Wael Tawfick, MB BCh, MRCSI discusses lower extremity revascularization procedures in diabetic patients with critical limb ischemia as well as outcomes following those procedures.
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Wael Ahmed Tawfick, MB BCh, MRCSI has nothing to disclose.
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Mike: Our next speaker, also from Galway, will shed some more light on the – what our vascular colleagues can do for us. I think a theme of this meeting and any – certainly any wound care meeting is the need for a close working relationship with our vascular colleagues who can get blood down there. I always like to say that, you know, “If there’s blood there, I think we can heal most things.” But the one factor that you can’t get around is no blood.
So it’s truly amazing, the techniques, and the innovations, and the technologies that have evolved over the last few years, that can open up a lot of reason and revascularize our limbs that in the years past, clearly would have been amputated.
And so, it’s my pleasure to bring up Wael Tawfick from – a vascular surgeon in Ireland. Wael has a special interest in wound management of leg ulcers. He has conducted a few studies in the use of oxygen in the management of ulcers and is currently conducting RCT or randomized controlled trial on the use of negative pressure in the management of venous ulcers. He has a particular interest in the role of tibial vessel revascularization, something that’s near and dear to our hearts and our neck of the woods and that role in healing of foot ulcers.
So, Wael, please come up and give us your perspective. Thank you.
Wael Tawfick: Thank you very much, Mike, for the nice introduction and thank you for having me and for the kind opportunity to present here today.
And as you’ve heard, I do have a special interest in ulceration and wound management. But today, my talk is mainly going to be on revascularization. So I’m going to concentrate on my vascular surgery skills and talk mainly about revascularization, especially in diabetic patients.
So our main objective here today is going to be to try and formulate an approach to planning of revascularization procedures in diabetic foot ulcer patients. Patients with diabetic foot ulcers, a lot of them have associated peripheral arterial disease.
That’s just part and parcel of the pathology. In fact, 50% of patients with diabetic foot ulcers have associated peripheral arterial disease. And the main issue here is that by the time most patients are diagnosed, especially type 2 diabetes – so by the time they are diagnosed, 50% of these type 2 diabetic patients already have established complications of diabetes. So they already have their neuropathy, they already have retinopathy and nephropathy, and more importantly, at least from my perspective, that the peripheral arterial disease has already set in by the time these patients are picked up and diagnosed.
So although we try and say that prevention is the best approach to management, but sometimes it can be a bit difficult to even prevent these patients from developing a PAD because they already have it by the time they are diagnosed.
And the main problem here is once a patient with a DFU has developed peripheral arterial disease, the peripheral arterial disease in itself and on its own, is an independent risk factor for major amputation, and it’s also associated with a high risk of failure for the ulcers to heal.
Well, we could argue then, well, the option would be, “Why don’t we just revascularize them, that should solve the problem. Once we improve their circulation, everything will be brilliant.” But things are not that straightforward. The type of lesions that we get in diabetic foot ulcers or in diabetic patients, we’ve got extensively calcified tibial disease, which for any vascular surgeon, that is the most difficult kind of pathology that we can deal with. So the outcomes of the revascularization itself can be a bit unpredictable.
So looking at a review article from King’s College in London, we can see that patients with diabetic foot ulcers with associated peripheral arterial disease, that have already been revascularized and their ulcers have already healed. You go and follow those patients up, 40% of those patients, within one year will have a recurrence. So the outcomes of revascularization are not really that predictable. And a lot of these patients will require an amputation even in the presence of a patent bypass graft or a patent vessel.
And that’s down to the multifactorial reason for why these patients develop DFUs in the first place. So, yes, diabetes, it is associated with macro vascular disease or peripheral arterial disease. And the ischemia from that can lead to an ulceration. But is that the only cause for ulceration? Definitely not. The micro vascular disease, the edema, the infection, the abnormal mechanical loading, all of those combined together to forming a DFU.
So if we’re going to concentrate on just the revascularization alone, which is probably my part or the easy part and ignore all the rest, these patients will not do well.
