptomatic karate bruit is going to be duplex ultrasound with carotid artery now how about the symptomatic patients well symptomatic patients with carotid Brewis those are patients with ti a and Stroke and a patient with a stroke you're not going to be worrying about what's going on in their carotid arteries because they've got a much bigger fish to fry you're concerned about their stroke so with those patients usually you're going to do a CT to work up their stroke and so I talked about this management of stroke in the neurology section so you can go back to that I'm not going to talk about that here so this is a duplex ultrasound you've got your transducer here and it just sends silent sound waves to the carotid artery like any altar sound so here's a normal duplex ultrasound and they're not quite in the exact same spot it's not these are the same devices here but here would be a good example of a normal finding so red is just is movement away and blue is movement towards I'm not a altra sonographer but you could wait what this just means is that all the blood is moving in one singular direction now what you see here on the abnormal ultrasound is that you've got blood moving in one direction but then right here you've got a part that is you don't have blood moving properly and so this is actually the the plaque right here and don't worry you do not have to read these for the USMLE I just want you to get a visual idea of what you're doing with a duplex ultrasound don't worry about having to read these you won't have to read these for the USMLE ever okay so when do we intervene surgically when do we do surgery for for patients with with blockage in their carotid artery instead of medical treatment well there are two studies that are sort of our landmark studies for for doing carotid endarterectomy which is our treatment of choice for patients with coronary or sorry carotid artery disease and those studies are nacet and a Cass noun a Scott is focused towards patients who are symptomatic and by symptomatic we just mean symptoms within the last six months so let's say you have a patient who had a TI a had a stroke you've treated them from their stroke discharge them now we need to take a look at their carotid and and see what we can do to prevent another stroke from happening these are still symptomatic patients if the stroke happened within the last six months or the TI a happened within the last six months so that what that mean doesn't mean acutely symptomatic I mean it can but these are symptoms within the last six months it defines what a symptomatic patient is so for symptomatic patients according to this study a carotid endarterectomy should be performed in patients with 70% or greater blockage now in asymptomatic patients so this would be like your your typical man or woman 65 years old comes in for their routine physical and you hear a carotid Brewery these patients when you do their ultrasound if you here if you see 60 percent or greater blockage then you should do a carotid endarterectomy it is indicated now there are contraindications to carotid endarterectomy usually this these are pertaining to the very sick patients so not so much the asymptomatic patients and the contraindications are going to be disabling stroke with an acute loss of consciousness mostly with this just referring to acute strokes we're not going to be doing carotid endarterectomy 'z with acute strokes we're concerned more about the blockage patients who have 100 percent or more occlusion we don't do carotid ender and carotid endarterectomy z' for those patients and in patients with a severe medical illness which results in a shorter life expectancy we'll probably not do and our direct means for them either and really most of this is just at the call of the surgeon and the anesthesiologist the last of which is probably the anesthesiologist the severe medical illness shorter life expectancy that just puts them at a higher risk of dying on the table so definitely though remember these two facts set of 70% or greater for symptomatic 60 percent or greater per day symptomatic now what is the carotid endarterectomy it's a surgical procedure you're removing an atherosclerosis now when you do this the patients are going to be monitored on EEG because you want to know what's happening with their brain function and the anesthesiologist or a trained professional who reads EEG s will be looking at the EEG and making sure that nothing wrong is happening because when you are doing this procedure you are clamping the arteries so you do have a relative decrease in perfusion so what you're doing with this procedure is you clamp your common carotid your internal carotid and external carotid and then you have your area to work with where you can then make an incision into the artery and once you make the incision into the artery you can remove the plaque and then stitch the artery back up and then take the clamps off sometimes surgeons like to have a like a conduit so that they're still shunting blood over back up to their brain and that's just on the that's the call of the surgeon you don't need to worry about whether or not you have to do that for the USMLE what you do need to know about the carotid endarterectomy for the USMLE is that the patient needs to be monitored on EEG that the patient may be awake or they may be put under general anesthesia that depends but either or and then the complications of course include stroke and ischemia you can get injury to the hypoglossal nerve or the vagus nerve and that's because they run so close to the to the carotid artery hypotension is possible and that's because of the of the at the bifurcation of the carotid artery you have your carotid sinus and that's a very sensitive space for detecting blood pressure so you can if you monkey up with that you can get hypotension so you have to be careful in looking at the patient's blood pressure while you're operating on them and then rarely hyper perfusion syndrome can happen and that would just be because you're getting sudden increase in inflow of blood where you've had decreased flow of blood for so long and then of course general surgical complication which I talked about in previous sections so this is just to give you an idea of what this surgery looks like so here's the this is the patient's ear you can see here and so this is like the sternocleidomastoid area and so here's the common carotid artery which is splitting into internal and external and the plaque is probably right around here so this is where you're going to do your incision and pull out the plaque that the clamps will be placed here here in here and the hypoglossal nerve is right here that's CN 12 so what you're doing is just making the incision pulling out the plaque pretty simple procedure I made a brief reference to carotid artery stenting earlier this is being done more and more commonly it's a good intervention you've probably seen it done or you've you've heard of it done and it certainly could be done in most patients but for this for the tests carotid endarterectomy is still the one that they're going to ask you about it's still it's the gold standard for surgical treatment of of carotid artery disease so you won't be asked to choose between the two carotid endarterectomy is the most studied and so this is the one that's going to come up on the test so just to recap cautery a carotid artery auscultation should be done proactively as part of any general physical examination in middle-aged and older patients I would say probably at least after age 50 and also in patients who have significant risk factors so early heart attacks and the family early strokes in the family familial hypercholesterolemia for sure patients with long-standing uncontrolled diabetes patients who have been smoking for a long time etc carotid Brewery is an indication for a full workup for an asterisk lark for atherosclerosis disease so the best initial step is going to be a duplex ultrasound of the carotid artery because we're one look at that first but after that then these patients should probably come in for an EKG they should probably do a stress test because you're looking to see if there is anything else that may have happened considering we know that they've got atherosclerosis so just kind of looking at it broad picture now the indications for carotid endarterectomy and if there's nothing else that you take from this lecture please at least take this the indications for carotid endarterectomy are at least 70 percent blockage and symptomatic patients and at least 60 percent blockage and asymptomatic patients medical treatment such as anti platelets and and blood thinners can be undertaken in other patients now you may be wondering why is it a higher blockage for threshold and symptomatic patients and a lower blockage threshold in asymptomatic patients I have no idea but that's what the studies say so if anybody knows why that is please feel free any surgery residents please feel free to explain that I don't know why just remember those numbers so contraindications are disabling stroke hundred percent occlusion or severe comorbidities and then complications for this particular surgery include stroke ischemia injury to local nerves and blood pressure instability and with that that should be it for carotid artery disease