Melanie Cole, MS (Host): Welcome to UAB MedCast. I'm Melanie Cole and joining me today to highlight Diagnosing Peripheral Arterial Disease is Dr. Benjamin Pearce. He's the William D. Jordan Jr. Endowed Professor in Vascular Surgery and Endovascular Therapy at UAB Medicine. Dr. Pearce, thank you so much for joining us today.

Can you start by giving us some of the most significant updates in our understanding of peripheral arterial disease since you began practicing medicine, since we have talked before?

Benjamin Pearce, MD: Well, thanks, Melanie. I really appreciate the opportunity to come back and talk about this topic. This is obviously, my life's work and our team here, we've got an incredible team that works on patients with PAD, which is sort of how we refer to peripheral arterial disease, just so it will save some time on your podcast.

And, probably the biggest thing that's happened in the last several years is really our understanding of both the non-operative management and then picking the right operation for patients with PAD. And I'll parse that out for you. I think, a lot of atherosclerotic disease, which at the end of the day is what PAD is. People know about heart attacks. They've heard of strokes, but PAD is becoming just as prevalent with this meteoric rise in diabetes in this country; the risks of getting peripheral arterial disease when you have diabetes is dramatically higher, and the risk of losing a limb, to where we're going to, I think we're all going to know about PAD the way we've known about heart attacks here pretty soon, but it's the same sort of risk factors, right?

So diet, lack of exercise, smoking, and management of lipids. Those are probably your big ticket items. So the things that have really changed just in the 15 years that I've been practicing this particular specialty is one, the dramatic change the statins have made in the outcomes of our patients, both their overall risk, their overall mortality risk, but specific to PAD patients, if you can get a PAD patient at the very beginning of their disease process on a statin; we can really halt a lot of the progression of disease.

And if they ever do come to the point that they need some sort of an intervention, they tend to do better with those interventions if they're on a statin, both from the limb standpoint as well as their overall mortality and morbidity risk standpoint.

 So, statins have been a huge, huge thing. Probably the second biggest thing in the non-operative realm has been a couple of really great studies that have looked at using low doses of direct anticoagulants or direct thrombin inhibitors. The main one that was studied in the trials is rivaroxaban or Xarelto. But there's an indication now for PAD dosing. I find it personally to be particularly useful in patients who have had a peripheral intervention and keeping those interventions open. And, and that's been another thing that's really, I think, changed sort of the success of a lot of our operations.

And the third thing in the non-operative realm has really been the understanding that exercise therapy for patients in the early stages of PAD really works. And quite frankly, avoiding an intervention, if at all possible, is probably in the best interest of a large majority of these patients. And if you don't mind, I know I'm kind of expositioning here, but I want to sort of expound on that a little bit because I think sometimes people think if there's a surgical or interventional correction to something, well, let's just do that, right? That's the easy thing. I'll eat cheeseburgers and smoke Marlboros right up to the point that I can't walk anymore and then you'll pop a stent in me and I'll be better and I can go right about doing what I want to do. But the reality is, is if we want to help these people long term, if we want to help patients with PAD keep their limbs, walk the rest of their life, as well as have a lower risk of all those other things like strokes, heart attacks, in a lot of cases with the cigarettes, cancers;

it really behooves us as medical professionals to help them to understand that those healthy choices, both from a diet standpoint, from a lifestyle standpoint, and the exercise standpoint, make a big difference. But there's also some really great data that's emerged that shows that if you can get a patient, off cigarettes and on a walking program, their actual objective numbers, their measurement of their pressure in their limbs goes up just from the exercise therapy.

So there's a lot we can do actually just being doctors, which is one of the fun things about doing vascular surgery is you get to still be a doctor in addition to do procedures.

Host: Dr. Pearce, thank you for that. And I'm an exercise physiologist and one of the things, and we're going to get into diagnoses, but when we think of the claudication that prompts someone to maybe go to the doctor, you're talking about exercise and prevention in the first place, but that certainly is a limiting factor sometimes. So I'd like you to speak about, and as a doctor that you're discussing and how exciting that is when there's that limiting factor and pain.

Benjamin Pearce, MD: That's a terrific, terrific question, Melanie, and something that comes up every time we have clinic. Someone says, Doc, the whole problem is my leg hurts when I walk and you're telling me I should walk. So, I think it's a really important question. It's a pretty nuanced thing, but any of us can help patients.

And someone like yourself, who's an exercise physiologist, I think can help patients understand as well. So, limb pain can be multifactorial, as you know. So, I think the first thing is it is important to get that right diagnosis. And I know we'll talk a little bit about that later, but the most important thing I would say is anybody that's presenting, if you're listening to this, and you're in primary care, or you're in the emergency room, or you're a nurse practitioner, who's taking care of patients in the community; a simple way to decide if there's an ischemic component to this patient's pain in their limb is to get a simple ABI. Believe it or not, everybody can do an ABI. If you can take a blood pressure, you can actually do an ABI, which is an ankle brachial index. And you want to do is you want to take the blood pressure in both arms and you get the one that's the higher of the two.

