Before we move on to the next case, we wanted to show the rectal follic specimen that Dr. Nam had performed the ESV on. And the important thing to note, as you can see, is the pinning of the specimen and ensuring that you're pinning the specimen outside of the margins. And in this case, you can see they've got good margins and take the measurements and then send it to pathology. So the next case is that of the gastric subepithelial lesion. A 67-year-old female was incidentally noted to have a gastric subepithelial lesion during an upper endoscopy for Barrett surveillance. And as you can see in this image on endoscopy, there is around a 1.6 centimeter subepithelial lesion along the greater curvature of the gastric body. And on EOS, you could see that it's around the same size, but it's originating from the muscularis propria layer. And the findings were most consistent with a gist versus a leomyoma. No biopsies were performed in order to facilitate future endoscopic intervention, and the patient chose to pursue endoscopic resection over surveillance. The plan is to perform an upper endoscopy with endoscopic resection. We have multiple options on which we would pursue, including ESD, endoscopic full thickness resection, or submucosal tunneling with endoscopic resection. Over to Dr. Khashab. Okay. So this is the lesion. Originally my intention was to tunnel, but it was hard because the scope was kind of retroflexing. So then I decided to go to, my plan was to do a STIR, submucosal tunneling endoscopic resection. But frequently in the stomach, as you guys know, that's difficult. So I changed now to a full thickness resection using an ESD technique. What do you guys think? Amol, I know you do a bunch of this. What would you have done? Well, I agree that stomach, although I would definitely try doing a STIR in this case because it's kind of safer and saves you a lot of headache for closure, I agree that it's not always possible. And then in that case, one has to do a full thickness. A few other things, which I would probably do, I can see you've taken off the mucosal cap. The mucosal cap, I believe you've resected off. And I usually try and retain the mucosa so that I can use it for closure. That's something which I do a little bit differently, but then, yeah, you know, you can do it. So what I like to do is, the reason I unroof is to, and we've done it together in India, and you've seen me always do that, is when I shave it, I mean, when we're doing ESD, if we're doing this ESD technique, I don't see any benefit for the mucosa, it's going to come off, we're not tunneling. But as I visualize the lesion, and my intention is to minimize the defect in the muscle. So once I'm seeing the lesion, then I feel, you know, I minimize that. So that's just the way I think about it, you know. This is looking like a gist. Of course, you get these sometimes, they end up being lipomas, you know, the referring physician is mistaken. I did take a look at the EOS, and it does look like a gist, to be honest, so. Moeen, you're using the insulated tip knife. Can you talk a little bit about why you're choosing that knife in this situation? I think here in this case, it's just to provide efficient cut, and I try to protect the muscle layer. There's a lot of swinging here, you know, with motion. It's a lesion from the muscle. It's not as clean as a ESD that you guys just saw. So the intention here is for a full thickness. So I just feel with the insulated tip, it gives you an extra protection here. Right. So does it also protect the capsule of the tumor? Absolutely. Yep. That's a good point too. Yep. Yeah. And so another thing I think that one should discuss is that, you know, when you're making the decision between tunneling versus a full thickness resection methods is, you know, what do you have available for closure? And how are you preparing for the moment of full thickness? Do you have decompression devices available? Is that part of the plan automatically? Yes. So we do have a kit, and this kit has all the closure devices from simple as clips to overstitch, X-Stack, Ovesco, all of the above. And also a virus needle or virus needle like device, just a needle guys, injection. And here, you know, occasionally we get lucky where the lesion starts in the superficial muscle layer, and then you can shave it off the muscle without causing a full thickness defect. Right. You know, but you got to, if you want to embark on this, you want to know you're able to close and you have to be good at the over the scope stitching or using the overstitch device. I think here we're going to have to use it at the end. Or at least some method for full thickness closure and as opposed to mucosal closure as you know, we've seen with the other procedures. Yeah. So now, you know, the layers, of course, with these cases, needle out are not as clear. Needle out, inject. So we're going to have to do frequent stop, needle back. What we can see over here, many