We wanted to cover a couple of questions before we move on to the next demonstration. The first one actually came through the previous session and it was related to whether traction can interfere with using a snare. And that is correct. Indeed, if you apply some type of a traction, you have to remove it before applying a snare if you are doing a hybrid ESD. Nevertheless, traction can help you do some degree of submucosal dissection. We recently published a randomized control study comparing hybrid ESD with standard ESD and to no surprise, hybrid ESD using snare in the final stage was faster. But it came with a price. We had a lower rate of unblocked resection rate with the hybrid ESD because of mispositioning of the snare. So yes, you can get a little bit faster with the snare, but you have to be very careful when positioning the snare to make sure you don't cut into the specimen. Let me take a look at the other questions. Oh yeah. Is it best to tap on the endocarp pedal or keep it pressed? Makoto, this is Dr. Nishimura from Memorial Sloan-Kettering Center and Dr. Eicher from Brigham and Women's again. And Makoto, do you tap on the yellow pedal or you allow it to cycle a few times? Right. So of course, the endocarp is automatically cut quad. So not necessary to tap, but I usually use tap technique, tap, tap, tap, tap, to make sure the next marking. So we don't want to cut completely one way. I usually allow it to cycle two or three times before I stop. Either way is okay. You have to realize though that if you're tapping, you're basically using a pure cutting current. You're not coagulating much at all. So that's the biggest difference. Definitely tapping gives you more control and less chance of cutting inadvertently into the lesion or too deep. Hiro, how about yourself? I tend to tap. So I think the reason behind it is sometimes, usually the scope, we need to change the direction and angle of the scope each time. So by tapping, we have some ability to control, still have the control on the scope. So that's my preference. But there is no correct answer. Yeah, there is more than one way to do it, but clearly the main message is tapping provides you more control. That's for sure. And less risk of complications. Let me check the next question. Oh, how do you apply steroids to the stricture prevention? So preparation, dose, dilution, et cetera. Hiro, do you want to take on that? So I typically use the triamucin alone. I think it comes with the five milligram in five cc. And I usually dilute it with the 15 cc of saline. So it will make like 20 cc of solution. And then I usually leave a small amount of the salmucosa so I can inject into the salmucosa layer. And then at the end, I typically use the closed tip of the injection needle. So I don't inadvertently inject into the muscle. So usually everybody says that if we inject into the muscle, it could cause necrosis of the muscle. So it's probably better to stay in the salmucosa layer when injecting. I usually do injection every two or three centimeters. And then the amount depends on the size of the D-pack. Sure. So just to be clear, when we are talking about salmucosa, we are talking a residual salmucosa at the base of the ESD ulcer, not in the salmucosa around the lesion. And I use the same dilution. So I add 15 milliliters to the five milliliters of the triamucin alone. And one vial is 40 milligrams. And obviously, it depends on the size of the defect. You may use more than one vial. And my usual approach is to do similar to Barrett's biopsy, like four quadrants and move up. But indeed, it is important not to inject into the proper muscle layer. Makoto, guide us now through ESD with a needle knife, in this case, the Pro knife. Hello, everyone. I like a Pro knife. I recently changed from a dual-j knife completely to Pro knife. Because the Pro knife has a nice injection function from the tip of the knife. So let me show you. So this is a disjointed stomach, and I already put a marking. OK. So needle out, please. Thank you. OK. So let me start injection outside of the marking. Usually I recommend to not inside. We should inject outside of the marking. Injection, please. Inject. Because even injection. Thank you. And already, we can see this area is lift up. This area is still normal. So I can just continue injection here, injection. No need to, after second injection, injection more. No need to inject to the normal area. So this is much easier. Thank you. OK. Injection. Yep. OK. Thank you. Thank you. And for initial injection, only initial injection, I prefer to use a saline injection. So once you, so basically you penetrate deeper and then slowly pull it back to find the submucosa. OK. Because we want to make