All right. Good morning, everyone. Just what you want to hear Sunday morning. Sunday, right? Okay. So, we'll talk about electrosurgery principles and ESD, also known as advanced electrosurgery. And I think that you've all had some introduction to electrosurgery, but you really need to understand electrosurgery on a whole other level if you're going to do ESD well. And there's a lot of untapped potential in the electrosurgery unit. So, these are my disclosures. So, we'll give an overview. I know in general, we don't like to talk about specific settings. So, I'm not going to talk about specific settings, but I'm going to talk about settings in general and specifically for the steps in ESD. So, for mucosal marking, mucosal incision, submucosal dissection, and particularly hemostasis. I think hemostasis is the one area that you really have to have a really thorough understanding of coagulation settings and all the different settings that are available on your generator. And then I know that this is a CME program and we try to stay industry agnostic, but I think a majority of the generators out there that we... Quick raise of hands. Who uses ERBI generators? Okay. Easier. Who doesn't use an ERBI generator? Okay. So, this will be easy. I know we're using the Olympus... Olympus, CONMED, they all make very high quality generators that are completely acceptable for doing third space procedures, but ERBI does have a special setting of EndoCut that I think it'd be worthwhile to go into some depth because there are some settings that really can change that you can modify to tailor towards how you want to do your ESD. The really important thing that I want to get across with this is that the generator settings are only a very small part of the equation, right? It's, you know, we have this, we think of this, we think of the generator settings as, you know, the end-all be-all, you know, the question that we often get is, what are the specific settings? And it really has to do with a lot more factors because, you know, at the end you want a specific tissue outcome or effect, right? And so, do you want more of a cut type thing? Are you trying to coagulate? But then there's a lot of other things that come into it, like patient factors, sometimes like, you know, how the current transmits through the patient, especially since most of these devices are monopolar devices, the circuit and what we call the tissue impedance. So, what kind of tissue are you dealing with? Are you dealing with fibrotic tissue that has low water content? Are you dealing with, you know, did you just inject into the submucosa and so it's just high water content? How much tissue are you trying to cut or coagulate at one time? What device are you using? Is it a thick device? Is it a thin device? What type of technique? That's the biggest variable is probably how you do it. And we'll talk about how you can achieve both high current density or low current density depending on what you're trying to do it and obviously the duration that you apply. So, you know, again, in the lab I saw people just kind of staying on the pedal for a long time versus tapping. And, you know, both are appropriate for the tissue effect that you're trying to achieve. Then the key is just to understand what you're doing and how what you're doing is going to result in the tissue effect. But again, the generator settings are only a small part of it. They're a very important part of it because if you don't have the right generator settings, it doesn't matter what you do everywhere else. You're not going to get the tissue effect. But these all have to be taken into account. And the bottom line is what current density do you want at your electrode tip? Do you want low current density to coagulate or are you trying to get high current density to cut? And that's really the two ways that you have to think about it. If you're trying to coagulate a vessel, you really want low current density because you don't want to cut that vessel. If you are trying to do a dissection or submucosal incision, you want very high current density because you want to cut. And then sometimes there's a mix, right? Sometimes there's you want to cut, but there's blood vessels in the way. And so there are certain settings that we can use to try and address both. So Norio went through all the various knives, but it's really important to know which knife you're using because the generator settings are going to vary depending on the knife that you use or even like, for example, the triangle tip knife. I love this knife because it has multiple surfaces. It has very sharp surfaces. It has very flat surfaces. It has high surface area. So you can do great coagulation with it if you use like the tip, the flat area, because that's a high surface area. You combine that with the coagulation current, you can get nice coagulation. But then you also just use the shaft or even just the tip of the triangle and you can get very sharp, high current density cuts. So that's a very versatile knife and you just have to know how to use it. The most common type of knife that we use is either the I or T type knife. So basically just a needle type knife. But it also depends on how much of that knife you're going to place on tissue. Are you using just the tip of the knife or are you using the blade or the shaft of the knife? And all those come into consideration when you think about the energy that you're using. This slide's up there, you know, just for reference. Again, we're going to primarily be talking about just the Irby settings since all of you are using the Irby system. But this is a kind of a good reference table if you're using a different generator, kind of how they all fit. But a lot of these devices, again, most of these devices are very effective in terms of doing third space as well. Some have limited functions, but for the most part you can still do an adequate third space procedure with