So it has to be a holistic approach and it has to be a multidisciplinary approach.
When we think of DFUs, this is what comes to mind, the small ulcers. But we have to remember that if we do not approach these patients properly, this is what could end up happening. In fact, every year over one million people with diabetes suffer a limb loss. And what we mean by limb loss, we’re talking about a major amputation.
And that’s the reason why if you look at any guidelines, be it the NICE guidelines, be it the Scottish healthcare guidelines, be it whatever guidelines you’re going to look at, they more or less all agree on the one thing, any person presenting with a diabetic foot ulcer should be thoroughly assessed and investigated for the presence of peripheral arterial disease. When? At the time of their very first presentation.
Now, how are we going to do that? We can – we have many tools to assess the patient from a vascular point of view and I don’t want to go into these in details because we can all agree that there’s a lot of debate about how reliable most of these tools are, especially in diabetic patients. But the bottom line is patients need to be assessed for vascular insufficiency at their first presentation with the DFU.
Now, do we need to revascularize every single diabetic patient who has PAD, who has peripheral arterial disease? Well, not according to the Society of Vascular Surgery and the American Podiatric Medical Association. In fact, the recommendation is against prophylactic arterial revascularization, just to prevent the patient from developing a DFU.
And the rationale behind that is that most primary foot observations in these patients would be due to diabetic neuropathy. They’re unlikely to be directly related to an impaired large artery blood flow. And the neuropathy of diabetes, it’s not actually an ischemic process, and there’s no evidence to support that if you revascularize these patients that it will reverse their ischemic neuropathy.
So ideally, what we should do is we look at patients who are diabetic, once they actually, and obviously, once they – if they are diabetic, we are going to assess them from a vascular point of view, but if they do – once they do develop a diabetic foot ulcer, and they have established peripheral arterial disease, then the recommendation becomes that we should revascularize these patients, regardless of the approach, be it a bypass or endovascular therapy.
So you see a patient like this, and they have ischemia – regardless of the segment, I would agree that most diabetic patients would be in the tibial segment, but still some of them could also have associated peripheral arterial disease, and not necessarily relates to their diabetes. So they could have aortoiliac, they could have femoropopliteal segment disease. And that’s mainly down to the fact that the risk factors for diabetes, and the risk factors for peripheral artery disease, they quite often overlap.
So once you have a patient with an established DFU and established PAD, then at that stage, the recommendation becomes that we should revascularize these patient and revascularization becomes well justified. How are we going to revascularize these patients?
Currently, I mean, we’re 2018 now, so we’re trying to shift away from open procedures. Everything is shifting from invasive or minimally invasive investigations to – towards non-invasive investigations. Even interventions, we’re moving from major interventions, or from open surgery towards more minimally invasive interventions. So angioplasty is now becoming the goal standard. But is angioplasty the solution and the answer for every single patient with diabetic foot ulcers?
Well, not according to the BASIL trial. The BASIL trial, comparing bypasses versus angioplasty. One of the words of caution were that if you do an angioplasty and you don’t get a good outcome, then your subsequent bypass after that failed angioplasty, actually has a significantly worse outcome than if you had done the bypass in the first instance, so we have to be very, very careful with how we’re going to approach this patient, and we’re going to decide which procedure for which patient.
Now, having said that, I would take that with a pinch of salt because the BASIL trial, it is quite dated back in 2004. So we’re nearly 15 years later, the technology has changed, and the techniques have changed, and currently BASIL-2 and BASIL-3 are still underway, so we still don’t have the results for those. They are even still recruiting. But with that, we have new techniques and new things that we could use when it comes to angioplasty. And the one word of caution when it comes to doing bypasses in diabetic foot ulcers is these patients have a much, much higher risk of infection, especially, graft infection following a bypass.
So, realistically speaking, in diabetic patients, especially those with DFUs, I would try as hard as I can to do an angioplasty before approaching or attempting to do a bypass.
What options do we have? They are different tools that we can use. We can do a subintimal angioplasty, which even from our own results, in long segments, so in TASC D lesions, so long occlusion, what we found is that subintimal angioplasty has similar outcomes when it comes to succinct clinical improvement, when it comes to five-year amputation free survival as well, in comparison to a bypass.