of them. Can you guys hear me well? Or I need to get the mic closer to my mouth. I think there's a bit of a hissing noise in the background. Can you guys help me here? We hear your voice just fine. Moeen, we hear your voice fine. There's just a background noise happening. Okay. Inject. We're putting it on the mask now. Is this a little stop? A little better? Back? Much better. Much better. Okay. Good. Out. Moeen, I just thought that you injected inside the muscle. No, I think here it's submucosal layer. Back? Do you think this is muscle here? No, this is submucosal layer. Okay. But yes, this can be a problem, of course. IT, IT, IT. Let's continue with IT. So here we're going to layer by layer, carefully. I like to go as slow as possible to go down and visualize where the muscular attachment is. That's the key for this procedure. The wider the attachment, the more difficult the procedure is. Exactly. So that's really the key. And you get lucky when that attachment is not wide. So here we're going to continue. By the way, I'm using forced coagulation, guys. What would you use for this type of open? Forced coagulation too. I would use forced coagulation too. Yeah, I mean, a lot of bleeding. Because we're going deep, you know? We're going... So you can encounter big vessels. This submucosa does look, you know, has a fair amount of fibrosis in it. It's not that crystal clear submucosa. Yeah, and we see this like peritumoral fibrosis, huh? Yeah. There's fat and there's fibrosis for sure. Sometimes the muscle also is a little bit thinned out at the point where the tumor is. And so the submucosa and the distinction between the submucosa and the muscle becomes a little bit unclear. Yeah. That can also happen sometimes. So these are, of course, you know, the challenging cases. I will say if you can tunnel, that just makes your procedure shorter. And just the closure, really, that's the key. Amol, I think you mentioned you tunnel. Then your closure is like a poem closure, you know? Very easy. Maween, we saw, you know, obviously a really beautiful demonstration of traction for classic ESD. What role do you think that traction has here? I mean, you've removed the mucosa. But if you had, you know, left a mucosal cap or something like that, do you think that would have assisted? Or do you think it hasn't? I'm not sure for a case, you know, where you're cutting the muscle. It's, you know, because the intention with the traction is to not touch the muscle. So I think the, can you put it out, please? Yeah. I don't find it as useful here. You guys, okay, let's clean the knife. And so here, because of the fibrosis, you see the lens is getting a little cloudy. But we're getting there. We can re-inject here. You know, I hear there is a new knife coming out, guys. It's similar to an insulated tip knife, but also it can inject. I am sure Amrita knows about this. Do I? I mean, that was the news to me. Yeah, so it's kind of cool. You retract the tip and then there is a needle. Because, you know, this is the problem with the insulated tip. You can't inject. So if they can give you an insulated tip with an injection capability, that's an amazing feature. Absolutely. There is an O-type knife from Irby which works a little bit like the insulated tip. Okay, back? I mean, I think it brings up a good point about the insulated tip knives. They are very good at protecting, but you do have to be able to access, at minimum, the bottom of the insulation. For example, in this case, the disc or the shaft. If you don't have enough room, then it can feel like very futile cutting. And that sometimes depends on the angle. The angle is very crucial there. Yeah, you can see the triangle tip that is there below the insulation. That's where you need to make contact with. And if you can't get deep enough, then it's not effective. That's where you're getting into the muscle now, Maureen, I think. Yeah, there is muscle there. Yes. Eventually, we're going to have to cut it, Manol. Yeah, yeah, yeah. We can't get anywhere without that. What do you do? Do you try and dissect on all sides before you cut through the muscle? Because sometimes what happens is, once the serosa opens up, then you lose distinction, and because of that, visualization becomes compromised. Yeah, no. Usually, you're going to see the defect while cutting. You don't have that luxury of waiting until the end to cause the muscular defect. Right. Of course, it stresses you, and then it can become an issue because insufflation can become more difficult. You just have to relax and do it. And here we see, I think we have to re-inject, guys. There is a question from the audience about the use of a hook knife in this situation. You know, I think it's good, especially if you have fibrosis, but I still think the safest thing here is this IT2. It slows you down a little bit because you can't inject, but I think the hook has also a role, but I mostly use this knife here. You know, I might change to a