 Welcome back to our discussion on breaking the barriers in peripheral arterial disease, in peripheral arterial interventions. Our guest today is Dr. Montero Baker, and he will share his personal views on this particular topic. Tell us a little bit about Wi-Fi classification, and what is the importance of this classification, and how it helps us in managing patients with critical in viscimia? So, in a very brief description as to why this article was developed, is for many years we were only using Rutherford classification to determine the complexity of our patients, and a lot of the industry studies were based on this Rutherford classification. The problem with Rutherford is that it's a classification based on tissue loss and some symptoms. And so it creates very big pockets for patients that may be very different amongst each other. And so when you have very heterogeneous groups of patients, then it's really difficult to understand how to better suit their needs. A Rutherford class five with minor tissue loss can be a patient with infection, with no infection, with some severe wound, or maybe a small wound, and it was to a certain degree very vague. The Wi-Fi is an attempt by the Society of Vascular Surgery to create an algorithm by which you unite maybe the three main drivers of major amputation and the need for revascularization. And those are the wound, and how extensive the wound is, the degree of ischemia of the patient, and then last but not least, the foot infection. So if you grab those three variables, you construct the wound ischemia foot infection and that makes Wi-Fi, which surely has nothing to do with our internet, but it was obviously a very catchy way to demonstrate this. Now this just shows, as I said before, the Wi-Fi on the right. Of course, you're gonna look at the patient as a whole, the status, the anatomy, the limb status, all these things, but Wi-Fi just was a way to try to say, what can we do easier? Now if you think about these, each grade goes from zero to four, and so it creates a 64 classification brackets, and then those 64 go on to be subclassified into four stages. So a group of those fall into the very low-risk patients, and then a group of those fall into very high-risk patients that actually are not only high-risk, but that would benefit the most out of interventions. We actually just now, about a month ago, published this one paper showing that within about four hospitals with almost 3,000 patients, the grid shows itself very nicely as to the risk of amputation. So on the far left, you see those that didn't have a lot of risk, and then as you go into the more complex stages, it definitely shows an increscendo risk. And one of the things also very important in this paper is that really the wound seems to be the most important driver in all these cases of what leads to be the possible alternative of this patient. At least we're trying to subclassify the patients better. So creating a logical construct that allows you to evaluate and treat the patient, it allows some predictability because if you can tell the patient early on that this is a long course of action, then they may be clear on what the expectations are. It may identify those that could be revascularized early. And then some people think that maybe in the setting of a good vein, depending on the wifi stage, maybe you should opt for an open versus an end-to-approach. Obviously, there's a lot of work still needed. And I would say for those of you that are techies enough and probably if you're looking at this, you are. But this is the Society of Aska Surgery app. And so if you go and you put it on your smartphone, you can actually classify your patients with wifi and then exercise as it takes about 20 seconds. So it's not that complicated. And I think in the future, it may be a way to audit and compare outcomes and costs, improve selection of the revascularization. It's a nice restaging tool because you can stage at the beginning. And certainly a tool to advise the patients of what their expectations should be. So I think it's fair to say that Dr. Joseph Mills, your colleague, your partner, and the Chief of Aska Surgery was instrumental in publishing this information in the early stages and also promoting it together with you and your other colleagues all over the world. So this is now well-accepted classification. Yeah, I would say probably the two main drivers were Dr. Joseph Mills and then Michael Conti and UCSF. They've been historical advocates for it. And then I think it's been nice to see that it's been well-received as I think it helps. Again, it doesn't matter what your background is, it's nice to be able to tell the patient some expectations and say, hey, we're gonna do everything we can. But you are looking at a long-term recovery with X percentage of risk in losing your limb despite whatever we can do or best medical management. And again, don't get me wrong, I don't think that this is a way to go back to the turf wars about end or open. It may just be that in a certain type of patient, you may have to prep them. That if you go the end or out because maybe they don't have a saphenous conduit, they may need multiple interventions in the stages three or four. And that's something that should be a conversation on the table. Understand you may have to have more than one procedure because patients, a lot of times, thinks is a one and done in medicine. And most times and none, it's not just one time. We have to go back and continue working on them. Right, so continue on that topic. I would like for you to mention to us, when do you use a hybrid approach? What are the typical scenarios? Give us some examples. So hybrid approach would be having two different techniques that work together. So getting the best out of endo and the best out of open, if you may. Many times driven by the vascular surgeons, but I'm very happy to say that I'm seeing more and more vascular surgeons and non-operative interventionists working together in a case. I think probably one of the most