All right, we are back with case six. We've got a 52-year-old female that has had their first screening colonoscopy at an outside institution in September of this year. There was a 30-millimeter non-granular lateral spreading tumor proximal to the ascending colon. There was no biopsy and no tattoo, and we're going to demonstrate underwater EMR of a non-granular LST and demonstrate post-resection tattoo techniques. Let's go to case six with Dr. Rex. Hey, everybody. I'm in the process of using the snare tip here and going around the margin of this lesion. I tell you honestly, I didn't do a great job because over here I got a little far away from it. The actual margin of it's down here, so I had to mark it twice. Now, this demarcation thing before underwater, I sometimes do this. I'll tell you honestly, I sometimes don't. But when we do EMR, we're supposed to have some kind of a demarcation process. If you do this again, if you're using the snare tip, be sure to use just the calculation current. Just a question for the audience about just looking at these lesions. You've already showed us a couple of examples of C colon, right colon lesions. How do you make that determination in this to use underwater versus in some of the previous ones, just injecting, lifting it, and just doing it that way? Can you just tell us the thought process of when to use what? Yeah, so I got to say that removing this by standard inject and resect methods is perfectly reasonable to do. Now, I would characterize this as a non-granular flat elevated lesion. The most worrisome lesions that we see in the colon are the, here's the TXI view of it with regard to cancer, are non-granular lesions that have a pseudodepression in them. Actually, the lesion that John removed earlier in the cecum was a more worrisome lesion, I think, than this one. But in general, there's more than one way to skin a cat. And if you become a big fan of underwater, there's a lot that can be done with underwater. And I'm sure that Ken Benmoeller would have taken off several of the lesions that we've removed underwater as opposed to conventional EMR. And the advantage of underwater EMR is, the main one is you have a higher rate of on-block resection because you're not making lesions bigger. And also, I think it's faster because you're not injecting. And, you know, kind of- Would there be like any lesions that you would say would definitely just should be removed underwater and not by standard injection? So I think that when you are, when you're in the range of about 20 to 30 millimeters, and you feel that you must get an on-block resection because of a high risk of cancer, that's a time when I would say you should definitely go on block. If you're, you should definitely go underwater if you're going to use a snare. Now, so- Hey, Joe, can I go to you? And just from the New Hampshire registry, I mean, just give us a sense of the prevalence of these lesions so that our audience can understand, you know, how frequently should they be encountering this? And if they're not, are they perhaps missing it? Because these are several of them, not this one in particular, but several flat lesions. So can you tell us, Joe, a little bit about the epidemiology of these lesions? Well, you know, in the New Hampshire registry, the prevalence of these lesions is extremely low. And so the question is, are we missing these? Certainly, I can't give you an exact percentage. If you give me about 20 minutes, I'll be able to give you an exact percentage, but they are- And in 30 minutes, you would have written that paper too, Joe. Yeah, the quick question I have for you, Doug, is that, so one of the things here that you do want to get on block with these lesions is that the field is often hard to control when there's a bleeding, right? So I don't know what tricks that you use or whether, if you get it in block, you don't have to worry about it, but if you're piecemealing it, like you're getting this one on block, but if you're piecemealing it, a lot of times you really have to be, you know, sort of, you have to really keep cleaning because you'll have a lot of bleeding if you're not using cautery. Yes, if you convert, we can always convert back to, to, you know, gas. Now, one thing it's, I think it's important when you're doing this is that you want to see the colon be fairly relaxed. The whole idea is that the lesion should float. And so I think it's reasonably, we did a reasonable job of that, but I would be a little careful. Like, for example, I usually take my foot off the water before I actually close the snare because I don't want the pressure of the water jet to push the lesion up against the muscle. And so let's see how we do here with the first piece. I think we should also mention that when we're doing underwater EMR, we're truly doing it underwater and we don't use any kind of special solutions that some people might use to submerge. Oh, right, right, right. That's important to, I mean, I think it's important to know about that. Let's open the snare again, John. A lot of people, when they are doing underwater, and this would include Ken Binmuller who invented this technique, they're actually doing the resection with saline. They're filling