any of these generators. Yellow pedal and blue pedal, I mean, at this level you should completely understand the difference between the two. But one thing to get across is just because you hit the yellow pedal doesn't mean that you don't have any coag. And just because you hit the blue pedal doesn't mean you don't have any cut, right? And so that in terms of the waveforms, there's a couple things that you don't need to know a lot about, but there's something called unmodulated waveforms. Basically, these are waveforms that are just put out by the generator. It doesn't vary based on tissue impedance. It's kind of a constant output and those are autocut and soft coags. Modulated ones, basically the generator is sensing the impedance and then it just modulates to vary the amount of cut and coag that's delivered. And so these are forced coag, dry cut, spray coag, and swift coag. And then there are special ones that are endocut, precise sect, and high cut. And so these are also all modulated waveforms, but they're modulated in even more complex ways than just the traditional modulated waveforms. So the differences in the waveforms, and again, this part isn't super important. There's soft coag, which is a low voltage continuous wave. You have cut, autocut, which is a higher voltage, over 200 volts peak-to-peak, and that will result in a cut and that's also continuous waveform. And then you have forced coag, which is a higher voltage, but what we call a shorter duty cycle, so it's not always on. So it helps to desiccate the tissue as opposed to a cut, but if you use a high enough setting, it will also cut tissue. But if you use a very low setting, it'll just coagulate. Dry cut is kind of your typical blend, right? So it has both cut and coag features in the waveform. And so if you want to use a cutting current that has coag, use dry cut. So I'll often use dry cut, like if I'm cutting and there's a lot of vessels in the way. Sometimes when I'm doing a poem and the myotomy is, you know, if there's a lot of blood with the myotomy, then I'll use the dry cut setting for that. And then there's spray coag, which I think a lot of people, especially coming from the poem side, use for dissection, but it's actually the best coagulative waveform. It's like the highest voltage, shortest pulse length, and is very good at desiccating. But the intended use of this is non-contact, right? So the reason that it's really good at coagulation if you use it as non-contact is the effective current density is actually super low, because as it comes off, it doesn't matter how sharp your catheter is because it spreads rapidly. And then as it spreads, the current density goes down. And so if you use the right settings, it's very effective at coagulation. And this is it on a continuum on the ability of coagulation versus dissection, right? And so at the extreme is soft coag, and that's just purely coagulative. You really can't get this to cut even if you try, just because the peak voltage is too low. But actually, the next coagulative waveform is spray coag, right? And even though I think most of you that have been exposed to spray coag have seen it purely for dissection, right? Submucosal dissection. And a lot of people like to use it because it dissects, and if you run into a blood vessel, it will coagulate those blood vessels as well. But it's a lot of energy. It's actually not a waveform I like to use for dissection. I do use it for coagulation, and I'll show you some video of that. And then you have forced coag, swift coag. So now the swift coag is a better cutting current. So swift coag and dry coag are kind of pretty close together, or dry cut, right? So swift coag has a little bit more coagulative effect, but is pretty good at dissecting. Dry cut is better at dissecting, not as good as coagulating. But both of these have coagulative abilities. And then you have precise sect, which is somewhere on this continuum. And precise sect is even more modulated, so it really senses the impedance. And depending on how fast or how slow you cut, it has either more dissective or coagulative features. And then you go over to more of the cutting. Endocut I is kind of not on here because it has two different—we'll talk about it a little bit more. It has two parts to it, right? It has a cut part and a coagulative part to it, and we'll talk a little bit more about that. So let's go to kind of specific steps in ESD. You have mucosal marking. And so mucosal marking is always done with a coag current, okay? This is the one thing in the ESD I'll say, don't ever use cut. But you can use a variety of coag settings depending on what you want your mark to look like. So it's typically done with the tip of the ESD knife. Again, you're using a coagulation current. And you could use, you know, oftentimes where it starts to use soft coag. If you use soft coag, you want to use a little bit of a higher power, so something like 50 to 60 watts. You could also use spray coag or forced coag, but you want to use a lower power for that. And the reason for these is they often make more stable marks in the mucosa. The key with mucosal marking is you do not want to penetrate through the lamina propria or the muscular mucosa, right? So you want to stay out of the submucosa, because if you put too high of a voltage or energy into that, you can pierce into the submucosa. And then when you do your injection, fluid will just come out of that hole. So you want to avoid that. But sometimes with soft coag, what I've noticed, especially like in the stomach, is it will just slough off. So you'll say, well, where did that mark go? And so if you want a little bit more of a punctate mark, you can use other coag settings. So this is soft coag, and you'll just see, it makes a very pretty, you know, mark that you would love to see in a nice journal article. And I often tell my fellows, take pictures like, you know, they're going to show up sometime in