frequent hybrid approaches that we see is when there's severe disease in the common femoral and the aorta iliac system. So a very nice approach is to do a bilateral endarterectomy with patch. And then right then and there, you could actually reconstruct the aorta iliac system with covered stents that may lead in complex scenarios to lung and good pain rates. So I think that's a very good scenario where we see this a lot. A lot of, more that I'm also seeing is patients that have had already multiple interventions and that unfortunately have maybe occluded bypasses or such. Then you have to get very creative with how can you get flow. And sadly, we don't necessarily are able to rescue the bypasses all the time. So we could do bypasses down to the knee or below the knee pop. And then we could go with endo through the bypass and then work on the below the knee vessels, which I think is also a very nice and very good way when you have a severely disease as a phase segment or again already occluded bypasses from the past. Then you can start using these very fancy bypasses off of the profunda into the lateral anterior tibial or into the popliteal. And then you bring the patient back or at the same time and go through the bypass and then work with endo from the knee down and then from the ankle down. Cause as much as we are good surgeons in the distal territory, it's hard to ever think that open can reach the distances that a wire can. Cause right now it's not rare that we'll do metatarsal artery angioplasty for specific cases. So I think it's really exploded in many ways our abilities to combine both techniques and have sound results for the patients. So finally, you are a very unique vascular surgeon because you had extensive and complete training in vascular surgery and also extensive experience in endovascular approach. You spent several years in the center where they were doing endovascular approach in a variety of scenarios and you gained tremendous expertise. Can you tell us where are we now as far as vascular surgery, training progress I'm concerned and vascular surgery in general as far as embracing the endovascular techniques. And is it almost mandatory at the present time that you have to have skills in both to be able to offer to your patients the best medical care that there is? It's a very interesting question. And if you look at the VQI analysis which is a vascular quality initiative that's actually a very large data set that's driven by the Society of Asks Surgeon. The practices in America are so different. You have actually practices that have 100% open and you have practices that are on the over 90% endo. So we clearly don't see eye to eye from one vascular surgeon to the other. But I do believe that if you look at the trends in endovascular therapy, overall when you compare all specialties maybe in the last 10 years interventional radiology has decreased and that has been taken up primarily by vascular surgery. So I do believe that we are in a process of morphing into being much more accepting and being more comfortable. I think most training, remember the VQI has training and not training practices. So you may have private practices that are driven by somebody that just does bypasses. But in most training, ACGME training paths it is a necessity to have endovascular therapy. Now, are they gonna be exuberantly trained on endo? Not necessarily and I do believe that that depends on the program. And so for trainees, it's very important that they look at what they like or what they're seeking in a program as when they apply that they can get what they want. And then we also have I think practices that are very limb exuberant, limb preservation exuberant like our own. And then we have practices that are very focused on the aortic pathology. It's primarily up in the northeast and northwest areas of America. The aortic belt, if you may. But this is what I believe we're seeing. And I really think that most vascular surgeons should feel comfortable with endo as it can create the most unbiased approach to your patient when your technical bias is removed from the algorithm of care, I think the patient will win. And that can be also bridged in non-vascular surgeons by working together with vascular surgeons. Right, I'm very impressed how the educational program at Baylor College of Medicine is rapidly progressing with your presence and Dr. Joseph Mills presence because I see that our program is advancing very rapidly towards endovascular field. Of course, surgical techniques are also very important skill that those physicians in training need to have in their momentarium, but I think it's very positive. The question is, as you mentioned, there are some practices, vascular surgery practices that almost exclusively use open techniques. And it's not that they don't believe in it, they just don't see a proper avenue how to gain skill and expertise in endovascular techniques. So that's going to be a challenge for them because in my opinion, I don't know if you share my view, they will be left behind in the next four or five or 10 years because the patients will demand, the institutions will demand to reduce the cost and mortality and morbidity of the procedure. So I think that's an important step in the future. Absolutely, I would say that if you go to the Society of Vascular Surgery work bank, alternate positions posted out there, most of them actually demand that there's an endovascular training on there. So even the professional scope now, if you don't have that, your alternatives to find an adequate job can be limited by that. So at the end of this presentation, I would like to ask you, and this is related to breaking the barriers in the peripheral vascular field as far as surgery and interventions are concerned, what are the unmet needs? Something where we still have a burning desire to get certain technologies, techniques, or even acceptance from the payers to be able to advance and offer better treatment to our patients. Yeah, there's obviously the more you progress