It's my distinct honor to be here. I really appreciate the invitation from the ASGE and the JGES. My own journey started in this very room, so this is bittersweet to be with friends and colleagues and mentors as well. Okay, so the title of the talk was basic settings for ESD, and the more I looked into it, there are no really basic settings. So I just figured I would talk, I would just change the topic entirely and just talk about basics of electrosurgical generators. So my disclosures, I'm a consultant for Boston Scientific, Irby, which admittedly helped me prepare this talk because it's really hard to do this without some actual insight from the people who manufacture this device. Also steroids endoscopy, and I should fully disclose that I have far inferior endoscopy skills than a lot of people in this room here today. So again, my own journey, this is from 2015 during my better looking days, and of course Abe Sensei was incredibly helpful to me, and I've continued to learn from him, and I think we continue to learn this day. So electrosurgery and flexible endoscopy, this is really the crux of how this all works, and there's several components that factor into how we actually remove these lesions. So at the user level, there's the duration of the activation, how long you're sitting on the pedal, the different types of movements, the contact or surface area, the pressure applied, you're going to learn a lot of knife handling skills. It's very different than just using a snare, for example. There's of course patient factors as well, the different types of tissue, whether it's really fresh or perhaps fibrotic, scarred down, there's prior interventions. The equipment, the type of instrument you used, you heard about the different types of knives that are available for this procedure. The size and position of the neutral electron, the technology, how it modulates the spark. And so when you think about the different types of kind of factors that really play into how we remove these lesions. So if you think about hemostasis, for example, it's caused by coagulation. So it starts by heat. So you desiccate the cells, you denature the proteins, it shrinks the tissue, and this leads to hemostasis. Cutting on the other hand is essentially vaporizing. There's intense heat, it vaporizes the tissue, and then it cuts with coagulation. So this is an example of a monopolar electrode and kind of different about the heat and how it transmits in a snare type of device. So the different influences on the heat. So you have current density as well as resistance, and the electrosurgical generators are constantly evaluating the tissue resistance, otherwise known in electrical profiles as impedance. So as far as your current density, your current, the more, the hotter that the tissue is going to get. The cross-sectional area, so the smaller the area, you're going to have more heat that's distributed. As far as conductivity, so the less conductivity, the hotter, and duration of activation, longer is hotter. So really it's all about the heat. So again, these are difficult concepts. So I thought about, how would Norio explain this? Norio comes from a really hot environment. This is last night, 7.15, his time is 89 degrees, it's pretty hot. But again, I'm not sure that this really illustrates. So I got a video of Norio driving into work. I heard he likes cars. He drives a blue car, I hear. Norio drives in style. So electrical resistance or impedance. So the resistance really depends on the cross-sectional area of the path. So you can use the needle tip, you can use the needle shaft. When you use a snare, for example, the resistance of the tissue is much higher than if you're using just the needle tip of the knife. And then you have the resistance of the grounding pad as well. So monopolar accessories. So you need to understand the difference between monopolar and bipolar. So monopolar, you have the circuit that is going to go from the tip of the accessory. It's going to travel through the patient, go back through the grounding pad, and back to the electrosurgical generator. So there's several different instruments. This is when you put the pad on the patient. Different types of accessories, snares, for example, a sphincter tome, and different types of knives. Bipolar, on the other hand, you're not using a grounding pad. The electrical current is going through the device and returning back through the device as well. So the path of the current goes through a return electrode as well. And then there's examples of bipolar instruments. And admittedly, in the United States, we don't use a lot of bipolar instruments. So getting into the generators themselves, there's different modes. And a lot of times, we get really focused on, all right, there's got to be some secret mode that everybody uses that makes them really good at ESD. That's not how it really works. There's different modes for different applications. So in the electrosurgical generators, there's a lot of different options. And I'll go through some of them and what people use most commonly. So there's AutoCut, there's TriCut, there's EndoCut. And what these are, they're different modes that have effects of cutting. And then you have your coagulation currents as well. So some of them are more of like a pure cut, but they do alternate cycles of cut and coagulation. So with some of these, like a dry cut, for example, you're going to have more hemostasis. You'll see a little bit more of a char. And then you have forced coagulation. And then so the effect is how much of this is going to impact in the tissue. So it's really, if you look, you can have a very kind of a smooth type of cut, a superficial. And then they're going to get deeper and deeper into the tissue. It's going to be more of an intense type of cut. So what we're going to see in the lab, this is the newest generation. It's called the VIO3. It's an electrosurgical generator based on constant voltage. And so what that means is that the machine is actually calculating the resistance of the tissue 25 million times per second. And what this does is it modulates the power output to the lowest effective need. So as the tissue is being