So what is a subintimal angioplasty? It’s basically that we try and move our way in the subintimal planes, so we go with our wire just between the intima and the media, and once we – you manage to go through with the wire, and through there, you advance your balloon, and what that does, once you’ve advanced your balloon, it kind of rams the plaque against the wall and creating a new lumen. So, effectively, you are creating a dissection plane.
So an example here is a patient who, as you can see here, had a peroneal vessel, and basically, nothing else. So it’s a very long occlusion which we have managed to go subintimally, and you can see here now that this patient has the posterior tibial as well, so at least we’ve managed to get something all the way down below the ankle.
Another patient here who, as you can see has a tibial-peroneal trunk, and nearly nothing else, whereas after subintimal angioplasty, we’ve managed to at least open a peroneal.
Now, this isn’t really ideal. Ideally, we would have been looking to treat either an AT or posterior tibial, and I personally try to work according to the affected angiosome. But sometimes, it’s not really an option, depending of what you can or cannot do.
Now, the issue with subintimal angioplasty, as we said, is that you are creating a dissection plane. And dissection planes in tibial vessels, you are at a very, very high risk of perforation or even thrombosing the vessel altogether, because they are small vessels and they are quite diseased with heavy calcification. So it’s not really ideal to do a subintimal angioplasty in a heavy calcified vessel. But do we have other option? We actually have plenty of other options. One of them would be a trans-collateral approach. With the trans-collateral approach, we go down into one of the collaterals, so basically, you are bypassing the occlusion altogether and you’re angioplasting the collateral to get back into the main vessel again.
Another approach, it would be what we would call the SAFARI technique. And the SAFARI technique is kind of still a subintimal arterial flossing, but we’re using an antegrade and a retrograde approach. So rather than going all the way down subintimally, you’re going with a wire from above and a wire from below and you meet in the middle.
So you can see, you go with a wire from above and then a wire from below. And once you meet in the middle, you go with a balloon from above, a balloon from below, and that would help disrupt the plaque and open the lumen. In a way, you are kind of, minimizing the length of the dissection that you’re going to do before you reenter back into the vessel. So you’re only dealing with the actual lesion itself.
So this is an 82-year-old gentleman type 2 diabetic. The main issue with this gentlemen was he had sustained a stroke about four years prior to his presentation, and he had full right-sided paralysis, so he was wheelchair bound. And this gentleman was using his left leg for support from bed to chair. He was being held from bed to chair, so you can understand that his left leg here is quite important for him.
And this is what he presents with. The picture itself doesn’t really do it much justice but if you try and concentrate a little bit here, he actually had an abscess around the area of his first metatarsal head. And he was quite unwell. He had a temperature 102, he was tachycardic, elevated white cells, elevated C-reactive protein. He was starting to become septic, so we needed to do something, and we needed to do something quickly. And his MRA showed that he had an anterior tibial artery and more less nothing else, but his AT was only reaching to the level of the ankle and not progressing beyond that, so that was no good for us.
Now, we had a lengthy discussion with this gentleman and with his family, and what they were quiet adamant about was they did not want multiple procedures. What I was trying to suggest was “Let’s drain the abscess, let’s do an angioplasty, let that heal, and then we will deal with the foot as we deem fit after things settle.” But he was quite adamant that he did not want that. He wanted a definitive procedure, he wanted one single trip to theatre, he does not want to go back to theatre again.
And with the understanding that that might mean that he would end up with the transmetatarsal amputation, he actually was quite happy with that. He said, “I would rather have that than going back and forth to theatre.” And his family were encouraging him with that as well on the basis that he was quite frail.
So we agreed to do that, as in we would do an angioplasty and then do a transmetatarsal amputation for him. And you can see the anterior tibial artery that was already patent and already opened. But we’ve managed to go down with our wire, all the way down to posterior tibial. You can see the balloon there just at the level of the ankle there, and we’ve done multiple attempts of ballooning here. But what you’re going to see here is that he has flow down to the heel but nothing beyond that. So we were still not happy that this actually would eventually heal, that his transmetatarsal amputation would heal.
