So theory. There's two primary factors that determine how much force is required to remove the thrombus. There's the force of impaction, which is the force across the thrombus. So it's a systemic pressure proximal to the thrombus
minus the pressure retrograde flow distal to the thrombus. Then there's the force of friction and adhesion between the thrombus and the vessel wall. So you can see in this little diagram here that the, is there a pointer here Sam? So the green arrow is the force of retrieval
from the stent retriever and then the P is the proximal pressure and the D is the distal pressure. So the gradient across that will affect the retrieval rate of the thrombus, then there's the friction force with the adhesion with the thrombus versus the vessel wall. So these are very important in trying
to get out the thrombus. If you look at some of the literature, the decreased rate of success with worse collaterals, that makes sense because the pressure's gonna be lower on the opposite side so you're gonna have a higher pressure gradient.
If you have fibrin rich thrombi you're actually gonna have a harder time pulling out the thrombus because you have more higher coefficient static friction. If the thrombus length is longer you're gonna have a greater frictional force, so you're gonna have a hard time pulling it out.
It's basically based on that little diagram there. So if you ingrain that little diagram in your head you can come up with a nice device and make a lot of money in how to pull out thrombus, although the devices are pretty good. Basically what we want to do is we want to optimize
the stent retriever integration with the thrombus. That green line here is the force retrieval is what we wanna maximize. So you wanna properly position the stent across the thrombus. You wanna use the close cell stent
because it integrates within the clot a little bit better. You wanna push that out so it integrates in the clot. You wanna leave the thrombus integration about five minutes after deployment. A lot of the current stents they have a radial force for integration, but they aren't that strong.
If you actually take them out on the table and press them, they aren't really that strong. There's a couple companies that are coming out with new stents with a little bit more radial force.
Another thing we use is intermediate catheter for local aspiration.
Basically it has a strong suction force right at the thrombus where you can remove. That's called the ADAPT technique, which I'll go over later. Basically you want the largest catheter you can get up there right near the thrombus because it'll decrease the impact force
proximal to the thrombus, and it's a relationship to the percentage to the vessel lumen cross-sectional area that occupies the catheter, so it'll actually decrease the pressure right where the thrombus is so you'll actually have a pressure gradient across the thrombus to actually be able to pull it out faster, like in that little diagram.
As you come into the thrombus the pressure will actually come down until the pressure head actually comes out or zero and then basically the thrombus is within the catheter and then you can pull it out. The problem is you don't want to try
and over suction the clot because then it can fragment.
Another device which we use is a balloon guide catheter. Basically what it does is it reduces the impact force on the thrombus, so you get more effective retrieval. It also minimizes fragmentation and distal embolization. You might not be able to get this if you have a Pcomm,
so if you have a flow coming in from the Pcomm you might not be able to get total flow occlusion. There's some data that actually suggests that if you get the guide catheter really high and you have flow occlusion, you can actually aspirate the thrombus out from the M1.
There's several studies now that have shown that a balloon guide with a stent improves revascularization. There are shorter procedural times and there's actually better clinical outcomes. People have went on further to combine stent retrieval
with local aspiration. Basically what it does is it increases the retrieval force that can be generated on the thrombus. You wanna have that F, that green line, as high as you can get it. It also diminishes the line-of-force where you have
the S-configuration with the carotid and the M1 segment. I'll show a little diagram a little later on that. Also what you want to do is when you pull the stent in you don't only wanna pull it in about 25% with the stent in the aspiration catheter 'cause then you don't get any fragment of the thrombus.
You do not want to pull the stent retriever directly in all the way in to the intermediate catheter. Sometimes it can be impossible, especially if the thrombus is very fibrin. It can actually be harder to pull it into the guide catheter and the partial capture technique I think is preferable
because you don't get any distal embolization. So this is a little diagram here. The two top slides on top, A and B there, which you can see I don't have a pointer unfortunately, it's just with a microcatheter. So where that arrow is and that little dotted arrow
on the upper part there, there's a gap in between there, so the vector forces are not strong to pull that clot where they just have a microcatheter with a stent retriever. If you get a intermediate catheter, like the two slides are down below, you can see that
there's no gap in that M1 segment. So this is that S-configuration I'm talking about on the prior slide.
