Vascular surgeon Shant Vartanian, MD, presents an update on understanding and managing abdominal aortic aneurysms and peripheral artery disease – prevalent age-linked disorders with significant morbidity and mortality. He provides clear criteria on risk factors, explains the value of the ankle-brachial index, offers keys to slowing disease progression, compares open and endovascular repair of AAAs, and gives priceless tips on diagnosing and relieving claudication.
my name is Sean and I actually grew up on the peninsula. I was born in Belmont um in the late seventies and then moved to Burlingame, went to Burlingame high school, then stanford and then I did all my um residency uh research and fellowship with UCSF. And I've been on faculty years since uh 2010, I'm sorry 2012. And it's um it's great to have such deep connections to the community um and to practice in our SAn mateo clinic which used to be Bay Meadows, which I remember remember fondly is where I learned to play golf at the little rock nine hole course inside the racetrack. So for sure, things have changed a lot um in the area and for sure in my specialty vascular surgery um I'm gonna talk I think today about two things that I get referred to most that seems to have lots of questions and anxiety, um powerful appeal disease. And I spontaneously added aortic aneurysm very briefly just to um make it maybe a little more comprehensive and interesting for the audience. So what is our scope of practice, who we um who do we treat? Um and cr Cynthia clinic? Um Well certainly more than just the aortic aneurysms and peripheral arterial disease, but carotid artery diseases us think of common way as well asymptomatic carotid artery disease will get follow ups for incidentally found aortic dissections. Um Sports medicine is a growing one, particularly young adults and athletes with thoracic outlet syndrome diagnostic testing. We can do the full gamut at SAn mateo as well. And I will say we have had great reviews from our patients because it's so accessible that can pull off the freeway park and be in our clinic within minutes. Um And it's nice to be able to do point of care testing at the time of our initial evaluation for vascular surgery. So Merrick aneurysms just real quickly. I don't know how many people knew, but actually Einstein died of an aortic aneurysm. Um and like many things in his life, he was just a little bit ahead of his time. Uh He actually had it reinforced by really famous general surgeon back in the day. Um Dr Neeson that's um there were limits on what they could do. They would try to take a mesh and wrap it around the aneurysm so that the aneurysm wouldn't grow. We now know that that's a field concept. And despite having it fixed in 1948 Einstein actually died of a ruptured aneurysm in 1955 just as doctors. Coolly and DeBakey pioneers and cardiovascular surgery came up with a way to replace the aorta with initially home a graft. So basically fresh cadaver aorta, they would just swap it out. But Becky very famously on his wife's sewing machine and a sheet of polyester from the fabric store. So the first the akron graft and that has essentially been Um largely unchanged and what we use to replace the Aorta over the last 70 years. Um and I'll show you a little bit about how times have changed in terms of how we can do that. Um so what is an aneurysm? You know, an aneurysm is basically a dilation 50% over its nominal diameter. There are no more grams. You can look up what's normal for different parts of the artery. I always say the circulatory system is like a tree. As you go up the tree, every branch should be a little smaller than the one below it. Um So if it's too large on the, on the other side, then um that meets the definition of an aneurysm, um Not all aneurysms are the same. Um What we're gonna focus on today are the degenerative aneurysms that are a result of smoking and that's by far the most common. Um and it's important to understand the ideology of the aneurysm because it changes the natural history and how we choose to surveil or do an intervention for each one of them. Um Why are aneurysms dangerous while it gets back to your uh Physics high School physics places law where attention in the sphere is proportional to the radius of that sphere. Um Wall tension. And so the larger the wall radius, the more wall tension there is on the surface. And of course, like any other structure if you exceed the rupture threshold, that can be catastrophic. So the analogy I often tell patients when you have a balloon and you start blowing up the balloon, it's very difficult, but once the balloon gets large, it's very easy for it to get larger. And so it is with aortic aneurysms. Um uh We learned very early for abdominal aortic aneurysms that the risk of rupture was proportional to the size. And there's lots of great natural history data on that. And um early in the establishment of the treatment paradigm, we've, as a society said, you know, we will only fix these when the risk of death is higher than the risk of doing nothing. Um And so it turns out the early operative mortality for eric aneurysms was somewhere on the order of 5 to 10%. Uh And they established that threshold that we use today. Um 5.5 centimeter aortic aneurism. Because the risk of natural the natural risk of rupture was the same as the mortality of surgery. Um So what's new in vascular surgery? The minimally invasive repair is new and as a result, the risk of death from repair is plummeted. Um And so one of the controversial topics now is wait, should we still be using the same thresholds for repair? Or should we revise this to an even lower threshold for intervention? Um And I'll get into a little bit about why that necessarily hasn't changed, but that was the magic number 5.5 centimeters. Um