It's my great pleasure to introduce the next speaker, Dr. Amy Tyberg. She's the Associate Chief of Interventional and Therapeutic Endoscopy at Hackensack Hospital. And Dr. Tyberg is an expert in interventional EUS, and she's going to go over all of the troubleshooting that may occur. Thank you so much, and thanks to the course directors for having me today, and also for giving me such a fun topic to talk about. These are my disclosures. So when we talk about interventional EUS troubleshooting, you know that Axios or LAMS has become really just an integral part of advanced endoscopy practices pretty diffusely. I actually remember the time pre-LAMS. I'm going to date myself here, but it came to market during my advanced fellowship, so I had a little bit of experience beforehand. But now it's not really a novel thing anymore. It's really a common device, and that's because it's designed to be very user-friendly and work very well. But there are adverse events that can and will happen no matter how good you are. Adverse events are going to be a part of your practice, and it's just as important as knowing how to deploy a LAMS in interventional EUS as how to manage the potential complications that can occur. And so I'm going to go through some of the most common adverse events that we see in interventional EUS, some tips and tricks to how to avoid adverse events before they happen, because that's, of course, the best-case scenario, but also some rescue techniques for management of them when they do occur. And then at the end, we'll go through some videos. So one of the first things to talk about is very similar to some of the other types of interventions that we've heard about today, but bleeding can occur during interventional EUS procedures. And there's basically three ways that bleeding can happen. You can get bleeding from vessels within the GI tract wall. And this bleeding is usually recognized and treated during the procedure, because obviously from the inside of the lumen, you can see when this bleeding happens. The more worrisome bleeding is bleeding that can happen outside of the GI lumen, and that can happen from vessels between the bowel wall or the stomach wall and the procedural target. Sorry about that. And these patients usually present after the procedure, usually with the physiologic consequences of intra-abdominal bleeding, abdominal pain, or anemia. And you can also have bleeding from vessels within the target lesion, whether it's the bile duct, the gallbladder, or a pancreatic cyst. And this is most commonly seen, actually, in when we're draining wall duct necrosis or pseudocyst. So how do we prevent bleeding during interventional EUS procedures? One, you always want to review your imaging ahead of time to look for abnormal vascular anatomy or other things that will potentially increase bleeding risk, like portal hypertension or vascular collaterals. I know we've hit home this point a lot, but looking at imaging is critical whenever you're embarking on these procedures. You want to use your Doppler on EUS to look for any vessels before you're going to access whatever target you're going for. And when you're using the Doppler, you want to avoid compressing the wall with the transducer, especially when you have an inflated balloon. Because as we heard about so nicely and we saw earlier, when you have an inflated balloon and you're pushing it against the wall, you can compress structures. And similar to how the bile duct can appear narrower than it is, you can also compress a blood vessel that may be there. So you want to be very careful when you're looking for vessels to make sure that you're not compressing the wall too much so that you can see any vessels that might be in your path. If you do see bleeding, there's lots of things that you can do. When you have bleeding at the insertion site, one thing that you can do is if you think about when you deploy a lumen-opposing metal stent, it comes out compressed and it will slowly dilate over time. And you can wait and see if that dilation of the lumen of the stent will actually cause some tamponade effect and control your bleeding. But if you have continued bleeding, you can actually help the process along by doing sort of a slow, gradual, prolonged balloon dilation of the lambs lumen. So this, you can put a dilating balloon within the lumen of the stent and just dilate a little bit to see if you can create some tamponade and stop the bleeding. But you want to be careful because if you dilate very quickly, you can actually cause some bleeding from the dilation itself. So it's a sort of a slow, gradual dilation that you're looking for. And then you can use other types of hemostasis that you would use for any other type of bleeding in the GI tract. So you can inject epinephrine or you can use other types of hemostatic devices to control bleeding as you see it. When you have bleeding between the bowel or gastric wall in the target or bleeding at the procedural target, there's not so much endoscopically that you can do in those cases. And generally, you're looking more at angiography-guided embolic therapy to manage