Next, I feel like we need to do some energy, some some thermal energy, bring some heat to this discussion. So there are, you know, you saw in the lectures this morning, you got actually very good lectures that have been well curated by the ASGE. That it's always important to know your devices and what you're using. So here I have a inner injection gold probe. So gold probes are devices, I'm going to put you on the spot, monopolar or bipolar, bipolar, right? So gold probes are one of the few devices in GI that we use in endoscopy that are bipolar. And bipolar means that it has a return circuit embedded within the device, okay? And so we're going to open this up. And you can see that everything in the packaging comes out really coiled and well packaged and you have to kind of just unfurl it in a nice manner, okay? So as I'm trying to figure out how this goes, we've got the gold probe here. The actual device is wrapped up in here, okay? So the first thing we're going to do is we're going to take a look at our generator here. So behind me, we have an Irby Bio 3. This is kind of the latest generation Irby electrosurgical generator. It is kind of really advanced for, I don't know if there's a kind of a glare, is that okay? Turn it this way here. Perfect. Okay. There. And you can see it's got a really nice touch screen and it's really capable of handling just about any device on this one. It's got APC, it's got just regular thermal energy, polypectomy settings, everything that you can potentially need. So you have to know your generator and every generator is different. So this device, which seems somewhat unwieldy here, is basically a bipolar hemostasis catheter. What I'm going to do is I'm going to help myself by giving you that, otherwise I'm going to split it everywhere. Oh, good. Thank you. And you want to hold that up and show them against maybe your hand. There you go. There you go. So that's a gold probe and basically you can see it has a gold coils and this can deliver energy anywhere along the side or at the end of the probe. So the device end, probe end, you can see, you can, it'll deliver, and it's better to see that probably through the endoscope. Okay. So what we'll do is go ahead and put that down the channel. In the meanwhile, I am going to set this up to the bipolar setting here. So I'm plugged in. As you can see, as you can see here, I've got this plugged into this generator here. And as soon as I plugged it in, it recognized that I was, that I had plugged this in. I've gotten my settings to bipolar and it's got to soft coag bipolar here. So you want to just ensure that you have the correct settings. So before we get started on this, Lilian, I think there's a question on, how do you decide what clips you use for upper GI bleeding, lower GI bleeding for those sorts of things. So there are a multitude of clips. A lot of this is driven by your personal preference and your institutional preference. So at our institution, we have several clips that are our first line. So we have our go-to clips, and then these are clips that we use that are workhorse clips for any sort of GI bleed, exposed vessels. And then we have second and third line clips that we use for special situations. So ones that have larger jaws that we may use for a large defect. So if I've taken out a big polyp and I want to approximate the margins and I want a really large clip, then I would choose something like that. We also have very small clips or clips that advance through a duodenoscope or a side view are much better. So in those instances, we would maybe choose a different clip rather than our standard workhorse clip. I would say rather than get too worried about which clip to use, I think you go with your workhorse clip and you learn how to use that one very well. That will pretty much take care of 90% of the clipping you need to do. So I hope that answers that question that came through, but it was a good question. All right. So now we're turning back to bipolar gold probe coagulation. And Lillian, I'm going to stop talking and I'm going to let you take it away. Okay, sounds good. So as Dr. Chandrasekhar mentioned, you can have the cautery effect along the length of the probe or kind of on face on the very point of it too. It's important to know that this is a contact method of thermal cauterization. And so there's a phenomenal co-option where you have to have pressure, for example, you're looking down to really have good apposition of the probe and the desired target, for example, like ulcers, visible vessels, or like dulafoil lesions too. And so I think early in the lecture today, when they're talking about thermo-cautery, you may usually have to apply cauterization for a lot longer, you know, five, seven, even 10 seconds, longer than you think. And so, oh, the other thing too is, so I don't know if you can see on the endoscopic view here, if I push out, you can see all the gold rings. You want to make sure that they're fully out of the scope because that could injure the scope, but you don't want it too far away so you can advance and then pull back. It's a little harder with the glare here, but you want to see all the gold rings outside of the scope to prevent any scope injury. Yeah, I was trying to turn down the light source there to help with visualization. I think if you go to a different area, you'll see it. There you go. Okay. And then so you guys can kind of appreciate that there. And then so I guess we can try to cauterize here too. And then so there's two petals, and you probably can't see on the floor. No, I don't want to see it, yeah. Okay. The blue petal. Blue petal, I think blue for burn, B for burn, to remember that as well. So what you want to do is make sure you have your foot, you know where the location of the petal is before you even start, because