We've also um understood that not everyone's rupture risk is the same and we now tried to individualize um the decision to intervene. Things that have clearly been shown to make an impact. Number one female gender. And lots of people argue you should have a you know, five millimeter lower threshold for women, ongoing smokers COPD aneurysm shape turns out makes a difference. And there's now emerging biomedical imaging techniques such as this finite dimensional analysis where you can really try to calculate the wall stress being applied on the aneurysm and try to establish a threshold for repair that is appropriate for that individual patient uh in the future which one of my partners is studying or biomarkers and genetic profiling with circulatory um tests. So you can do a blood draw and try to risk adjudicate the chance of rupture for individualized patients. Um So who is at highest risk for aneurysm growth progression and death? Um Aneurysms, abdominal organisms are by and large a disease of smoking uh and it's pretty unusual to see an abdominal aortic aneurysm, somebody that isn't a former smoker or an active smoker. Um And it's both an issue of the duration of smoking uh and the volume of smoking. So it's like a classic dose. Um uh relationship response. Um And um multiple studies have shown aneurysms or patients that continue to smoke are at risk of aneurysm growth. Um So we get asked a lot, is there anything I can do to change. My risk. This aneurysm growing number one by a mile is stop smoking that will slow the rate of aneurysm progression. If you continue to smoke smoke, your aneurysm will continue to grow um if they quit smoking. Um It doesn't necessarily get them out of the woods but it does slow the rate of progression. Um And also been shown though not as um dramatic of an impact is diet to a degree. So fruits and vegetables, nuts and fish are all protective meets seem to increase the risk of injuries and progression. But again, these are really minor gains, minor influence it's um smoking um by you know, an order of magnitude that is the predominant path of physiology and aneurysm progression. Um over time. Uh one other really interesting observation which I think is really important because we're progressively diabetic society, diabetes is actually protective against derek aneurysms. Um and it's not really well studied. It's possibly due to glide constellation of some of the connective tissues um that that line the brick wall. There is some speculation that perhaps Metformin the drug itself is what's protective and not the condition of diabetes. Um This is all that's being sorted out but interestingly, you know, progressively dialect society that is protective against the labor of gainers is um So what is the normal rate of growth? And this is super important because we'll see patients with small aneurysms far more commonly than we see patients with large aneurysms? Uh And we know um due to the law of applause. The rate of growth for this wall tension increases with size, smaller aneurysms grow slower than larger aneurysms. And the normal rate of growth for most aneurysms that we see in the four centimeter range is about $3 million per year. Um so this is great when we do our initial um uh intake with somebody with a new diagnosis of New York aneurysm, let's say that one that's at four. And we say if you stop smoking and we keep an eye on this aneurysm um It's only gonna grow you know 2 to 3 millimeters per year for most patients. And the threshold for repair is typically 5.5 centimeters. So you can do a back of the napkin calculation and say you know don't worry we're gonna keep an eye on this but it's unlikely you're gonna need to repair for let's say you know 3 to 5 years. Um And in some ways this is a wake up call. Again it's commonly smoking related. And so it's an opportunity to deliver a message linked to a behavior modification that can hopefully be impactful and help prevent growth because of this data. The rate of growth data. Um and um other data that's been out there. Um there are now pretty clear recommendations that have been endorsed by the us preventative services task force. We do all our surveillance with abdominal ultrasound. So it's very low risk. Um it is very cost effective. Uh and there is a strong recommendation for any particularly men over the age of 65 with any history of smoking to get a screening abdominal ultrasound. Um uh There was some backlash when this recommendation was made because it specified male gender. Um uh CMS adopted this and expanded it to women as well. So now, as part of a welcome to Medicare onboarding an abdominal aortic aneurysm screening is reimbursed for any patient over the age of 65 with any history of smoking. Um For aneurysms that are identified, our surveillance interval varies by aneurysm size because of the rate of growth. So aneurysms under four centimeters. We don't look again for three years. Aneurysms between four and five centimeters will look again at 12 months and once you're at five centimeters you're approaching the threshold for repair and that's what we'll do um imaging every six months um to capture them early. Um There have been studies that have looked at the safety of doing a surveillance program like this and it turns out it's very safe. There's very low risk of harm to the patient by doing surveillance all the way up to 5.5 centimeters, particularly in men. Okay, so let's say reaches size threshold. How do you repair it? This is again the old fashioned way. There's two ways to um work on the plumbing as I like to tell patients. You can either replace the pipe or you can realign it. The old fashioned ways to replace the pipe and for the aorta you would clamp the aorta above and below open aneurysm sac and replace that with