Our next talk will be by Dr. Douglas K. Rex, who's the Chancellor's Professor at Indiana University, Purdue University, and President of previously both the ASG and the ACG. The title of the presentation will be EMR Techniques, How to Choose the Optimal One. Thank you very much, and great to be with you. Coming way back down to earth now, talk about something that we always do, EMR, that we all do, EMR in the colorectum. So I'm going to talk about some of the tools that I employ that I find to be useful in being successful in patients that are referred to me. These are the issues that we typically face, the size of the lesion, shape, access, fibrosis, and sometimes just the number of lesions. So I want to talk a little bit first about fibrosis. Size is what we'll come back to with some larger lesions. The general approach is to start on the anal side of the lesion, inject, resect, and move to the other side. But we do sometimes encounter fibrosis, more often in non-granular lesions, and you need a way to be able to deal with it. So the technique that I like to try first, especially if there's a large area of fibrosis, is the cap technique. And this cap is a very short cap. This is the Olympus Distal Attachment, Steris makes one also. And we just stick it out about three or four millimeters beyond the end of the scope. And then you take a small snare and lay it over the tissue. You can see some of this fibrosis that's been pulled up here. Lay it over the tissue, get very close to it, and then suction the tissue up through the snare into this cap, at which point you're blinded. So there's the snare, we're very close. We've suctioned it, and now the technician is closing on the tissue while we're blinded. And this is a way to get a hold of fibrotic tissue that is resisting your snaring method, which is something all of us encounter during EMR. You want to use a small snare because you're blind at the point that you close. 15 millimeters is about the biggest that I ever use, and most of the time about 10 or 11 millimeters. When your techs are first learning it, it's nice to use a flexible snare. There's the snare. We approach the tissue very closely so that nothing else can come in when we suck. Suck the tissue up through the snare, and then close on it blindly. And they have to go by feel. If they're using a flexible snare, like a CaptiFlex instead of a Captivator, the throw is smoother. So when they're first learning, it's easier to feel that tissue when they squeeze it. You hold it there until they tell you, I've got the tissue. And then you release the suction, look at it, and cut through it. And you can get through fibrotic material, especially when you have to cover a large surface area. That's called the CAP technique. Now, the CAP technique is also a way to get through flat disease. This is a non-granular, flat, elevated lesion. I'm going to come back to the issue of non-granular because I'm tending to use underwater resection more. Non-granular lesions, which are not lumpy bumpy, they have more fibrosis, the flat elevated type has a very low risk of cancer. And when you inject them, you make them even thinner and even harder to snare. But again, this technique can help you with flat disease if you have injected it. So very simple to do, but it requires a little practice. Can't give up the first couple times you do it if your tech has a hard time feeling it. You let go of the tissue and they haven't closed enough. Or the first couple times, they might cut through it, the tissue, during that blind phase. But can be very useful approach to fibrosis. Now the other technique for fibrosis is avulsion. I think the modern EMR has to use avulsion. Avulsion just very simply refers to pulling tissue off with forceps. And it's not as efficient as the CAP technique because you can only get what's in the forceps. This is a lesion that was partially resected. In my practice, almost a quarter of all the lesions that are referred, somebody has already removed part of it with a snare. And it's usually the distal side of it, the side that's easiest to access. So you can see the part over here lifted well. There's a nice submucosal stain. But this part down distally, this is residual polyp that is very fibrotic from the previous resection. And avulsion in general is more effective than the CAP technique. The CAP technique will still sometimes fail. It'll be so flat, so fibrotic that even when you've got it sucked up in there, the snare comes right over the top of the tissue. But avulsion will almost never fail to get a hold of flat or fibrotic tissue. I like to do hot avulsion, the Greg Haber technique for it. And the basic technique is you grab a hold of the tissue. You don't want to have a huge amount of overlap into the submucosa. So we'll see here, we'll put the forceps out and maybe overlap into the submucosa by a millimeter or two, especially if you're right on the tip of a fold. The muscle comes up closer to the surface at a fold. Grab it, then pull it back so that we've got mechanical tension on it. And then we're taking this off with endocut. Endocut I, I have it on the 141 setting, so it's almost pure cutting current. And you can see right there that that tissue is coming off in the same plane that we were resecting in. Now, some people do avulsion without electrocautery. And then after they take the tissue off, they take the snare tip on soft coag and burn the whole thing. That's the cast technique, cold avulsion snare tip, cast technique. We have no comparative data to say which is best. But I think avulsion is a key tool for the modern EMRs because, as you've heard, we're never, ever, ever supposed to ablate visible