the lumen with saline rather than, I'm just gonna try to get this a little bit out of the way here if I can. Yeah, we also do like this with the saline. Yeah, so- For the current. For the current, yeah. So one of the things that people talk about with underwater resection is that you get, let's open here, is that you get a so-called heat sink effect. And, okay, you can close now, with either water or saline, but that heat sink might be better with saline. The reality is we don't have a randomized controlled trial to compare water to saline. But I think it's important for people to realize that when people are talking about underwater, they often are using saline. Now, Olympus says that if you use saline, that there's some chance over time of causing some damage to the channels of the scope. And I don't really know how true it is that that happens. But we have- Daga, we do thousands of resection with the saline. It never happened to our scope. Yeah. Nothing happened to our scope. Yeah, so I think, I don't really know what the evidence is, but that's what the manufacturer said. Now, when we talk about underwater insertion, for example, we do insertion with water, but there are people that do it with saline. And a disadvantage of, open again, John, a disadvantage of saline, of water, is that it causes mucus to build up after 10 or 15 minutes. And it basically causes the colon to secrete mucus. And let's start to close there, John. Okay, and that's a little bit more submucosa that I wanna get on the left, open. Now, I tell you that I start, and there's quite a bit on the far wall too. I'm gonna be a little bit more, I'm not the world's craziest guy here when it comes to snaring normal tissue. So I'm gonna use a little bit more control. Start to close now. And I'll just wait- What about injecting? Why don't be flexible? Why don't what, Cesare? Why not injecting this part of the polyp? Over there? Yeah, he's saying why don't you mix techniques? So maybe one worked and then you shift to another. I'm not like wildly opposed to that. I don't think that's absolutely a wrong thing to do. Very nice. If you mix technique. I don't think a lot's been written about it, but I do it sometimes too, especially if something is relatively hard to get a hold of, it's on the far side of a fold. Now, just looking at the defect here, I feel comfortable that this is all submucosa. And you see this fat over here in the hepatic flexure. And that's submucosal fat. That's not like omental fat or something, but it is important, I think, for everybody to realize that it's common to encounter fat when you're in the right colon. And on the ileocecal valve, you'll invariably get fat. We're gonna do snare tip now. Now- Do you expand here? So after you've cut it, you want it really collapsed when you're cutting, right? You're trying to have it all collapsed. But afterwards, Doug, do you then expand this fully to see the borders or do you still keep it pretty collapsed at first? Well, I have the feeling that you're gonna tell me I should- No, I'm not saying either way. I'm trying to have you explain your technique. I basically will do whatever I think is gonna make life easiest for me. And so the reason I'm doing this, this would be an area, because we don't really have data on snare tip soft coag after underwater EMR. We don't know if it's necessary. All of our snare tip soft coag data is really after conventional EMR. And so I could be wasting my time here. I certainly had- But I think, Doug, if you go back to the principle of why we think that this works, even for that, I think the same principle should apply to the resection no matter how you do it, right? Because I think the key is that even in the cases where you use conventional EMR techniques, you think you've removed it all, but still there's tissue left behind. And I think the same would probably apply here too. Right, right. That's exactly what I'm thinking, Prateek. And that's why I'm doing this. But just from a data, let's switch snares. Just from a data standpoint, I would say perhaps we don't have the data really to support it. That little- How often do you switch snares, Doug, in the soft tip, I mean, the snare tip soft coagulation? As soon as I feel like I'm not really frying things. I do think part of the, tip again, Joan, part of the thing that's important, if you're gonna do snare tip, I mean, I like to do it the way I see Michael Burke do it because his study is the one that proves that he says that he gets a 1% recurrence rate. And so, and I think he's quite aggressive about it. And so, and the thing about snare tip is that it doesn't increase the risk of a complication. And so, given that, I think there's not much of a downside to doing it and to being pretty aggressive with it. Now- Doug, there's a question about the current settings that you use for underwater EMR. Well, okay. So, I'm gonna be interested in what the panel says here. Let's get a mantis clip here. Yeah. So, my experience has been that any current that you use will work well. And if you look at Ken Binmuller's original report, he used auto cuts and I can't remember the settings, but, and then more recently, dry cut. And I have tried just about everything and