a manuscript. So these marks look very, you know, uniform. They're precise. But the problem with these are, these are very superficial. And in certain areas, they'll, you know, the cap, if you run across it with the cap, it'll just come off. This is one with a low force forced. I think this is probably like around 10 to 20 watts of force. And again, it makes a little bit of a deeper, kind of more And again, it makes a little bit of a deeper, kind of more punctate lesion that you can see a little bit better. It scrapes off a little bit. It's a little harder to scrape off. Sometimes you get a little bit more coagulant on the tip. So you have to come out and clean the tip in order to get uniform marks. And then this is spray coag. This is like 10 watts of spray coag. And you can see that the marks can get a little bit deeper and sometimes have this like charred appearance to it, kind of this, you see that brownish appearance. So it really depends on, you know, what you want your mark to look like. You just want, don't want them to penetrate too deeply. But you want them to be able to stay there so that throughout your procedure, they're not going to disappear. Okay, so that's mucosal marking. Mucosal incision is almost always done with a cut current. And you can typically use endocut eye or a dry cut current. So endocut eye, and we'll go into it in more detail. It's a complex setting, right? Because you have to put in an effect, you have to put in a duration, you have to put in an interval. So, you know, sometimes you'll hear endocut eye 2-2-2, right? So that talks about what the effect is, what the duration is, what the interval is. And we'll talk a little bit more about what that does when you're changing those settings in a little bit. But the thing to note is when, if you just tap doing endocut, you're only going to deliver the cut part of that waveform. You're not going to deliver any of the coag. So if you, again, it's a two-phase cycle. It's the cut followed by coag. So if you want the coag part of the endocut, you need to stay on the pedal and listen for two tones as opposed to just tapping if you just want the cut. So in this video here, I'm just tapping here because you see very little coag, right? And so, and you know there's coag because you'll see the bubbling. Coag causes some bubbling. So, you know, here there's no bubbling. It's just, we're just tapping and trying to make as clean a cut as possible. And then I'll add the coag if we encounter bleeding. If it's vascular, so oftentimes the stomach is quite vascular, you should consider using a dry cut current to do your incision. The key with dry cut is it's not pulsed. So you cannot sit on that pedal. So it'll deliver energy as long as you put the pedal. So you are at risk of doing a zipper cut with the dry cut if you are not careful on how you use your pedal. But there's a couple settings with dry cut. There's a power setting. Basically it determines the cutting strength and then the effect which determines the coagulative ability of your cut. Now moving towards submucosal dissection. So submucosal dissection is something that you can pretty much use any waveform, right? Depending on how you want to do it and what it looks like. Is it fibrotic? Is it vascular? Is it wispy? So you can pretty much use anything except for soft coag. And you just have to understand the current to figure out what you want to do with it. If you use coag settings, you need to use a higher power in order to get a higher current density to do the dissection portion. Otherwise, if it's too low, you'll just get coagulation. And then it really depends on what knife you're using. Are you using a sharp knife, like are you using a dual J or a pro knife or a hybrid flex? Is it a sharp knife or using one with more surface area like a TTJ? And then a key thing is it's always better to prevent bleeding than to treat bleeding. So consider coagulating vessels before cutting through. I know that there are some settings where I can just cut through it and it won't bleed. But if you can, I mean, my principal and Peter kind of referenced it yesterday, I use cut to cut and coag to coag. So I typically use like an endo cut setting for my dissection. And then I will use either a low force or a low spray setting and pre-coagulate vessels before I cut through them. But you can use, a lot of people love this precise sex setting where you can just cut through smaller vessels and hope they don't bleed. My preference is not to test fate and I would just prefer to coagulate vessels and not hope that they don't bleed. So that's my approach. But everybody has a different approach and has a different threshold for dealing with vessels and bleeding. A couple of things with fibrosis, if you're dealing with fibrosis, you want to use a sharpened knife as possible. And when you use that knife, you don't want to lay into it. You just want to use the tip of the knife. You want to achieve as high a current density as possible. If it's really dense fibrosis, then consider using an even sharper knife like a hook knife and potentially with a high cut or an auto cut setting. But for the most part, most of it can be addressed with an endo cut eye setting and our standard eye type knives. So now moving on to hemostasis. I think hemostasis is where there's the most versatility and you really have to understand the coag settings. Because all these coag settings here, soft coag, spray coag, force coag, precise sectants, swift coag, they all are designed to coagulate. They're all designed to either prevent bleeding or to treat bleeding. And things that factors to consider when you're using the coag setting, is there active bleeding and is it arterial or venous? If it's arterial venous, you really need coag graspers because you have to, flow will act as a heat sink. And so you have to coag that vessel to diminish the flow and then deliver the coagulation. So that's in particular