the dacron graft polyester tube that we've been using forever. Um How does that work in the modern era? Super durable. Works great if you can select the right patients who are at you know low or moderate um anesthetic risk. Despite that it is a major operation. There's a roughly 15% chance of cardiac uh morbidity, typically atrial fibrillation 2 to 5% risk of my depending on their pre op risk stratification. There's a number of other lower risk um in low magnitude or low frequency complications that can occur with open repair. Um But I think the hardest thing for the patients is the recovery. So they spend about three or four days um in the ICU and they'll be in the hospital about a week. Um And just because they get discharged home doesn't mean they're back to where they were pre operatively. The recovery is really two months until until their energy level until their appetite until their strength really returns to where it was pre operatively. Um So it's it is a big operation. It's major vascular surgery. Um And offering it to patients should be done um cautiously. Um In uh you know, I don't like using the word disruptive innovation very much because it's so hackneyed, but for sure it applies to the minimally invasive repair of the abdominal aorta. Um This was the initial description done in Buenos Aires um in the late or I'm sorry in the mid 19 nineties. And all they did is they took a palma stand which is basically a balloon hand mounted balloon stent and they sewed a dacron graft to it. They put it on a catheter advanced into the aorta and somebody who wasn't a candidate for surgery and inflated the balloon. So it's like a wind sock here and it, fortunately for them kind of sealed this into place and now your circulation goes through the graft instead of into the aneurysm sac. And in theory depressurize is this um they you know, realized that most of these problems involved the identification. And so there were some modifications. But this really opened people's eyes on what is possible in a minimally invasive way. And now uh there are at least you know, eight commercially available devices with you no more similar than dissimilar that largely do the same thing. Um And what they are these are metallic um um frameworks with um fabric, either gortex or dacron. And that line it and help exclude the aneurysm sac. Um I often show patients. Um this animation just to kind of get them comfortable with what the repair looks like. You'll see lots of patients have ever in their chart what is an IV are. Well um and eve are an endovascular aneurysm repair is like building a ship in a bottle. Um and I'll show you why. But one of the key things here is the patient experience. The patient doesn't have to be under general anesthesia. They can be awake. Um You just need some local anesthesia where you access the groins. This is the aneurysm right here. Um As always, first order of business is to put in a wire into the circulation. Um This is a particularly complex aneurysm because this aneurysm extends down into the common iliac in the pelvis. So we'll have to exclude anything that's abnormal. Um And the way the way these devices work um These devices are made out of this spring, that's um nickel titanium alloy. It's um super elastic with shape memory. So they're designed to be in a very specific shape but they're compressible and as soon as you release the constraining mechanism it springs back open to that shape. And so they're designed as basically a pair of pants. Um And you know there's different sizes and you pick the sizes that you want. And then from inside each one you can then extend a pair of pants into a seal zone of normal artery above and below the aneurysm. Uh And um the reason why we can do this under local anesthesia is because the arteries don't have somatic nerve endings. They're totally insensate. So patients might feel pressure with like a balloon angioplasty but in something like this where you're just realigning it, they cannot appreciate um any kind of discomfort. Um And uh so here you go. And then this is the aneurysm usually starts at the renos, here's the other pair of pants. Um And then like I said, just like building a ship in a bottle will advance another device to bridge the gap here and then the circulation will be able to work its way from the aorta above into each one of these branches into the limbs and the pelvis without actually communicating with the aneurysm. Sac patients get discharged home the following day. Um It doesn't take a lot out of them physiologically. So the recovery is very brisk, most patients just need some Tylenol on discharge. Um They're up and they're walking around normally on the following day. Um There's a big push, at least for the less complicated ones to make this a reimbursed procedure and ambulatory care surgery centers right now it's hospital based, so there's that overnight admission but just to give you an idea on the safety profile for the majority of patients. Um it was very controversial when it came out. Um industry has done a great job of progressing the technology. There have been a series of randomized randomized trials now comparing the two unequivocally and the vascular repair has a much lower 30 day mortality, much lower morbidity. Um and I'll show you now, 80% of all patients that get repairs are done minimally invasive and the 20% are because they have really complex anatomy. Um you'll see this a lot in ct scan reports and endo lick what is an endlich? Um Well, um an end alec is basically any circulation in the sack outside of your stents. Um You know, the illustrator here shows you that there's one artery in into arteries out. But in truth, there's dozens of arteries, little branches all along that. The aneurysm, every segmental vessel has paired