polyp tissue. Used to be we would just kind of, you know, burn that tissue up with the APC. We're treating the margin there. But we never ablate actual visible polyp tissue. We either snare it. If we can't snare it, we avulse it. This is a lesion that the referring doctor had worked on four separate times before referral. It's in the rectum. And the whole thing was fibrotic. And so I had to really resort to the use of forceps. So when you, when you grab a hold of the tissue, sometimes it's helpful to push a little bit. You want to squeeze the forceps slowly, or the technician is squeezing them slowly, so you can see it kind of grab a hold of it. And then you're going to pull away from the tissue. And you just tap the yellow pedal. And you can see the forceps literally many times kind of peel the tissue off. And this is a little bit laborious. But it's actually still a reasonably efficient way to salvage a really fibrotic lesion. This patient I've already followed up, and no recurrent disease. Second, I want to talk a little bit about access, and I want to talk about water. We talk a lot about water now to try to improve rates of on-block resection. But I think it can also be a useful tool for access. This is a pedunculated lesion in the sigmoid. Now, pedunculated lesions, as we all know, we want to remove them on block. We never want to piecemeal them unless it's just absolutely essential. And so we want to get the snare over the head of the polyp, then pull the snare back so that we see the far side of the snare hit the stalk on the opposite wall. And you can see this is catching. So one way to get better access here is to start injecting water, to just fill the lumen up with water. Maybe you need to come back. So that tends to make the polyp float up into this water column, makes it easier to get around. Incidentally, I never put endo loops on anymore. If you want to practice sort of oncologic medicine, which is the argument for ESD over EMR, the easiest place to do that is in pedunculated polyps. If you put an endo loop on, you force yourself up toward the head. And you've got to remember that a third of the time if there's cancer, it's invasive into the stalk. So I always resect low on the stalk with forced coagulation current, and then clip the site closed to get the biggest distance between any tumor that might be present. Water floating for access can be very useful on the ICV. This is a lesion that's not very big on the sacral lip of the ICV. This patient was actually sent to surgery and then sent to me. And you can see this is not a very big lesion. But you can see that once we're underwater, the valve is literally turning at us. It's just turning its face right at us. And this small polyp that was going to be sent to surgery is going to become very accessible. So sometimes, I always say that if you can't see the sacral margin of a lesion, you should never underestimate how much polyp can be over there that you can't see. But you can either get around, retroflex, try to inject it to get it up to look at you. Or going underwater a lot of times will relax the bowel and make it more visible. I'll try to hit the right place here. But you can see how visible that lesion looks now underwater. Very small, easier to access. Underwater of course has a lot to say for it with regard in randomized trials to on-block resection rates. So this is a lesion in the right colon of a patient who is not a good surgical candidate. And it's clearly got a very high risk for cancer. There's central ulceration. There are nice three changes in the middle of that. So we want to take it out on block. An alternative to ESD for lesions that are up to 30 millimeters or so in size is to remove them underwater. And because you can get lesions out that are 25 to 30 millimeters in size with the snare. I think the biggest mistake people make when they do underwater EMR is to not use a big enough snare. I often say with traditional EMR to limit your snare size to avoid muscle injury. But with underwater, you want to go big if you're going for on-block. And then I mentioned earlier non-granular lesions. Non-granular lesions, these flat elevated ones, still a low risk for cancer. If you inject them, they become very thin and harder to snare. So I think whether you're going for on-block or whether there's a larger lesion that you want to remove piecemeal, that underwater is a particularly attractive approach for that set of lesions. If you do get the lesion out on block, of course you would pin it to a flat surface, the same that you would with an ESD specimen. And with pedunculated polyps, if you can't see the stalk, if it's retracted, I like to stick a pin in it to make sure that the pathologist is going to bivalve the lesion. Access, I'm not going to mention retroflexion, but access can be very helpful, especially in the hepatic flexure, it can be improved by retroflexion. A lot of lesions on the ileocecal valve sent for referral, a disproportionately common location for referral. This was a very common indication in the past for surgery, but basically all these lesions can be removed endoscopically now. The cap is very key because it allows you to turn the distal lip down and look on FOS. And you want to start the injection on the side at the opening to the ileocecal valve so that you push polyp out from the ileocecal valve orifice. And then if you actually, as you're snaring, push the snare into the valve and then push against the opposite wall of the ileum, that'll help the snare open over this tissue. So we're actually resecting first the part that is closest to the valve orifice. The valve is very thick, it's almost unheard of to perforate