move into probably some of the reason you got into advanced endoscopy, right? Which is access, particularly therapeutic EUS. We're all really excited about this. The luminoposing metal stent, awesome, awesome addition to our toolbox. And in particular, the electrocautery-assisted luminoposing metal stent really allows us to get into things and to help patients in ways that you wouldn't have thought possible 15 years ago. So this is really exciting stuff. The Axios stent from Boston Scientific, you'll want to make sure, and you can actually have your Boston Scientific rep actually come and I would have them come watch your cases. If not, they can help assist you with getting some proctored cases, but they'll even go so far as to help you set up your Irby or whatever electrocautery unit you're using. So here you can see we have hot Axios setting. This is exactly what I use at my institution as well. So we'll, we have our VIO hooked up to autocut and effective five and then max watts of a hundred. So this is a pure cut, puncturing, cutting current. This is no coagulation. This is really just a max cut. We're just trying to puncture through something. Again, we want to make that tissue in front of us, in front of our catheter, like butter. We don't want any slow burn. This is, we don't want coagulation injury. This is just trying to cut through like a needle. So the device itself, it has a hydrophilic coating. So we're not going to probably do it today just to keep ourselves from getting too messy, but I usually have my nurse run some water over this catheter. It gets really slick, which is nice. Often you're doing this in a patient who has gastric outlet obstruction or pancreatitis with gastric outlet obstruction and a big necroma. And so there's a bunch of crud in your scope channel. It's all sticky. Maybe you've injected some contrast to see what's going on through your scope. So I make it as slick as I can by putting water on the outside, makes this catheter really, really slippery. And then let's find a location. This looks like a heterogeneous, maybe walled off necrosis. Yeah, so we could, you know, we're looking at the ultrasound screen here. And again, it's going to be a little bit different in the human versus our explanted tissue model. But the gist here is we're going to look at our collection. I'm pretty intentional about picking the spot for my drainage procedure. So let's pretend this is a patient with a 50 year old guy, a chronic alcoholic. He had a big episode of acute pancreatitis a few weeks ago. He's now back and we can see on a CT scan, there's clearly a nice, well-defined wall around this pseudocyst near his pancreas. Looking at the ultrasound here with me, you'll appreciate that it's not homogeneous. This is not a completely anechoic fluid filled structure, right? So this is probably, using our model here, this is probably more like necrosis than it is like a pseudocyst. So probably a necroma. It looks like there's some solid tissue in there. And I'll put Doppler on like we were just showing. Mostly I'm looking for blood vessels in the wall of where I'm going to puncture. Although you have to acknowledge the stent itself will actually cause tamponade. The stent is a coated metal stent, so nitinol stent with a nice coating. And that Teflon coating will seal off any vessels in the area. So I'm not too hyper about avoiding tiny little vessels in the wall of the stomach if we're doing a transgastric puncture. But I am very intentional about looking like we are here at the far wall of the cyst. I have to imagine as this cyst starts to collapse or as I'm doing necrosectomy, I want to know if there are big blood vessels running through this collection. I want to know if there's a blood vessel, maybe the splenic artery or vein on the far wall of this collection, that as that collection collapses, particularly in a pseudocyst, is it going to rub up against my stent? That's someone I'm going to keep a closer eye on, probably bring back for closer interval imaging. Like Dr. Tyberg mentioned today, I'll probably place a, like I do in most cases, a coaxial pigtail stent to help keep the far wall as it collapses off the internal flange of the axios. If you look at an axios up close, it kind of has a serrated edge on the edge of either barbell. So on the luminal and then the extra-luminal flange, it's kind of a serrated, almost serrated knife-like appearance. And you don't want that to rub on things. There was a question today about removing axios from the gallbladder, you know, or from the, well, gallbladder, but from the bile duct as well. My own thought is that there's, we're not seeing many reports of trauma from the axios stent in the gallbladder or in the bile duct. If you leave it in there for a long time, that seems to be in most patients pretty safe. That's how I do in my own practice. But necroma, pseudocyst, totally different story. There, there may be an increased risk of bleeding, particularly if you leave these longer than they should have been left. You'll see this is not your, you know, grandmother's stent. So the deployment catheter here is a bit different. You see that there's, it's going to lock onto your scope. So your tech or assistant doesn't really have control of this unless you're using it in a gastroscope. If and when you use the axios stent in a gastroscope, it's going to hang out about half a foot and you're going to have to have somebody hold that there for you so you can use the outer portion to deploy the flanges. But this will lock onto your therapeutic scope, again, which is a little longer than a gastroscope. That's why it fits on nicely. Your elevator function works the same and you're going to be able to see it on ultrasound. This portion is really just going to help, this bottom portion we've just unlocked. So this is kind of step one. You can see BSC has labeled this fairly nicely for you. So one, you know, they're telling you, you know, first thing you're going to do is advance this. To do that you have to unlock down here. So I've moved up a bit. There's our unlock, unlock. So there it's locked. This is how it comes packaged. I move over to unlock. I'm going to move back up here and this is step one where you're just closing this gap. So this is going to open and close and this is just to advance the catheter out of your scope. This does nothing with stent deployment. That's why I'm very comfortable. You can see, you know, the stent deployment portion of the catheter is right here in front of me. This does nothing except advance that catheter in and out of your scope. So we're going to start long and lock it. Up here, this is step two and four. So this first portion is to deploy the furthest, most distal flange. This will be the intracollection flange, this first portion. The second will be to deploy the flange within the stomach. So I'll hand this to you. Again, wet this nicely. You'll see it, that hydrophilic coating is really nice. And what's your stent of choice for walled off necrosis? Usually for collections, do you go by the size of collection or? Yeah, I'm stingy. So the 20 millimeter stent is a bit more spendy. It's a bit more expensive. So if there's a lot of necrosis, we're going to be doing a lot of necrosectomy. I think the 20 probably has a lot of merit. That's a stent that we're going to be able to easily get in and out of, easily drag big