arteries for the back and spinal cord. Your I. M. A kind of comes in there too at the bottom of the sack. Um is an entirely bad. Well, they're super common. Their presence in roughly 25% of all cases that we do. Um but they're rarely pathological. Um you need a surgeon to look at it, understand the ideology, the endo leak and almost all just get observed and we only stage an intervention if it's a very particular end a leak or there's still aneurysm growth despite having an intact repair. Okay, so I'm just to give you an idea of how transformative this was the technology was I think the initial device was introduced um uh an FDA approved in the late 19 nineties. Uh and now this is a solid black line at the top, 80% of all repairs are being done um in the vascular early uh in the early days, there was a cut down to put devices in the devices have been miniaturized now that's totally pre cutaneous. Um So the recovery is even better. And what happened to our population over time? Well if you look at uh mortality, mortality plummeted like Iraq, there was at 5.4% that was stable and still stable for open repair. But since we're doing so many more of these per continuously, I'm sorry endovascular li the overall mortality is at 2%. Um and you know, in elective repairs, it's probably much lower than that. Um And here you go. So um in terms of death from triple A death is plummeted because we're doing so many more elective repairs and patients that probably were not candidates for open repair because of age or cardiopulmonary disease now can be safely repaired without putting too much stress on them. Um So I love this slide. It's one of my favorite slides, I show it everywhere. Um I just showed you that we're doing a great job of reducing death in triple A. And what I really just shown you is the very back end of this curve here where these two lines cross the data line is cigarette smoking usage number of cigarettes and then this solid black line is triple immortality. This is more than causation or correlation. There's definite causation that's been shown between smoking and mortality and as our population stop smoking so too has death from Triple A dramatically. Um So we've made an impact on, you know, the people in front of us, but the far more important thing is smoking cessation, particularly um for aneurysm progression. Okay, so for Triple A's in summary highest risk populations, anyone over the age of 65 with the history of smoking should get screened. Um smoking cessation slows the rate of expansion. Um We have some better risk stratification and we're trying to apply a little more of an individualized approach to a threshold for repair, but the reality is the overwhelming majority of patients now can have a very safe um minimally invasive repair with low risk of morbidity and mortality in a very brisk recovery. So um that's Triple A's in a nutshell, um peripheral arterial disease. Um what is peripheral arterial disease? People think that it's just atherosclerosis of legs in technically it's in any non cardiac festival. Uh and um uh you know interestingly there are afro prone areas. It turns out one of the big stimulus for atherosclerosis is a hemo dynamic stimulus. Um So turbulent flow gives you low share in that location. Low shear activates into a helium activated enough helium in the setting of all these other inflammatory signals results in the development of apple sclerosis. Uh and so these afro prone areas very classically involved. Parts of the aortic arch, the carotid bulbs, um visceral branches uh and branch points in the pelvis and the lower extremities. Um So these are entrepreneurs and we know, you know, um where to look to find uh the burden of disease. Um There's a technical definition as well for the lower extremities and A. B. I. Of less than 0.9 um Is you know basically diagnostic it's what's used in all um um clinical studies. Um And maybe I is super easy to do and you don't have to send them to us to do it. If you have a typically we use a manual stigma manama. Ter check the pressure in both arms and use the Doppler pencil to get the including pressure and the radials and then apply it into the limbs as well. Um You you know if your experience and you have the stuff there you can do it in under 10 minutes. I understand you probably all have busy clinics um and it's easier to send them for the test. Um. Uh So oftentimes what we'll do is if someone has a high diagnostic suspicion on on boarding we'll get an A. B. I. Before we see them just to confirm the diagnosis. Um Okay super high prevalent. Unlike aneurysms which are regressing the prevalence of P. D. Is increasing roughly 30% increase particularly impacting um uh Low and middle income countries and um low socioeconomic regions throughout the United States there's a rapid progression of P. A. D. Um Regionally and worldwide um the prevalence now stands on the order of 12% of the general population who is at highest risk. Um I'll show you some data, Age is a big deal. Um There's almost a hockey stick type curve with an inflection point wants to get to the seventh decade of life, even the absence of other traditional Framingham risk factors. The three highest risk groups, patients over the age of 70 patients over the age of 50 50 with the history of smoking or diabetes or patients over the age of 40 which is pretty young with diabetes in at least one additional risk factor for P. A. D. All your classic Framingham risk factors apply. But some really stand out smoking diabetes and age. Those are top three by a mile in terms of risk of developing preferential disease. And here it is. Let's get this one. Okay. Province by age this time stratified by male and female gender. Um And you can see under the age of 60. Um It's a pretty low incidence in the general