up on the valve. Of course, if the lesion extends down into the cecum, then things are different. But the rest of the lesion, you don't even necessarily have to inject. You can remove it underwater, but you don't have to worry about injection as a way of avoiding perforation when you're up on the valve. I want to say a little bit about numbers of lesions because I think when you have referrals or you're in situations where there's a polyposis syndrome that you're going to manage endoscopically or a referral where there's just a lot of lesions, that going cold is very attractive because although the risk of resecting individual lesions is very low, when you add up the risk, it becomes substantial. So this is a patient with FAP who's had a subtotal colectomy, disappeared for seven years, has come back. And in about an hour, we're going to take out about 270 lesions from his colon. I've gone over 300, four different occasions, managing polyposis syndromes without concern about a complication. And also cold resection is much faster to perform. We actually count the lesions for the purpose of when we bring the patient back, we want to see that there are fewer lesions and smaller. So we count the number of lesions that are 10 millimeters or larger, the number that are less than 10. So for polyposis syndrome, same thing for SPS, cold management throughout, extremely attractive from the perspective of it works and it helps you to avoid a complication. Here's what the rectum looks like after the resection. I get this kind of referral a lot. I think it's partly because of the reimbursement system that we have, right? But it's somebody who's 70 years old and they're found to have 30 or 40 polyps and none of them is particularly difficult to remove, but the number of them that needs to be removed is daunting. I think it's more efficient and a whole lot safer to do multiple resections cold. Sometimes a combination of EMR, sometimes just mostly cold snare resection. And I think you can think of this as debulking the colon of these lesions, none of which is particularly scary, but getting the colon debulked with very low risk of a complication. Now this is another area where I am now tending to go cold. This is the massive homogeneous granular lateral spreading tumor. It occupies about 80% of the right colon and it's got a very low risk of having cancer in it. These are the biggest lesions that we see in the colon because they have a very low, very small tendency to turn into cancer. And so they grow laterally for very long periods of time and that's how they get so big. You're not going to see non-granular lesions that are going 80% of the way around the bowel. They're typically granular and they typically have very little submucosal fibrosis, which makes it easier to do cold resection. If, however, we remove this using electrocautery, what's the problem we're going to have? It's going to be too big for us to close, right? It's too big to clip. And even if you're using X-TAC or some other suturing method, it's going to be difficult to close something that is this big. So if we remove it cold and then come back in a few months, probably good to feel like you have a reliable patient, there's a very high chance they're going to have a recurrence because that's the problem with cold resection, at least for large adenomas, that the recurrence rate is high. But the recurrences are very small and easy to deal with. And so you can get through the process without complications. And so it takes a little while to do it, but you can see this enormous cold defect goes around most of the right colon up over the ileocecal valve. That's fat on the ileocecal valve. And the thing is that we've taken probably a risk of a delayed bleed that's on the order of I would say 25-30% with electrocautery down to essentially zero by the cold method. So here's another one of these lesions, very big, same thing. Easy to lift, easy to remove cold. And there's the defect at the end of it. And then here is this patient six months later. So now the scar is retracted. Here's the ileocecal valve. The scar is retracted. We expect there to be a recurrence. Sometimes there'll be two or three recurrences. But that's the recurrence right there. It's maybe seven or eight millimeters. So something that was over 100 millimeters has now been converted without a risk of complication to something that's a few millimeters. And now I would go hot because if you use cold snaring, in my experience, the snare tends to bounce off the scarred tissue. So now we're going to use electrocautery, usually a 10-millimeter stiff snare will take care of it. Try to get a little bit of a margin of normal tissue. Use forced coagulation current. And then we're going to burn up the margin with the snare tip. And then I close these with clips. We don't know that that's necessary. But this has allowed us to get a lesion that has a very low risk of cancer through the entire process, effectively with almost no risk of a complication. Okay, selected issues to talk about. Guys, if I hit 20 minutes, just cut me off. I think that Charles talked about cold piecemeal EMR for serrated lesions. This morning we have the options of injection or no injection, so I won't talk about this. I want to say a word about current, because a lot of people are very attached to endocut. And I will admit that I used endocut for EMR for more than a decade. But we now have a randomized controlled trial comparing endocut to forced coagulation current, both of which were delivered by a microprocessor-controlled generator. And forced coag won that battle. It's the only randomized controlled trial in the literature. And