chunks of necrosis out of. I think it remains to be seen whether it reduces the number of necrosectomy procedures, whether it increases the safety or efficacy of drainage. I don't see any signal yet that it causes more problems like bleeding. Have you guys thought or talked about that at all? 20 millimeter stent, are you guys using that? I've used 15 millimeters mostly. Yeah. So the 15 millimeter stent, that's usually our go-to. You can get a scope, a therapeutic, single channel therapeutic scope with your snare, your raptor, whatever tools you're going to be using for necrosectomy through that just fine. So I agree. We're usually using the 15, the 20 is great when you say, man, this is going to be a many multiple session necrosectomy procedure, then I'll go to the 20. So here we're looking on ultrasound. Do you use guide wires for every procedure when you're using a Hot Axios or is your group sometimes just doing freehand? So I've seen it both ways. I've seen it with the guide wire under flora as well, introducing guide wire, like .035 guide wire, and then mostly, but I've seen freehand. Yeah. I wish I could pull the audience, but this is also a contested thing, right? I'd like to tell you, hey, if you're just starting to do therapeutic ultrasound, if you're going to just start using this in your practice, I'd like to say you should use a wire every time while you're learning, but I'm not, I don't know for a fact that that increases safety. So you can absolutely see a collection like this. You can puncture it with a 19 gauge needle, loop your guide wire. So there, I will say, you know, just a standard .035 jag wire, .035 wire is great. You can loop that in your collection, pull out your needle, and then advance your hot axios or your cold axios. If you'd like, you can advance and place your stent. If you've dilated the tract, the cold axios is fine. I think that's all great, but eventually you will have a case where you actually push yourself away. And we see this with gastrojejunostomy in particular. I think in our learning curve of gastrojejunostomy, my partners and I all started doing this initially with some type of guide wire. And then we learned that guide wire actually gets in the way more often than not. And so I think in general, most of the thought leaders in the U.S. will say, we're not using a guide wire, we're free handing most of our things. So I love the freehand gallbladder, freehand GJ. Basically, you just need a big enough fluid cushion. You need a nice place to land your stent. And often it's, I find the axios deployment catheter really follows its trajectory nicely and it's going to get you where you want to go. Where you can get in trouble is if you have a lot of tension on that guide wire. And as you advance your catheter, which is fair, you have to advance it to get it into the collection. You push the wire further into wherever you are and that pushes it away from you. And then you have a gap and there you're in trouble. So that's a situation where, that's why I'm not sure what to tell you to do. I think using a wire is fair. Maybe your first few pseudocysts, you get a wire coiled in there and get comfortable, but it's also not a hundred percent necessary. I think there'll be some folks who would teach without a guide wire. We have a question from the audience. I've sweat through many shirts with sluggish release of the proximal flange. You're not the only one, my friend. When deploying lambs, seems to get hung up on the elevator. Can you go through this to avoid shirt soaking scenario? Unfortunately, I think, you know, you're going to be using fluoro and lead and I think you've just chosen a specialty where you're going to soak through shirts. At least that's what I've learned even now that it's less stressful for me. I'm still soaking through shirts, so apologies. I may not be able to help you with the shirt problem, but we'll definitely talk through the proximal flange release. That's an important point. So here we're looking at our collection. Here I'll unlock the bottom portion of the axios and we're going to advance and I like to see it whatever we're aiming at. Gallbladder, bile duct, pseudocyst, necroma, jejunum, remnant stomach, which we'll talk more about tomorrow in lecture. I like to see it tent whatever I'm looking at. So often that means I'll have the big wheel pulled back towards me. So big wheel back is going to bend that scope. You're going to get a little bit of pressure on that necroma and here you can see there's the stent coming out and it's it's tenting here and you can see it's tenting the tissue. This is the point where you can come back and if you want to use a guide wire, so another yet to further complicate the guide wire issue, what I have started doing particularly with gastrojejunostomy and gallbladder drainage and or edge, I'll often have a wire a jag wire or other 035 straight wire just loaded in my axios catheter. So can you, I hate to do this to you because you're like in a great spot, but if you look at the top, if we go to the camera and zoom in on the top of this flange deployment portion of the catheter here, see that little white circle? You can load a wire in there. That's where your wire is going to load if you're doing this over a wire. You can also load a wire on the back end if you place your axios and now you want to stent, you want to dilate your stent or maybe your axios was a little too short and you wish you had used a longer stent, you can get a wire through here. Don't lose your track. Don't panic. You've deployed the axios. It hasn't gone well. It's a little too short. You see maybe like my shirt sweating friend that the proximal flange hasn't expanded because it's still stuck in your tract. Put a wire through. Keep that wire. That is your pathway to success, your golden brick road and come out with your axios catheter. You can then go down with a balloon dilate and then place a viable or some other covered biliary sized stent through there to bridge the gap and help let that tract heal before you pull out all the stents and start fresh with something longer or different. I've had that work for me. That's why I'd say more often than not now I am one of my friends and colleagues, Ryan Law, taught me to just go ahead and load that wire before I even start the case. So I do almost exclusively freehand axios, but I do load a wire almost to the tip of the catheter. You just don't introduce it into the cavity. Yep. Okay. So once I've punctured into the cavity, we'll go ahead and advance the wire because then we're in, we'll deploy our stent and then I have a wire through my stent so that if it doesn't go well, I've got an access point, you know, through which we can dilate, place another stent, you know, do an overlapping stent. Almost all axio stents, I would encourage you to dilate, you know, so if this is for necrosectomy, we're going to dilate so that we can let things drain and come back later for necrosectomy. If it's a GJ, you want them to be able to tolerate a diet quickly. So I'll often dilate a GJ stent right away. We'll dilate to the gallbladder. No matter what you're puncturing into, I think it's usually fair to say we're going to dilate that stent. Maybe not the whole way. You know, if you're worried about it being a little short, you may not fully dilate the stent, but it's nice to have that wire for multiple