And then you take a Doppler probe and a blood pressure cuff and you just measure the closing pressure in either the dorsalis pedis or the posterior tibial with just a regular old blood pressure cuff, and you create a ratio. It really helps if you can get it done in an actual vascular lab, because then you get a nice printout with an interpretation, and you get other things that go with it like pulse volume recording waveforms and some other things that you can do in patients whose ABIs are a little unreliable.

But if you can get an ABI and you can say, look, there's clearly an ischemic component to this patient's leg pain, then you can be pretty confident in telling them, if you walk to discomfort, and then you rest, and then you walk some more, A, you're not going to make yourself worse. So it's okay, because a lot of times, right, I think what you're getting at is patients are conditioned to think that pain is something that is there on purpose to stop you from doing something that's going to make you worse.

Or pain is just a barrier in general, a psychosomatic barrier. But in the case of true claudication, patients who are having ischemic pain in their ambulation; walking to pain, that's really the first line of therapy. And again, they can rest, they can walk some more. A neat trick that I like to use, and this was taught to me by professors at every level that have been mentors of mine, is that you can challenge people, right?

We just got done watching the Olympics this summer. How awesome was that? And you see that every year, right, there's a world record set. You can't believe it. You think there's no way a human can swim faster, jump higher, run faster. But all the time we do it, even if it's incremental. Well, this is the same thing.

If you give somebody a challenge, if you say to them, the first day of your walking program, I want you to go out in your neighborhood, or wherever it is, or the track at your local high school. I want you to count mailboxes. How many mailboxes can you walk before you hurt? And make it back home again. And the next day I want you to try one more mailbox. Something simple like that, you'd be shocked at how patients can improve their walking distance, when you give them a challenge.

Host: What great advice you just gave. That was an excellent answer, Dr. Pearce, from start to finish and giving providers such great advice on that diagnosis and some of the criteria is really so important here. So, as far as diagnostic tools and techniques for definitively identifying it, tell us anything that's exciting.

I mean, AI is coming in, in so many different ways and even being able to be used by someone who's not a surgeon to look at various components of disease. Tell us what's exciting.

Benjamin Pearce, MD: I do think a lot of our standard implements that we use to assess this would be amenable to AI, right? We're going to be able to plug ABIs and pulse volume recordings into these huge databases and generate some machine learning where a patient could hopefully one day go to a kiosk at the Whole Foods, and let the Amazon doc say, your pain is, you know, 60 percent likely to be related to ischemia. And these are things that you can do to mitigate that and to improve that. But that's not really down the pipe at the moment. The honest answer Melanie, is that, right now in the way medicine is structured in the U.S., is that we really pay for interventions. So most of the real exciting things that are being done in vascular are on the intervention side. But good old fashioned exercise therapy has received approval from CMS to have a CPT code. So we're certainly seeing more and more people, I think, taking up the mantle of exercise therapy.

But as far as diagnosis, if you still do really good physiologic studies, and like I was saying before, you really need to do both. A duplex gives you a lot of information about what the arteries look like. Is there calcium? Is there soft plaque? Are there things in the blood vessels that we need to be worried about? Maybe we need to adjust their statin medicines. Maybe we need to adjust their anti platelet or anti coagulation. But you need the ABI, as well, especially a treadmill ABI can be very helpful, but we need the ABI and the pulse volume recordings as a part of that because there'll be patients that'll have some stiffening in the arteries, especially with things like diabetes or some other unusual disease states like advanced age, which is coming up more and more.

People are living longer. Things like sarcoidosis, other things, end stage renal disease that put calcium in the wall of vessels, and they can cause your duplex to look abnormal, but the actual pressure in the feet is still intact. And so I think doing both those studies is really helpful.

But to your point, I think, yes, eventually a lot of these things will be automated and a person will be able to hook up a blood pressure cuff to their iPhone and be able to generate their own ABIs and probably can get a lot of really great information, over a telehealth sort of thing and really begin things like exercise therapy and counseling on good decision making as far as their health is concerned without having to take the time and the trouble to go to an urban center where the majority of vascular surgeons are located.

Host: Dr. Pearce, what an engaging discussion we're having. I'd like you to tell us about the program at UAB and the multidisciplinary goals that you have, team members, because as you're saying with exercise, there's nutrition, there's smoking cessation, there is the place for surgery, and we're going to get into that in just a minute. But there are so many people involved for this particular condition.