population. This is from in Haines. Um 2000 participants that had a b idea available. Um But once you get over the age of 70 it's increases substantially in patients over the age of 80 it's well over 25% have um uh diagnosable perform material disease. Okay. Um when I see a patient with P. D. Um a really easy framework is this asymptomatic, is this claw vacation or is this limb threatening the problem because it has totally different ramifications for the work up interventions and the conversation. We're gonna have a potential treatment. Um Asymptomatic is by far the most common three times more common in patients with clarification. Um These are patients that will typically have an abnormal pulse exam picked up on on physical examination or commonly in our area, patients that are getting lifeline health screening. Um and just get a screening A. B. I. And there is some abnormality. Um um Asymptomatic disease. Why does it matter? Well, uh you know, P. A. D. Is a manifestation of systemic atherosclerosis. Um And just because they have an abnormal A. B. I. Doesn't mean that they have um uh afro in other parts of the body. If you have a diagnosis of pd, you roughly have a 20% chance of having some elements of coronary disease and some elements of coronary artery disease. Um So I you know, I don't have a lot of jokes for the medical students and clinic, but my favorite is a knock knock joke. It goes something like this knock knock. Who's there abnormal A. B. I. Abnormal FBI. Who it's not a joke, it's a wake up call. So if you get if you if you have an abnormal A. B. I. Even if they're asymptomatic, which you should really be doing is trying to identify risk factors that have led to this that probably would lead to coronary disease vascular disease and stage your efforts and your interventions for the fate of the patient, not for the fate of the limb. Um Other important point about A. B. I. S. Um The worst your A. B. I. The worst your prognosis from cardiovascular mortality. Um And just to kind of, I mean logically it makes sense if you have a really high burden of afro sclerosis, your A. B. I. Is going to be lower and if you have a really high burden of atlas crisis in your limbs, you probably have a higher burden of afro sclerosis in your heart or in the brain. Um So um there is emerging evidence that if you were um in the vascular medicine world to superimpose A. B. I. Into your risk models, your risk calculations etcetera. You might be able to refine that particularly in sub populations. Um We don't typically do that but that is kind of where the where the ball is moving to. Um And I think it just drives home the point that there is some information in an A. B. I. In an asymptomatic patient, even though we're not going to stage a particular invention. Um What about screening then? Should we be screening all these patients? Um Should we just get a B. I. S. And patients over the age 70. This has been studied exhaustively. This is a meta analysis with something like 100,000 patients um uh that got published as part of the US preventive services task force. Ultimately they decided to give it an indeterminate recommendation and FBI is easy to do, it's cheap, it's low risk but they weren't showing um enough of a benefit for the general population to endorse screening. What you should really use it as more selectively in patients, high risk patients, sub populations that might be um that might do better with more aggressive or targeted medical therapy. Um And that's typically how we use it in our practice. Um So patients asymptomatic P. A. D. It's really noninvasive testing to make the diagnosis and then work on risk factor modification. Okay. What about claudia cation? This is another super common referral um to our clinic. Um I have pain in my legs. Um And uh you know, pulse exam was difficult and it gets sent to us. Um So a couple of things about Claude occassion nine times out of 10. Um You can make the diagnosis very accurately with the thorough history and physical examination. Clarification has some very unique features, very reproducible onset. The problem is the muscles at rest or welp refused and they have to experience a certain amount of physiologic stress in order to develop lactic acidosis. And that's the pain signal. It turns out that the level of physiologic stress is always the same. So they'll say reproducible. E I know I can get to this bus stop before I have Pain. Um If I'm not walking. Um As far I don't get pain if I walk slower I don't get the pain if I walk up a hill or on stairs where there's more physiologic stress, then you get the pain. That's a key part of it is very reproducible. You need the stress component and you need the reproducibility component. Um it usually is quickly relieved with rest. So if they rest and for most people five minutes can be as long as 15. But if it persists for longer than that, it's almost certainly not true clarification and this is other key one. It's not affected by position. So if they tell you they have the symptoms lying in bed or when they're seated um then that's not a manifestation of preferential disease. Um The classic claw vacation is calf clarification. It's certainly the most common it tells you the problem is um The problem is more proximal, you you get symptoms one level below where the problems are. But you can have what's called syndrome, thigh or buttock location. That's a little different than the classic symptoms. It can give you hip pain that gets mistaken for arthritis. And oftentimes there's impotence to the inclusion of the internet or X. As well unless common leaflet clarification. That's um that's pretty unusual. Um I would say uh somewhere between 10 and 20% of the patients we get referred to for clarification do not infect have communication