those types of bleeding. I'm going to have some videos at the end. Don't worry. It's not just going to be me talking the whole time. But moving on, I'm going to talk about migration. So this is important to distinguish migration from maldeployment. Migration is when you have movement of the lumen opposing metal stent out of your intended fistula tract after you have initial satisfactory deployment. So this is your stent is deployed. It looks great. And then for whatever reason, it migrates out of this satisfactory position. And this can happen either. I like to divide it into early migration or late migration, meaning before the fistula tract has formed or after the... I don't know why my slides have a mind of their own here. I'm moving on their own. Or after the fistula tract has formed. So when we talk about late migration, we're talking about after... Usually it takes about 10 to 14 days for a fistula tract to mature after you place a lumen opposing metal stent. And this is generally not a big deal because if the LAMS migrates at this point, the fistula tract is mature. Those two lumens are going to stay together and you don't generally have major complications associated with that. Early migration is the more serious issue because if your lumen opposing metal stent migrates before that fistula tract is mature, when it migrates, the tissues are no longer held together. And that's when you can end up with leakage of contents. The good news is when you're draining something that's fused to the abdominal wall, like a pseudocyst or necrosis, you're generally not going to have that much leakage because there's so much inflammation that the pseudocyst or necrosis is going to stay close to the GI tract. But when you're talking about gallbladder drainage or coli don't go to adenostomy, you can have significant complications from bile leakage, which can cause peritonitis, even bilomas. And when we're talking about EDGE procedures and EOS gastroenterostomy, you can get leakage of bowel contents into the peritoneum also with peritonitis. And these are complications that can be very significant for the patient. So how do you avoid migration? I think the biggest one is to try to avoid having tension on the flanges. So if you think about your lumen opposing metal stent has two flanges and the distance between those flanges is generally one centimeter. If you're close to one centimeter or a little bit more, you're going to have a lot of pressure on those flanges and the more tension you have on the flanges, the more likely one is just to flip out and the stent can migrate later on. So if you think that your distance between your GI tract and your target lumen is close to a centimeter or more, you want to use a little bit of a longer diameter lumen opposing metal stent. There is a one size that comes as a 15 millimeter length. So if you're close to the one centimeter, always reasonable to size up to avoid having tension on the lambs. And this is not so applicable right now. The only lumen opposing metal stent we have in the U.S. right now is the Axio stent. But there are other lumen opposing metal stents that are used worldwide and eventually will have in the U.S. And they have different apposition forces. So it's important to understand the different forces of these stents, meaning how much force they can generate to bring the tissues together. And when you think about the lesion that you're trying to drain, you might want to use stronger apposition force lumen opposing metal stents if you're doing a procedure where leakage would be a significant issue. And if it does happen, as I said, with late migration, oftentimes there's not really significant complications here. You can often just remove and replace the lumen opposing metal stent and potentially even close the fistula site. For early migration, it's a little bit more difficult to manage. You can attempt to manage the stent endoscopically. Sometimes the fistula track will be still open endoscopically if you catch it early. And you can try to salvage endoscopically by putting a wire through and putting a new stent in. But oftentimes, these patients are going to end up needing some additional therapy, whether it's percutaneous drainage or even a surgical washout of the contents that have already leaked out in the interim. And sometimes in these cases, surgical management is required. I promise the videos are coming soon. Occlusion. So this is what happens when the lumen of the lambs becomes obstructed. This is generally going to result in recurrence of the symptoms that led to the indication for the initial procedure in the first place. And this type of occlusion can be from food debris. It can be from necrotic debris. In the case of necrosectomy, it can be from biliary sludge or stones if we're talking about choledochoduodenostomy or from tumor tissue ingrowth. And there's actually a nice classification that was published by the Milan group showing the different types of occlusion that can happen specifically in choledochoduodenostomy. This is where we see occlusion the most. And you can see I've just listed them on the side