reasons. So we'll go ahead and advance now to the wall like you were doing. So you're, you're, yep, so there, there we're seeing some tenting. I will attach the, before I make the puncture, if we can attach the quadtree. And let me find that for you. That's right. So this is where, you know, airplane pilots have it up on us, you know, so the, the safety checklist is important. Have everything in the room. I know Amy kind of hinted at this today, and I think they'll talk about it more during tomorrow's lectures on complication management, but you really want to have everything that you might need. Have that viable stent or whatever stent you need for bridging in the room. You know, have endoscopic scissors if you're suturing. Have your tools, have the wire in the room, right? You don't want to send someone looking for something afterwards. So one of my safety checks is I always make sure, I always shout out, are we hot? And so your assistant will tell you, yep, we're plugged in. So you make sure that you're good to go. And then a couple different techniques here. I personally like to see, I like to see the tenting on the top right side of the screen. Can you suction there? I think there's bubbles or something in our, maybe our balloon. Whoever had commented on the balloon issue earlier, you know, there may be some wisdom there. If your balloon's really misbehaving for you, then you may, you put some water in and then suction again. So if you don't have a good EUS image, do not proceed, right? That's a, you know, do not pass go kind of thing. I really want to make sure, particularly that upper right, right portion of the screen, that's my, that's the money for therapeutic EUS. That's where my tool is going to come out. And why don't we go ahead just because it's, just because it's more obvious. Can we find that kind of gallbladder structure? Okay, sure. Let me unlock my. Sorry to mess you up. No, that's completely fine. 45. So it's on the other side. I'm just going to move my school. So while we're finding our, we're going to find a collection that may be nicer for you guys to see. I just realized this isn't showing up perfectly on, on, on the screen here. We chose sort of a darker fluid collection. Let's see if we can, we have a, almost a gallbladder structure here. When you come back for necrosectomy. So this is, this is also hotly debated, right? Everything in the U.S. is still controversial. My personal opinion, since you said you, is I place a stent, I dilate it, and I pretty much walk away at the initial procedure. A lot of our complications, if and when they happen, happen right after or at the time of necrosectomy and prolonged necrosectomy. So I think you're going to see that the field is moving towards placing a stent, walk away, let the patient decompress for a few days. If they're in the hospital because of poor nutrition, acute pancreatitis, pain, other issues, I'll have them get another CT scan in about three to five days, even up to a week. If that shows that there's necrosis that needs work, we'll do a necrosectomy at that kind of three, five to seven day window. If they've left the hospital, I repeat a CT scan, curious what you guys do, at about 10 to 14 days. So these are patients that you can't walk away from for a month, right? They came to the hospital because they had essentially an abscess in their belly. You need to see them back soon. I'll have them come back in that kind of one to two week range, get a CT scan, make sure that things are looking okay, probably schedule same day or next day a necrosectomy procedure. Again, my goal when I place an Axios is to get it out. So I'm working towards getting it out as soon as possible. So specifically your question, when do you come back for necrosectomy? Inpatients, three to five days. Outpatients, probably 10 to 14 days. I'm bringing them back for that necrosectomy. So this is a nicer fluid collection. Maybe you'll buy this as somewhat more anechoic. Maybe it's, we could say maybe this is an infected pseudocyst because it's got a little bit of that haziness that we see when it's just filled with pus or mucin for that matter. But you know, let's say that this is an infected pseudocyst. So now we've got really nice opposition with the wall. Here's a couple things I do. We put Doppler on. We want to make sure there's no blood vessels in the wall. So we already did that. Again, I study the far wall to kind of see where things are. I definitely, and we don't have the opportunity to show you this here, but I am studying fluoro. I want to know what's the scope mechanics. Am I placing a stent somewhere that's going to be easy to get into, easy to get into and subsequently do necrosectomy? Or am I placing it very proximal right at the gastroesophageal junction, for example, or on the lesser curvature that's going to be a very tight angulation to get into? And is there an opportunity to place that stent where it's going to be easier to do necrosectomy in the future? So let's just say for this case, we see on fluoro that we have a just slight J shape to our scope. We're down in the distal body of the stomach. That's a perfect spot for placing our stent pseudocyst drainage. And then the last thing I do, we'll have my fellows do before we start, is to actually measure the thickness of the wall. And it's going to look a little different on everybody's home ultrasound equipment, depending on the system that you have, but you'll use your caliper to actually measure. And I do just to be extra generous. Yeah, kind of like we're showing here. Do you mind if I drive for a second? I'll actually do it at a bit of an angle. So I'm imagining, you know, my catheter is going to come out here. I'm assuming that the wall thickness right here at 12 o'clock is very similar to the wall thickness over here, where we're actually doing the physical puncture. But just to be sure, I'll give it a little extra. So I do a little bit of an angle here. So I set my first cursor point just inside the collection. And then I want to imagine, just like we are doing with the catheter, I'm coming in at an angle. So my stent needs to be long enough to make that full path. We know that the stent that we're using today is a 15 by 10. And then we also have a 20 by 10 here. So I want to make sure that 10 millimeters is in range. So here you can see on the bottom left of the screen, we're at 8.37 millimeters. I know I'm, you know, the thickness of that wall is not going to prevent this stent from deploying nicely. So I'm good to go. And again, we're not showing fluoroscopy today, but that's a really important part of placing Axios and doing transluminal procedures in general. You really do need to have, you know, I put my ultrasound screen right in front of me. I have fluoro up and to the left. And I have endoscopy, you know, the endoscopic view, which is important for that proximal flange release. I have that just up and to the right. So you really do need that room, specialty room, that's outfit with the ability to show you all three things. You're using three modalities and you're kind of like an organ player because you're also using your foot for the pedal with the Irby, right? So you're, you're like playing an instrument. You're really kind of all over the place and you just have to practice that coordinate. Again, I think pseudocyst drainage is really the place to start. This is