and that's because there are a number of um syndromes that mimic Claude vacation most commonly. Um uh spinal stenosis. A ridiculous apathy, sometimes verily compartment syndrome or there's venus claw vacation symptoms that can develop as well. Um But a lot of these can be teased out with just really careful history. Um And if you need to that's where the FBI. Is useful, adding some objectivity to very subjective history and physical examination. And again maybe I is really easy to get really easy to do. And then if you do an A. B. I. That shows a western 0.9 then you've made the diagnosis. Um There are patients rarely that kind of are in this great area where it seems like it's clarification. They do have palpable pulses and their A. B. I. Is close to normal. Um In those situations we do something called an exercise A. B. I. Um And um during exercise, your peripheral systemic resistance falls dramatically. And what that does is it it drops your pulse pressure. So if you see um if you do an exercise A. B. I. And somebody who's essentially close to normal, you'll see the FBI dropped dramatically during exercise. Um There's a couple ways to do this. We can you know you you can either put them on a treadmill. Um And I don't recall if you have a treadmill it um cemetery or not. But there are bedside exercises that you can do very commonly. We just do heel raises. So you just have a patient grab the edge of the gurney and just do 20 calf raises over a period of two minutes and then recheck the FBI and that usually is enough physiologic stress to to give you change um in your pressures. Do we get diagnostic imaging for um classification? Almost never unless we're planning revascularization. So we don't need a C. T. Scan. We don't need an M. R. We don't need an angiogram. Um And the work up it's really just history, risk factor modification. We'll get into all this year. Um uh And maybe I just for confirmation. Okay this is one of my favorite natural history studies. I doubt you can do it. I doubt it would get through an ethics board today but it was a study of patients with Claude education um from the Manchester Royal Infirmary in the 19 forties. Uh And what it is they had 1500 patients. Um And they diagnosed, diagnosed them all with angiography angiography back then was crazy. It was a direct aortic puncture. They take a needle and just right in the back and punctured the aorta blindly And then fill it with dye and shoot the next Ray. Um so we know these patients for sure had true clarification and then they put him on a treadmill every three months and they said what would happen. I just want to remind you this was in the 1940s so no aspirin, no statins, no medical therapy available. Um and other key difference is how much our populations have changed diabetes was only present in 4% of their patients. Um today. Um it's, you know, in our practice, it's probably closer to, you know, 50%. Um what happens to a patient with claudia cation if you just watch them well? Um 55% improved. They improved probably because they're putting these patients on treadmills, 35% never changed. Um 10% had worsening symptoms, but that doesn't mean they lost their limb. Less than 5% of patients progressed to amputation in the 1940s. No medical therapy patients that probably continue to smoke. Um so clarification um uh is a quality of life problem. It's not a limb threatening problem. And I think that's one of the key messages we try to drive home to patients now. Quality of life is important and you know, we do a lot to help people, you know, um feel better about themselves. Um But we have to understand what the natural history is in order to stage an intervention that is of the appropriate risk benefit profile. So, goals of therapy. Um two things a I didn't put in there, but the risk of cardiac death in that natural history study was something like 20% over six years. Um So the goal of therapy is still fear the patient over the limb. It's about risk reduction and preventing coronary events down the road and then the next stage is functional improvement. Um You guys are primary care doctors. So I'm not going to hammer home this point. You know what to do for medical therapy, patients with atherosclerosis, right, smoking cessation, Disl epidemiology, diabetes hypertension. Um We now recommend um a single agent anti platelet therapy. These patients are different than the general population because they have some manifestation of a sclerosis. This is not the same as just the general population, this is secondary prevention. Um And then what else can we do to improve the limb function? So there's 22 things we can do pharmacare therapy and exercise. Three things in surgery. We'll go go through them in that order. Um So in the United States F. D. A. Has two medications that have an approval for use in P. A. D. One is the last as all the other ones pent up fix a lean rental. Um europe also has Nafta funeral. We don't have that. But I mean maybe you've got a patient that gets treatment in europe and comes to your clinic, they might be on that medication for them. Um Trent calls an old medication they got approved by the FDA 1984. I question whether it would get approved it had if it had to go through the investigational new drug process today for lack of efficacy. Um the idea was that reduced blood viscosity and maybe platelet aggregation. Um commonly patients will have nausea, headaches, drowsiness and anorexia more problematically. It can exacerbate hypertension. Um I still see patients on Trent all that come to our clinic every once in a while and our first order of business is largely to discontinue it. Um Some of the early studies showed that there was a clinical benefit but multiple studies have showed have failed to show and improved A. B