This is just a little diagram showing that as you pull in the clot, if it's very fibrin you're gonna get a lot of shearing and then it'll actually
go around, the catheter will actually go around the stent and you'll get disembolization. So you don't wanna pull the stent completely in to the guide catheter, you're gonna get a lot of shearing and you're gonna get distal embolization into the anterior cerebral artery circulation
and the MCA, which you don't want. Another factor about the procedure, there's frictional adhesion forces with the thrombus of the vessel wall. So you want to minimize the procedural manipulations because then there's so interaction with the thrombus
of the vessel wall and as you pull it out you want to overcome the static friction so the thrombus is actually within the vessel wall and as you have the stent retrieval with intermediate catheter you wanna pull it out as one because you want the kinetic friction you want to have
greater than the static friction of the thrombus actually within the vessel. If you stop it's very hard to then overcome that. So you wanna pull out the stent retriever and the intermediate catheter all as one in a continuous motion into the guide catheter.
The other issue is that if you keep going up into the thrombus, if you can't remove it out, you're get impaction of the thrombus and it's gonna be very hard to take that thrombus out. This is just a little diagram here where you can see the friction goes up as the clot gets compressed,
so if you go in there multiple times, the clot's gonna get compressed, you're gonna have more friction. You can actually have a harder time getting the clot out. The little diagram on the bottom is just basically a flow model where it shows that the clot, they try to recapture this clot in a flow model three times.
You can see that the clot on the far end got compressed. We actually have a lot of really good techniques, but I think we can actually get them better. We basically wanna identify the techniques that maximize first pass success. These are very important because if you get compaction
it gets harder to get the thrombus out, so you just want to go up there one time and pull it out. If the clot remains in place for a longer period of time is actually more difficult to remove the clot because there's a compressor from the water-hammer effect on the systolic blood pressure.
This might have some implications for a thrombectomy greater than six hours out, although the data, the DIFFUSE and the DAWN trial did hammer that point home.
None of the trials talk about removal of embolization from the distal M2 segment. There are three millimeter stent retrievers
where it can actually do a thrombectomy with an anterior cerebral artery and there's a high revascularization rate with low complications. If you start going into the PCA and the MCA, there's a little bit of a higher incidence
of focal subarachnoid hemorrhage and you can get perforation which obviously you don't want. It's actually pretty interesting, if you take some of these thrombectomy devices up in the distal MCA the vessel will actually straighten out which I always start to panic when that happens.
If you look at the literature the most important area that damage is where the frontal operculum is where it actually goes over into the frontal operculum. That's where you have a big problem there. Distal fragmentation you can actually use IA tPA. The doses are about 10 milligrams.
I wouldn't go anything about 10 milligrams. Then there's some small series that you can give the gluco IIb/IIIa inhibitors to actually clear out thrombus if you have distal embolization. Those have been shown to be safe in small series.
So some of the endovascular trials.
This slide's pretty busy here, but if you just look at the red line there, you can see that the MRS at 90 days the line where the stars are means that it's statistically significant. It was basically the difference between the MRS with medical therapy
minus with thrombectomy. You can see that the thrombectomy rate rates the MRS at 90 days ranges from 30%, up to 43%, up to 54% versus anywhere from 20 to 12% with a medical therapy group. These are two recent trials. These are late thrombectomy trials, out six to 24 hours
and six to 12 hours, the DAWN trial which was published in January this year in the New England Journal of Medicine and the DIFFUSE 3 came out, I think, the end of February. They basically used the RAPID software, so I don't know if you guys are doing stroke.
The RAPID software is really nice. You do a perfusion then you get all these maps and it's easy to tell what's Core versus Penumbra and what the ratio is. So you can see in the DAWN trial the time window was six to 24 hours or diffuse three to a six or 16 hours.