So what we ended up doing is we did the transmetatarsal amputation and did a retrograde approach of what we would call the SAFARI approach. Now, normally, I would go with the wire percutaneously, but as we already had the wound open in front of us at the time, we went with the wire through a digital vessel retrograde into the arch, and we managed to open the arch until to let the wound heal.
Other options, we can use drug-eluting balloons, very famous in the coronary area, and more recently now, starting to become more common in the peripheral arena as well. So drug-eluting balloons, they deliver a drug, paclitaxel, to the endoluminal surface of the artery, and that gets absorbed into the muscle there of the vessel, into the media. And this inhibits smooth muscle cell proliferation, and it helps inhibit myointimal hyperplasia. And as such, what that does is that it potentially will prevent restenosis. So you have less restenosis rates with drug-eluting balloons.
Another gentleman type 2 diabetic who was quite independent up until five months prior to his presentation, he was a known arteriopath. He already had a previous angioplasty, a stenting of his right external iliac, his left common iliac, and his left superficial femoral artery. And when he presented, he had rest pain, so he was already in critical limb ischemia at that stage as well as a heel ulcer. And if you look at the heel ulcer, it was basically a gangrenous left heel ulcer. He had a thick – a flexion of his left knee, but it wasn’t a fixed flexion.
So we investigated him further. There were no signs of any obvious osteomyelitis, so we were happy to proceed with an angioplasty. Now I know the images are great but if you try and concentrate here, you’ll see the stent, and you can see that there is an in-stent restenosis in his previous SFA stent or the superficial femoral sent.
So looking at the guidelines, the European Society for Vascular Surgery guidelines, if a patient has a drug-eluting balloons – if a patient has an in-stent restenosis, the guidelines would recommend using a drug-eluting balloon. And that’s a level 2-B evidence.
So his iliac segment was fine, but if you look over here, you can see the stent, and you can see there’s no flow going through the stent in his superficial femoral artery. So there’s flow until there, and then the stent itself is more or less nearly occluded. So we used the drug-eluting balloon, we went through the stent with the drug-eluting balloon, and you can see it inflated there. And after the first inflation, we’re starting to get a good result, and we’re starting to get a flow but it’s still not ideal. So after a second inflation of the drug-eluting balloon, you can see now we have a great outcome.
And this patient, post-operatively, he had a palpable dorsalis pedis pulse and his – the toe pressure increased from 16 mmHg to 40 mmHg. Obviously, we still needed to deal with the gangrenous patch. That was debrided and he was managed with negative pressure therapy.
So drug eluting balloons, what’s the evidence behind them in peripheral arterial disease? According to systematic reviews, do they work? Yet they have less re-intervention rates, so less restenosis rate. They’re safe. But according to the current evidence, there’s no significant difference in major amputation and mortality rates between drug-eluting balloons and your standard balloon angioplasty.
But again, that was according to pool data from a systematic review. But sometimes it might be a little bit beneficial to look at what each one of those studies was looking at. And in fact, if you look at the studies that were dedicated to diabetic patients with below-knee lesions – so the debate BTK study which was dedicated to patients who are diabetic with critical limb ischemia with below the knee lesions, they found that drug-eluting balloons had strikingly reduced one year restenosis rates, target lesion revascularizations, and target vessel occlusions in comparison to standard angioplasty in this particular cohort of patients.
Other options that we have, we can use cool excimer laser. This is something that was in fashion up until the turn of the century and then it kind of disappeared. And it’s starting to come back in vogue again as the technology starts to improve.
It works on the concept of photo-acoustic and photo-chemical and photo-mechanical pulse waves that disrupt the plaque. So you can actually traverse through the plaque and go through it, and then go in with – once you’ve created your lumen, you go with your balloon and you can open up your vessel.
