SUTAB tip of the week. First strategy I want to demonstrate is central injection. This is often the best approach with a flat or relatively flat lesion in the two to four centimeter size range that's completely visible. It's out in the open. We want to inject it so that it's going to end up on the top of a dome of fluid. Central injection put it right on the top. If we inject in the proximal half it'll tend to tip it toward the anal side toward the scope and make it more visible. For almost all serrated lesions this is the best approach and for many flat adenomas it's also the best approach. Sometimes I hear reluctance to inject through the lesion. There's no evidence that that is a problem although I think it's common sense to not inject if there's overt evidence of cancer or a high suspicion of cancer. Here we're demonstrating central injection in a serrated lesion injecting right through the middle of it or a bit toward the proximal half to raise it up on top of this mound of fluid. The lesion is right in the center of the mound of fluid. That's right where we want it for central injection. The lesion again a good candidate for this is relatively small flat. It's out in the open. We can see the entire lesion. It's not draped over a fold and it's ready for resection. Another serrated lesion this one a little bit bigger about 30 millimeters in size. We started going through the lesion on the proximal half moved to the center now we're coming down to the distal side the anal side injecting enough to get fluid underneath the circumference see the edge. Well still a little bit on the right side that will need to be injected later but we're at a good starting point. I think for most serrated lesions the great majority of which that you're going to consider as candidates for EMR are going to be in the 10 to 40 millimeter size range. Then this injection through the middle or proximal half injection is the best strategy. Here's a flat adenoma a little bit less than two centimeters in size being centrally injected being nicely lifted up onto the top of this dome of fluid. Here are the strategy of central injection on this lesion which is out visible in its entirety not draped over a fold is very nicely prepared for resection by the strategy of central injection. A second very important injection strategy is that a proximal edge injection. This is the strategy we want to use when we have a lesion that's partly invisible from the anal side because it's draped over a fold or a turn. If we inject on the distal side we'll push it further out of view. So we want to make the initial injection ideally right at the junction of the lesion and the normal mucosa lift this up and push the lesion toward us so that it becomes completely visible. Injecting out here is too far away. Injecting on this side will push it away. The best way to achieve this is to take the needle with it out and just deflect the lesion down or come around the side to get at this point or we can go into retroflection or one other trick that I'll demonstrate on video. So here's a lesion that's partly draped over a fold and when you can't see the proximal edge of a lesion in general it's a mistake to underestimate the amount of polyp that could be invisible to you. So we've got the needle out we're trying to deflect the lesion back we're starting the injection hopefully right on the edge. Sometimes if you make the initial injection and it starts to lift you can then pull the needle out and you'll be able to reinsert much closer to the edge of the lesion. But this is the idea of injecting on the proximal side. We don't want to push it away from us we want to turn it up toward us proximal edge injection. Another way to access that proximal edge when you can't see the proximal edge in the forward view because the lesion is draped over a fold like this one is to go into retroflection. In retroflection here you can see we can get that initial injection right on the margin of the normal mucosa and the lesion. Then we will have the option of initiating the resection either in retroflection or going back into the forward view in some cases. In this case we're going to start the resection in retroflection. Here's another lesion that's draped over a fold we're again in the proximal ascending colon. It was difficult to access that anatomic proximal edge that edge on the sacral side so we've gone into retroflection to access it. We're pushing a large amount of fluid into the semicosa on that sacral side that sacral edge and then we're just going to turn around again in the forward view we've had fluid come all the way back onto the anal side of the polyp and we're going to perform the resection in the forward view. All we needed retroflection for was to access that proximal edge but it's the principle of proximal edge injection for a lesion that's draped over a fold. Here's a non-granular lateral spreading tumor and adenoma in the cecum and it poses the problem that part of this lesion is extended over this thin fold in the cecum. You can see the appendiceal orifice not too far away and so we need to access that proximal edge. We don't want to inject on the ileocecal valve side or the anal side because we're going to tend to push it over that fold. Again never underestimate when you can't see all of the polyp because it's draped over a fold how much polyp could be hidden on the other side. It really could be a significant amount. So we're we have no choice here but to try to get at it with the needle and a good trick in this instance is usually to start on one side either the right side or the left side of the lesion. Try to get into that fold that the polyp is on make an initial injection create a semicosal bleb and then use that bleb to basically move down from one side of the polyp to the other accessing the proximal edge for injection. So we got that initial bleb and then we it was on the right side so we move to the left edge of the bleb and now we're extending it and as we inject more fluid into the semicosal the bleb is going to get bigger moving from right to left and we'll just keep that up until we get the entire proximal edge exposed. You can see in fact there was quite a bit of polyp on the proximal side of that fold that needed to be exposed. Good proximal edge injection here exposed all of it. The final general strategy is that of inject and resect and then repeat the process. Inject and resect again until the entire lesion is resected. This is the approach we want to use with the very broad lesion extending over multiple folds. We start at the anal side do an injection make a nice semicosal mound resect that. Here's this resected area now we repeat the process injecting through the lesion or directly into the exposed submucosa resect that continue till we get to the proximal end. Here's a demonstration of this principle of inject resect inject resect until you're finished. So this is a very large granular LST in the sigmoid most of the circumference extending longitudinally quite a distance. We're starting on the anatomic distal edge the anal edge. I think if you're using EMR with electrocautery this is the best approach in almost all instances. If you're doing it cold it may not be quite as important but for EMR using electrocautery start at the anal edge inject resect. Now we've moved over to the left side we're going to inject this and then resect it and then we'll just continue the process until we get to the proximal edge. This is the inject and resect repeatedly method of EMR. Thanks and see you next week on the ASGE SuTab tip of the week.

endoscopic mucosal resection

lesions

injection

resection

EMR procedures