for arterial bleeding. Also the size of the vessel should be considered and then the device being used for hemostasis. So we often don't want to exchange devices. So lately, there's been a huge trend towards trying to do as much coagulation with just the side of the needle, like using low force coag. But recognize when there's a genuine arterial bleed and switch out rapidly for coag graspers if it's a real arterial bleed. I think Noria mentioned yesterday, use your cap to tamponade. If there's active bleeding and you're doing an exchange, use a cap and also water. I like to use water irrigation. I want to clearly identify where the bleeding is coming from because you don't want to guess as to where you want to coagulate. You don't want to blindly grasp tissue with your coag grasper if at all possible. You want to target it because the other thing about soft coag, because you're going to use soft coag with coag grasper, soft coag penetrates pretty deeply. So I always tell these companies that soft coag or gentle coag, they're misnomers, right? Because it's really deep. It's deep coag. It's very effective coagulation. But this is where you get the... If you don't know how to use this energy and you're using it up against muscle, this is where you get delayed perforations because it doesn't cut the muscle, but it devitalizes that muscle. And so you can easily get muscle injury if you're treating a bleeding vessel on the muscle and you deliver coag too long or you don't deliver it appropriately. So you have to be very cautious with how you use soft coag. And that's what worries me with this whole snare tip soft coagulation phenomenon that's going around. I think people don't understand or appreciate how effective and how deep soft coagulation is. So on tips, expose the vessel prior to hemostasis, especially if it's large, really get a precise grasp of it. And that's why I tell companies, I joke, it's like I want physician rotatable coag graspers. But the reason for that is that you don't want to be torquing your scope in a narrow field to try and get your coag graspers aligned correctly. You don't want to have your tech rotating because then they'll helicopter. You really want to have precision on coagulating these vessels. And so hopefully soon we'll have physician rotatable devices that will allow us to be more precise and more rapid in terms of orienting and targeting vessels. So here's a couple examples. So this is a low force coag. So this is becoming very popular. Use 10 watts of force coag. I think it's like effect 0.8 or something like that now. You just you take the shaft of the knife and you lean it up against the vessel. You really lean into it. And you want to treat it along a length of the vessel. And then you want to divide that kind of at the middle of that. You don't want to divide it right down at the muscle base. Again, you want to coagulate along the length of this vessel. And then you want to divide in the middle there. The other one that I like to use is low spray. So this is, again, we talked about spray. I like to use low spray for coagulating. So this one, you can look at it. It's on FOS. So if you see any vessels, I love to use it when a vessel's oozing. If you have a oozing vessel, you don't have to actually make contact of it. You just have to hover over the vessel at 10 watts. So again, most of the dissection is done at like 40, 50, 60 watts of spray. This is only 10 watts of spray. And you just coagulate that vessel, and then you divide it. So it's one of my favorite ways to coagulate vessels preemptively. And it doesn't require you to completely skeletonize the vessel so that you have to come at it from the side. And again, spray coag is designed to coagulate vessels, not to cut. But somehow, we've adopted spray coag to cut. So now I want to go into a little bit more in-depth last couple of minutes discussion on endocut. So endocut, you have the ability to adjust the effect. Think about the effect as the amount of coagulation current that's going to be delivered. The duration is the amount of cut time that's going to be delivered. And the interval is the duration that you're going to deliver coagulation if you stay on the pedal. So we have effect, which is the intensity of the coagulation. It's from 1 to 4. You have the duration, which they call the sharpness of the cut, which is also 1 to 4. But it's really the length or the duration that the cut is delivered. And then the interval, again, this is the duration that the coagulation is delivered. And it's 1 to 10. So we'll go through various scenarios of this. There's an endocut I and an endocut Q. And I think a lot of people don't know the difference between the endocut I and the endocut Q, but they're different. So endocut Q was designed for snares. And what endocut Q does is it actually ramps up the voltage if you stay on the pedal. So it starts at a lower voltage, a lower cutting voltage, and then it escalates up over three cycles. And then after three cycles, it looks like endocut I. So if you're just using endocut Q, you're actually using a lower voltage for cutting. You can. There's no reason that you can't use endocut Q for doing when you use an I-type knife. But you just have to understand, especially if you're staying on the pedal, you're not delivering a consistent voltage. Each time, if you stay on a pedal for three cycles, you're going to deliver three different cut voltages. The other part that's different about endocut Q is their coagulation voltage scheme is quite different. So an endocut Q, so effect one basically means there's no coag delivered. So there's no additional coagulation. So if you just want cut, you do effect one. If you want some coagulation, you do an effect two. If you want a little bit more coagulation, it's an effect three. So this is during the interval. So this is the duration. And then this is the interval. So if you go up in effect, you're going to