Arterial Thrombectomy Device Selection & Clinical Decision-Making

[Dr. Alexander Ushinsky]
Not that long ago even, the two main offerings we had on our shelves were the AngioJet, which is now by Boston Sci, and then the penumbra thrombectomy catheters, the Indigo Systems. Those were our tried and true. The nice thing about those is both those vendors have offerings for very small vessels and larger vessels. You have the 8 French AngioJet, which I don't know that a ton of people are putting in for arterial thrombectomy and the extremity, but you have all the way, and down to three or four French systems for small vessels.

AngioJet rheolytic thrombectomy has been around for quite some time. Over the wire system, the only thing that I think about is it can cause some bradycardia. We always warn our fellows about that, especially if you're using it more centrally. In our venous cases, we still use AngioJet quite a lot. Then you always warn the patient, they're going to have dark-colored urine afterwards.

To be honest, I haven't used AngioJet in an arterial thrombectomy case in a very long time because we like some of our other offerings, but I know that at some labs, that's kind of tried and true. It's been around for a very long time.

The next device that we had been using and has been on our shelf for a good while is the Indigo line from Penumbra. Again, just like AngioJet and some of the others, they have a pretty wide variety of offerings in terms of catheter size, from the smallest coming from their coronary and neurovascular lines. I think they have a 3-French version, and then going up all the way up to right now it’s 12-French. Then I think they have a 14 or 16-French offering that they're going through with a limited market release for PE. Obviously, I don't think people would use that in the lower extremity.

[Dr. Chris Beck]
Seems bold.

[Dr. Alexander Ushinsky]
The nice thing about the Penumbra system, in my opinion, and actually AngioJet is the same way, if you have the engine to pump that runs the system, you can connect any of the catheters to it. That's really nice for the lab that may be does the occasional peripheral vascular case but is otherwise a cardiology lab, but happens to have CAT RX on their shelf, you can call the rep and bring it in or just use the CAT RX, but you can call the rep and bring in the other size catheter that you may not normally keep on your shelf.

Otherwise, the system works just as you expect from your experience, whether it's in coronary thrombectomy or whether it's in venous thrombectomy. The system works the same between sizes of the catheters. We can speak more on any of these particular systems going forward and how we like to use them.

The next one that we brought on board in our lab is the offering from AngioDynamics, which is Auryon, which is a laser atherectomy system. We brought this on as an atherectomy system for chronic limb ischemia, but the two larger sides of the 6 and 7-French sizes, the 2-millimeter and 2.3-millimeter size also have a thrombectomy lumen. It's actually on label for thrombus removal thrombectomy.

We've used that really successfully in quite a number of patients because it's also approved for treatment of stent restenosis. For a lot of my patients who are coming with baseline chronic limb ischemia, may have been stented, treated in the past.

[Dr. Chris Beck]
Stent goes down?

[Dr. Alexander Ushinsky]
Exactly, the stent goes down, and the patient's foot is numb again. These are the less acute cases, the patient calls your nurse, you set them up for the next day in the lab at 8:00 AM. That has been a really nice option because it really fits the wire and catheter and Sheath profile of the way I treat chronic limb ischemia, which is much more of my volume. The other nice thing I'll say about those types of systems, and we'll talk about their competitive Rotarex in a second.

These systems that can offer both thrombectomy and atherectomy, in my mind, give you the benefit of then immediately treating not just the acute thrombus but also the underlying chronic disease that may have caused the acute thrombus to lodge. You do two aspects of the single-session treatment all at once because you're providing atherectomy plaque modification and you're providing thrombectomy at the same time.

[Dr. Chris Beck]
Well, this is one of my questions about these devices that are treating the plaque and the clot, are you getting the best of both worlds or are you getting a device that does each of them okay? Do you know what I mean?

[Dr. Alexander Ushinsky]
Yes. From my perspective, if I'm looking at the devices that only do thrombectomy, I would never say that I came away super satisfied with how a peripheral acute limb ischemia case went with those. For example, the Penumbra catheters generally are not over the wire other than cataracts. You can put a wire through it, but they're not intended to be done that way.