there. So things to think about when we're talking about occlusion. You want to avoid leaving the lumen opposing metal stent in place any longer than is medically necessary. The longer you leave it in place, the more likely it is that it's going to get occluded over time. You want to try, if possible, when you're choosing your window for drainage to avoid going through areas of the GI tract that contain inflamed or neoplastic or post-surgical tissue. These are more likely to cause tissue ingrowth. Even though the stent is covered, over time that covering can erode a little bit and you can get some tissue ingrowth. When you're talking about choledochoduodenostomy, it's critical to treat gastric outlet obstruction if it's present. Because if you're draining into the stomach but you have gastric outlet obstruction, you're actually not providing adequate drainage there. And then when you're talking about choledochoduodenostomy or gallbladder drainage, you want to consider placing a second stent like a double pigtail plastic stent through the lumen opposing metal stent in order to avoid occlusion. And if it does happen, a lot of times this can be managed endoscopically. You can go down. You can remove the debris from within the stent lumen. You can dilate an ingrown stent. Again, placing a double pigtail stent, especially in places where the obstruction is from misalignment of the lambs or obstruction against the contralateral wall. For instance, if you think about the bile duct is like this and the lambs is like this, you can actually, as the lumen collapses, it can cause obstruction just by resting against the distal plant of the lambs. And a double pigtail plastic stent can significantly help with that. Sometimes just removing and replacing the lumen opposing metal stent is required. And in rare cases, an alternative drainage technique would be required. And lastly, I think the one that most of us fear the most and probably the one that does lead to the most significant adverse events is the maldeployment. And this is when deployment of either flange of the lumen opposing metal stent is in an unintended location outside either of the target lesion and or the gastrointestinal lumen. And this results in content leakage into the extraluminal space. This is basically synonymous with the perforation, and it tends to occur more commonly when the target lesion for the distal flange is mobile and small. So for instance, large fixed lesions that are adherent to the GI lumen, such as pancreatic fluid collections, tend to have lower rates of maldeployment, whereas the highest rates can be seen in those procedures like EUS guided gastroenterostomy, where they have a small diameter and they're very mobile. And this is a nice classification system classifying the different types of maldeployment. This comes from the EUS guided gastroenterostomy literature, but it can really be applied to most of the therapeutic EUS procedures that we do. And you can see the type 1, type 2, type 3, and type 4. I think cartoons are the best way to visualize things, so I just put the cartoon there. And I say I would add here there's also a type 5, which is when you're skewering a bowel loop between the GI lumen and the target lumen, which can happen occasionally as well. So how do you avoid maldeployment? I think these are critical tips and tricks that need to be employed every time you're embarking on a therapeutic EUS procedure. One, take the time to find the right window. It's worth taking an extra 5 or 10 minutes to see if you can find the window that's going to give you the best chance for success. You want to find the window that has the least amount of space between the GI lumen and your target lumen, the least amount of vessels, and has your scope in the most stable position, which is going to give you the highest chance of having a good deployment. You want to let the cautery do the work. And we talked about this yesterday for those of you that were in the hands-on with me. When you're deploying a lumen opposing metal stent, it's the opposite of when you're doing an FNA, where you're using force to generate getting the needle through the wall of the GI tract. Here, it's actually the cautery that's doing the work for you, and you don't want to use a lot of force. You want to let the cautery create the fistula tract, because if you use too much force when you're pushing out the lumen opposing metal stent, you're going to push the tissue away, and you're not going to actually make it into your target lesion. So it's really thinking about it almost opposite to how you would do an FNA. You really sort of let the cautery do the work and just guide the catheter into the target lesion. You want to deploy the flanges slowly and adjust your position as needed. So once you're happily in the target lesion, you don't want to just immediately deploy the first flange very quickly. You want to go nice and slowly. You can actually see on EUS the flange start to deploy, and you're going to see it come back quite a bit. So as you're watching that stent deploy, if you realize that you're very close to being outside