where my fellows start their, their Axios procedures because number one, I can help you if something goes wrong. It's, it's fairly easy to rescue. And number two, it's a little slower pace. So it's okay if we're puncturing slowly, if we release the stent slowly, there's not as much issue with like the small bowel moving away or that sort of thing. So we'll go ahead and, and look here on ultrasound. Let's see if we can tent the gastric wall here and, and, and just show that we're going to cause a little bit of tenting there. So there's our catheter. We have our, uh, uh, pad on the patient. We've got electrocautery hooked up. So hot, we're hot. And then you're going to stand on the yellow pedal and you'll see a little bubbles. So this is, you know, literally the water boiling, the, uh, reaching the boiling point, uh, around the catheter and then advancing that beautifully done. So there you can see the catheter. We actually went through and through so more aggressive than you needed to be. And part of that is because I moved you to a tiny, a tiny drainage point. So this would be one where, you know, just this is perfect because we can talk about complication management. If you go through and through the far wall, the gallbladder, no problem, but you need to pay attention to it. Don't forget it, study it. If there's leakage there, you're going to put probably an extra stent or two, uh, through your Axios just to make sure you get really good drainage. I mean, I've done gallbladder drainage for perforated gallbladder. So perforating the gallbladder, you don't try to do it, but, um, if it happens, like maybe we could say happened here. Yeah. Um, if you go through the far wall, um, just be ready to manage that complication and try to recognize it. So here I would, after we've placed our stent successfully, which we're about to do, I would inject a bunch of contrast and actually make sure that there is, or isn't a leak. I want to know about it. I want to know, should I bring the patient in the hospital, put them on some extra antibiotics, um, and just make sure that, that, that they're healing nicely after the procedure. So here you're going to, you're going to see some foreshortening. This is important too, when you're learning how to use the device, you do want the tip deep, right? Which is what you did initially. You went, you went pretty far. So as soon as I see bubbling in the collection, you can actually come off. The electrocautery, the cutting part of the tip, uh, on the catheter, which I'll show you on another device here, um, that cutting tip is, is just at the very, very end. Um, so it's a little ring of metal right at the tip of the catheter. Um, so this is going to be nearly impossible to show you on camera. Um, but as I move my finger back, if you look at your Axios at home, there's a little ring, um, of, of, of current just at the tip there and a wire, which maybe you can see on the side here. There's a wire that takes that electricity up to the tip. So that's all the cutting you're getting is the very tip. Once you see bubbling in the collection, like we did, you can come off the pedal, which she did very nicely. And then, then I advanced my catheter and you're less likely to puncture that far wall, if you're not continuing to cook as you go through the entire, uh, collection. Advance it to oppose this. Yeah. Yep. So, um, there you can see here, we're not hot, but you can advance to the far wall and it's not probably going to hurt anything. You don't, maybe you don't intentionally do it because you don't, you don't want to push the gallbladder away, for example. But, um, this is, this is, that's a really nice example of how you can advance it as far as you'd like, um, within reason once, once you're in the collection, then the catheter. And you're off the hot cautery, then there's a low risk of causing a puncture. Yep. Um, so I'd come off the cautery. As soon as I enter the collection, we advance a bit further, like we've done here. And now you're going to watch on ultrasound as we, as we deploy the flange. So, um, the distal flange, you have to release this, um, little, uh, yellow plastic, uh, uh, safety here on the, on the catheter. So it's, it can either be with the pull of your thumb and a flick, um, however you want to do it. This needs to come off. You can have someone assist you if you're worried it's going to make your scope, you know, jump all over the place. Um, stillness and stability is very important in therapeutic EUS. You want to make sure you maintain a stable scope, particularly once you've punctured something, you don't want to be swinging around here. So now, now that we've released, uh, the safety, um, this little button, she slid that over to the side. So this little button came over to the side. And now we're going to do step two, um, on Boston's instructions here. So just, she's going to pull the plunger, um, and she's going to pull this up to the second step. So go ahead and, um, pull that back. Can you give the EUS view? So we'll go, oh, sorry. Yep. We'll go to EDS. We'll go to EUS. And this, you know, this is not what's happening, obviously in a, in a, in a not live tissue model, but this looks to me like bleeding. So this would be an example of where you, maybe you puncture and you're starting to get bleeding into the collection from where you punctured. Trust me, that's probably going to stop as soon as you place your stent. That's going to cause tamponade, but watch here how that stent, even though she was at the far wall, maximally far away, almost with the catheter, it's still foreshortening to the point where she's now up against the, uh, nearly up against the wall. So that, that internal flange is almost where she's going to leave it when we go to deploy the second flange. So it really foreshortens. You do want to make sure you have a fair amount of the catheter out. Um, here I'll unlock the bottom portion. So she's unlocked this bottom bit that was locked. It was down here for deployment and she's going to pull that back. And I want to see it pull up against the wall of the cyst or the gallbladder or the bile duct or whatever we're deploying into there, there it's tented. So I wouldn't pull it more than that. In fact, I'm a little nervous. I'm a little nervous. You might just, you might pull it out of the track. So I would advance it back in just a hair. So where you see that, that structure, um, right now it sort of looks like a U to us, but, um, where you see the stent start to collapse, stop. This is a good time if you haven't already to advance your wire through your, through your stent, because if this next step doesn't go well, then you have a safety wire. So that again, that may help with the, you know, sweating into your shirt kind of situation. Um, the distal flange is released. And then here, if you have that tenting and you have a less than one centimeter thick wall, you have to trust me. I guarantee you, you can deploy the flange into your scope. Not everyone will teach it this way, but you can go ahead and deploy the proximal flange into the distal portion of your scope channel, your therapeutic scope channel. And then push it out. Alternatively, and this is, this is what I try to do with most procedures. I'll actually flip to my endoscopic view. I'll give myself, um, I'll start putting in CO2 here. So I'll start pumping in air and then I'll