deliver more coagulation at a higher voltage. And then this is kind of what they call a modulated voltage. And then endocut four also is at a high voltage and modulated, but it has more coagulated effects. So there's a couple of ways that waveforms could be modulated. You can modulate the voltage, so you can deliver more power, a higher voltage. Or you can change the duration, so you can modulate the time or what we call the duty factor. So more information than you need to know. But you have to understand that if you're using endocut Q, the type of coag that you're going to get is different than when you're going to use endocut I. So endocut I gives a constant. It doesn't matter what cycle you're in and how many times you've stepped on the pedal. It's giving a constant voltage of 700. That's the peak voltage. And then again, endocut I without any effect one has no coagulation. So it's pretty rare for us to do it. So oftentimes, we either put in an effect two or an effect three. So an effect two has some coagulation. And then effect three, again, has technically more coagulation, but it's still a low voltage. So the endocut I delivers a lower voltage than the endocut Q. And it has to do with the fact that snares typically require more power for coagulation as opposed to knives. And so the Q is designed for large surface area devices. And so that's why I think endocut I is probably better. But it's probably nuanced. And you can experiment and see if you really even notice a difference. The problem with all this and the lab that we're doing, the coagulation settings are only important if you have perfusion. We can't teach and we can't test coagulation effects in ex vivo tissue because there's no perfusion. And so I would say in your journey to learn ESD, try and get as many opportunities to do live pig labs as possible because they'll have at least some bleeding. And you'll be able to really test the coagulation settings. And also, the generator settings for ex vivo tissue are drastically different than for live pig tissue. So in live animal labs, the generator settings are going to be very similar to what we use in humans. So then if you go to NF4, you'll see that the voltage for the coagulation isn't increased. But what they do is they modulate the time and the duty factor. And so there's still more coagulation that's delivered. But it's modulated in a different way that's designed more for a knife as opposed to a snare. So what about the duration? So a cut duration means a very short cut. We almost never use a cut duration of one. The shortest cut duration that I ever dialed in is a cut duration of two. But that's basically just if you're putting in a cut duration of one, basically you're just saying I want a little cut and I'm planning, I got a vascular incision and I need more coag. And I want to go carefully cut coag, cut coag. So that's when you would use a cut duration of one. Cut duration of two means that the length that the cut is being given is a little bit longer. Same thing, three. And then four is even longer yet. Four is kind of the longest cut duration. It'll travel the most. Urbi likes to say it's the sharpest. But it's the sharpest because it's the least amount of coag that's being delivered. So sharpness is actually related to how much coag you put into it because the sharpness decreases with the amount of coag that you put into it. And so now we're going to go into the interval. So the interval is the duration that the coag is. So it's that blue cycle. So longer intervals, if you stay on the pedal and allow it to cycle all the way through, that's when you're going to get more coag. So you will increase the cutting interval if you want more coag or a longer duration of coag. And that interval can go all the way up to 10. I've never gone over three, I don't think. But you can keep it going. So in summary, I mean, I threw a lot at you here. But I consider it the basics. I think this is, at a minimum, what you need to understand in terms of harnessing the potentials of the generator. So understand your generator. Spend some time with your generator. When I'm doing ESD, I have my generator on a stand next to me so I can adjust the settings. If you have a great tech who knows how to adjust the settings really well, then do that. Spend some time with your representative and get your device programmed. You can program it so that you can put multiple settings in there and be able to toggle through. So spend some time with your rep. Spend some time with the generator. Program the generator how you want to do it. And just remember that these are all a start. I adjust my generator settings constantly during it. You don't have to. Most people don't. But I have a particular, I want a particular tissue effect, and I'll get it. Occasionally, I go underwater, Sergey. Just occasionally. And those are completely different settings. They actually are. If you want to coag under saline, and depending on the knife, you actually have a different set of settings that you want. And we're not going to go into that today. So it really will depend, the settings depend on the knife you're using, the setting that you're using, the technique that you're using. And you want to adjust your generator settings for mucosal incision, submucosal dissections, when you deal with fibrosis and hemosasis. So you're going to want to at least put in a few settings, pre-programmed settings into your generator, just so that you have a basis to start. And then you feel free to adjust as necessary. So with that, I would like to acknowledge the slides. Ankit Vyas gave me a lot of the slides, the Irby slides. So I appreciate that. So be careful with the generator. It's very powerful. But if you know how to use it, it makes doing the dissections even more precise and more rewarding. So thank you.

electrosurgery

ESD

hemostasis

generator settings

waveform settings

submucosal dissection

coagulation