sure injection is correct injection going to submucosa layer. Sorry, this is big stomach. Some areas are very difficult to lift up. Injection here. OK. Dr. Nishimura, how much of the circumference of the lesion do you inject initially? Usually depends on the location, depends on the size of the lesion. But for this one, this is not so difficult location. So I want to inject especially like a distal side. And OK, thank you. So if we are doing injection, please, pocket creation method, I usually inject only proximal area injection. Injection. Okay, needle in. Okay, so let me start cutting. And even using pro knife, we can inject additional injection into sub-lumcosal layer. So this is a big stomach, very thick stomach. So I wanna make a start incision from the distal side. Open, please. The reason I'm asking about how much you inject is that some people argue that with injection type of knife, you don't have to inject at all, only your initial entry point. The downside of injecting more is two. One is that you can hit a vessel, and then you have a bleeding with your needle injection. And the second one is that the injection will wear off by the time you arrive to the site. Right, and injection, please. So now I'm cutting the mass mucosal layer injection. So see, we can see the, we can do nice injection. Okay, thank you. Through the knife. That was a nice adjustment. You want to see that white ring of the knife gliding over the mucosal. And also I'm cutting outside of the marking. So we should not cut inside of the marking. Injection, please. Injection, please. Thank you. Injection, please. Injection, please. Okay, then I'm still, my tip of the knife is still inside of the sub-mucosal layer. And I'm sure my incision, even though knife is completely inside of the mucosal layer, but my incision is still inside of the mucosal layer. Injection is not deep enough, so I'm exactly coming back the same line. Injection. Thank you. So this is a trimming. Until sub-mucosal layer, we can see nice blue layer. We need to continue this kind of trimming. Okay. Here, I cannot see well. So now I'm using the water pump to make sure I'm cutting correctly. So here, I think it's a little bit too dark. Here, the mucosa is very thick. That's the problem. Very, very thick, right. You will never see that degree of thickness in humans. So this is just a foreseen model. Yeah, injection, please. Thank you. Thank you. Okay. Now, slowly. Finally, we see the sub-mucosal layer. Finally, yes. Let's cut here. So we need a nice separation. Otherwise, we cannot get inside of the third space. So this kind of tap, tap, tap technique. So here, we can see sub-mucosal layer completely open. Here, still connecting the musculoskeletal mucosa. So now, okay, injection, please. Thank you. Here, right there, we can see the white layer. That is a musculoskeletal mucosa. So we need to cut completely here to start sub-mucosal dissection. Okay, nice. Okay, so now, I think I could exactly open up the distal side, okay? Then, I'm starting incision here. So you started with the distal side because that area is a little hard to access, is that correct? Or why? Yeah, otherwise, because of big stomach. But usually, right, but sometimes, even the colon, sometimes, if the distal, the other side is very difficult to see, it's better to start from the difficult side. Difficult side, okay. There's so many, okay, injection, please. Yep, injecting. So many different strategies. So if we are doing pocket, okay, thank you. Injecting. We can inject, start from the oral side. Injection, please. Yep, injecting. So this is a very nice injection capability by ProKnife. Okay, stop, thank you. So guys, can you record this? Stomach tissue. Injection? Yeah, injecting. I think you can see the stomach is completely collapsed at this point, so I think he wants to make, limit the amount of the air, so. Yeah, that reinforces the message that we talked about during the last lesion. The tendency is to keep your finger on the air and you keep insufflating, and that is usually not very productive. You make your life actually more difficult. So Dr. Nishimura is keeping the stomach almost completely deflated. Thank you. So in the colon definition, do you typically finish the incision first? I think it depends on if you're using traction or not. So mainly you usually do... So usually for eye injection prints, colon, usually I do a pocket method. Pocket method. Yes. Pocket method is very easy. So starting pocket method or for C-cum injection prints, I do underwater ESD. The C-cum unit. Right. I don't need a traction device at all. Okay. Now, still he has connecting white tissue. Can you show there you have some muscularis mucosa, I think, if