I can tell you that in a diseased artery, I have run into the issue where the lip of the Penumbra catheter catches on a piece of plaque, and then I'm uncomfortable. Do I push on through it? Do I pull back in turn? Am I going to embolize a little plaque? Not that you couldn't embolize a plaque with another catheter, but suffice it to say that I don't think that the pure thrombectomy systems are all that superior at thrombectomy than some of these thrombectomy atherectomy systems.

Let me give you this example. When I have done thrombectomy with the Auryon system, my blood loss is about 200 ccs. When I do thrombectomy in the extremity with the Penumbra system, my blood loss is about 200 to 300 ccs. It's sucking a similar volume of free blood and hopefully thrombus as well.

I will say that both the Penumbra system clogs and the Auryon system clogs and the Rotarex system clogs. That is a challenge with all those systems in my experience. You have to pull the catheter out, flushing on the back table, get out some chronic material, some acute material, and then reintroduce it. That's definitely a frustration of these single-session procedures.

[Dr. Chris Beck]
We've named four devices, the AngioJet, the Penumbra, the Auryon, and the Rotarex. What are you guys using most frequently? What's the go-to?

[Dr. Alexander Ushinsky]
At this point, my go-to is the Auryon. I'll give you the reasons. First of all, I use it relatively frequently in my lab for chronic limb ischemia. My techs are relatively comfortable with it and I'm relatively comfortable with it. If there's a tech who doesn't know how to use the system, I can.

[Dr. Chris Beck]
You can fill the gap.

[Dr. Alexander Ushinsky]
Yes, I can fill the gap, exactly. Then, like I mentioned, I like that it does some atherectomy and that it's approved for in stent restenosis, so I know it will, to some extent, treat some of that chronic material or chronic plaque as well. It tends to follow the guidewire pretty well, and it's on that 014 system, which is what I often use initially anyway. I usually run it in over a Spartacore Guidewire once I've gotten distal access just to have support.

[Dr. Chris Beck]
To back up, it's Glidewire Advantage to cross and then get your catheter in and then you change out for the Spartacore.

[Dr. Alexander Ushinsky]
I usually will. You can run a lot of these devices over the software Glidewire Advantage. Especially when I'm working with residents, there's a lot of wire manipulation skills that we're all still learning. I'll try to put a supportive guidewire in if I'm going to do that type of intervention for sure. I think Rotarex comes with its own 018 guidewire that you run the system over as well.

My workhorse has lately been the Auryon. The other thing I'll say that's nice about that system is it's relatively easy to switch catheters. I've been in this situation where I've chosen the larger thrombectomy catheter, the 7-French, and it has trouble getting through, catches on the edge of the stench or something like this, or there's a really severe chronic stenosis.

I'll take that out and downsize to a smaller catheter and then the system's still running. It's pretty easy to hot-swap your catheters. Once you use it, you don't have to toss it. You can put it right back into the machine and reuse it afterwards once you've treated the severe stenosis with a smaller catheter, for example.

[Dr. Chris Beck]
Is it one of the systems where I haven't used it, so pardon me if this becomes a dumb question. Is it one of the ones where it's pulling out into a canister and you have the clot shot afterwards?

[Dr. Alexander Ushinsky]
It does pull out into a canister. It looks just like the wall suction canisters that you see in the patient's room that they use for like the Yankauer suction. For that system, you have two sizes that do not do thrombectomy and two sizes that offer thrombectomy plus atherectomy with laser fibers along the edge of the catheter lumen. Then the inner lumen is a suction. That goes to a little thrombectomy canister that sits on the machine.

I will say that the clot picture afterwards is never all that impressive. Really, the best clot picture that you get is when you flush the catheter on table and sometimes you get this kind of chronic yellow material, especially from that in stent restenosis. That's not the same as the atheroembolis, but I try to advise my fellows not to play into that social media clot picture.

[Dr. Chris Beck]
Sure, right.

[Dr. Alexander Ushinsky]
Whose-clot-is-bigger game. I don't know.

[Dr. Chris Beck]
That's not helpful. That's not moving the ALI service.

[Dr. Alexander Ushinsky]
We can all put pretty pictures on social media, but the real goal is to provide useful and good patient care. I think that should be where our focus is, I hope.

[Dr. Chris Beck]
Actually, it segues nicely into one of the topics on the outline is endpoint. When are you done? Is it angiographic? Is it clinical? Is it a combination? Speak to that, but dig in a little bit further like, when is the case over whether a case you're succeeding or a case that you're succeeding at failing?