desiccated, for example, you're going to lower the resistance. And since the voltage is constant, it can decrease the amount of power. As opposed to generators that have a constant power, it will be too much and you'll perforate. So this is based on a power voltage relationship. So power is equal to the voltage squared over the resistance. So as resistance goes down, the power will go up. But with a constant voltage, this machine is going to modulate that. So you can see that on a power curve. And again, with a constant voltage, there's going to be different points. So it's going to be, there's a lot of high resistance. Remember, so high resistance is going to be low power. And then as the resistance decreases, the power will increase. So this is how it's going to be modulating. So you really need to understand how the pedals work. So you have the yellow pedal, the blue pedal. But what's important to remember is that there are cycles. So in the EndoCut, for example, you have an initial incision stage, which is this kind of striped line here. The yellow is the cutting stage and followed by a coagulation cycle. So these are at intervals. And so the EndoCut's not a pure cut. It's going to also coagulate tissue as well. Of course, none of us are Zorro in the room. You don't want to be really slicing through tissue, perforating, doing all sorts of bad things. So I took an example from a case I did yesterday. This is a poem. So I learned this in Japan. And really, what we do is we're tapping on the pedals because we want to incise the tissue. But at the same time, we don't want to slice through the muscle and things like that that are going to make the procedure dangerous. So here you can see, you're just very carefully incising the submucosa. And what you're going to learn about is the different wall layers. It's very hard to understand initially. But the dye is not taken up by the muscle. So it's only in the submucosa. So when I'm doing this, I'm just sitting here. I'm just tapping on this pedal. And you're moving the instrument and your body and the weight. If you hold on to the pedal for too long, you're going to slice through tissue. You're going to end up in muscle. And it's going to be a bad situation. Are we still tapping in Japan, right? Yeah, OK. Just make sure we're up to date here. So endocut, there's a couple of different factors. So you have your effect. So the effect is the level of intensity. So the hemostasis level. Your cut duration is the length of cut. How long is the cut cycle going on for? And the cut interval is the time between the cutting phases. So these can be adjusted. This is on the older VIO 300. On the VIO 3, you'll see the effect. But you can go into a secondary menu where you would adjust the cut duration and cut interval. So for example, if you have fibrotic tissue, you may want to increase the settings to be able to effectively cut through that type of tissue. So everybody wants to know the different settings. So I'm going to go through some of the common ones. So dry cut is a reproducible, slightly slower cut with good hemostasis. So common effect that's used is 3 to 4. I find that the dry cut is a little slow for me. So I actually tend to use more endocut. The precise sect is the newest mode. It's actually a very phenomenal type of mode because it really optimizes submucosal dissection. But you actually get really good hemostasis at the same time. So it's kind of like the best of both worlds. So in comparison, the common setting for this is about 5.6 to 6. Some will use like 4.5. Swift coag was the mode of choice in Japan. But now that precise sect has a lot of benefits with a similar cut profile to endocut. Abe-sensei, what are you using these days? I use swift coag. Swift coag. OK. Still going swift coag. All right. Interesting. So we could, of course, try these different modes as we're going on. I did see a lot of swift coag when I was in Japan, and apparently it's still being used. Spray coag, about 3.5 for POEM. So not really advised in ESD. It's really a non-contact. It is useful for POEM. It can spray. It can splay the fibers. I prefer still to cut what I'm doing on myotomy in POEM, for example. You don't want to use this in ESD, really, because there's a high peak voltage and there's no power dosing. Because since it's non-contact, it's not going to measure the tissue resistance. Soft coag, still awesome mode, especially for coagulation of vessels. It's nice because it's a slow. You're not going to get a lot of deep tissue injury. You always want to tent the tissues if you're using a coagulation grasper, for example. So here's an example of some pretty big vessels. So these are large penetrating vessels as you're getting close to the cardiac, the stomach. And of course, you can grab the coagulation grasper. But what you can also do is you can use the knife. And so what I'm doing here is I'm really trying to decrease the surface area so that when I use my knife, that I can really coagulate this without having to do a device exchange. As you're learning, obviously, you want to use what's safest. So a coagulation grasper would be great. So here I have two vessels. So I've actually separated them a little bit with some submucosal injection using this knife that can also inject. You can see the flow. So now I've basically cut the submucosa. Now I'm going to use the shaft of the knife because I'm going to have a better surface area. And I can just slice right through and cauterize without getting a bloodbath. Bloodbaths are bad. And then you can see. So there's no bleeding. There's no bleeding in the shaft of the knife. So with bigger vessels, about one millimeter in thickness, this can be effective. And again, you don't have to do any needle exchanges or anything like that. And then you can proceed forward. So when we're here today, some of my tips are to really learn from the experts here the different types of strategies. When you're first learning ESD, the difference between being here and in Japan, there's a lot of mentors or someone over your shoulder that's literally telling you exactly what to do. But when you go back to your institution and you're doing this, you don't have that. And