you can show it to our audience. Yeah. Here. We can see muscularis mucosa. So you see that whitish looking... Mucosa is cut, but muscularis mucosa is not. So now Dr. Nishimura will cut the muscularis mucosa and the space will open nicely. Beautiful. Yeah. I think I did a circumferential incision. Almost, except here. I need to completely open up here. Injection, please. Injection. Okay, thank you. So what we have been doing over the last five minutes is basically trimming. Oh, there is a small... Okay. And also, to hold the scope, I usually hold the scope and also use the up, down, right, left angle by my left side. So I've been holding the scope with the pinky finger and then holding the device with the other fingers, so he has control for both. So now you switch to coagulating current. Yes, but here still we can see the mass transfer recorder, so we need to cut by the yellow pedal. But basically, the end cut is very too strong, so we need to cut very carefully. Okay, now I'm collapsing, completely collapsing the stomach. Then we can easily get inside. So the way he opened the submucosal space was by deflating the lumen. That was a beautiful demonstration. Injection, please. Thank you. Okay. Now I'm also now suctioning the air and also fluid, and now we can easily approach to submucosal space. Thank you. So when Nishimura deflated the stomach, the muscle layer became more parallel to your scope, so that's the biggest advantage of deflating the stomach. Injection, please. Injection. Thank you. So one of the reasons I like pro knife is I don't need to ask assistance to needle in. So in case of dual-j knife, that is also a great knife, but I need injection. Thank you. I need assistance to close the knife, so that is a disadvantage. And right now I'm cutting from side to side. So here is connecting, so I'm advancing the knife, and I'm cutting in the middle of the submucosal layer. Especially for the cancer, it's better to cut SM3, and in case of SSP or completely adenoma or benign tissue. Can you show us which layer is the muscle and which layer is the submucosal? So now this is expanded submucosal layer, and I'm using the gravity nicely. And here, still injecting, but we can see this white layer, this is a muscle layer. And if we cannot inject well by the tip of the knife, sometimes I make a small hole. And advance, and injection. Thank you. So here the same principle applies as we discussed in the previous case. You want to start from the edge. The tendency sometimes is for novices to start digging in the middle, but Dr. Nishimura is going all the way to the edge. Now he starts from the other edge, and he'll move to the opposite edge. Injection, please. Thank you. Injection. Some areas still here, where we can see some muscle layer. Muscular submucosa is connecting. Okay, now we need to think about where is the gravity. So this is gravity. So this is completely out, opposite of the gravity. So still we have about 30 minutes. Injection. Thank you. And initially I already completely cut the other side, so I don't have to go back to the other side. The distal side. Can you give us some tips how to avoid overshooting and dissecting more submucosa beyond the lesion, which sometimes happens? Oh, right. So you mean in case of pocket creation method or tunneling? No, right now. Right now. Sometimes you can actually go beyond your distal incision. Okay, so first we should not push the scope too much. If we push the scope too much to submucosa layer, that makes a collapse of the expanded submucosa space, and also we shouldn't advance the needle too much. And also to finalizing the ESD, the other side, this side, should be completely separated. If some area is not separated well, we cannot finalize. So there's some couple of different approach to finalize ESD. So right now here, of course, we can cut here, but I don't know how much left behind. The other method is going the other side and retroflexion view. Then I can approach the other side to cut from here to open up. But if you have made your initial incision deep enough, you should not have any problem, correct? Right, right, right. And also this third method is lateral approach from here. So we can cut this side. I can grab the tissue and I'm going to this side. Now I'm rotating scope completely upside down. Now six o'clock we can see the muscle layer. Still I'm cutting a little bit away from muscle layer to prevent unnecessary perforation. So this is very effective to cut from here. Not necessarily retro. Retro is a little bit difficult to understand. And also the Olympus scope is a little bit tough to do retroflexion view. So you always catch the edge close to the mucosal incision at the end. Right, correct. And