[Dr. Alexander Ushinsky]
The most important question is, how is the patient doing? There've been a couple cases where I've been doing a chronic limb ischemia case that becomes an acute limb ischemia case, and very quickly the patient is not doing well. You need to assess how quickly I can fix the immediate problem, and can I get the patient's pain under control and the patient comfortable enough to continue the procedure. We alluded to some of this earlier when we were discussing who is well-suited for an anesthesia or a deep sedation case.

Aside from that circumstance, as we're doing the procedure, my general practice is I'll pass my desired thrombectomy device a couple times and I'll assess if I'm now drawing good blood from the thrombectomy lumen. You can also get a lot of tactile sensation from some of the devices. Is it flowing through freely? For example, the AngioDynamics, the Auryon device, when it's in plaque or thrombus, there's an audible noise that comes from the catheter, maybe from the laser energy that becomes duller. Then when it's in a free lumen, it becomes sharper and easier to hear.

I use that to tip me off. If that span that is dull sounding is becoming shorter and shorter and shorter, I know that I've created some patent lumen channel. When you get some tactile and auditory feedback from the Rotarex device in that regard as well. Once I've done a few passes with these devices, I'll shoot an angiogram and see what I have. To be honest, almost always, what I end up seeing is two, three-millimeter patent lumen with some residual chronic or acute thrombus. Then if I'm unlucky, what I see is some embolus that has maybe gone down to a tubule. That's usually a point where I stop and reassess.

If I've made a really decent channel and there's no off-target embolization, I'll proceed to treating the residual chronic and maybe some acute disease. I'll usually do balloon angioplasty and possibly stenting. If needed, if there's really a chunky chronic thrombus. I've been in a couple situations where there's in-stent restenosis with this rubbery chronic material. In those cases, I'll use a stent graft to exclude that or sometimes a stent to exclude that. Otherwise, I treat the residual underlying disease most often with just balloon angioplasty.

In the setting where there's maybe some distal embolization, depending on what thrombectomy device I'm using, we have some options to go ahead and tackle the tubules. I probably would be hesitant to take the larger thrombectomy catheters from Auryon into a tubule, the 2-millimeter and the 2.3-millimeter. I'll use some of the laser catheters that are more intended for chronic limb ischemia and chronic plaque, the smaller catheters, which are intended and sized for the tubules, and take those down there and see if I can just burn through this chronic plaque.

With some of the other devices with Penumbra, you have another option, which is I think 5 French. Then the catheter 3 from the neurovascular side, which you can pretty safely take down into the tubules to try to thrombectomize those, same with the angiogram. You have that smaller omni, the small size.

Then, honestly, if there's not a massive acute thrombotic burden, I tend to have a good result with just plain or balloon angioplasty to try to macerate that thrombus and get it cleared up. If I'm able to achieve all that, my goal is to get a good angiographic endpoint as long as the patient is comfortable.

[Dr. Chris Beck]
How aggressive do you have to be for maybe the uninitiated? If you've got some distal emboli, which clots do you have to go after and which clots can you say, "We're going to heparinize them and it's going to take care of this stuff?" Can you talk a little bit about flow limiting or the degree of inclusiveness that prompts you to say, "Now we have to go and intervene further?"

[Dr. Alexander Ushinsky]
In the tubule space, if you have some embolization to the tubules, the initial question is, what's the baseline status of the tubules? In a patient with pretty severe arterial disease and maybe one or two vessel runoff below the knee, there may not be much tolerance for a small amount of embolus. Now, we have the technology to go all the way through the pedal plantar loop and perform thrombectomy. If it is an acute thrombus, it's pretty easy to get down there and to try to treat the acute thrombus.

If, on the other hand, it's a patient with a pretty healthy-looking runoff, three vessels, not a lot of arterial disease and there's a small thrombotic burden, I think it's reasonable to consider heparinization, especially in light of how long the procedure may or may not have taken up to that point.

To go after chase, perfect is the enemy of good, is the saying. To avoid a very lengthy and involved procedure with increasing risk of morbidity, it's pretty reasonable in a patient with good runoff to leave a little bit of tubule thrombus that the body can normally clean up.