One example here is a gentleman, a type 2 diabetic. And as you can see, the lesion on his first and second toes. Now, this gentleman, he had anterior tibial artery stenosis, and it was fairly occluded. And you probably might actually wonder, is that really patent or not on the CT? I don’t know if it’s that obvious or not, but in fact, it’s not patent, it’s heavily calcified.
So what we did is we went down with our laser all the way down the anterior tibial, all the way down to the ankle. So we have managed to open with the laser using a 1.7 probe all the way down to the dorsalis pedis.
Our completion angio shows that the dorsalis pedis was patent. However, it kind of had an abrupt stop after that. It’s very difficult to use laser on the dorsum of the foot, so we ended up just doing an angioplasty through the plantar arch, all the way back up, opening a second vessel. And as you can see, through a retrograde approach, we’ve managed to open our second vessel as well to make sure our arch is open.
We ran a study over in Galway where we compared traditional angioplasty in tibial vessels in comparison to cool excimer laser-assisted angioplasty. Our primary endpoint was sustained clinical improvement. Our secondary endpoints were binary stenosis rates, target lesion revascularizations, amputation-free survival, and survival-free from major adverse events.
So over a course of five years, over 400 patients who had undergone procedures for critical limb ischemia, 80 patients with tibial disease were recruited in that study and underwent 89 procedures. And they were randomized into either tibial angioplasty or into excimer laser-assisted angioplasty. They were all managed with dual antiplatelet therapy and followed up at six weeks, three months, and then six-monthly thereafter.
You can see, there was no difference in both groups regarding their demographics, and there was no difference in both groups regarding their vascular risk factors. Now, I have to mention, this was not – the study itself wasn’t designed particularly for diabetic patients, but just because of the fact that we’re dealing with tibial disease, you can see that diabetes was about 80% in both groups, so most of our patients were diabetics. And all of them had critical limb ischemia, so they were Rutherford 4 or higher, and there was no difference in their ABIs or digital pressures. And even anatomically, there was no difference between both groups regarding the number of lesions, be it exclusive lesions, Denovo lesions, or calcified lesions, and there’s no difference in even proximal concominant disease. So the vascular load of both groups was fairly similar.
And looking at the outcomes, the major amputation rates were similar and comparable in both groups and was not significantly different. But more importantly, the clinical outcomes, the clinical improvement to Rutherford category 3, so you’re shifting them out from rest pain to a Rutherford 3, was significantly higher in the laser group as well as hemodynamic success being significantly higher in the laser group as well.
Did that transfer on further? It did.
So at five years, sustained clinical improvement was significantly higher in the laser group than the traditional angioplasty group. And the restenosis rates, they were in favor of the laser group albeit not significantly. However, the number of times these patients require the revascularization was significantly less in the laser group.
Overall, amputation-free survival was not different between both groups. But if you look at the numbers, we’re talking at five years, 88% and 91% free from major amputation.
So in conclusion, there are multiple modalities that we can use when it comes to angioplasty in diabetic foot ulceration. But it comes down to the appropriate decision-making and trying to decide and tailor per patient what is more appropriate for each and every patient. If someone has a hard plaque or a calcific plaque, I probably personally would be more inclined to use the laser versus if someone has an echolucent plaque, I would be more inclined to do a SAFARI technique or a subintimal angioplasty. And if they have a long lesion or an in-stent restenosis, I would use a drug-eluting balloon.
So it’s horses for courses. You have to know your lesion and you have to know how you’re going to approach your patient in order to get the best outcome individually for each individual patient. And going back again in the end to the same review article from Kings College, we have to remember that DFU is multifactorial. So just by revascularizing alone, that’s only one part. So it’s only one hurdle that we need to overcome. But beyond the revascularization, the work starts into trying to see how we’re going to salvage that foot, how are we going to salvage that limb by addressing the other factors, the infection, the edema, the microvascular disease, and the mechanical problems.
Thank you very much. And again, I would like to invite you all, as Caroline mentioned, to our Transatlantic Wound meeting in Galway in 2020, which, as you’ve already heard, is going to be our European Capital of Culture in the year 2020. Thank you.
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