I'll go to a live case demonstration by Dr. Rex. So this is case five. This is a 63-year-old male who had a screening colonoscopy in June, found a 40-millimeter lesion in the hepatic flexure. No biopsy was taken. A tattoo was placed on the contralateral wall. The non-granular LST, fly-elevated type. Four other 2- to 6-millimeter lesions were removed, which were tubular adenomas, planted aids, high DMR, and clip closure. So thanks, John. So this, I'm in the cecum. The lesion's back in the hepatic flexure. But I think there's a couple of interesting things here worthy of discussion. One is this adenoma right here. And there's another one right there. And then as you come back, there's an adenoma a little further back that's probably both, I mean, those are both really small lesions. But right here, there's a lesion that's probably, I don't know, I'd say that's 12 or 13 millimeters. And so, and then on the way in, I saw a couple of lesions. So it reminds me that the high level of synchronous disease in patients who are referred for large lesions, lesions that are over 20 millimeters. So I will tell you that we find at least one more adenoma in 80% of the patients that are referred. In 40%, we find another advanced adenoma. So that would fit here because this is technically an advanced adenoma because it's over 10 millimeters. And in 20%, we find a second lesion that is over 20 millimeters. And in a little bit less than 1%, we find a second lesion other than the one the patient was referred for that has cancer in it. So it's a reminder that we really want to clear the colon, you know, carefully. Now, I'm going to do what, in this patient, what I sometimes do, which is I tell the patient they've got more polyps to remove to try to get them to come back. We have patients who travel from quite a distance. And everybody's got a variable perception about how much trouble it is to, you know, to come to the city. But I tell them, you know, I know there's some more lesions in there. We got the big one out. So here's the lesion the patient is referred for. And I'm interested in people's characterization of this. I would call this non-granular because the surface of it is smooth. And I would say flat elevated. I don't feel that it's got a really significant pseudodepression in it. And if looking over the surface of it, I think the vascular pattern is intact. But it is a little bit altered, you know, in the center. I mean, this is not a vascular pattern to me that suggests cancer. But I'm interested in the panelists. Does anybody feel that there's any depressed component in this? Or would you characterize this as flat elevated? I feel that we should insufflate it a little bit more because between the two folds, like this lesion is extending over two folds. And the area in between them could be just simple depression between the fold versus real depression. Okay. I'm in there now between the folds. And I still think that vascular pattern, although it's altered. But I see exactly what you're talking about, Mohamed. There's that place kind of deep in there, this recession. But I don't see anything that looks like NICE 3 or ACUTO 5. I don't know if there are other spots. What I find interesting is you see actually a type 3L and type 3S pattern. And it seems like almost there's like an area that's more 3S and then you have more 3L at the margin. So and then in that depressed area, there was a little more like the punctuated vascular pattern there in the middle of it, I think. And so that makes me always suspicious there to the right of it, up on the margin there. And then you have to the right of it. This is like a 3S, I would think. And then to the right of it there, you have a different pattern. So you see the difference between 3L and the 3S. And I wonder, and that's also more depressed. And you see the same change, by the way, in this umbilical polyps with the valley sign. And I wonder whether those polyps just have a different growth pattern, that there's more growth from the margin. Yeah, it seems like there's two process. One area is granular polyp and other is non-granular. And they even have totally different, like it's almost like two different pathologies in one polyp. Yeah. Okay, so I'm interested in people's options for how to remove this. We know that in general, non-granular lesions have a higher risk of cancer. They have more submucosal fibrosis. The flat elevated type has only a risk of about 5% of cancer. If there is a pseudodepression in it, then, you know, the risk of cancer is much higher. You know, this is, I would not do ESD up in this part of the colon. And I don't do a lot of ESD. And when I have done it, I've done it just for rectal lesions. And I think, you know, in some of the discussion we talked about, you know, the, it may have come up that the value of avoiding surgery is greater for rectal lesions than for lesions up here in the colon. So I think it's probably too big to take out with a full thickness resection device. I don't think you can get the whole thing up there. The data says that up to about 15 millimeters, you can usually get the whole thing out, or almost always. 20 millimeters, you have a little bit of drop-off. I think this is probably, you know, at least 25, if not 30 millimeters from tip to tip. I am, myself, I am tempted to, let's take a look at this underwater and see what it looks like. But the other thing about this lesion, if you inject it, is that it will get really thin. And, you know, it will be even harder to snare. Whereas, if we take it off, if we take it off underwater, you know, I think we have a better chance of being able to snare it, you know, reasonably. This kind of lesion, I think, we'll probably end up using the cap technique a lot if we just try to do traditional EMR. So, I'm thinking about doing this with underwater EMR, but I am very interested in what the panel thinks that is the right thing for this lesion. Any other thoughts? Well, I feel like if we are not going to do ESD and we're planning to do EMR, understanding that if we come positive, we'll go for surgery, I feel the safest way to achieve complete removal would be underwater. And the reason is we have this slightly depressed part in the middle of it, and we also have a lesion extending over two to three folds, very close to the