The groups were pretty much equally matched. The mean on age stroke scale was about 17 in both groups. The mean time to intervention was about 13 hours in both groups. In the DAWN trial they predominantly used a Trivo stent retriever where the DIFFUSE 3 basically used
anything, they could use any type of stent retriever or aspiration alone. So aspiration alone was done in 25 of those cases. You can see that the MRS, which is patient is functionally independent in 90 days was 49% in the treatment group,
versus 13% in the medical group for DAWN, and similar with DIFFUSE, so these are positive studies. I think we're gonna take everybody to the lab 24 hours out from an acute stroke. We might be able to take out patients longer than that, if they have a good perfusion profile.
So this all the theory, the theory and all the data basically. So we're gonna get down to how to do the procedures. You go and evaluate the patient. There's anesthesia issues. We're lucky, we have anesthesia right in our lab
readily available, so we can put the patient under really, really fast. We're actually really, really lucky. This is a meta analysis which basically took all the general anesthesia versus conscious sedation groups.
This is a busy slide, but you basically just want to look at the bottom there, where the good outcome was basically similar to conscious sedation versus general anesthesia, and the successful reperfusion. was basically the same conscious sedation versus general anesthesia.
GA is general anesthesia and conscious sedation is CS. Then you just wanna look at the bottom line here. The procedural complications were basically the same. The anesthetic complications were similar. There was a higher incidence in pneumonia with general anesthesia there.
The symptomatic intercranial hemorrhage rate was roughly similar and the 30 month mortality was the same. I don't think the data's out about which if you should put the patient under conscious sedation versus general anesthesia. So there's issues.
We try and do all the patients under conscious sedation, if we can. It just goes a lot faster. This is just a summary of the data. The success reperfusion was the same. The neurological condition 24 hours was the same.
Functional independence at three months was the same. There was a higher rate of pneumonia in the general anesthetic group. If the patient gets on your lab and they're just moving around, we'll just put them out immediately.
It just makes the procedure go way faster than trying to fight them. You're trying to pull this thrombectomy device and the guy's going like this on the table. It can be very nerve wracking. So any movement, uncooperative patient, we'll just
put them under general right away. Posterior circulation stroke, you want to probably put the patient under general anesthesia right away because there could be issues with airway issues. If they lose their airway issues while you have a stent retriever up there that's really bad.
So all the posterior circulation strokes we usually put under general anesthesia. You wanna also tell the general anesthesia people to not induce with the patient hypotensive. So you wanna keep the blood pressure up. Pretty much all of them know that.
The only problem with the general anesthesia is usually the loss of the neurological exam.
So we have the patient come into our lab. We usually get a CTA with a CT perfusion. CTA is done in the emergency room. You wanna look at the aortic arch.
If it's a type one, type two. You wanna look at the carotid arteries/vertebral artery tortuosity, see if there's calcification, atherosclerotic plaque in any of the arteries. Access, we usually go common femoral in the majority
of the patients, although we've done direct carotid access in, I think, about eight patients, radial access. We usually use ultrasound on all our accesses. Single wall, 21-gauge micropuncture kit. If the artery's really, really severely calcified we'll use a 19-gauge single-wall
so you can get a larger guide wire in there, stiff wire Amplatz wire to actually dilate it up. Sometimes that helps.
Common femoral, if there's tortuosity of the iliac or abdominal aorta we'll just put a long sheath in right way, about a 45 cm sheath to get you up
to the diaphragm, so you can actually torque the catheter a lot better. We'll also usually put in a 9-French sheath in the groin so that we aren't screwing around trying to get an arterial line to measure the patient's blood pressure. I just like it.
I tell Anesthesia that when they come in the room we'll get you an arterial line so that they can monitor the patient's blood pressure, then they get an arterial line in the wrist under elective procedure. We commonly just place a 24-French sheath,
or put 24 cm sheath in the common femoral just to throughout the tortuosity of the iliacs 'cause a lot of these patients are very, very old.