dual-J if I need to inject frequently open. So, just to make it more efficient, so here's inject. Amrita, the issue with the hook knife is it cuts really too fast, and one can really go through too rapidly, and then you don't want that kind of a situation with a full thickness because you can lose control sometimes because of the speed of the cutting. Yeah, I agree, and I think the lack of, you know, every portion of the knife can transmit energy. It really does lend itself to causing sort of peripheral damage. So, can you guys comment on this back? Give me the IT2. You see here the muscle fibers are at like different planes. You see this is a muscle fiber here, muscle fiber here. This is submucosa here, and this is the tumor. So, not really easy to distinguish the layers. Yeah, see I think the tumor is coming from the deeper muscle layer, and it's pushing its way through the superficial muscle, and there's a reason you're getting this kind of a picture. So, you may have to split the lower side, and then another tumor pops out. Yeah, I mean here I think patience is important. So, and as we said, delay the muscle injury or the muscle, the complete muscular defect as much as you can, because the procedure can become trickier, you know. Yeah, and at this point where you find that, you know, the next cut is potentially muscle might be where you go to the other side of the lesion to see, you know, how much you can dissect there. Yeah, I know I'm starting on the easy side here actually. Relatively easy. One of the differences, Amrita, with muscular tumors is that they don't flip over like mucosal tumors do. For ESD, as you dissect, the tumor flips over. The polyp or whatever we're dealing with flips over, and some mucosa becomes more evident. Can we change the... Amol, have you ever had any issues with the lesion falling into the peritoneum or in that direction, making cutting difficult? Yeah, see, when we've done full thickness dissections, occasionally we've had the tumor going into the peritoneal cavity, but not into the free peritoneal cavity. There's still some muscle attachment remaining, so we need to pull it back into the lumen of the, you know, into the stomach and then work on it for the rest of the dissection. That is a distinct problem that one can face and one needs to identify that because you don't want the tumor to fall off into the peritoneal cavity because probably you'll never be able to find it unless they do a laparotomy or something of that sort. It would be really a nightmare to get it out. So here, guys, we're starting to see the connection. And here it's clear that this connection is going to be a wide connection to the muscle. So we see here, right? Yeah, you can clearly see the capsule extending down below the muscle right there. So we have to cut through these fibers to get to the lesion, and that is once you cut these fibers, then it's a full thickness. So we'll try to delay it a little bit. This is a great time for that knife that you're using now, really just inching your way, actually, I said millimetering your way. You want to avoid the inevitable. Sorry? You want to avoid the inevitable. The pink tissue that you see there rising up almost like a volcano, do you think that's capsule or do you think that's muscle? Yeah, that's the tumor. That's here. Yeah, this is the tumor here. This here, where my knife is, is the tumor. It's important to recognize that. And we see the normal muscle here, and this is the tumor growing through. That's basically it. Can you go from the other side, Mouin? That's what I'm trying to do here. Let's inject, guys. Mouin, in these kind of cases, do you find that body positioning and changing it helps? As Amal said, the lesion doesn't really move when it's attached to the muscle. No. I mean, the only reason is pooling, and it's not an issue here, but I don't think positions change. Patient is on her left side. You know, most of the lesions I resect in the stomach are typically in the fundus. So you do them in fully retroflex position. It must be the same to you guys, right? This is where most gastric gists are. Yeah. Gastric gists are the most common. And actually, that's a nice position to be in, because in retroflexion, your scope is in a relatively stable position, and even closure is relatively easy, because we tend to use a loop and clip technique for closure. We occasionally use the Apollo overstitch for lesser curve defects, but fundus, I think, the loop and clip works the best. Yeah, you know, that's the endo loop that he uses. Works very well. We don't have that detached endo loop. Right. Let's get the chiropractor for a second. You can detach even the Olympus endo loop. It's just that it becomes very difficult to secure it again, because the hook is very thin. That's the only problem. We've tried doing that with the Olympus endo loop. It does work, but just becomes a little bit more tricky. So I'm just going to treat this tumor vessel here. Yeah. And