ASGE SuTab tip of the week. Here are some keys to success in the resection of lesions on the ileocecal valve, beginning with the very important cap or distal attachment on the end of the colonoscope. So this is the Olympus distal attachment, it's a soft, plastic, transparent cap and it fits over the end of the scope. There's a little hole in it that you put next to the lens. US Endoscopy makes a similar device and we just leave it sticking out a few millimeters from the tip of the scope. It's got a variety of uses in colonoscopy, but with regard to polyps on the ileocecal valve, the issue is that as we approach the valve, if my hand is the valve and that's the orifice into the ileum, we're often tangential to the lesion. So we can take this cap and bend the distal or anal side of the valve down so that we're looking on FOS directly in and seeing the lesion better. Also if there is lesion extending into the medial wall of the cecum between the valve and the appendiceal orifice, we can go over the top of the valve and bend the entire thing down in order to look directly at the lesion. This is an adenoma on the ICV that extends around the entire circumference. These are kind of unusual to go around the entire circumference, but the principles that we'll be able to demonstrate with this lesion apply generally to lesions that are on the ICV. This is an adenoma. The part that extends off to the left off the valve looked granular. The part that is on the ICV going around the orifice looks a bit like a non-granular adenoma. And we're going to demonstrate some principles that I think are useful. The first one is that the injection should start on the margin of the lesion that is closest to the ileum. And that's simply because you want to push the lesion out away from the ileum where it's easier to access. If you inject the margin that is farthest away from the ileal orifice, you'll have a tendency to push the lesion down into the ileum. So this of course is an adenoma. You can see the adenoma's pattern. I've never actually seen a serrated lesion completely encircle the valve orifice. You'll see serrated lesions on the valve. They're usually on one side or the other. But they usually don't get this big that they go all the way around the valve orifice. Now there's kind of a nodule right here of adenoma that we're about to remove. And you can see that I actually removed some of the polyp distal to it before I took it out. And that's because when I was first looking at it, I was having a hard time deciding if it was adenoma. And that's because there is a transition zone, I call it a transition zone, normally right around the lip of the valve where you have mucosa that doesn't have obvious villi like we're seeing in the ileum adjacent or on the margin of this lesion. And also it's not typical colonic mucosa with a uniformly spaced pattern of dots. Rather it kind of has a nice two pattern to it, but not clearly villi. The villi are blunted and it can be quite difficult to see the margin of an adenoma in that transition zone. In this case, the lesion extends far enough down into the ileum that we're really seeing villi on the edge. For most of the lesion, it's pretty clear where the margin is. But the key things are we started that injection on the ileal side, the ileal margin of the lesion. And we're also for the most part, we're doing the resection that way. We're trying to get the parts that are hardest first, move those out away from the orifice, get them more accessible, and then we can resect the rest of the lesion. The other thing that's very helpful here is this cap that we have on the end of the scope. You can see how we're bending, in this case, the distal edge of the valve down. We're basically using that cap and turning the valve orifice directly on FOS to it. You can also use this on the medial wall of the cecum, see that mucosa that is between the ICV and the appendiceal orifice. And then you'll notice that sometimes when we're snaring, we just put the snare right down in the ileum and sort of push the snare in as we open it, it'll pop over a piece of polyp that we want to resect. And finally, we're going to do snare tip soft COAG around the outer edge of the lesion. Now there's, this is a kind of a unique lesion because it has sort of two margins to it. One is this outer one on the colon that we're doing STSC2. While I was doing this, I noticed a little area that I thought was not resected in the right plane. So we're stopping to avulse that. And then we're going to return to STSC. But I don't usually treat the margin that's down in the ileum. It could be safe to do that. I've never actually seen a patient develop a clinically significant stricture or bowel obstruction from doing this. But just to reduce the risk of narrowing and make it a little bit more accessible when we come back for follow-up, I usually just STSC the part that is out on the colonic margin. It's very common to see fat. We see fat on the ileocecal valve. You sort of expect to see it. Also common in the right colon. You really can see it anywhere in the colon, but you expect to see it on the ICV. The ICV is quite stiff. There's almost no risk of perforation. I've never seen one or really even heard of one. But there is a risk of bleeding. However, it's quite difficult to close the defect that's up on the valve. The valve is too stiff. I usually try to close part of it. And you can see the orientation of the clips so that we're getting it basically across the lips of the valve. But it's hard to pull the entire lesion together because of the stiffness of the valve. So these are some of the key tools to use in approaching ICV lesions. Here's a demonstration of what I refer to as this transitional zone of mucosa. I see this in virtually every ICV that I look at. And in white light, a little bit hard to see here, but here we are with near focus and narrow band. You see that sort of dark band. Now we're out in the colonic mucosa. That's the normal pattern of colonic mucosa, that tiny pattern of white dots. But as we move up toward the valve, we'll see this band. Right there it is. It's sort of cuboidal, oblong. In this case, it looks a little bit darker, but it's not distinct villi. If we move just to the right into the ileocecal valve, we'll start to see villi that tell us that obviously we are in the small bowel mucosa. They're starting to appear there. And this strip goes all the way around the ileocecal valve. There's more normal villi. But I think that this transitional zone is part of the reason that the recurrence rate is higher on the ileocecal valve. Part of it is just that lesions are hard to access. There you can see it. But if the edge of the lesion is in that transitional zone, especially if you don't have a high definition scope, it may be unclear where the edge of the lesion is. Just to make sure that we're on the same page about the appearance of this transitional mucosa and what we're looking at, I've got yellow lines on the borders of it. So to the left of the left yellow line is normal colonic mucosa. To the right of the right yellow line are typical small bowel villi. In between the two yellow lines is the transitional mucosa, which is flatter than the typical small bowel mucosa and small bowel villi. But the pits are more elongated and ovoid than the normal colonic pits. This is a six month follow up of a large adenoma removed from the distal or anal side lip of the valve. And you can see this nodule right next to the edge of the scar. And here it is in neuroband imaging. And this nodular area I initially felt was recurrence or residual of the original polyp. This is a still MBI image of this area that caused me initial confusion. So the yellow arrows are on the scar. The red arrows are on the transitional zone mucosa above the nodule. The nodule itself is within the green line. And it's the pit pattern within that little nodule that I initially thought was residual adenoma but on closer inspection is really identical to the transitional mucosa within the red arrows and on biopsy was not residual adenoma. So you have to deal with this transitional zone during the initial resection and during follow up. Much of this discussion has been about how to access ICV lesions for resection. And next week we'll add on the tools of retroflexion and water floating for accessing ICV lesions for resection. But those two tools are not specific as specific for ICV resection because they can be useful in a variety and even many colonic locations. Thanks and see you next week on the ASGE SuTab tip of the week.

successful resection

lesions

ileocecal valve

colonoscope visualization

injection technique