of the lumen, stop deploying it. You can actually pause midway. You don't have to keep going, and then you can push the catheter in a little bit more, deploy a little bit more, push your catheter in a little more, deploy a little bit more. You can do it very slowly and watch what you're doing so that you make sure that even if you're in a sort of almost in and not fully, you can save that and still make sure that you have a good deployment. And you want to consider using a preloaded guide wire. So most of us that do these types of procedures are not going to deploy the lumen-opposing metal stent over a wire. You get a better deployment generally if you can choose your window and go freehand into the lumen, and you also avoid the risks of any leakage during exchanges when you're not going over a wire. However, especially in something where you're at higher risk for maldeployment like a gastroenterostomy, preloading a wire ahead of time allows you to, once you're in that lumen and you have your first flange deployed, you can immediately advance your wire and coil it, and it gives you the benefits of having that wire safety net without sacrificing your excellent deployment window. So I think, you know, certainly in the beginning, a good way to give yourself an extra safety is to use a preloaded guide wire. And if it does occur, similar to what we've heard over the course of the morning in these lectures, stay calm. Many of these maldeployments can be managed endoscopically. First thing always, you're going to stabilize the patient. This is when, if you haven't given antibiotics already, you're going to want to give them. And similar to some of the third space procedures, you need to keep an eye for the abdomen. And if you're getting too much CO2 leakage from CO2 and air that's escaping, then you need to do a decompression of the abdomen with a 14 or 16 gauge needle. And this oftentimes is done both by physical exam, appreciating the abdomen, but also by being in touch with your anesthesia colleagues. If they start to see the CO2 rising, you want to tell them to let you know and then check the abdomen and see if a decompression. And once you have a needle decompression, and you can generally continue with your closure safely because then you have an open circuit. So CO2 that's escaping comes right out and the patient is not at risk for complications related to that. The next thing to do is you want to determine what type of maldeployment it is. And that's going to really guide how you're going to manage it and how you're going to close it. If it's just a type 1 maldeployment, you can often just remove the lambs and close the puncture site and start again somewhere else. If it's a type 1, 2, or 3, you have the option to salvage it either by using another fully covered metal stent or sometimes even a second luminoposing metal stent. We call this the stent and stent technique or even using a notes procedure. And I'll show you some videos of all of these in a few minutes. And then in some cases, you want to let the fistula mature, then bring the patient back to remove the lambs and close the site. I call this cleaning up. So this is specifically in like a type 4, for instance. And for all of these types of maldeployments, you're going to follow the patient closely, you know, set expectations for the patient of what they should expect post-procedure. And of course, you're going to obtain backup from your colleagues as needed. Okay. So now on to the fun. And I think, oh, I'm a little bit over. So just tell me when to stop with the videos. And I have a bunch, but we can do maybe just a couple and then we can stop. Okay. All right. We'll start with this one. I like this one. This is actually one of mine. And I will encourage you that, you know, it's as important to publish your successes. I mean, as important to publish your complications and how you've salvaged them as it is to publish your successes, because others can learn from how you've overcome some of these adverse events. So this is one where you can see that you're deploying your lumen-opposing mental stent. Everything looks okay, but it's a little too close to the gastric wall and whoops, it gets sucked out here. So this is a case where luckily in this case, we were using a preloaded guide wire. And so we were able to salvage it. This is a nice illustration of what we call the stent and stent technique. So you can see, I don't know if it's, I'll just kind of pause it here one second. But so this, basically this flange of the, this was during a US gastroenterostomy. This flange is in the bowel, but this flange is outside of the stomach, just floating in the peritoneum. So what we're doing here is there's still a wire communicating across the fistula tract. So I'm going to start it again. And you can see here, there's another stent being deployed. So this stent is being deployed with this end in the, in the small intestine as we wanted to going through the misdeployed flange that's in the peritoneum. And then the proximal flange is going to be deployed in the stomach. And you can see the endoscopic image up here at the