push my big wheel away from me. Again, I have that big wheel turned towards me to look up at and press up against the wall that I'm gonna puncture. Now I'm gonna let it go a little bit. I don't wanna lose my ultrasound view, but I will actually let go of that big wheel just a little bit so that I can get a gap between the scope camera and the wall of whatever I've punctured. And then you can actually deploy the flange under direct visualization. So let's see what we can do here. See if we can pull that off. Can we get a- So the endoscopic view is currently not- That may be because our light timed out. Perfect, thank you. Yep, here we go. So let's see what we can do here. And if we have an issue, I'm happy because then we can talk about a complication management, but if this goes beautifully, it'll be a good example. So you want me to push it down to see the black part, right? Exactly. So I'll undo. So here I'm watching on ultrasound. Again, I want all my procedures to be ultrasound, completely ultrasound guided, not just ultrasound associated. So I'm looking for my catheter here. Try to keep a little closer, cause I don't, here's where I don't- Yeah, I don't wanna lose ultrasound view ideally. I kinda like my ultrasound view, but you can see the black portion of the catheter there. Just a hint of it. One way, yep. One way is to actually push out your catheter a little bit. Push, yep, so we'll push this away from us. There's the black portion of the catheter. So now what I want you to do is unlock. So she's gonna unlock this top portion again. So now we're going from stage two to stage four. So we've done- And then lock the catheter here? Yep, you can lock right there or leave it unlocked. You're maximally in, so there's no harm to leave it either way. Now, as we pull back, it's gonna foreshorten, but in a good way. So you're gonna see the stent actually be deployed and I'll keep putting in CO2 because I want the lumen to kind of blow up in front of me. And this is where, without fluoro, you don't really know what's going on. This is why fluoro is important for these procedures. But I'm hoping that the stent's deploying into the lumen here. You would see that nicely on fluoroscopy. And then I'll actually unlock this. You can actually tap it out of your scope. So if you saw it deployed there, and this is an important point. At the very end, after you've deployed either into your scope channel and then backed away, or backed away and then deployed the stent right in front of you, you'll often have to, and this is what the question was getting at, the stent will hang up. It'll hang up inside your channel, actually. It's not usually hanging up on your biopsy, your elevator, which is a good question or good thought, but it's hanging up in your scope channel itself. And what I do is I just, just this last inch, I'll just tap it. And I don't know if you can hear over my microphone, it's a pretty loud tap. I'm giving it a good click. And this little, last little inch here is gonna tap it out of your scope channel. And you can be gentler, you can go slower the first few times, but you'll learn, when I'm doing a GJ and deploy it into my scope channel, I'll back up just a little bit, and then I'm just gonna tap, tap, tap the stent right out of the channel. It's gonna open up nicely here. And then whatever fluid we had placed on the other side, be it contrast, methylene blue stain contrast, whatever, you'll see that pouring back at you and you can rest easy, let your sweat dry off, that kind of thing. Good, so that's actually a really nicely placed Axios there. So that's a point, when we pulled that catheter back through the stent, I find particularly with the 20 millimeter stent that the ceramic tip, this white tip on the stent deployment. Maybe I can pull this out and you can show it. Yeah, it can actually, it'll hang up. This tip will hang up on the poorly dilated stent. And so what I don't want any of you to do is to accidentally dislodge the stent as you pull it back, as you pull this catheter out of the stent. That's again why having a wire is nice, watching on fluoro is nice. I wanna know, so here we're looking at the endoscopy view. I wanna know in real time, am I pulling that stent out as I go? My other concern, I use a nasobiliary drain to irrigate the small intestine for gastrojejunostomy. And when I'm doing that, I worry someday we're gonna catch, I usually have that drain beyond where we're doing, sometimes have that drain beyond where we're doing our puncture. I worry someday that pigtail on the drain may catch an axios flange and pull it out. So until everything is away from the axios, I'm always watching on fluoro to make sure we don't disrupt that axios because a fresh tract, we don't want that to separate. So you explained like you don't want the ceramic tip to catch into the axios. How do you avoid that just by pulling slowly and gently? I was gonna say, I'll just watch slowly. I've never had one where we needed to alongside everything place a dilator, but definitely if you just rip it out or let your assistant just rip it out for you, I worry that someday someone's gonna have a problem where that actually pulls the stent out. It can catch right on the waist of where the stent is poorly dilated. So in this case, I would have had you load a wire. We would have placed our wire, curled a couple of times into the collection. We've placed our stent. And then here now we'd be able to dilate over that wire. We'd have exchanged off over the wire. We dilate the tract and then we're ready for necrosectomy or maybe here we would just do a pigtail, a coaxial pigtail through that stent. Do they really oppose the lumen and adhere? I'd say yes, it's pretty dramatic. And we'll show lots of videos tomorrow during the sessions as well. But these two flanges, they'll actually, they do curl back on themselves. So what we'll do is I'll just deploy a stent here in front of you. So if we can zoom up here on my jacket. So you can see this is, I'll try and do it. We'll do this right next to each other so you can see what happens. But here's the first flange. So I think it helps to understand where the stent's deploying in relation to the black tip of the catheter, right? So this is all pulling back and that's why you see so much foreshortening on that distal flange. And sometimes you will see the stent almost, it almost feels like it's taking some time to open up and that's fine. So let that flower form an ultrasound. And then the second portion here, similarly, it's coming out at the distal tip of the black portion of the catheter. There's our waist and here's the big portion of the flange. And then again, this is the 20 millimeter stent. So my index finger almost fits through here. So your big therapeutic scopes are gonna fit through here. I think it's nice for EDGE where you might try to do a same session EDGE or something where you need to fit an EUS or ERCP scope through the stent. The 20 is really necessary for the EDGE procedures. So EDGE is endoscopic ultrasound directed ERCP, transgastric ERCP. For EDGE where you're doing transgastric intervention, maybe you're gonna go to the remnant stomach and do necrosectomy. You need to be able to get through with your ultrasound scope. If you look at your ultrasound scope, it's much bigger at the tip than your ERCP scope. So you really need the 20 for that too. We didn't