Direct access. We're usually trying to just put a 6-French sheath in, a short one 13 cm in length.
You wanna puncture low on the neck just below the level of the clavicle. It gives enough length so that you're not puncturing near the carotid bifurcation, and with a 6-French sheath you can do carotid stenting through it. It'll actually accept an ACE64 aspiration catheter
through the sheath. I've actually put an 8-French sheath in the carotid direct puncture and not had a problem, but I get a little leery when that happens. I wanna make sure that the sheath is sutured in place 'cause it's a short sheath
and you can't really see that well up there, so it could easily come out, so we'll always usually suture them in place. It can be done under general anesthesia or conscious sedation. I think we've done about half and half
under conscious or general. If you're gonna stent you might want to put in the Oregon sheath where you can actually take off the valve and then put a Y adaptor on it. It allows that the stent's not gonna move back and forth through the valve, so if we're gonna do that
I'll usually put an Oregon sheath in. It's a lot easier to perform carotid stenting from the neck down.
A radio access, there's limits in the size of the sheath that you can put in. Usually it's a 6-French in a female, 7-French in a male.
You put the wrist out, a lot of people do on radial access in their place. You want to do a Barbeau's test, put some nitropaste/ELMA cream on it, and then there's radial access kits. The Merit and Terumo radial access kit.
Once you get in, this is a drug cocktail we give. It's 200 micrograms nitroglycerin, 2.5 milligrams verapamil, 3,000 units of heparin. Do not make an incision where you puncture because the sheath will come out. It's very, very hydrophilic.
It's amazing how fast that sheath will come out if you don't tape it down and secure it. Do not connect the sheath to the flush. You'll get ischemia of the hand. So that's a very important point. Do not take that sheath to a flush,
you'll get ischemia of the hand. Then basically you can see that the size is there, so once you get the sheath size similar to the radial intraluminal diameter greater than one, you're gonna get occlusion. So we'll try and measure it.
We'll do the Barbeau's test which I'll go over here. So the Barbeau test basically what you do is you include the radial and the ulnar artery, then you leave out the ulnar artery and you wait about two minutes and you get a wave form here. So you put the pulse ox on the first or the second digit
and anybody with a type D wave form on the bottom you can't do a radial access.
These are some of the catheters here. There's a Davis, vertebral, Berenstein, Simmons. We usually use or just start with a Berenstein or vertebral. We very rarely have to go to a Simmons 2 or Simmons 3.
If you've got a form of reverse curve catheter, there are several ways you can do it. You can form over the aortic valve, left subclavian artery, over the aortic bifurcation. Suture technique if you have a really capacious arch you can actually form it in the aortic arch
which I don't like to do. I don't like to form the verse curve catheters in the arch. I think it's dangerous. We usually use a suture technique. So suture technique basically what you do is you backload the catheter with a suture,
put the Benson wire out and basically what you do is pull down the suture as in C, remove the wire and then you've got a nice reverse curve catheter you just push it up over the arch. It's very easy to form the reverse curve catheter.
So you get access and then you gotta get access
up in the carotid, so there's two different techniques. There's front loading telescopic technique were you have the sheath with a catheter and you just advance the sheath up in the catheter. Then there's a back loading technique where you basically put a catheter up in the extreme carotid artery
along with a stiff glide wire. Then you basically advance up everything over that. There's issues with that in you get a lot of times you have a lot of thrombus on the wire which you can never clear off. So you're probably getting microembolize of the brain
doing a huge exchange. Then remote, carotid or radial access. This is just the serial stiffening technique where you come up with a catheter here in the arch in two, catheterize in three, advance it up in the internal carotid artery and then basically
what you do is you advance the sheath up in the internal carotid artery. It's very simple to do in a type one or type two arch. This is the Penumbro system here. So you have a eight or 9-French sheath. You put the Neuro Max and then you put the catheter
through that 6-French Select catheter. You put the Select catheter up into the internal carotid artery and then you advance the sheath up.