I either both resting or exercise while on this medication and I'm gonna show you one example, I'm here coming up. Um This is a far more effective and this is a first line agent for me for a patient who comes in with a new diagnosis of communication. It's celeste. Little um it's a phosphor diasporas inhibitor and a direct nasal dilator. The big issue um is patients have symptoms of flushing and you cannot use it in Hartfield area. Um So you cannot use this in all the patients that come to you but in the patients that fall outside of those two scenarios um we all always will try to last as long as our first line therapy. Um and it's been shown to improve maximal pain, free walking distance and as short as four weeks of therapy. Okay, this is a great um comparative effectiveness trial. This was published in Jama, I wanna say roughly 2010 or so. Um randomized placebo controlled with three arms. Um uh There's the celeste is all. Transall and placebo. Um Mantel and placebo are identical. These are the bottom two lines. So you get no benefit of Trent all over placebo. Mind you all patients approved. And this is study effect patients being on treadmills, patients being motivated patients quitting smoking probably. But celestial for sure had documented improvement in treadmill testing up to six months on on that regiment. So if the patient can tolerate it and there's no country indication to its use um It's a good way to get a little bump and functional um improvement with pharma co therapy. Um Other things that have been shown to work. This one's interesting remote pro um uh This was a randomized placebo controlled trial. 200 patients getting ram april with significant improvements in praying, free maximal treadmill walking times. Um So what we typically tell our colleagues in internal medicine primary care is to consider an ace inhibitor as a first flight agent And treatment of hypertension in patients with P. A. D. Because you might be able to kill two birds with one stone with this medication. Um And then of course uh negative fuel oxygen is not available in the United States but also been shown to increase walking times on treadmill. Okay, what about exercise? So we say exercise but what do we mean by exercise? We really mean just light exercise. Light aerobic exercise, walking basically. Uh And there's lots of evidence of the biomechanical and biochemical changes that happen when you apply light exercise to the vasculature. Um uh And it's not purely a mechanical issue. For sure. You can remodel the collateral vessels around an inclusion. But it is also an issue of um tissues being much more efficient in extracting oxygen due to metabolic exchange. You see this in the performance athletes all the time. You know, they might have, you know, they might develop uh with very high intensity training that might develop lactic acidosis a certain threshold. Both just vigorous training. They can extend that over time. So same applies to Um you know, a patient in their 60s with Caucasian. Um What is um the right exercise? It's been studied extensively. Walking is the best superior to cycling. Um Although we use cycling sometimes um stair climbing, um uh weight training, um upper arm exercise et cetera. So we're not asking for a lot. We're just asking for a walking program. A low intensity looks like it works just as much as high intensity. And the key threshold that's been established is you're walking session must be 30 minutes three times a week. If you exceed that, you're gonna start really seeing the benefits of a walking program. Um If you're below that, you're not gonna get as much out of it as you could. Um When we say walking for 30 minutes, a lot of these patients Claude Akins can't walk for 30 minutes without pain. Um We reinforce. Uh It's okay to stop when you have pain a you're not doing any damage by experiencing pain. Let the pain go away and resume walking and just try to make the total time walk, 30 minutes and over time they'll see an improvement. Um turns out it's difficult to get people to adhere to a walking program. There are a number of apps that are available that can be downloaded. Um There are services, um phone based services for coaching, basically um supervised exercise program has been shown to be far more effective. That's when a patient comes to a center and literally has, you know, in this case a physician coach who is making sure that there is adherence to the program. If they do that, then you really garner all the benefit out of that supervised exercise programs are now reimbursed by Medicare. Unfortunately for us, there's not a lot of options in the Bay Area and we've been trying to work with Mills Peninsula down in Burlingame to be able to um structure a program for the SCT. Excuse me for supervised exercise, who do we offer procedures to remember? It's a quality of life issue. Um The fate of the limb is relatively benign. You really want to target people with a pretty profound functional impairment that is impacting their daily living. I will say. Um more often than not when we see somebody, we say, let's try uh pharma co therapy, Risk factor modification exercise program for three months and let's and then we'll discuss the procedure if you're still not happy. Three out of four patients are happy and they're not interested in having a procedure. Um as a profession, we also realized that, you know, in these minimally invasive interventions, there's a really limited durability. And so you want to choose patients with the right anatomy so that the risk benefit profile really match. Um So basically procedures where you'll know you'll get a sustained benefit over at least two years. Otherwise you're probably not doing anybody any favors by doing multiple interventions to keep a stent open without