and on the ASGE suit tab, tip of the week. Here's an example of such a lesion, ascending colon, no overt evidence of cancer, very broad, very bulky. Our EMR challenge today is the very bulky, large Paris 1S lesion. And the first thing about this is that endoscopically, it's more difficult to predict the presence of cancer by the surface features. We wanna look over the surface carefully for signs of cancer, but the sensitivity of those for cancer is in the range of 50 to 60%, as opposed to a very flat lesion where endoscopic assessment of the surface features has sensitivity above 90% for the presence of cancer. And some would argue that that's a reason to remove these lesions on block by endoscopic semicostal dissection. But my own feeling is that the absolute risk of cancer is low enough that above the rectum, where the risks and the morbidity of surgery are not as high as in the rectum, it's acceptable to remove them by EMR. The second thing with this very bulky lesion when you're performing EMR is that we don't have snares big enough to get over them. So you're gonna end up placing the snare and cutting through part of the polyp. There'll be a bit of a tendency for that portion of it to bleed a bit more. But the key thing is that even though we are stuck with cutting through part of the polyp, we've gotta get into the semicostal plane. So we inject the lesion, and then we have to take the snare and wedge the snare very firmly into this semicostal cushion on the normal side. So that as we close the snare, we've gotta keep firmly anchored right there so that we can get into the semicostal plane. It doesn't matter if we get a huge semicostal defect, but we've gotta get started in that plane that we can then utilize to continue to cut across the polyp. The final tip about these big bulky sessile polyps is that often they'll have an area of fibrosis in the center of them. Now, fibrosis can be an indicator of cancer, but big sessile lesions like this often have an area of fibrosis even in the absence of cancer. And so as we're doing our EMR, we are likely to encounter some area of fibrosis. And that's designated down here where we see the blue in the semicostal defect, and then this area of residual polyp that's on top of fibrosis. And we can deal with that as we expose it, but a lot of times a good approach is to work your way around it so that you finish the EMR in all the non-fibrotic areas and then go after that central area of residual polyp on top of fibrosis using some combination of the CAP technique and avulsion. So here's the same lesion that we saw earlier, this bulky lesion in the ascending colon. And the first step in removing it, of course, is to inject it. You can see the large mound of fluid that we have underneath it. And we're using a large snare. This is a 25 millimeter snare. Even if you go up to a 33 millimeter snare, you're not gonna get around the whole thing. So we know that we're going to cut through part of the polyp, but we also need very much to get into the semicostal plane that we want to transect in. So we have to have the tip of the snare on normal mucosa, this blue mucosa out here adjacent to the polyp. And we're working our way under there to get very close or fairly close, and then pushing the tip of the snare very hard against the mucosa to anchor it in place as the snare is closed. Once the technician says they can feel the tissue, then we're gonna go ahead and transect with forced coagulation current. And what we're hoping to see is some blue submucosa. So we're working our way under there, and there you can see it. It's not a very big opening into the submucosa, but the key thing is that is the semicostal plane, and that's where we've gotta get into. So now we're just gonna extend that. We're getting over as much of the polyp as we can. Again, this is a very bulky polyp. When it was finished, I made four trips out of the colon with polyp tissue in a basket in order to retrieve it all. So we're pushing that tip of the snare sheath again into that semicostal space to anchor the tip of the snare there, and we want to continue to extend that transection in that semicostal plane. And as little as possible across the polyp. Now, as I mentioned, these big bulky lesions often have an area that has significant fibrosis often in the center, and in the absence of cancer, there'll still be an area of fibrosis. And if we encounter that, we can remove it using a combination of the CAP technique and the avulsion technique. There you can see it, and we're taking part of it off right now with the CAP technique, sucking it up through the snare into the CAP. And you can see that white fibrosis on the rim of this area that has been snared. But the other approach is to just go around it and isolating it. So we're finishing here going around it. And when we're done with that, we have this area in the middle here that is fibrotic. That's this red area here. And this was very difficult to snare. It resisted removal with the CAP technique. And so we're going to avulse it using hot avulsion, grabbing it using the endocut I-141 current and getting some mechanical tension on it, and then tapping the yellow pedal to pull that off and to resect this in the plane. So, but I think that the keys to this kind of a lesion are first of all, you've got to get that snare anchored into the normal mucosa so that at least part of your initial transection extends into the submucosa. It's really the anchoring on the normal mucosa that makes sure that you're not cutting completely through polyp, at least part of the transections getting down into the submucosal plane, and then follow that plane across. If you hit the area of fibrosis, you can start to work on it as you're going, or you can go around it and isolate it and then remove it either with hot avulsion or with the cast technique. And in some cases, there's going to be a significant amount of tissue that needs to be avulsed. I think down at the bottom there, we need to do a little bit more. And then when we're finished, we've got a nice transection in the submucosal plane. This turned out to be a benign lesion with only focal high-grade dysplasia. We're doing STSC to the margin. We're going to remove all of this before we clip it, just so that we're not banging a lot on the clips and knocking them off. So we're going to make several trips in and out of the colon. And then the very final step will be to clip close it because we've got a large right colon lesion removed with electrocautery. So we do have a risk of bleeding that we can reduce by clip closure. Next week, another challenging EMR, accessing a difficult lesion in the cecum on the ASGE SuTab tip of the week.

endoscopic mucosal resection

Paris 1S lesions

ascending colon

cancer risk

snares