So you really wanna look at the arch. So if it's a type one or type two you can usually
get up from the femoral portion. Type three you gotta think about going direct carotid access or radial. Some of the balloon guides we use. There's Cello balloons. Merci and the FlowGate.
We usually use a FlowGate Balloon Guide Catheter because it has the largest intraluminal diameter. There's differences between some of the balloon guides. The Celo Balloon Guide is pretty flimsy. It's not that stiff. It actually can kink if you've got
a really tortuous aortic arch. Merci Balloon Catheters a little bit more stiffer. That was probably the first balloon catheter on the market. The FlowGate's like a combination of that. So this is just showing you that you wanna have the greatest aspiration as possible
so the FlowGate's 0.084 which is nice as you get a really good aspiration. I don't like this balloon guide 'cause I have a kink on me. Sometimes I don't think you're fully aspirating. Basically what you don't want to do with the balloon guide when you get it, you wanna inspect it, test the RHV,
put some saline through it and put the inter dilator or catheter. Hook it up to heparinized saline flush. You also wanna prep the valve so we'll usually use a 20 mL syringe with 50:50 contrast and do a negative prep. There's no valve on the FlowGate.
There's no valve on the Celo, but there's a flow valve on the FlowGate. Basically what you do is you get the balloon guide up, blow up the balloon with a one CC syringe, then we hook a three-way with two 60 CC syringes, blow up the balloon, then we just aspirate
through the two 60 CC syringes.
If you're gonna use a sheath, there's three different types of sheaths. We predominantly use a Cook Shuttle Sheath and Neuron Max. That's our go-to sheath, a Terumo Destination Sheath
and they're all in 6, 7, 8-French size. We usually try and put an 8-French in. There's differences between those. The Penumbra the distal shaft is really soft versus the other ones. The proximal stiffness for the Penumbra
is a little bit better. I don't have stock in Penumbra, but I think the Penumbra is probably the best sheath on the market to get up in the ICA. Some of the stent retrievers with a prominent indication for the solitaire and Penumbra is
eight hours from symptom onset. Trevo now has indications for 24 hours from symptom onset based on the DAWN trial. There's differences in the revascularizaiton devices. The Solitaire Device is basically an open cell system here. It comes in three millimeter, four millimeter,
and six millimeter diameters. Then the Trevo comes in six, four and three also. The Trevo is more of a closed cell system so the Solitaire you can see there's opening on the stent. The Trevo is more of a close cell system. When you deploy this you wanna push it out
versus unsheathing with the Solitaire. You can both see these under x-ray pretty well here. So the bottom slide here you can see actually the stent retriever is very radiopaque. Penumbra has a 3D revascularization device which is a little bit different.
It's a bunch of different chambers and you can see it very well on the x-ray here. There's four little dots where the four little chambers are. Then there's some newer devices that are coming out that are not currently available in the U.S. One's called an Embotrap, which is that blue slide there.
Basically what it is is it has a central thing where it can actually flow completely through the thrombus and it has a bunch of little cages. These cages close. The Eric device is the one down in the bottom where it's a green micro catheter
with a bunch of different little chambers. Then the Tiger Triever has a little bit more radial force so you push it out and it has more radial force than all the other available currently stent retrievers and the bottom one is the Golden Retriever which is the three ones on the micro catheter.
Then the Lazarius Re-Cover device, so you put the stent retriever up there and you have almost a wall stent with a thin mess that you slide over the stent retriever to capture the thrombus so you don't have less distal embolization.
We don't have a pointer? This one, all right. Then the suction catheters Penumbra's the only one that actually has an indication by the FDA. Medtronic's Arc catheter recently got approval. The Catalyst, Sofia and the Revive by Cordis,
they're currently in trials to try and get FDA approval.
So the technique. Basically there's seven different techniques of balloon guide with a stent retriever. Basically what it comes with with the balloon guide, then you have the microcatheter.
