We have five minutes for some quick questions before we go back to the lab. I have maybe some comments regarding the pocket creation method. I think most of us now don't do the class KSD. We tend to tunnel everything as long as it's possible. So in pocket, I have two comments. The first is just put in your mind the distal end of the lesion. This is really important because I prefer to start with the sacral side of the lesion first before creating the pocket, and then connecting both sides together, what I call bridge sometimes. And then you can go through this bridge and do retroflexion. This gives you more and more traction. This is really important to think of the sacral side of the lesion before you start. Second is when you do your pocket or your tunnel, make it a wide tunnel. Make it a wide pocket. Because if you do just a narrow tunnel like the poem, at the end, you will have to do another tunnel on the right, on the left. This is really important. I cannot agree with you more. Can you clarify something about your first suggestion? You're talking about going through the tunnel, retroflexing with the scope inside the tunnel, and then dissecting the sides. It's amazing. You have to do very gently. Otherwise, you will evolve the lesion. You rip it off. But it gives you a very, very good counter-attraction. Interesting. And do you use a needle type of knife or IT type of knife to take the sides? No, we usually use the needle type of IT. Needle knife. Interesting. Interesting. I've never tried that. That's certainly, I mean, in general, one of the benefits of retroflexion is scope stability, because now you're not flopping in the middle of the lumen. And the other one is that it gives you parallel to the muscle approach. And we used to do OESDs, tried to do them in retroflex because of that, but with retraction and stuff like that and pocket less often. But this combines two techniques, which I will be eager to try at first opportunity. Thank you. Yes, second is the underwater or the water pressure under saline. I really find it's amazing. It gives a very good magnification. It helps you creating a flap, because it eases the most difficult step is that you go below the lesion. But the problem is, and I want to hear opinion from others, what do you do with the excess amount of saline you immerse inside the patient? Because they usually put a nasogastric, a nasogastric tube around the scope just to help to deflate the patient, because the patient is distended where the water is much worse than CO2. CO2 is absorbable, but water and saline are not absorbable. So how could you manage with this problem? Yeah, a couple of suggestions as far as I can give you, and I'll be eager to hear what the people have to say. But one is, at least in the United States, we do all of our upper ESD under general anesthesia. Certainly in Japan, people do sedation upper ESD, but in the US, it will be foolish to do so. The second thing is, which is something that I learned very early in my ESD experience, with every single instrument exchange, you use that opportunity to suction. So you keep suctioning. Every single time when I exchange instrument, by the time the nurse or the tech is handling me the next device, I suction. One of the biggest enemies of underwater is bleeding. So I will tend to be much more aggressive with preemptive coagulation. Because you hit the vessel, and the entire water stains bloody, you have to suction everything out and start from scratch. So that is kind of one of the drawbacks of underwater. But in between intubation and suctioning with each exchange, I find that overdistension not to be a big issue. Any other suggestions from the faculty? Sergei? I'm sorry to spoil your holiday, and you say bad things. Nothing that you can tell against Paul. And I know that I will probably never be invited again. But I think that it's a travesty to do underwater ESD. Because, especially in the United States, because in the United States, we have difficult lesions, which somebody before you tried to remove partially, creating fibrosis, or injecting indium, creating fibrosis. So regular ESD, especially in the colon, there is a risk of perforation. If you do an ESD, especially in the colon, and somebody tried to do it before, then chance of perforation is much higher. And here you are, putting water in the colon, and then you know that there is a chance of perforation. And all this infected water will go into the peritoneal cavity. It's a horrible idea, because if there is air which is going into the peritoneal cavity, you can save that patient. But if there is infected water going into the peritoneal cavity, you cannot save this patient. I think that it should be abandoned, and it should be done only in the upper GI tract. And that's my take on this thing. Absolutely. So Sergei, I agree with some things. I mean, you're speaking from experience. I've been told that perforations do occur. So thanks for sharing that. Thank you. I appreciate it. But the second point, on a serious note, indeed, location matter. I don't see anything wrong to do underwater in the rectum, which is a common site for resection, at least in the United States, and certainly in the stomach. In the esophagus, obviously, it tends not to work, because everything runs into the stomach. So like any other technique, it's not one size fits all. I don't want to even talk about duodenum, because I don't want people to get the idea of going and doing duodenal ESD. But it works great in the duodenum, because that thin mucosa tends to float up quite nicely. So it clearly has its role, and it should be part of the armamentarium. But did you see that great case that Dennis showed? I mean, that dependent portion of the pocket would have been extremely difficult to take down, and it looked so beautiful the way he did it. So as long as you're working under direct vision. So there is no perfect method that solves our, in my opinion, the more techniques you have in your head, the better. Because one will work in one case. It will not work in the other. What is better, in your opinion, is that you get 10 techniques, and each of them, you do it so-so. Or you just stick with one technique, get it to the level of mastering it 100%, and just stick with that technique. And don't try to spread yourself too thin, trying to do this and that and that. Sure. So many techniques, yeah. We shouldn't be married to a single technique. We have to have multiple options. My point exactly. Sergey disagrees, but that's OK. I mean, Philip has something to say about that. Please use the mic, Philip. I have a question for all the great masters in the room. Slightly different, but similar question is, how do you guys deal with submucosal fat? So there are certain parts of the body, colon, right colon, where people like to stash their fat in the submucosa. When you start doing ESD there, and you start putting heat there, it greases. You're cooking bacon, and then the bacon grease covers your lens, and then pretty soon, you can't see anything. Right. A couple of things quickly. One is, I tend to use cutting current, rather than coagulating current, because coagulating current tends to fry the fat, as you correctly, and then it comes onto the lens. Overtube can be helpful, so you can quickly go in and out and clean your lens, which indeed gets gunked quite easily. So those are my two quick tips here, or you wanted to say something? The other thing is that, you just talk about the underwater water pressure ESD. So if you are underwater, I think that you will not get any type of grease on the lens. So I think that helps if you are underwater. You can tackle with a cut current, and then sometimes you can find the space underneath this cut above the mask layer. If you cut into that area, you should be able to. You don't need to cut into the pad. Even if you need to cut into the pad, if you are underwater, you don't need to worry about those grease. I asked that question 10 years ago to a professor only in Japan, at Shizuoka Cancer Center, and he told me that he uses oolong tea to flush through the scope. I tried green tea. I didn't get my hands on oolong, and it did not work. But it is a problem, particularly in the right column, because if you have, yeah, Makoto. And also, today, Fujifilm company brought anti-fog. And in the United States, we can mask OR, and OR use anti-fog for laparoscopic robotics. So that is another. You know, this is a good point. Actually, in our unit, what we use is we use a baby shampoo. We put Johnson & Johnson, a few drops. And it's basically a surfactant. That's what the anti-fog is. And there is commercially available solutions, but they cost money. The homemade remedy works as good as any anti-fog agent. But it does help. I agree with you. Thank you for bringing this up. OK, everybody's eager to go to the lab. You know already the drill. I'll see you inside. Thank you.

Endoscopic Submucosal Dissection

pocket creation

underwater ESD

retroflexion

lens fogging