Today I want to show some examples of the use of hot evulsion to complete EMR in cases of increased submucosal fibrosis. In many instances, you can predict the risk of increased submucosal fibrosis because of the morphology of the lesion, 1S lesions tend to have more submucosal fibrosis. Areas that have pseudodepression, non-granular lesions with pseudodepression, you can anticipate in that pseudodepressed area, there's more likely to be fibrosis. In this instance, the issue is ulcerative colitis, I actually showed this lesion in one of the earlier tips on the use of the CAP and we used the CAP technique to remove the overwhelming majority of this lesion because it didn't lift well. We have nice staining of the submucosa, but you can sort of tell that there's an increased amount of fibrosis here and we've got some residual flat tissue that really resisted snaring, and so we are finally reverting to evulsion, perhaps a bit more evulsion than we'd like to do, but it's allowing us to salvage and complete this EMR. The basic technique again, we're getting the forceps around the target tissue, getting a millimeter or two of normal submucosa on either side, lifting up and then just tapping the yellow pedal in order to excise this using cutting current. And so one example, the patient with increased fibrosis as a result of UC, now we can see STSC has been completed around the margin, but the base of the defect looks well cleaned up, the entire lesion by CAP and hot evulsion. Here's another lesion that we can anticipate is going to be a problem with submucosal fibrosis. This is a non-granular lateral spreading lesion in the transverse colon, and it's that center part of it that's going to be a challenge. Now this lesion has an increased risk of having cancer in it, non-granular lesions with pseudodepression have an increased risk of cancer. It's been biopsied twice, and I did look very carefully at the base of it and did not find any actual disruption of the blood vessel pattern suggesting so-called NICE 3 or Cluedo 5 changes that would indicate that cancer is actually present. And as you might expect, the edges of this lesion are considerably easier to remove than the center part. The part that tends to be fibrotic is that center area where the pseudodepression is, and that's certainly the case in this lesion. And now you see we've got these areas of red in the base of it after we've used the CAP technique. I demonstrated a couple of uses of the CAP technique, but you can also see a lot of white in the submucosa indicating increased submucosal fibrosis. Now some people would say that this lesion should be removed by ESD. I will tell you that ESD here is also going to be considerably more difficult than ESD on a granular lateral spreading tumor that lifts easily. So submucosal fibrosis is a challenge not only for EMR, but also for ESD. And you can see as we take off this area in the center that the orientation of the forceps is important. If the forceps were not coming out oriented in the up-down plane or mostly in the up-down plane, I would probably rotate them in order to be the best chance of sort of sinking the forceps onto this tissue. And so this is a bit of work. We're going to have to push in. I actually had to use manipulation of the abdomen several times in order to get the lesion to turn well against the forceps. You can see the amount of tissue that we have grasped there, a pretty good amount. We again, we have to be sort of careful to not burn the sidewalls in this instance. And we really have a fair amount of tissue to remove by avulsion. So this is a challenging type of EMR, but avulsion is basically allowing it to salvage. That's a really nice demonstration of peeling off. You could almost see the taps, the one, two, three taps, and the progressive, there it is again, the progressive separation of the mucosa with each tap. The separation is achieved, first of all, by the mechanical tension on the tissue. And then the mechanical tension is accompanied by those taps on the current. There again, you can see very nicely, there's a first tap, second tap, and a little bit of tension, and then a third tap, and off the tissue comes. We're just tapping on that current. That's actually just mucus up there on the right. We're getting close to having completed this process, but hot avulsion has allowed us to complete this. And fortunately, this lesion did not have cancer at pathology. Another situation where we can reliably see submucosal fibrosis is when a lesion has been partially snare resected in a previous attempt. That's the case here. This is a 1S lesion in the transverse colon where the distal edge of the lesion, this is often the case, it's the distal aspect that has been removed, and then the referring physician stopped. We've done a lift on the proximal or sacral side. We have nice submucosal staining, but along this distal edge, there is a lot of fibrosis. And rather than just burn that up, I'm choosing to remove a few more millimeters, and to do that, we will use avulsions. We've grabbed it. We're tenting it. We're going to use cutting current to remove it, and there's our first avulsed piece. Here's a still image just after that first piece has been avulsed from this rim or section of fibrotic material at the anal side of the lesion, and the yellow arrows are