So we usually use an 0.072 inch microcatheter. It allows you to put in six millimeter diameter, stent retriever of four millimeter diameter. Use the aspiration syringe. We usually use two 60 mL syringes. We usually cross with an 0.016 guidewire.
We usually use a Fathom wire. Basically what you want to do is you want to bring the microcatheter up passed the thrombus with a small microwire, so a Fathom wire. You want to get it distal passed it. What you want to do, the stent retrievers have
this little sheath on them, you basically introduce it to the RHV and you have flow back through the sheath and once you have back flow through the sheath you then hub it with a microcatheter and then you basically introduce it until you get to the stiff end of the wire. Then you want to basically advance it
through the microcatheter so it's distal to the thrombus. Then you want to deploy it. So you wanna have about one cm distal to the thrombus. If you're using the Trevo, you basically wanna push it out. So you wanna basically unload it 'cause it will integrate with the clot better versus the Solitaire.
The Solitaire I've done that too, but I don't think it works as well. So Solitaire will easily just unsheathe. You basically wanna then unsheathe the microcatheter then have the stent retriever so it's distal about one cm in the middle portion of the stent retriever
and then distal and then basically there's a radial pink marker on the distal end of the stent retriever. You wanna then advance that microcatheter just where the radial pink markers align. Let it wait for five minutes so that it can incorporate
in the stent. There's actually one article I think came out last month saying that you actually had better incorporation at eight minutes, so we've been going to eight minutes, although I can't wait that long. So recovery, basically what you then do is
inflate the balloon guide catheter and then you aspirate with the 60 CC syringe and then you basically pull it down. A lot of times a minimal amount of thrombus was in the stent retriever, the majority of the time the thrombus is within the balloon guide. So the balloon guide you keep suctioning
you aren't going to get anything back. We'll suction until you get negative aspiration. Sometimes you will not do that, so then we'll just hook up with 60 CC syringe and then just deflate the balloon and pull everything down, then sometimes the thrombus is then released so we don't fragment into the brain.
There's a Solumbra technique which is basically the Solitaire with the Penumbra. So basically what you do is you place a large sheath in the cervical ICA, you advance the triaxial system consisting of the distal aspiration catheter or the intermediate catheter along with the microcatheter
and the micro wire passed the clot. You then deploy the stent retriever within the clot. Basically what you do is you then advance the intermediate catheter 'til it's almost near the clot, turn on aspiration and then advance the intermediate catheter until you do not get
anything back from it. Then pull the thing down as a unit. So you do not want to advance the intermediate catheter. You do not want to pull the stent fully through the intermediate catheter. You just wanna make sure that it's approximate 20%
of the stent retriever is within the intermediate catheter so that you don't share it. What we also do is since a lot of times you aren't using a balloon guide, although the data says that you should use a balloon guide. We'll put the sheath way up high.
So we'll put it up in the, we'll put the sheath up in the petrous segment of the ICA. It's almost occlusive so it almost acts like a balloon guide, and with the Penumbra system it' actually very easy to get it up there. It's atraumatic.
We haven't had a dissection. A lot of people get freaked out about it, but it's not a big deal.
The other technique is a CAPTIVE technique, basically continuous aspiration prior to intracranial vascular embolectomy was developed by the Brown group
to minimize emboli during release of the stent retriever and when it's withdrawn with an aspiration catheter. This technique basically what you do is you place a large sheath in the internal carotid artery, advance the triaxial system, then basically what you do is before you deploy the stent, you turn on aspiration.
So when you turn on aspiration, when the stent starts getting incorporated you aren't gonna get distal emboli. Then basically what you do as you have aspiration on the intermediate catheter you then run the intermediate catheter up in the stent retriever until you get no flow back from it, then you basically
pull the whole thing back again. Again you do not want to pull the stent retriever through the intermediate catheter.
The TRAP technique is the Trevo Retriever with aspiration and proximal flor rest. It was developed by the guy at U. Mass.