mention it earlier, but that's another reason why you'd want the 20. The 20 can be really helpful if you need to get a big, big scope through. If you need to do over the scope clipping or if you need to do endoscopic suturing, you need that bigger stent, absolutely. So yeah, I would say they do really oppose the lumen. They do it here. The tract, this is anecdotal, but we say that the tract is gonna heal similar to a PEG tube. So, you know, the same way you're comfortable pulling a pool PEG after about four to six weeks, you're comfortable that this tract is well healed at four to six weeks. And I think a lot of us would say it's probably healed somewhere in the three to seven day range so that it may not be perfectly adherent. There may not be a lot of fibrosis, but tissue fibrosis starts to happen in about that one week range. So there should be nice healing of the tract between whatever you've connected at about a week. So that's where I'm comfortable if we need to pull out the axios for some reason. Around that range, that's why some people will do two session edge. You place the stent, come back in about a week and do that next portion because probably it's a lot safer. Probably there's true apposition, like our question asker, true apposition at that point and some healing of the tract. I have a question for you, Dr. Storm. Like when we're deploying the stent, this last step four, if there's stent migration, how would you troubleshoot right away? If it migrated forward or backward? If it migrates into the cyst cavity. Yeah. If it migrates into the cyst cavity, your administrator is not gonna like you, but I would grab a second axio stent and start fresh. That would be mine. So don't quit, don't walk away, right? You can fix this. This is an issue that absolutely you can fix, particularly for pseudocyst and necrosis. You're gonna go out into that collection anyway. It's no big deal. So if you lost a 10 millimeter stent, maybe switch to a 15 so that you can drive a scope through and pull it out. You don't have to do it right away. But I will say the nice thing about Axios, it's very soft. I would take a therapeutic scope through my 15, same day, and I would actually try to pull that stent. You know, it collapses nicely. Again, this is something that, this is off label and, you know, but it's been reported. So I don't feel like my friends at Boston Scientific can get too angry with me, but you can actually twist and turn this stent almost into a rope and pull it into your scope. So if you disrupt an Axios, you can actually load it into your scope and push it out. And look, you know, that nitinol memory metal, that nickel titanium alloy is beautiful. It comes right back to its original shape. You can use this again in the same patient, of course. So, you know, you could roll up this stent, place it into a therapeutic channel. It takes some work, takes some practice, but you can get that back into a therapeutic channel and reuse it. If that's, if you've deployed the stent or pulled it out maybe accidentally during necrosectomy, but you have a well-heeled tract, you can drive through and actually push out a flange, pull back, push out the proximal flange into the stomach. It's a kind of a slick way to save yourself buying another luminoposing metal stent. But for the issue of losing a stent into a collection, just don't quit. Maybe phone a friend, get somebody in the room with you if you feel like you just need someone to, you know, even when you're, when this is all you do every day, it can be really helpful to pull someone else into the room if possible, and just have somebody to kind of talk through what's going on and help you troubleshoot the issue. But I would just place another stent. You'll be able to drive out, grab your stent. The one caveat I'd have is you probably don't want to, if it's a pseudocyst and there's not a lot of necrosis, there's a chance that if you wait a week to go get your stent that you've lost in the collection, that it may have sealed off or healed around that stent, and that could be a real mess. So I would probably try to go get it the same day. If there's a lot of necrosis, it's almost certainly gonna still be there when you go looking for it. I would just worry it's a foreign body, it could cause bleeding, so I'd bring them back for necrosectomy sooner rather than later. But go ahead and place that second stent. The other question to ask is why did it happen? So why did your stent maldeploy? And that's usually just from misunderstanding or inexperience with the stent deployment catheter. So again, have your Boston Scientific rep join you for your first few cases, have a senior colleague or mentor or proctor be available. We're starting to do more virtual proctoring, which is really cool through Mayo, and I think ASGE will offer resources as well in the future. It's really nice to have somebody, again, kind of looking over your shoulder. Did I answer questions that you had? Yes, yes, thank you. So we had a couple of questions. I had trouble passing the EUS scope, same session edge procedure, any tips? And this person also anchored with sutures, which I congratulate them. I think it's, I don't wanna say irresponsible, it's definitely risky to do same session EUS after placing a transgastric stent. We'll talk about it more tomorrow, but use a 20 millimeter stent, number one, you can actually over dilate. So if you used a 15, you can actually dilate the axial stent. I'll sometimes dilate it to 18 or 20. Does it truly stay at 18 or 20? No, but you can get a little extra stretch on that stent if you over dilate the stent, that may help you. Even with the 20, I'm often dilating to 20, and then I have my tech or nurse actually go over the burst pressure and just really try to over dilate that stent so I get maximum diameter. The other thing is to be intentional about the trajectory in which you place the stent. For edge procedures in particular, look at your fluoro. If your scope is not fairly straight, your scope's not gonna, the scope that accesses that stent is not gonna be straight. And anytime you have angles where you're pushing through a stent, you're gonna number one, be at risk for disrupting the stent, and number two, you're gonna meet friction with the stent. And this kind of sticky coating on the Axio stent can grab your EUS scope in particular. That may be one time not to use your balloon, actually, the latex balloon, just to take away one more sticky thing. Yeah, one of the endoscopists that I'm familiar with would use PAM spray. Yeah. I'm doing the same. Yep, so PAM, or that's, I'm from the East Coast originally, and we use PAM. In the Midwest, I guess they have Vegelene, so whatever vegetable cooking spray is helpful. A lot of hospitals are cracking down on the use of just a can of vegetable spray in your room, so you may have to buy the more expensive silicone spray. That's fine. It's good stuff as well. For whole foods. Make your scope slippery. Another question, another limitation is we can access the collection only one centimeter away. What's your approach if the collection is more than a centimeter away? And that's a great question. You know, they make a 15 millimeter stent. I anticipate there's gonna be many different sizes of stents and lengths in the future. So my main answer to that question is, you know, we've got esophageal stents, and originally