top. And then, and there it is. And it's important in these cases, you want to try to use a stent that's going to be bigger than the diameter of the lumen-opposing metal stent that will cause, that will help anchor it in place. Always a double pigtail combining all the stents is nice. And you want to anchor the gastric end in place just to try to prevent migration. Remember that if you're not using another lumen-opposing metal stent, it doesn't have the flanges on either side. And so you do want to try to anchor that in place. Okay. Okay. This is another of mine. This is the opposite problem here. Again, we're doing a US gastroenterostomy. We think everything looks great. We're dilating the lumen of the stent. And then whoops, once we've dilated it, we're not looking at the inside of the bowel. We're actually looking at the outside of the bowel. So this is a type of misdeployment where the lumen-opposing metal stent is, the gastric end is nice, but the distal end is not in the correct place. So in this procedure, you have a lot of options for what to do here. In this case, we chose to do a notes type procedure. So we've now put down a double channel scope, and you can see with one, the rat tooth forceps through one of the channels, we're grasping that bowel so it doesn't go anywhere. And using the other channel we're using, that was a needle knife catheter to guarantee us access into the bowel loop that we had wanted to be in, in the first place. We're then putting a catheter through and injecting contrast so that we know we're in good position here and threading our wire. And now we're going to, again, use the stent in stent technique. So here's the stent being deployed. So now we're going through the lumen-opposing metal stent into the small bowel. You can see one end where it's supposed to be now in the small intestine, and here is the other end coming through the lumen-opposing metal stent into the stomach. And again, injecting contrast, there's no leak there. And of course, you want to put a double pigtail there and anchor the stent in place, which I didn't show. Do you want me to stop here? Such nice videos. I have to find a part of it. Yeah, yeah. Okay. Do you have one more video that's like a really good one? Sure, we can play that. I mean, they're all so great. So this is another, yeah, most of these are EUSGE videos. That's really where we're going to see the most maldeployment. So I'll play this one. And then if anyone wants to see more, I have them on my computer so I can show you later during the break. So this is a case, again, EUSGE. Everything looks like it's going fine. You can see the lambs being advanced into the GI tract here. They're using both endoscopy and fluoro. Looks fine. The first flange is deployed, pulled back. The second flange is deployed in the stomach. Everything looks okay, but shortly you're going to see that there's a sort of an inkling that there's maybe a problem here. There's no methylene blue that's coming back out. And then on EUS, it looks a little bit maldeployed. So here they're actually injecting contrast. And you can see, unfortunately, instead of staying in the GI lumen, it's just extravasating into nowhere. So that's certainly a sign that there is a misdeployment. And I'm just going to pause this for one second. I think when you're doing these types of procedures, and if you are worried that your stent is not in the correct position, you want to find that out before you end the procedure. So like in this case, they took a catheter, went through the stent, and injected some contrast. You want to use some kind of test, whether it's endoscopic visualization or contrast injection, to make sure that your stent is in good position if there is any question. So here what they're doing, actually, is going to use another variation of the notes technique. They dilated the stent and actually advanced the EUS scope through the lumen-opposing metal stent into the peritoneum. And then did another GJ, basically, from within the peritoneum. So here you can see the lumen-opposing metal stent being deployed under EUS into the small bowel loop that was the initial target. There's the flange being deployed. And then they're going to use this as a retractor, not just to bring the bowel loop closer to the stomach, but close to the other lumen-opposing metal stent. And then basically deploy a second lumen-opposing metal stent through the first one. And then here you can nicely see, I think they're going to point it out, there's the first lumen-opposing metal stent and then the second one going through it. And then again, contrast is injected. And now you can see it's very nicely filling the small bowel, you can see there, as opposed to just extravasating to nowhere. So I will stop there. There's lots of videos like this. As I said, it's critical to publish your adverse events so others can learn from them and how you've overcome them as much as it is your successes. So I will stop there. Thank you so much.

interventional endoscopic ultrasound

lumen-opposing metal stents

adverse events

Doppler ultrasound

stent deployment

bleeding management