Basically he looked at 12 randomized control trials and he has his own clinical experience. He thought it increased TICI 3 revascularization and decreased distal emboli. This technique basically what you do is you put the FlowGate Balloon Guide catheter in the ICA
and then you advance the guidewire along the microcatheter and the intermediate catheter to the clot. You then exchange the glidewire for the stent retriever. You deploy the stent retriever since it's a Trevo with a forward technique. So you basically push it out, so it'll basically
get incorporated within the thrombus a lot better. You wanna remove the microcatheter. You then inflate the balloon and then you start initial aspiration from the intermediate catheter and you wanna continue until you get no flow back from it. Basically what you do is you then blow up the balloon guide
and start, turn that aspiration on in the balloon guide, then you take a syringe through the intermediate catheter and then pull everything back. So this is probably the best of both worlds. You got negative aspiration from the balloon guide. You got negative aspiration from the intermediate catheter.
So you're probably gonna get less risk of distal emboli.
SAVE technique is stent retriever assisted vacuum-locked extraction. It was developed by the Germans. Basically their technique is a little bit different. You deploy two thirds of the stent retriever distal
to the clots utilizing the active push of the deployment technique with the Trevo device. You then advance the intermediate catheter to the face of the clot, then you start aspirating to it. Once the close is wedged between the retrieval and intermediate catheter you then switch the aspiration
over to the guide. So you hook up a pump to the guide, then basically what you do is you hook up an aspiration syringe so the intermediate catheter and then you pull them down as a unit. So this one's a little bit different in that you don't have
flow occlusion with the balloon guide. You have negative aspiration from the sheath, but you don't have flow occlusion with the balloon guide.
There's a FAST technique which has been described, and when I started doing this talk I didn't know there was all these techniques.
We basically used the Captiva technique. The FAST technique is forced arterial suction thrombectomy. Place a large balloon guide catheter or sheath in the parent vessel. You then advance again the microcatheter, microwire and a large bore-aspiration catheter.
You wanna do this proximal to the thrombus, so you don't wanna go passed the thrombus. You then remove the microcatheter and micro guidewire. You apply negative aspiration on the intermediate catheter with a 50 mL syringe and then you basically wanna advance this as you inflate the balloon guide
until you get no flow back and then you basically pull it out. So this, it's a little bit different, you're not using the stent retriever. we just use an intermediate catheter with a balloon guide. I haven't tried this.
Then there's the ADAPT technique which is basically the same technique that we use in the peripheral. You basically stick in a large guide catheter up into the vessel, engaging the thrombus and then hooking up to a pump and just aspirating it out. They thought this was unique, it's not that unique.
It's a direct aspiration first pass technique. So with this technique there is some issues in trying to get around the carotid siphon here. You usually want to have a microcatheter that's compatible with the intermediate catheter so that there's not a step-off 'cause sometimes
it can be hard to actually get through to the carotid siphon here where the ophthalmic artery comes off. It can actually get caught on the ophthalmic artery. So we usually try and get a microcatheter that matches the intermediate catheter so you don't have a step-off.
That's why we use a 02710, intraluminal Dailmer microcatheter. So this is the ADAPT technique. You basically put the large guide catheter up here. You advance everything up over a microcatheter and intermediate catheter over a wire.
You pull everything out, and then basically what you do is you turn on negative aspirations through their pump and then push it up into the clot and it'll suck out the clot. The problem with that is you're gonna get some distal emboli.
There is a little bit higher incidence of distal emboli using the ADAPT technique. This is the Penumbra pump. I have this slide because Penumbra used to be the only company that actually had FDA indication for aspiration for acute stroke.
They have a variety of catheters here. You can see the ACE 68 is predominantly used for the ICA and the M1 segment. The ACE64 is predominantly used for the M1 segment. The ACE60 for the distal OM1 and then once you start going out into the M2, it's the 4MAX,
and then the 3MAX farther out. We usually always use ACE68. I think you try and get the largest guide catheter, largest intermediate catheter up there. You have the highest chance of actually recovering the thrombus.