necrosectomy, a friend of mine, Dr. Barron, Todd Barron at UNC, he was doing this at Mayo Clinic first, and he did not use ultrasound, and he used, you know, fundamental anatomy. He used CT scans, cross-sectional imaging, and then also landmarks in the stomach to find the impression of a collection. He would actually puncture it with a needle, can inject contrast, find that area, and then cut into it with a needle knife. So, you know, the way we used to do this, it was before my time, was to actually place an esophageal stent. So a short esophageal stent. There you've got 23 millimeter by six centimeters. You've got nice long stents. If you have to, that's an option and remains an option. Plus you have the ability to use EUS. One thing, another one of my colleagues and I reported on was reusing this catheter. Again, you know, if anyone from Boston Scientific is on the line, just plug your ears, but you can reuse this catheter and actually use this cautery tip. So once you've deployed the stent, you can still use the tip here as a cystotome since we don't have any available in the U.S. I'm hopeful that a company will bring us that six, seven, eight French cystotome in the future that we can use under EUS guidance. But basically you need to find a way to access. That's kind of my short answer. Another limitation, do you have a minimum size of the bile duct to place the Axios stent? So that's a tricky thing to answer too. So Axios into the bile duct directly is tricky. You definitely wanna be really good at using Axios before you move into that realm. For our hands-on session happening outside here, folks are able to use the six and eight millimeter Axios stent. It's a little bit shorter. So you have to keep in mind, you don't have that full 10 millimeter distance. And there, it all depends. I've had some patients where I've deployed the Axios stent up the bile duct. And if you zoom in on my hand here, the stent itself never fully deploys that pretty flower. So it kind of stays the shape of a longer bile duct. And that's probably fine. For example, that patient did well for a choledochoduodenostomy. The stent looks up the bile duct and then makes a turn often. And then the flange and the duodenum obviously opens normally. And you can stent coaxially as well with pigtails if need be. I don't often do that. I've also seen with a very, very dilated pancreatic duct, you can place a transgastric into pancreas duct Axios. You just need to be careful of the distance. The size of the bile duct then, just to answer your question, there's not a minimum size, but you're gonna be using this for bile duct obstruction. So I'm usually looking for at least a centimeter if I'm gonna think about a choledochoduodenostomy. That said, personally, I just, I like rendezvous. I like hepatogastrostomy. So I often look to other options before choledochoduodenostomy. Something we'll also, I think, talk about tomorrow during lectures is just gallbladder access for malignant biliary obstruction. And often that can be helpful too. There, you've got a bigger target, probably a safer target than the bile duct, which can be challenging early in use. Well, we're getting close to the end of our time for live cases, hands-on stuff. I'd be happy to take any other questions if there are any from the audience. Anything else come to mind? You were just talking about bile duct drainage, and I don't know if most of it will be covered tomorrow, but besides Axios, what other stents would you suggest or you've used in your own experience in the past? Yeah, so I think there will be many other options, but right now the Gore Viable Stent is a really nice, so it's a biliary stent, fully coated. It has anti-migration flanges, and I think it works really well for a lot of therapeutic EUS techniques. In the US, because we don't have a hepaticogastrostomy stent, the Viable Stent is our best alternative. And so that's usually my go-to. I will often, if it's, for example, that one centimeter or less bile duct that we need to address, I'll actually achieve deep biliary access with my wire. So I'll puncture the bile duct with a needle. I'll get a wire up into the biliary tree, dilate my tract with a balloon. And I do find that the Hurricane works really well. We can actually use an angioplasty balloon, four millimeter, three millimeter angioplasty balloon if you have a smaller wire. But something to dilate that tract. Your other options for tract dilation, if you're getting into therapeutic EUS, you need to get good at tract dilation because you are not always gonna have the electrocautery assistance of the hot axios. You can use a Sahendra dilator. Have you used any of those yet? Sahendra, yeah. So you have a tapered tip, very stiff catheter that can help dilate. And then absolutely, you've gotta be comfortable using a needle knife. I wish I had an example here to show you, but we'll actually just put the tip of the needle knife out just a little bit. Or if you don't have a needle knife and you just don't use it enough to justify keeping one in stock, you can actually cut with wire cutters the tip of your sphincter tome. Just take a look at it. I flex it just a little bit and then I cut it off with my wire cutters. And then you have a nice needle knife based off of that. And the needle knife is gonna be under EUS guidance. Really nice. And you'll actually see it, just like with the Axios catheter, you'll see it kind of cook through the tissue. Again, I use a pure cutting current like we did and you'll see it actually puncture through and then the little radiopaque marker, you'll see that slide into the bile duct or pancreas duct or whatever you're cutting through and that can work really nicely. But you've gotta have those backup techniques for tract dilation for therapeutic EUS. When you access the gallbladder, is it from the antrum or duodenum? Do you have any opinion? I've seen it done actually from the bulb and antrum both. Yeah. Yeah. I mean- My feeling is antrum, one of my first reports, one of my first patients as a GI fellow actually in Boston was a patient who was something from a gallbladder drainage that was done from the antrum. And ever since that day, I'm wary and I fear, again, I don't have a lot of data to back this up, but I know Dr. Diehl, some of the other faculty members who are here feel pretty strongly that when possible, avoiding the antrum is best and going for the bulb. Also, if you look at most CT scans of patients with cholecystitis, stones, whatever you need to drain, it's usually right against the bulb. So I actually really like that bulb position. I often use a 15 millimeter, rarely a 20 unless I'm going after a big stone. I actually don't use the smaller. I thought maybe I'd like the six and eight millimeter stents for gallbladder, but I actually like that bigger patent drainage. So I've mostly used the 10 and 15 for gallbladder applications. And my understanding is you just leave them in then. And then I just leave them in. So that, a part of the prospective study was finished and reported at DDW. We were a part of it at Mayo as well. And I'd say most folks, again, when you're doing a gallbladder drainage via EUS, it's often someone who's not a great surgical candidate. So number one, be careful. They're not a good surgical candidate. You don't want them to have to go to the OR emergently. But number two, you definitely