Benjamin Pearce, MD: Yeah, this is a team sport. It's certainly nothing that the doctors were doing in a silo. In the time that I've been at UAB, and I came here actually as a fellow in 2007, to work for Dr. Jordan, now I'm honored to have his name on, my professorship. But our group has expanded dramatically. So now we've got a team of podiatrists. We have four tremendous podiatrists that have joined the division of vascular surgery, so we can offer much more advanced foot care when it comes to limb salvage, but preventative foot care, because that's a huge part of it, right, avoiding those ulcers and those neuropathic problems in the first place, not having a wound is the best way to not lose your limb.

So podiatry has made a big difference. We've had clinic and inpatient Nurse Practitioners and PAs who have joined our group who can really do things like when we're stuck in surgery for 8 to 10 hours at a time, they can actually help talk to those patients, manage those patients. They do an incredible job at looking at their medicine lists, of giving them counseling on the right decisions to make.

 So that's made a huge difference. Our office has grown. We've got Nurse Coordinators that work in our office and they talk to patients who are outpatient on the phone every day. And they can handle a lot of these problems now because everybody in medicine is being empowered to be a decision maker, to be a team player, and so I've seen our limb salvage practice really dramatically change because of the support that we get from all of these other specialties that look at every little different aspect of care, maybe a little bit differently than we do. And they can look at those things that are non-operative to help make patients better.

Host: Before we wrap up, Dr. Pearce, I'd like you to just briefly go over chronic limb threatening ischemia. It's got several stages and I'd like you to speak to other providers about what marks that demarcation between those stages. Why are there some people for whom there is no other option? Speak a little bit about that, what you're seeing in the trends as far as that end stage manifestation.

Benjamin Pearce, MD: That's going to be our white whale in this country, in the next 20 years is patients that a lot of times are even skipping that sort of claudication. I think what we thought about PAD for a long time, was sort of the classic progression of the non diabetic, Caucasian, smoker, because that was sort of the people that Michael DeBakey got famous on, so they are pretty active. They live their life, but they smoke cigarettes and they probably eat in the south biscuits every day. And they begin by having cramping when they walk and then if they don't get it addressed, it progresses and it progresses and eventually they may present with an ischemic wound.

But now with diabetes, we're seeing a dramatic change in that because these patients are preferentially have small vessel disease. So there are patients who are younger and who maybe never smoked, don't have the classic risk factors, are presenting with actual limb threatening tissue loss and limb loss because of distal disease.

So, it used to be a pretty easy to understand spectrum, and now I think what we're seeing is a big change. And so, when you talk about new things, it's not quite so new anymore. But vascular surgeons started to recognize this probably about a decade ago and sort of changed our grading scale of patients that present with limb threatening problems.

The newest thing is called Wi Fi. You got to come up with a clever name, right, if you want something to stick. So it's Wi Fi, just like, we all log on to every day now, but it's Wound and, and ischemia and foot infection and how those things are playing into a patient's risk of limb loss.

So a patient who presents with a wound on their extremity, especially from the ankle down, is somebody that your first thought has to be, this is a PAD problem. Occasionally, they will have purely neuropathic ulcers. The patient will have a totally normal pulse in their foot, or they'll have normal non-invasive exams, and there's no ischemic component.

But if you really start looking at patients and almost anybody who presents with a foot wound, there's almost always an ischemic component. So those are people that need to have a vascular surgeon involved from the very beginning of their care. At UAB, as we talked about earlier, we're lucky because you're going to have probably a diabetic specialty podiatrist and a vascular surgeon involved in your care, which I think is going to give you the best chance to heal that wound.

The things to really worry about when you talk about critical limb threatening ischemia are patients that are having, like I said, either wounds that are spontaneous or pain at rest. You still need to do those non-invasive studies to start, but those are patients are going to need to have an intervention.

And I think that's probably the biggest distinction between claudication and CLTI is that patients with CLTI when you reach that, those are the patients who are going to need intervention. And so, they really need consultation with one of us in the vascular division. I will make a push for vascular surgery because, we do everything. We do the non-operative management. We do minimally invasive interventions for patients, including our own angiograms, people may not realize that we do our own angiograms. We do our own peripheral balloon angioplasty, stent, arthrectomy, all the different modalities you can think of. But we also still do surgical bypass.

And so, when we do your procedures, we can look at the initial diagnostic angiogram, and we can understand what are the targets if we were to need to do a bypass, what are the options for doing a minimally invasive type intervention, and we can make sure that the choices that we make continue to give that patient long term both chances for success as well as what we like to call failing forward, which is meaning that we're looking to do something to get them out of this initial problem, but we don't want to burn any bridges for their next episode if they unfortunately have something like that down the road.

Host: Thank you so much, Dr. Pearce, for joining us today. This was really such an important discussion that we had. Thank you again. And for more information, you can always visit our website at uabmedicine.org/physician. That concludes this episode of UAB MedCast. I'm Melanie Cole. Thanks so much for joining us today.