cecum. Underwater EMR would be the safest method to do it. Okay. Now, I don't think I can...I don't know. I understand what Helmut says, but I think that there's a fold in this thing. And, you know, to get it on block is going to be challenging for me underwater. Yeah, I think... Yeah. Go ahead. Yes, go ahead. I guess a very difficult lesion and all the locations, and in this situation, we do now this randomized trial comparing EMR, ESD. So for underwater, I think you won't get this depressed lesion, but at least the part that you try now. Sometimes we combine it with when the center is not lifting, there's a full thickness resection of the center. So a hybrid for thickness resection performing piecemeal EMR. In other words, take the perimeter off piecemeal and then take the center off and do a full thickness resection. Exactly. Exactly. That can be one approach. And then the other for sure, I would say if Yutaka Saito would definitely go for an ESD. It's quite a challenging location. I think for the moment in Germany, nobody has really good skill to do it without a high complication rate. The complication rate for perforation was in our ESD registry almost 10%. And in the colon, though, that's the limitation for the moment right now. So piecemeal EMR in combination of a full thickness resection of the center could be an approach from my point of view. Okay. That's very helpful. I think I'm tempted to do underwater on the, you know, trying to get a portion of the lesion out or all of it. And then if I fail in the center, you know, we could do FTRD open. And so let's see how this goes. The center always has a tendency to buckle closing. I think the biggest mistake that people make with underwater is, at least in my own sense, is to not get a big enough snare. And, you know, but I'm not trying for on block here. You know, maybe Ken Bidmuller would. I'm out from under the water, but I have the thing on there. Yeah. Should be okay, right? I think it's not possible to do an obloxious lesion. It's too large and the depression in the middle. I think there is for sure fibrosis in the middle of this, and therefore you don't have a nice floating of this lesion underwater. It will not end up in a complete obloxious lesion. Yeah. Yeah. I hear you. Okay. I'm going to pull this fragment back a little bit and go in and just take a look at what we did. I don't know if any of you have had the experience, but I usually think injection, if you inject with a lesion that is, you know, this thin with that sort of depressed fibrotic center, you can get into a lot of picking around and, you know, trying to finish the thing off. So, yeah, if we inject here, the central will become more depressed and it will be even harder to remove the borders. So, yeah, and maybe you might inject at the end once you remove most of it for the central part. Right. But for now... The cap technique, we might get the... The cap technique I was talking about in my lecture is where we, you know, we just suck the flat or fibrotic part up into, you know, the cap and then close the snare around it opening, right? So I'm going to do a bit of rotation around here. Take off the... Try to take off this right hand edge if I can. So there's the lesion again. Okay, start to close, right? So there you can see that buckling in the center, but it is, you know, it's, at least parts of it are floating pretty nicely. And so let's take this piece off and see what we have. And we'll pull that away and bring it back here in the transverse, I think. Okay. Okay, so we've still got our little buckled area in the center. So, but otherwise the resection is, you know, going okay. So let's go back in the water again. Any other thoughts? Now we're, you know, we're probably getting close to a size where we, you know, it would come into the full thickness resection device. I'm just wondering whether you're going to change to a smaller SNAN or to take off the last marginal area? That's a really good question. Just to leave the depressed area for it by itself and then take it all at once, if you could. Yeah. Okay, I'm going to take Heiko's recommendation. Let's go to a 15. I have, my own experience has been like, if I have a 20, 25 millimeter lesion where I'm going for an on-block resection with underwater technique, that's the most common mistake I've made is to not use a big enough snare, you know, because the surrounding mucosa, if you cut quite a bit of it off, you know, it doesn't really matter too much. And if you're shooting for on-block, I'd rather have a nice margin because of course it's being underwater that's giving us the safety of the whole process. I mean, I don't think it matters too much to take off, but, you know, this, you may be right here, Heiko, and the snare will be a little bit probably easier to open in this tight space. Dr. Dex, nice demonstration. So we will transition to another room and we'll come back towards the end. Okay. I'm gonna back off here for a second. And so you can see the defect. We're just getting ready to start closing this with X-TAC. And actually the entire lesion really came out underwater. There was one, two or three millimeter piece. Ryan, will you squeeze the rear end a little bit so we can get this inflated? This little place right there, I sort of tried to evolve, but I think it's all semi-coast. I thought maybe the plane wasn't quite deep enough, but I'm overall pretty happy with this. I went around the margin and did snare tips off COAG. I mean, there's no evidence that you have to do that when you're doing underwater, but I kind of figure if it's good for the goose, it's good for the gander kind of thing. So I usually, if I piecemeal underwater, I will do that. And, but overall I'm happy with the resection. I think that this was a good lesion for underwater resection. Sorry, we're having a spasm here right now. It was a good lesion for underwater resection because of the non-granular aspect. And I think piecemeal resection was okay because I don't think the risk of cancer was extremely high. So anyway, we just got the first tack in. I think it's a nice size lesion for a single X-tack closure. I'll come back here and show you this edge. And so we're gonna go ahead and do that.

colonoscopy

63-year-old male patient

hepatic flexure

synchronous disease

underwater EMR