it's very easy to get lost. And I remember about 2013, there was a talk given by someone who came from Europe. And he said, there's not a single endoscopist in the entire Western hemisphere that has the endoscopic skills to perform esophageal ESD. And I was like, wow, we're pretty terrible. But what we've learned from our Japanese colleagues is some really good techniques to make us better. And the C-shaped incision technique for esophageal ESD, for example, was a life changer for me. And Amit Bhatt published this. And I think we learned this from Abe Sensei. And what it is, it's very remarkable. So when you're doing esophageal ESD, what happens, for example, is you're progressing along. And all of a sudden, you get towards the end, towards the GE junction. And you get lost. And everything is swollen and edematous. And you can't find your plane between the lesion and the normal mucosa. So what they do in this technique is they do a C. So you're going to do the proximal portion first. You're going to make a transverse incision. You're then going to go to the GE junction, the distal aspect. You're going to make your incision there. And then you're going to go on the left of the lateral side, which is the gravity-dependent side. You're going to make your incision there. So that's the C. And then what happens is that the tissue just kind of flops over. It's amazing. So when I tried this for the first time, it was like seeing the matrix. It actually finally came together. And Dr. Bhatt has published on this recently, the outcomes even for T1B esophageal cancer. So this is really moving the needle forward. How are we going to incorporate this? And our group wrote the editorial on this. And as Dr. Ahera mentioned, it's really about having these procedures that can serve as staging procedures. So you can get this full pathologic analysis. And you can actually spare patients from getting major surgeries like esophagectomy. So what's a talk at an ESD course without some actual video? So here's an example. And this is incorporating the principles of electrosurgical generators. So you have this lesion. This is a Barrett's, what was reported as a Barrett's intramucosal cancer. This is like, people who ESD love this sort of lesion. It's skinny. It's long. This is like perfect example for this C-type incision. So you're going to make your marks. So when you insert the knife tip, you don't want to have too much of the knife that's far out from you. You want to be able to maintain your control. This is using an endocut current. It's very nice in that it's sharp. These white little fibers here are the muscularis mucosa. So it's important to be able to recognize the wall layers because you can get confused. What's going on? I'm seeing blue. Is this a muscularis propria? That was the actual muscularis mucosa. So that's the second part is at the GE junction. So this here is thicker. You may want to increase the effect, for example, on your settings. And then you're going to work your way on the left lateral side. And again, the tip of the knife, you don't want too much of the knife out. This maintains your control. And this is an endocut current. And you can see, you know, you're just connecting the dots that you made with your soft coagulation current. And what's nice about the soft coag for marking is that you're not going to get the char that you would with a forced coag. So you made a nice, clean incision. And now, you know, you can really just do just submucosal dissection. And now you're basically going to burrow underneath the lesion. And this part, you know, is very easy because you're not dissecting through tumor. Essentially now you've flipped the lesion over. And now you have that final right lateral side. And then again, with this, you know, you can use, you know, endocut is very capable. And so I like to make my marks close together that as I'm kind of walking myself up the lesion, I can follow exactly where I'm going. I'm not zigzagging and, you know, all these sorts of weird maneuvers. And, you know, with these generators, which you're going to be able to use, you know, you can, you should just try and flex it. Just try the different modes. Try to see, you know, what gives you the best, you know, what works best for you. So of course, this is, you know, once the lesion is completely removed. So this is a T1A, negative deep and lateral margins. Here is the pathology report. So invading into but not through the superficial layer of the muscularis mucosa. So this is a curative resection. And no high-risk features, no paraneural invasion, no lymphovascular invasion. So this is a good outcome for the patient. So in conclusion, don't worry about the settings, okay? Everyone gets fixated. When people put up slides at meetings showing the different settings, people are taking their cameras because everyone's thinking that, you know, this is the secret. It's not about the settings, okay? Just understand the principles, adjust the settings, adjust the different, try the different modes to see what gives you your desired outcome. You know, it depends on how you handle the knife, okay? For example, Nouria, what do you use? What's your most common mode that you use for colorectal ESD? Are you endocot? Are you SWIFT-COAG? Do you do... Yeah. So the point is like everybody here, you know, all the experts here probably use something a little bit different, but they've adapted their technique based on how they use the knife. So again, there's no right answer. Try the different modes and see, you know, what you feel is going to be the best way for you to utilize the knife. And really just maximize your time in the skills lab. You know, try everything out and see what happens. Talk to the different experts. Again, there's not a secret here. It's learning about the technique. It's your knife handling skills and understanding how the machine can work for you. I'm happy to take any questions. If anyone finds themselves in Chicago next month, we have a master class where we'll be demonstrating some live cases. Thank you.

electrosurgical generators

endoscopic submucosal dissection

coagulation

cutting

heat generation

knife handling skills