so you are not going to miss the... Do you usually go up into the mucosal layer when you're finishing the semicolon dissection? Doesn't matter because I can cut from here. But this scope channel is coming from seven o'clock or eight o'clock, so we cannot see left side what's going on. So that's why I didn't want to see... Sorry, Dr. Fukami made that point. But particularly with the Olympus scope and Dr. Nishimura is nicely demonstrating that it's much easier to cut from left to right because you see where you're going. Do you mind, Makoto, just for a second demonstrating cutting from right to left? Right, so if I can cut like here... I mean, do it the wrong way just so people can appreciate. So if I'm cutting... You can cut from here this way. If you can. Now grabbing the tissue here. Yeah, it's much more difficult. And now the knife is obscuring your view. Right, so now I don't know where is the maximum... He doesn't see very well where he's going. So I'm not comfortable. So that's suboptimal. This is much better. Much better. Yeah. And here, still connecting that mass or some submucosal layer, especially musculoskeletal mucosa. So injection, please. Injecting. Thank you. So now Dr. Nishimura is approaching from the other side of the lesion. So he will not miss the last part of the submucosal dissection. There we go. And also we can use an IT knife here. Well, but one of the beauties of using a needle knife is that you can complete the entire procedure with one knife. Right, and much cheaper. And cheaper, yeah. How often do you use an IT knife in gastric ESD? Um, like once or twice a year. Once or twice a year. Usually I can finish in one knife. Well, I want to make sure that this type of decision is a personal preference. I use it pretty much for all of my gastric ESDs. Right, right. Yeah, because IT knife is quicker. Yeah, and it's more efficient. It's faster. Yeah. Inherently faster, but it does not inject. So you usually have to work fast or use some type of viscous solution. So there is downsides to each approach. With IT knife, we would have been done five minutes ago probably. But that's okay. Speed is not the most important thing. Safety and unblock resection are the primary goal. I think you're overshooting here by a little bit. Just that at all, yeah. Mm-hmm. So almost finishing. Still here is connecting the musculoskeletal cord. Yes. Musculoskeletal, yeah. So now the dissection plane is a little higher side because we don't want to overshoot. So there you go. That overshooting is a common problem actually. It happens. Right. So you have to check very frequently towards the end. So now finishing. Very nice. So here we can see no damage of the muscle here. Nice. Wow, you did a very big lesion very quickly. Yeah, thank you. Actually for hands-on seminar, big lesion is easier. Yeah. Because we can use like a gravity. Yes. That is correct. Because once you get underneath the flap, you can just keep cruising. Mm-hmm. Makoto, do you routinely close the defect after ESC? Actually, I do not. You do not. Because sometimes we are removing 8 centimeter, 13 centimeter, and I'm already tired. Sure. And if I cannot see any like a muscle damage, not have to. Right. But if we can see some muscle damage, I deploy some minimal clip, like two, three clips. But bleeding, yeah, bleeding is the most important. Bleeding, okay. Because there is so many study about. And all outpatient procedure. Usually, my hospital, so I stay, let the patient stay one night or two night. One night, okay. Usually one night. And patient can go home. But we have some patient who had also ESC bleeding because I'm not closing. So recently, I decided to put so many clip after ESC if the patient who is taking anticoagulant. Oh, so close the defect to like clip to close it. Mm-hmm. Sometimes patient admit to local hospital because of bleeding. Yeah. Okay. So the decision is individualized, admitting, admission versus no admission, anticoagulation versus no anticoagulation. I tend to favor closing because I try to discharge the patient to home. And I favor over stitching the stomach just because the gastric mucosa is thick. Very difficult to buy clip. Difficult to close with clips. Or mantis. Even with mantis, maybe difficult. Yeah, difficult. But with standard clips, very difficult. Very difficult, yes. Well, very well, guys. Thank you very much. Let's see whether we have any questions online. I don't see any. So thanks again. Thank you very much. We'll be back in five minutes. Yeah. Thank you. So next, Dr. Sawani Nam will be doing ESD with a dual knife. Thank you. Thank you very much.

hybrid ESD

snare technique

endocarp pedal

submucosal dissection

steroid application

Pro knife