microprocessor-controlled forced coagulation current did not increase the risk of delayed hemorrhage, and it decreased the risk of immediate intraprocedural hemorrhage. And if you look in the trial, this is Heiko Pohl's study in gastro, there were three perforations. They were all in the endocut arm. I think there's a possibility that using forced coagulation current, that the tech is more likely to be able to tell you something's wrong, you know, I'm cutting through something that might be muscular appropriate, and you need to do something different. But you can see that we're using forced coag here, and we still have a defect that looks like it has very little thermal injury to it. So I would just remind you, there are two ways to limit thermal injury. One is cutting current, which I'm suggesting, you know, we could abandon for EMR, except for, you know, I'm using endocut I, the low voltage endocut, for avulsion. But for endocut Q, I think we could abandon that in favor of forced coag. If you squeeze the snare really tightly before you hit the blue pedal, then you'll still come through very fast, not as fast as cutting current, but still in a second or two. And that's because the current density, when the snare is really tight, becomes very high. And it's probably the speed of transection that limits the thermal injury. The faster you come through, the more likely you are to have this nice, blue, non-charred-looking defect. Okay, so this, I just want to mention these blood vessels. We have a couple of randomized controlled trials about cauterizing those blood vessels to see if it prevents delayed bleeding, and it didn't work. And so I don't think you can really see the blood vessels that are likely to bleed. So you can do that if you feel compelled to, but no evidence that it works. I will say that we have a monthly live course, and probably the question that comes up most often is that I sometimes, in a defect like this, I'm clipping in the middle of the defect. If you look at this thing clipped closed, you can see that some of these clips are going down through the edges of the defect. There's nothing wrong with putting clips into the submucosa. And sometimes with a very wide defect, if you put a couple of clips right in the middle of it, you can pull the edges close enough together that you can now overlap the mucosa and zipper from one end to the other. So there's no harm in putting clips directly into the submucosa. Anytime we're piecemealing in the colon now, I do this even after underwater if I'm piecemealing. That hasn't been studied, but I just think as a concept it's good. We do this snare tip soft coag thing now because it reduces the recurrence rate. I think it's important that you do it well. And doing well means that you burn 100% of the circumference. You've got to get down in the little nooks and valleys. And some people think that part of the way it works is that when you do that, when you go around the entire margin looking carefully, you sometimes see a little bit of tissue that you left on the margin. If you do that, I would open up the snare and cut it off. You can cut off little bits of tissue like that with the soft coagulation current. The key things are be very careful to get the entire thing. It works best when it's very thorough and pretty aggressive. This is low-voltage current, so you can burn that edge quite hard. And then just remember now that we've got an easy-to-apply method to suture. Clipping doesn't work in the left colon, and we don't have any really randomized trials looking at X-TAC. This is the through-the-scope suturing device, but I like to use this now, especially in defects in the left colon where clipping doesn't work as well. And the observational data with it so far has been quite good. One final point that I would make has to do with the whole issue of NICE-3 and KUDO-5. This area right here, which has a different color in NBI, and the vascular pattern is distorted, that's NICE-3 or KUDO-5. That has very high specificity for deep submucosal invasion. And we used to say that if there's deep submucosal invasion, then the patient should go directly to surgery because it predicted a high risk of lymph node mets. But now we have pretty good evidence from multiple studies that if it's the only adverse histologic feature, there's no pore differentiation, no lymphovascular invasion, that it doesn't predict a high risk of lymph node mets. So one way that when there's a small area like this that you can get this out, again without ESD, is to EMR the rest of the lesion and then take out that area with the full thickness resection device. And that's a pretty efficient way to get an area out like this and still get an excellent pathology specimen. And so increasingly, people are talking about that as an approach. So to summarize, we can now take the entire class of serrated lesions out cold, except for traditional serrated adenomas, which are, of course, rare lesions. For fibrosis, you need some tools. CAP or Evulsion, I think, both should be the tools of the standard EMR-ist. For access, CAP, retroflexion, underwater. Underwater actually adds, I think, to access. For debulking and lesions that are too large to close, consider cold. Primarily, this would be homogeneous, granular lateral spreading lesions. Underwater helps with on-block resection. I think it's very nice for non-granular lesions. And snare tip ST to all the piecemeal EMRs. And then we know the rules for clip closure, proximal susplenic flexure, 20 millimeters or larger, and resection with electrocautery. Thank you.

EMR

Endoscopic Mucosal Resection

colorectal lesions

fibrotic tissue

CAP technique

avulsion technique