any real significant functional improvement. Mhm. Let's get this. Okay, so another excellent um comparative effectiveness trial randomized trial. Looking at opera medical therapy, supervised exercise program and stenting. And it this study got a lot of praise because it addressed all the other studies that showed the same thing but had some criticisms, basically they cherry pick the patients that we're gonna do the best with a cutaneous intervention with a stent. So they so that was, you know, just to help um silence the criticism of the studies before them. And then they looked at the opera medical therapy in this case with uh statin 81 mg of aspirin. And then supervised exercise program. Both arms got optimal medical therapy, One arm was exercise, one arm was revascularization and then they did two things um tread level testing because you have really objective evidence of what happened. Um And then secondary endpoints like quality of life and the more subjective stuff And these are the key results. The panel here on the left is peak walking time. The green line is supervised exercise. Red line is a stent. Blue line is just a medical therapy. So everyone did a little bit better at six months. But the walking program outperformed the stenting. And even though um the trial, the supervised exercise program was only for 24 weeks, the results persisted over a year beyond when the study concluded. More so than you what you got with the catania's revascularization with the stent. Um And then um this is Claude occassion onset time. Um So the qualification onset time, you know, both groups did well it tells you that the stent group, you know had effective revascularization, they were able to um uh you know, walk without onset of symptoms but it's the behavior modification and the walking and when they had patients with odometers, even the patients that got stents very few actually went out and were actively walking more. Um So there is that component as well, the behavior modification that goes with uh supervised exercise. Um So you know, that's why the first line therapy now for patients with clarification is um risk factor modification opt in medical therapy and supervised exercise. We'll try that for three months and then we'll reassess um And here it is in textual format. Okay and then the last thing I want to say here is um limb threatening ischemia, which is the majority of our practice and something probably very few primary care doctors have to see frequently but it is the time when urgent referral is actually actually necessary because uh this is where time is tissue and patients really face um amputation. It used to be called critical limb ischemia. We've moved away from using that terminology now we call it chronic limb threatening ischemia. Uh And what it looks like is an ulceration which oftentimes is mistaken for a little trauma from their shoe. Um Rest pain which is dependent rubber that oftentimes gets mistaken for cellulitis and more obviously gangrenous toe. Um And just to give you an idea what this looks like. My pictures. Um I can't tell you how many times this picture on the left will will go to the E. D. With a painful foot um and we'll get placed on a course of antibiotics. It won't get better. A new course of antibiotics and it won't be until their third effort or they say well you know the policy here is normal. Let's refer them to a vascular surgeon. Um So this is um uh dependent rub or unlike cellulitis when you elevate this leg it will blanch immediately. So what this is is you know the tissues are so starved. There's basically Visa dilation, maximum Visa violation in order to increase the profusion even just a little bit um it's trying to compensate for ischemia in the foot. And obviously once you elevated and the pressure gradient changes, it totally goes away. And then this image here on the left is a skeptic ulcer. And again this is uh pretty mild physical exam finding they're typically very painful. Oftentimes diabetics that have neuropathy in our insensate. So you so you just have to fortunately take the sock off and look at the foot and make a make a uh diagnosis by exam. Um this is a real big problem. This is a curve of mortality and the annual mortality is roughly 15%. This is a big randomized trial from about 15 years ago looking at bypass for blue angioplasty. Um again this kind of speaks to the burden of athol sclerosis that these patients have. That it's a systemic problem. Uh and these patients are often near end of life due to cardiovascular morbidity and mortality. Um uh These patients will have classically severe pain that they're not diabetic. That's unrelenting and very difficult to treat with medical therapy. Um You really need effective revascularization to address the pain issue. Um You know, your skin protects you from the outside environment. Um We have these chronic open wounds bacteria can come in and give you infection particularly diabetics and that's the path of physiology of limb loss and diabetes. It's the ulceration that lets the night is for infection Develop. Um and these patients often have lots of ambulatory function deterioration of their functional status. Um that kind of compound the cardiopulmonary manifestations of the underlying disease. Um the risk of amputation is roughly 20% in the first six months unless you do one of three things effective revascularization, hopefully not amputation, although some patients, that's the right answer. Uh and patients that are really at end of life, we seek more of a palliative care kind of option. Um That's largely what I have. I think we kind of came in right on the just just under the time limit. Um uh Again, we treat lots of things, but certainly happy to um uh, take all your PhD referrals that you feel are critical.