want this to be a one and done thing, probably not putting them through another general anesthetic, just to pull a stent or exchange stents. They usually leave that stent indefinitely unless they're having problems. I see. More questions. So we said duodenum, that first question, gallbladder access. I prefer the duodenum. I think it's usually the right place to go. And then can you list the stepwise growth you'd advise for growing in transluminal EUS skillset? One, pancreatic collections first, then gallbladder edge, EUS bile duct. So I would change the order of this question a little bit. I'd say, or what you suggested, which it's a fair suggestion and you may wanna pull the audience from the other faculty members tomorrow. Pancreatic collections, absolutely. A nice big suit assist with your Boston rep and maybe another faculty member over your shoulders. Great place to start. You're gonna have a comfortable first drainage procedure. I would put at number two, actually, probably edge. And this may be controversial, but I actually think edge is a bit safer and a bit more of a sure thing than gallbladder access. The problem with edge, and I think a lot of the complications reported around edge are misidentifying the remnant stomach. So I know one of Dr. Diehl's colleagues reported on maybe accessing the colon during an edge procedure. It was in GIE as a focal point image. So you have to be careful. You wanna know that you're accessing the stomach. That said, the remnant stomach, unless they have gastric outlet obstruction of the remnant stomach, the remnant stomach is usually totally decompressed. So you have to hit it with a needle. So in almost all edge procedures, I puncture first with an FNA needle and pump in a lot of fluid. It can be a 22 gauge or a 19 gauge. You're usually in a straight scope position. So the 19 gauge is easy enough. You'll puncture, fill it with fluid. Why not fill it with fluid that has contrast? And that contrast will show you very quickly, whoops, I'm in the colon. Stop, no problem, no harm done. You've FNA'd the colon. It's not great, give them antibiotics, but it's not the end of the world. You've not cut any tissue. So you can pull out and go looking again. If you see that it's filling the stomach, like you're used to seeing, and you see it flow to the antrum and then to the duodenum, you know you're in the stomach. So that contrast is really helpful. So I actually put edge at number two, edge type procedures at number two. That includes everything up to, you know, passing an EUS scope through the edge. That can get hairy, and I certainly wouldn't use it right away for that indication. I'd let that tract mature. EUS, I'd probably put, honestly, rendezvous. There's not a lot lost by trying a rendezvous before sending someone to a percutaneous strain. If you're already in there, you've failed ERCP. I find our success rate at least pretty high. You can either access a left duct of the liver or the common bile duct like was shown today. You know, and Amy showed, there's a couple different options for rendezvous. Get that wire placed down into the duodenum. Go find it with your side viewer. Externalize. I use a forceps, but you can also use a snare. Externalize that wire and work over it backwards. You want a long wire, a 450 centimeter long jag wire or longer. Use that, pull it out, work over it backwards. I put rendezvous at like number three. And then I'd say EUS bile duct and gallbladder. Gallbladder probably ahead of bile duct. And then finally, the last skill would probably be EUS-GJ. I see. Yeah, and maybe EUS pancreas rendezvous. That can be very challenging and risky. While we're talking about rendezvous, just a quick question, and I think you kind of alluded to it in the beginning. What's your choice of wire there? For rendezvous? Yeah. Yeah, I love the O2-5 Vizzy. It has an angled tip. And so it allows me to steer myself. So if I'm in the pancreas, sometimes you're gonna hit a side branch. If you use a straight wire, you might end up going out the minor papilla or something you didn't intend. You're definitely gonna want a steerable wire. So I like that O2-5 angled tip wire, whatever the flavor. And I'll use that to actually steer my way out. Same thing, sometimes you'll puncture into a bile duct and you find maybe from the left duct, it then wants to always go up to the right. And so again, having that angled wire is gonna help you find your way back down the common channel. When you do axios drainage, it looks as though the axios in the way of in the way of passage, not very flush with the wall. Like I said, you know, in the viaduct valve does it block the lumen? I don't know if that's what they're trying to elucidate. Oh, does axios block the way of food passage? Great question. No, I find that it doesn't, right? It's gonna find its way up to the wall. Particularly, that's actually why I will dilate the axios stent for almost all procedures, including gallbladder. Before you dilate, the stent is kind of mal-deployed. It's just not fully distended or deployed. And so if you actually go ahead and dilate the stent, it shortens, which pulls it up against the wall. And then you'll find that your efferent flow down the jejunum is actually excellent or duodenum is excellent. So I've not seen that be a problem. That's one reason though, why I don't like it planted right in the antrum because it's staring right at you like the pylorus. And I think that's why patients sump. They get food and stuff into their bile duct and gallbladder and it causes cholangitis, other issues. Do you routinely place double pigtail stent through the axios for gallbladder or bile duct drainage? I don't, but I know again, some really great faculty members here do. It's just a personal preference. I like the stent to maintain patency. When I've got necrosis and I'm worried it's gonna clog. So I guess as a caveat for the gallbladder, I'll use it if there's a ton of stones and I'm not removing them. So if I'm leaving the stent there with stones, I like the pigtail is gonna stay there and it may not drain itself, right? The pigtail itself may clog. It will clog after a couple of months, I expect. They kind of get barnacles like the bottom of the ship. They will clog up, but it wobbles around and is constantly providing some patency through your axios. So anytime you think you're gonna have a clogged axios, which is necrosis and probably gallbladder stones, that's the time to use pigtails. And then bile duct drainage, I don't routinely, but if it clogs and fails, they come back, then we can stent through the, just like you would do with a bare metal stent or a covered metal stent, you can stent coaxial to it. Just to segue into that question, what's your choice of double pigtails for your pancreatic necrosis? I almost uniformly use a seven French, four centimeter. So just short, even if it's a 15 centimeter collection, I just like a short stent that's gonna sit right there and just keep the very end of the, just to keep the axios open. Got it, thank you. Well, we're about out of time. Thank you again so much for joining us virtually and we'll see you tomorrow for the rest of the session. Bye-bye. Thank you.

Axios stent

therapeutic endoscopy

pseudocysts

necrotic tissue

electrocautery-assisted Axios stent

gallbladder

bile duct

stent deployment

ultrasound guidance

transluminal endoscopy