and the more you find questions that need answers. But one of the main needs, I think, that would help all of this moving forward, technology, catheters, stents, whatever you want, is creating objective performance goals. So an electrophysiologist, when he's working on the table in a patient's heart, has EKGs of multiple types that guide him in this process of getting the patient to a better spot. For us, we don't have a lot of things. So I'll invite you to see this first slide where it shows it seems like we have an ischemic tissue and a magic threshold that turns him into non-ischemic. But then that threshold itself may be, in a way, altered by patterns of disease, the wound care, or even the comorbidities of the patient. But when we don't know what the threshold of oxygenation or perfusion is, then in many ways I feel we're trending blindly. I have done some work with this particular technology and not that I'm saying this is gonna be the answer, but just starting to see disruption in the field of how to measure objectively what our results are, if you can get an on-the-table objective feedback, this will be beautiful. So this is an oxygen sensor that gets injected into the patient's skin. And then with a special reader, you can actually identify conditions of low or high oxygenation. So we moved past, we did many years ago, the first in-man protocols in a study called CSE puede, which I authored in the Journal of Ascular Surgery with the objective of showing that it could be done, that we could sense oxygen and defeat it. Sounds political a little bit. A little bit. But this is now the new and improved omnia, which means oxygen monitoring near ischemic areas. And we have three sites actively enrolling in Europe. And we're looking at patients that have CLI, and we put a sensor in the arm and then three sensors in each foot to try to hit every angiosome of the foot. I'm not gonna go into extreme detail, but we do follow these patients very closely, and we try to identify what their on-table oxygenation changes were, what their monthly oxygenations are, and how these patients did clinically. The operator is blinded, because at this point we don't really know how to interpret the information. So we're not sharing it with anybody, we're just looking at trends of oxygen. And so here it shows very quickly how these patients have shown in these clusters, how you can actually find those that increased oxygen during the procedure improved very well. And then some clusters showing that these patients may have not necessarily done very well on the acute setting. Now, one of the things that I think will lead, and this is very preliminary data, but I would like to think that we would have some degree of information like this. This just shows on the top, your angiographic assessment, technical success, partial success, or maybe technical failure. On the y-axis, you see the looming, in other words, the oxygen change. You had a high oxygen change, a moderate oxygen change, or a low oxygen change. And if you interlace these, then you can find that these two patients probably may be seen maybe in a month, maybe in two months they did good. It's a success at all costs. Then you have this gray area where it's patients that you're not happy with the angel, but the oxygenation actually was good enough to maybe you stop the procedure, you don't push the patient, you don't give them more contrast or radiation, and reexamining the patient. Certainly in those that obviously look bad on both fronts should be immediately referred to either a bypass or a secondary procedure like arterialization. And then certainly those that may require even palliative care because they may not have any options. So who knows? This is just a very preliminary proposal of what technology that assesses perfusion may allow operators in the future to know. And I wanted to share it because I think people should follow this study as it matures because it will be the next frontier. We need more information to better take care of our patients. So Dr. Montero Baker, can you tell us what are the overall conclusions related to the topic that we just discussed? Yeah, well, what a great discussion and what great topics, but I would say I'll maybe invite you to walk through this conclusion slide that I put together. I think peripheral arterial disease has certainly devolved into a much more complicated disease pattern based primarily by severe calcification in patients that have renal failure and longstanding diabetes. I really think multidisciplinary teams are a must in order to offer good solutions. And this means collaborative and unbiased work. I really think highly trained tow and flow teams should be developed and this goes to the foot surgeon too, whoever that will be because it is not your typical foot surgery. I think revascularization techniques have evolved to treat a wider portfolio of complex lesions. I do believe classic surgery, open surgery, will continue to be mainstream. That is part of some particular cases. Advanced bidirectional and oascular therapy has certainly emerged as a safe and effective tool and no option patients, these are terializations of venous plexus, have what seems to be some strong signals, we will have to see how they do and how they pan out. We're now certainly part of some of the studies moving forward. And last but not least, least risk stratification and development of objective performance goals and profusion goals will help better delineate care of these patients in the future. Very good, excellent. Thank you very much for this very informative presentation on treatment of patients with peripheral arterial disease related to breaking the barriers in vascular interventions. We certainly hope that the individuals that are interested in this particular topic will see this of benefit and use it in their future for treatment of patients with peripheral arterial disease. Thank you very much. Thank you, Dr. Frazier. As always, it's an honor to be here with the Texas Heart Institute Group.