Welcome to UAB MedCast, a continuing education podcast for medical professionals, providing knowledge that is moving medicine forward. Here's Melanie Cole.

Melanie Cole (Host): Welcome to UAB MedCast. I'm Melanie Cole. And joining me to talk about chronic limb-threatening ischemia is Dr. Danielle Sutzko. She's an assistant professor and Associate Program Director for the Vascular Surgery Residency at UAB Medicine.

Dr. Sutzko, it's such a pleasure to have you with us today. As we get into this topic, explain a little bit about chronic limb-threatening ischemia. What separates it from peripheral arterial disease? Why is it important to make this distinction? Tell us a little bit about it and what you've been seeing in the trends.

Dr Danielle Sutzko: Yes, definitely. Well, I'm glad to be here this afternoon as well. So the difference really with chronic limb-threatening ischemia is it's under the umbrella of peripheral arterial disease, but it's a more severe condition of peripheral arterial disease. So with chronic limb-threatening ischemia, the patients that we're seeing with this disease process are patients that have such bad blood flow in their legs from occlusive disease, that they are starting to have pain all the time or something called rest pain, or they have such bad perfusion that they've developed arterial ischemic ulcerations or wounds on their feet. They also sometimes have trauma to their feet and when they have trauma, such as potentially getting their nails clipped or hitting something on the floor, they won't heal their trauma or their wounds as easily as other patients that may have normal blood vessels, with normal perfusion. So that's the big differentiating factor, is that people with chronic limb-threatening ischemia have rest pain and something we call tissue loss, which is the wounds that aren't healing.

In terms of the trends, a lot of times, unfortunately, we see a lot of patients with peripheral arterial disease with pain with walking, which is known as claudication in our clinics. But a lot of times, the chronic limb-threatening ischemia patients, we end up seeing in the emergency room, when potentially some of this could be prevented if they were diagnosed a little bit earlier and sent to a vascular surgeon sooner.

Melanie Cole (Host): Thank you for making that distinction and the distinction between claudication and rest pain. So what had been the thought previously about these? Tell us about what's been going on with standard therapies and how this has evolved.

Dr Danielle Sutzko: Yeah, definitely. So, I think we have gotten a little bit better in terms of medical management. So I think probably historically anyone with peripheral arterial disease would immediately get an operation or potentially a minimally invasive procedure to help their blood flow. And I think we know a little bit more about the natural history of peripheral arterial disease in the way that if a patient only has claudication or more mild peripheral arterial disease, we're more likely to treat them with optimal medical management, which is including aspirin, a cholesterol agent, such as a statin, making sure to counsel them on smoking cessation and also getting them on an exercise program, which unfortunately, a lot of insurance programs don't necessarily cover. But what I tell patients is if you have a watch and you can go walking for about 30 minutes a day, whenever you have to stop because of pain in your legs, then stop the clock. But if you can do 30 full minutes of actual walking a day, that should be able to help your walking distance.

I think a lot of claudicants now that we see in clinic, if we recommend medical management first, a lot of those patients actually don't necessarily need surgery, but they definitely do need surveillance and monitoring usually in a vascular surgeon's clinic so that we can monitor them over time because some of the claudicants will progress to chronic limb-threatening ischemia.

The other thing that's the big differentiating factor is if patients have claudication, if it's really lifestyle-limiting or not. So some patients have claudication, but they're able to do everything they need to do and it's really not limiting their lifestyle. Whereas other patients may really depend on walking for, say, their occupation, such as a mailman if they're walking a lot or a UPS delivery driver. And for those patients, we're more likely to intervene with a surgery after medical management has been optimized if they have lifestyle-limiting claudication.

I think the other thing that really matters is where their blockages are. So if their blockages are in their aorta or their iliacs, those are larger vessels and they're more easily treated with surgery and they also stay open longer after, say, a bypass or a stent. Whereas if the blockages are really in the smaller vessels in their legs and even below the knee, those patients we're a lot less likely to treat with surgery or endovascular therapy if they're only a claudicant because we know those procedures won't last as long. Whereas if you have chronic limb-threatening ischemia, it really doesn't matter where the blockages are, those patients really need an intervention.

Melanie Cole (Host): So then, if they were claudicants and they go to become chronic limb-threatening ischemia, are their vascular guidelines and have other specialties that work on revascularization of the lower limb and brought together to incorporate some sort of guidelines?

Dr Danielle Sutzko: Yes. So they actually have a global chronic limb-threatening ischemia guideline put together for patients with chronic limb-threatening ischemia. You know, there's constant collaboration with vascular surgery, as well as interventional cardiology and other interventionalists that will provide care for these patients. And I think the big push nowadays is to not to intervene on claudicants until they really have been medically optimized and really only reserve that treatment for lifestyle-limiting claudication and then obviously treatment for chronic limb-threatening ischemia.