pointing to the submucosal defect where we've just completed the first avulsion. And notice that even though this entire ridge did not lift at all, that the color of the submucosal defect is blue, and it points to an observation that is often made that even when the lifting is very poor, that when you get the polyp tissue off, you still see that blue color. So the blue color helps to delineate and mark the submucosal plane, even in cases where there isn't good lifting. The green arrows are on a couple of folds that you can see radiating up toward the scar. The scar is often delineated by a sort of puckered look and folds radiating up toward it, but a nice demonstration of despite the absence of lifting, there's still nice demarcation of the submucosal plane by the contrast agent. I proceeded then in this case to remove several millimeters of this very flat tissue along the distal edge of this lesion by repeated hot avulsion, and then when this is finished, we are still going to do thermal treatment to the margin, and I will admit that I sometimes in this case when there is previous resection or recurrence, I will use APC. There's no evidence that APC is better than snare tip soft coag, but I've used it for years in this instance for treatment of the fibrotic edge, so I did it in this case. But some form of thermal injury to the edge, either STSC or APC is appropriate even after all the visible tissue has been removed by snaring and avulsion. There's a similar lesion, a granular lesion in the transverse colon where you can see the puckering along the distal edge. The entire distal edge of the lesion was removed by the referring physician, and we've done an injection and snare resection of the sacral or proximal side of the lesion, but the distal edge is scarred down from this previous resection, and we are resorting to avulsion. Now when we see this, we like the referring physician to know that in general when you begin an EMR, you should finish it in one session, but when it's stopped for one reason or another, we also want them to know they should not send the patient to surgery because using tools like cap resection and avulsion, we can complete EMR even when a lesion has been previously partially resected in almost all cases. And so we're taking off this entire fibrotic area along the distal edge. We're using our standard technique. We are sort of up near a fold, and so we're watching carefully to make sure that we don't get too much tissue. You can see some of the submucosa now is being exposed, and we are just repeating the process, grabbing the tissue, putting mechanical tension on it, and then tapping the yellow pedal until the tissue comes off, and we'll use avulsion to take off this entire distal edge of the lesion. When we're done, we'll be able to see the submucosa scarred but visible all the way across the distal edge of the lesion, just a few bits now that need to be removed by avulsion. So avulsion has allowed us to complete EMR in a lesion with extensive fibrosis along one edge of it by previous resection. We can clearly anticipate that this fibrosis would be present. Now we can see the submucosa beautifully exposed. We still are going to use thermal injury to the margin. We did it with APC and then clipped because we're proximal to the splenic flexure and size. Finally, an extreme example of this problem of submucosal fibrosis resulting from prior attempts at resection. This is a lesion in the rectum where four previous attempts were made to remove it before referral, and there is essentially fibrosis underneath the entire lesion, or whatever scar was present, the polyp regrew over the entire area. You can still see that there's some staining of the submucosal plane, but there was very poor lifting of the lesion. We did remove parts of it using the CAP technique, but our salvage method because of resistance to snaring is avulsion, hot avulsion. Hot avulsion is allowing us to salvage EMR in a lesion with four prior attempts at resection. The technique, whether there's fibrosis or not, consistently the same. Grab the tissue firmly, getting a millimeter or two of submucosa on either side, tent an appropriate amount, and then apply short pulses of cutting current there. It's the completed EMR before thermal injury of the margin. To summarize situations where we can anticipate submucosal fibrosis and an increased need for avulsion. First of all, lesions with Paris 1S morphology or significant 1S components, large nodules. Second, non-granular lesions, especially if there is pseudo-depression. Third, when there have been one or more prior attempts at resection with a snare, either hot or cold snaring will consistently induce submucosal fibrosis. Next, cold biopsy of serrated lesions or the flat components of adenomas or the edge of either type of lesion will cause localized submucosal fibrosis. Finally, tattooing I think is more of a problem for ESD than for EMR, but especially if the tattoo has been injected directly into the lesion, it can be a problem for EMR. All of these are situations where we can anticipate an increased chance of submucosal fibrosis and the need for avulsion. Thanks, and see you next week on the ASGE SuTab tip of the week.

hot avulsion

endoscopic mucosal resection

submucosal fibrosis

lesion morphology

previous resection attempts