then continue cutting. Actually, that might be a good segue, Moeen. We'll watch you treat that vessel, and then maybe we can show a short video on some issues with bleeding and perforation. Yeah, please go ahead. I mean, this is not going to finish anytime soon. So just to point out, you're just treating it with the tip of the coag graspers. You don't need to actually open and grab that vessel. Yeah, very small, and I'm not trying to get it away from the muscle or anything like that. I want to re-inject here and then go with the IT2. We'll work on this side. So maybe when you come back, we'll show you the work with the retroflex position. Okay, guys. We are still working at this. I think we're going to need some significant more time with this, just because of the degree of attachment. The patient is still doing okay. So this is the other side, and you see the whole thing has deep attachment. So we're thinking about what you guys mentioned in terms of traction, and we thought of snare traction, but not sure really what that's going to accomplish. I think we just have to start cutting the muscle, to be honest, and then prepare for – because look here, I'm pushing on the muscle now, and look how deep this thing is. Yeah, I think, Maween, what's interesting – I've had a case that was similar. If you start your cutting right here, there is still serosa that it may be attached to. It might go all the way through muscle, but you might be able to do the peeling that you were describing, at least in this part. The other side definitely looks like you're going to have to go right through. Yeah, so I'll continue working on this, and we just want to – we have five more minutes here. What will your closure method be again? We're going to do overstitch. Okay. Yeah, so we're prepared. No pneumoperitoneum yet, so we've delayed it up until now. So we'll see what happens, but the plan is to close with overstitch. Some of the mores extend beyond the muscle, and their larger component is beyond the muscle, and that makes delivering it beyond the muscle, from the muscle, a little bit more difficult. Yeah, so – You might open that muscle a little bit more. Yeah, so if there is an exophytic component, then that's no serosa, nothing. You're going to expose the peritoneum, and these are, of course, difficult. If your scan shows that this is a place where it's easier for the surgeon, right? So if there is an exophytic component, then I will just refer for surgery. They will do a small wedge resection. Surgery, of course, is more difficult for lesions up in the fundus and cardia, but this is an easy place. So we really don't have to push this if there's significant exophytic component, but we don't have that evidence yet, so I'm hoping that it ends there and we will be good. But Amol, if you have this, will you still close with your technique that you mentioned, with the endo loop? Actually, this is a little bit lower down, Muin, and in this location, the endo loop really doesn't work well. Sometimes, basically because you can't get the loop all around because it keeps flopping here this way and that. So in this area, we prefer to use an overstitch, and that works better. But in the fundus, you can really position the endo loop very well around the defect, and then you can use clips to fix the loop and then close it. So there it works better, actually. Especially in the midbody, which is always a tricky location to work with. Muin, there's a question about the full thickness resection device. Now there is one available for the upper GI tract. It looks like this is probably too big, but it's worth kind of mentioning, you know, when that might be used feasible. Yeah, you know, that also is part of the things we went through this morning to decide what to do. This is a little bigger than what we can do usually, but since we really exposed it, so there's no mucosa, there's no submucosa, we know exactly what it is, it might be an option now, you know? So this is now one and a half centimeter because there is nothing else, right? This is like the hybrid technique that Greg described for EMR in the colon. Yeah, so it might be a good idea. I mean, when I saw it initially, it would be impossible because it's kind of buried down, we don't see it well, it's going to be hard to suction it. But we may go for that, guys. I think just for the sake of time, we may go for that. What we will do is, I'm just going to conclude. Let's actually set the FTRD device, guys. Give me a 20 millimeter CRE, let me dilate the UES. So we're going to use an FTRD, so thank you for whoever suggested it, I think it's a good idea given that we unroofed it. I like to dilate the upper esophageal sphincter to 20 millimeter before I go in with the FTRD device. We're going to use the 21 millimeter device to make sure we get the entire lesion.

gastric subepithelial lesion

endoscopic resection

FTRD

endoscopic submucosal dissection

submucosal tunneling

overstitch