I have not found anything that doesn't work. Now, what I'm gonna do is I'm going to see if I can pick up the bottom- Doug, here in Europe, we have a new setting named EndoCut Underwater that make the first cut faster. Because the problem with underwater is that the first cut is usually a bit slower. The first, I'm sorry, Jeffrey, the first cut is what? It's a bit slower. So, Herbie changed it in EndoCut Underwater so that the first cut of the mucosa in underwater EMR is faster. But of course there is no yet evidence about it. But I was curious about the management of this patient. Do you admit them overnight and- No, no, no, no. Or you send them home, you give antibiotic, you do not? We would typically not admit this patient. We'll discharge them if they feel good in probably about 45 minutes. We won't do, we won't put them on antibiotics. First position. We're also doing this in our, basically this is our outpatient ambulatory surgery center as well. Yeah, so- All of our resections under sedation with propofol and non-intubation, most of our cases are plotted for about 30 minutes to an hour, depending on the size and the burden of disease. And yeah, most patients get discharged within 30 minutes of the propofol. Okay. Hey, Doug, the other thing I noticed is you started with the clip right in the center, rather at the edge. Was there a specific reason to do that? I mean- I was using- That's a great question. That was the easiest position. I was using actually a mantis clip. And so I picked up the edge. Usually with a mantis clip, we will go in the middle because we're just trying to bring the edges together so that using standard clips becomes easier. So if I was doing a zipper technique, open and pretty much sideways, John. If I was doing a zipper technique, starting at one end, I would usually go with just a standard clip. But in this case, here you can see, I'm using the right prong of the clip. First position and fire. Using the right prong of the clip to bend the defect toward me so that I can get the clip, get the defect on fast to the clip. We want the arms of the clip to be completely filled with tissue. So you can see that if you look at the clips, there's no gap between the arms. And I think that that helps the clips to stay on. And of course it secures more tissue. So, and then sometimes you can go over the clips and actually let's open the clip and turn sideways. You can actually use the clips, manipulation of the clips you've already placed to help you manipulate the defect into a position where continued clipping is easier. So here I'm holding the previous clips down, first position, fire. And- Nice technique, Doug, that's great. Yeah. And now we'll just finish up with a clip down here at the bottom. And then we're going to, if somebody could get me a tattoo ready, we're gonna quickly tattoo. We've already actually demonstrated tattoos. So if we need to go to another room, we can do that. I think, Doug, we're gonna have the discussion about bowel prep right after this, so. Okay, perfect. So stay with me until it's time to go. I am gonna tattoo this. Now we talked about tattooing and tattooing for follow-up. I tend to tattoo if the lesion is not in the cecum or in the proximal ascending colon. If it's either one of those, then I just try to get a good photograph of the lesion with the ileocecal valve. Open, John. With the ileocecal valve in view. And here we're gonna push down with the clip. That's not working very well. First position and fire. And we'll have to stick another one in there. There you go. Aga, how sure are you that this patient will come to surveillance? Because in Europe, 30% of patients are lost to follow-up after EMR. So do you have an active recall of the patient at six months, or how are you confident on that? We do have, well, I don't wanna talk too much about things that aren't necessarily feasible for everybody to do. But we have a first position, John, fire, and then we'll go with the tattoo. Okay, I think we'll be okay there. So we have a coordinator who tries to chase people down for us. Some of our patients come from a long distance and they will do their follow-up with the original physician who referred them. But we try to encourage everybody to come back for at least their first follow-up. And we do lose some, Chesiree. And so I think that it's a real problem when we lose people. Sometimes there's, okay, good. Yeah, now what I'll do here is when we write the report, I'll say that I put, yeah, back. I put this tattoo just to the left and just distal to the defect. And I think it's very important when you're tattooing, always, always document where you put the tattoo in relationship to the lesion you're marking or the defect that you're marking. And that will help you later. So from around the hepatic flexure to the back to the rectum, oftentimes with a large lesion that we're gonna follow up, we will put a tattoo on for our own purposes. I think I'm gonna break away now so that you guys can start the panel discussion. I'll try to join you shortly here after I collect the lesion.

underwater EMR

endoscopic mucosal resection

lateral spreading tumor

snare tip soft coagulation

post-resection clipping

patient follow-up