I think the other thing too is patients with diabetes used to not be included in this peripheral arterial disease spectrum. And we have now included diabetes in chronic limb-threatening ischemia. So those patients are not being left out.

Melanie Cole (Host): I'm glad you mentioned that, because I was going to ask if they're included in these guidelines. So tell us about some of the interventions and an update on anything that's changed as far as research studies that you're involved in. Tell us about what you're doing.

Dr Danielle Sutzko: Definitely. So I think the biggest thing is a lot of times when you have chronic limb-threatening ischemia, it really depends where the anatomy of the blockages are, is going to determine kind of the procedure that we go for. So it also depends on the overall picture of the patient and how many comorbidities or how healthy or unhealthy that patient is and whether or not they could tolerate a larger operation. I think most vascular surgeons, when treating patients with chronic limb-threatening ischemia in the aortoiliac segment, typically will try to treat with an endovascular first approach depending on how severe the blockages are or how long the blockages are. So there is a task classification that we go by. Task A meaning a short stenosis or narrowing versus task B gets a little bit longer narrowings versus occlusions. Task C, a little bit more severe and task D being long severe blockages in multiple arteries. And so there's task classification for the iliac segment, that a lot of times we will utilize. And most of the time, if you have a task D lesion, would be the only time that you go straight to open surgery.

Now I will say that sometimes if they have blockages, we will attempt to do the operation minimally invasive or with endovascular technology first. And sometimes we're not able to get the wire to cross the lesion. And so if that's the case, we will always have open operations as a second plan. But a lot of times, these lesions, we can cross with minimally invasive techniques with good results and good patency of these stents.

In terms of the below the inguinal ligament occlusive disease, I would also say that in most patients, we would try an endovascular strategy first, as long as the lesion is not too long or too calcified. And if we can't get across with a wire, then we always have another option to treat with open surgery.

The other thing is if the patient has certain disease that crosses the knee or has only one tibial vessel as runoff, then typically we will usually try to do an open operation in that patient, just because of the risk of damaging that one vessel runoff during an endovascular procedure.

Melanie Cole (Host): What about some promising new therapies? If you were to look forward to the next 10 years in the field, where do you feel will be the most important areas of research and I'd like you to add in there about when you feel it's important for other providers to refer to the specialists at UAB Medicine.

Dr Danielle Sutzko: Definitely. I think, there's definitely some exciting basic science research that's happening. Now, I'm more on the outcomes side of the research. So I don't know all the details, but there's a lot of exciting research going on with looking at diabetic wounds and how we can improve the neovascularization or new blood vessel development in patients that have diabetes and have peripheral arterial disease.

We do know that the patients that do have claudications that go out and walk, they can generate new blood vessels on their own that are always better than our own bypasses. So some of the technology and research being done on generating new blood vessels in these patients is pretty exciting if they can end up getting the solution to that problem.

I think in terms of outcomes research, which is more kind of in the realm that I study, I think it'll be really important to look at different specific patient populations within the chronic limb-threatening ischemia patients. So right now, I'm doing some grant writing work and research work in looking at the vulnerable population of patients with end-stage kidney disease that also have chronic limb-threatening ischemia. And unfortunately, those patients aren't necessarily included in the guidelines because they've been excluded from a lot of the research clinical trials that have been done in this space.

And so I'm hoping to get a little bit more kind of granular answers about how these patients do with open and endovascular options and also looking at who are the patients that regardless of what we do end up in an amputation anyways, because I think it is really important that if there are certain characteristics about people's blood vessels, that if we know ahead of time that they'll ultimately end up with a high risk of amputation, I think a lot of those amputee patients would appreciate getting the amputation sooner instead of doing multiple procedures, still being in pain and really being debilitated so that when they do get the amputation, they may not be able to walk on a prosthetic as easy as if they had just had it initially.

Melanie Cole (Host): That's interesting. And speaking to other providers, just wrap it up and what you would like the key takeaways to be.

Dr Danielle Sutzko: Yeah. I think if you are seeing someone in your clinic and they're complaining of pain with walking, and you're not able to palpate distal pulses, I think starting with an ankle brachial index, which is kind of the gold standard screening study for peripheral arterial disease, would be a good idea. And if they do have a decrease in their ABIs, referring them to a vascular surgeon for further management.

I also think if there's any patients that have wounds on their feet that aren't healing after a decent amount of time, I think it's always good to investigate if it's because they have lack of blood flow and, obviously, anyone with pain all the time in their feet without good pulses should be a referral to vascular surgery. And hopefully, we can get these patients in earlier to be able to treat and offer them operations if indicated sooner.

Melanie Cole (Host): Thank you so much, Dr. Sutzko, for joining us today and sharing all of these updates in this field. So thank you again. And a physician can refer a patient to UAB Medicine by calling the MIST line at 1-800-UAB MIST or by visiting our website at uabmedicine.org/physician. That concludes this episode of UAB MedCast. I'm Melanie Cole.