So we always try and get the ACE68. I've had the ACE68 actually up in the portion of M2 segment. It's usually not a problem.
Additional equipment you'll need for revascularization. You'll need some carotid stents, a closed cell or open cell.
We usually like to put a closed cell system in for the acute 'cause you wanna gel off the hot plaque. You wanna have some monorail balloons on 135 cm shaft and three to six millimeters in diameter. Then you also wanna have some protection devices if you're gonna do carotid stenting.
So you wanna have a proximal and distal protection device depending on the anatomy of the ICA. So if the ICA is really, really tortuous you probably wanna use proximal protection. If the ICA is pretty straightforward use distal protection. You wanna have a wide range of guidewires.
Then you wanna have some balloons which navigate the intercranial circulation. You might wanna have a gateway balloon or some small coronary balloon so you get up there in case you have like a stenosis in the caverness or petrous segment, or even the M1 segment.
Then you also wanna have some intracranial stents. So you wanna have a Neuroform stent or some wingspan stents or even some coronary stents in case you cause a dissection or if you have an underlying stenosis and you can't open up with a ballon angioplasty.
You also wanna know some of the pharmacology, some of the anti-platelet agents and the dosing if you're gonna do some carotid stenting. Some of the glyco IIb/a inhibitors Integrilin, Reopro Some of the vasodilators.
Parasympathetic agents if you're gonna do carotid stenting, atropine and glycopyrrolate. Some of the anticoagulation agents, antihypertensive agents. These are some of the antiplatelet agents. So there's clopidogrel, which is Plavix.
Prasugrel. Brilinta and Cangrelor. Prasugrel actually has a black box warning by the FDA so do not use this in acute stroke. We usually use Plavix just because it's cheaper, the problem is that it has to be activated.
So Prasugrel and Plavix have to be activated by the liver where Brilinta basically is the medication goes in, it doesn't need to be activated. Cangrelor is a new medication, which was recently approved by the FDA. It's given through an IV method, and the peak onset
is 30 minutes, so we're gonna start using this in some of the acute stroke cases where you need to give anti-platelets. Basically what we'll do is if we've got to stent the guy we'll using put an NG tube down him, give him 300 milligrams of aspirin,
600 milligrams of Plavix. The aspirin if it's not enteric-coated it usually takes effect within 30 minutes. The Plavix is two hours. So there's a time period there were the guy is not going to be completely protected.
We'll then start him on a gylco IIb inhibitor. We usually start him on Integrilin versus Reopro because Reopro is an irreversible inhibitor of the platelets whereas Integrilin can come off the platelets. So I think it's a little bit safer in acute stroke case.
Then finally the closure.
We usually close all these patients with Perclose or Angio-Seal. Radial access, Trevo makes a nice system there with the balloons where you wanna get patent hemostasis. So basically what you wanna do is you wanna blow up the balloon, take out the sheath
so you got complete occlusion then you wanna let up the balloon until you get a little bit of blood back and then you put two mL of air into the syringe so you've got patent hemostasis. That's what you wanna do with the radial access. Carotid access, you can put a Perclose in,
I'm sorry an Angio-Seal versus a Perclose. I think an Angio-Seal's a little bit easier to get in the carotid, it's usually not an issue. I've actually held direct pressure on the carotid without a problem. If the patient's been given IV tPA prior to intervention
it can be a problem. So we usually close with an Angio-Seal. So in summary I talked about the theory, some of the trials, anesthesia, some of the access issues, number of the devices that we use and then seven of the different techniques for thrombectomy
and some of the additional equipment. I think if you're gonna do this, I think the best system would to use a balloon guide, the largest intermediate catheter and then a stent retriever. Then use one of the techniques I described
utilizing the balloon catheter. I think the balloon catheter's the way to go, although I don't use it. Thank you. (audience applauds)
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