Essentially, when we're looking at a lesion like this, it has a combination of a lateral spreading component, which is granular, which is generally an indication of the granular or villiform appearance is associated with benignity, and we're not worried about it. But when you have sort of the semi or sub-pedunculated areas or the raised areas, especially as you see here, that saddle shape with loss of the granular pattern, you end up with a non-granular pattern. We haven't gone in here to look at the pit pattern necessarily, but now we're more concerned about malignancy. This particular lesion had high-grade dysplasia, so we elected to perform ESD. Let's go ahead and play that. So this was tattooed, referred to me by the referring gastroenterologist. We'll pause there, go back just a little bit, just to show you that when we're evaluating these lesions, depending on where you are in the GI tract, if you are entertaining ESD, there are certain considerations. One is the ability to retroflex and get to the backside of the lesion, which is often necessary with ESD. The other thing is to make sure that you can see the complete periphery of the lesion and all the margins, because the critical aspect of ESD is to try to remove the entire lesion on block, which will then allow the pathologist to make the assessment as to depth of invasion with respect to the muscularis mucosa and the submucosa. So in this case, if we have lesions on the left side, this is sort of rectal sigmoid. We almost always use a gastroscope because the radius of curvature, the retroflexion is much easier to do. Carry on. So you see here now, similar to EMR, we inject a solution. There are many choices of solutions, but in the colon, which lifts relatively easily, I tend to use just simply saline with methylene blue and diluted epi. And now we're using, we'll pause here for one sec, the first stage of ESD is to create a mucosotomy. So we're going to try to enter into the submucosal plane by cutting through the mucosa. The type of current that you use here is different than what we use when we dissect in the submucosal plane. Cutting through mucosa requires a little more current, a little more cutting ability, and in this case, we're using Endocut Q222, and we're using, in the colon, because the mucosa is thinner, we're using a knife which has only a 1.5 millimeter length to protect us against going too deep. Carry on. Thanks, Lyle. So we're doing a peripheral mucosotomy. We're trying to open up the submucosal plane, and you can see here now, we're in the submucosal plane. We'll pause here for a second. But once you're in the submucosal plane, then we use a somewhat different technique. We use a hybrid knife which can inject into the submucosa to get the lift we need, and then, of course, we can do the dissection with both cutting and coagulating current. My particular settings are Endocut Q222, which I use with the hybrid knife, and that's for cutting. For coagulation, I use forced coagulation, really affect to about 40 watts. So we'll show how that's done. We'll carry on. And now we're in the submucosal plane. We can inject fluid and dissect with the so-called hybrid knife. And we're going to go through here and expose this as best we can. We'll pause here for one second. What happens in ESD frequently, especially in the colon where you have different angles, especially at the flexures, the rectosigmoid junction, you don't have a flat plane to create the axis of dissection that you like. So we're now looking at many choices for traction. And in this case, we can see on the right-hand side, we can see the bluish tinge of the submucosa. Relatively easy to dissect. But the difficult part here is on the left-hand side, where the lesion is sort of turned over on itself. We do use gravity. We do move the patient around. But in this case, I want to show traction. We'll carry on here. Thanks, Lyle, I can play that. That's right. And so the traction we're going to use in this case is a simple three-circle rubber band. We'll attach one end of the elastic band on the opposite wall with a clip. And then we'll take that band, and we will put the other end of the elastic band on the tip of the lesion. And when we're doing that, we suck air out of the colon. So we collapse the lumen to make it easier to bring the elastic band over to the leading edge of the lesion we want to lift up. And then when we're ready to dissect, and after we've attached the elastic to the lesion and the opposite wall, we then insufflate with air. And as we insufflate, we then create a little bit of a pull and a stretch. And that will make it much easier for us to dissect. I think you can clearly see here the plane of dissection. At this point, we're going around just to the edge. And in randomized controlled trials using traction versus no traction, the time for ESD has been cut by about 40%. So when possible and when appropriate, we do use traction. Now, of course, in this case, once we remove this lesion, it's not so big, but we examine the muscularis propria for any perforation. And then we have to take a loop cutter to cut the elastic band to allow removal of the specimen. So that's kind of your basics of ESD. Of course, there's a lot of subtleties that we're not going to go into at this point in time.

gastrointestinal specialist

lesion

endoscopic submucosal dissection

malignancy

muscularis propria