you don't want to start, you know, about to cauterize and you're just looking all over for the petal. So you have your foot over the petal. You pick a desired target here, for example, and then you can cauterize. So here, what is cauterize here? And you can see it's slowly burning. We have it at a very, very, very low setting. You can always change the settings to get more of a burn, okay? But this is just really kind of meant to show, demonstrate the technique, not necessarily burn. And so what Lillian has just shown you is two different methods. One is the end of the gold probe. The one is using the side of the gold probe, and you can see what happens as you kind of coagulate. It really, it didn't look like it was doing a whole lot, but now you come back and look at it, you can see the effect that she was able to generate. And as you can see that, I was like, oh my gosh, she's stepping on it for a long time, but that's really what you need, five seconds, if not longer, to get a really good effect. The other thing is with these needles, with these thermal therapies, you can get a coagulant that sticks to the gold probe. So when she's burning, so go ahead and burn, and as you're burning, try to get, don't push it into the wall as much, because I don't want to put a dimple into it, but more, yeah, like that. Perfect. So go ahead and step on it. And so what you'll see is that it chars, as the tissue chars, it sticks to the gold probe. So go ahead and stop. Now here, one of the options you have if you're stuck, it's like ripping off a scab. So you don't want to just pull it to the right and get it away from the tissue. You want to slowly back away from it, or in this case, what you can potentially do, this has an injection needle here with it, is you can just take, you can take the injection needle and I put a little bit of water into it, and basically what will happen, I don't have much water here, but it basically will separate that from that. And then you've all of a sudden been able to use the water to help you separate from the tissue. So here, I'm going to put a little bit of water here as you, as you move to the side. And you can see he's putting in water and then you, you come off to the side. That way you're trying to separate the tissue from the gold probe by putting a little bit of water in, you can see it's coming out of the tip there just to demonstrate that technique. And that will, that'll help get the tissue off of the gold probe so that the thermal desiccated tissue, you're not just ripping that scab off and it bleeds again. You want to demonstrate the technique one more time and then we can move on. So she's going to show you again, another area here, yep, beautiful. And sitting on it and charring to effect, okay. Now the length of duration people ask me, is it three seconds, five seconds, seven seconds? Well, it's based on, and I'm going to put some water here. It's based on your treatment effect. Okay. So you want to see it coagulate. You want to see a tissue effect. That's when you know you're done. Some other things is you try to avoid liquid because what's going to happen is the heat is just going to cause the liquid to evaporate. So you won't get much of a thermal therapy on the tissue, a coagulation like you're anticipating. You're just going to burn the liquid and it just evaporates and you're getting less reliable delivery of thermal energy to the anticipated tissue. So you want to try to suction up any water puddles, any blood or bile or other gastric contents prior to therapy. If it's bleeding and the whole area is bleeding and you can't clear it, then you have to just accept the risk that you're just going to put this through and it may not be perfect, but it can help slow down the bleeding so then you can do more definitive therapy. So we're going to, if you have any questions, please let us know, but otherwise we're going to move on from bipolar coagulation. And next what we're going to do is APC. Now, Lillian, you want to talk a little bit about APC when I get this, as I get this out? Yeah. So APC stands for argon plasma coagulation, and this is a non-contact form of cautery. Basically you have, you're basically shooting little ions, particles of argon gas, and then once you hit the pedal to cauterize it, the electrons will travel through the argon particles to the tissue. And so important to remember is this is non-contact, so you want to stay away from the wall, and what I've learned is you can touch the wall and then pull back a little bit, maybe one or two centimeters. You'll be able to see, kind of it's like toasting a marshmallow, making s'mores. You want that kind of, not quite that dark brown, maybe more of like a golden crusty kind of appearance too. With argon plasma, you're also, the amount of air, you want to make sure you're periodically suctioning because it's at quite a bit, liters per second insertion and insufflation with gas. So you want to make sure that you periodically are suctioning out the argon, or the gas there too. And APC is good for, oh, there's a question. Is the technique different between bipolar and monopolar, other than grounding the patient? Yeah. Good question. Yes, so techniques are different. So with bipolar, there was no grounding pad needed. For monopolar, which is what we're doing with APC, we are going to be using a grounding pad. However, there is a, here, go ahead and take this. So we'll show this down the camera here. There is a big difference in technique with APC. So it's not about monopolar versus bipolar, it is, is there a difference? Is there a difference with the technique that you're using? So here, what we're going to show you is APC, which is very, very different than Gold Probe. So as Dr. Wang had mentioned, you may want to take some of that air out because we're going to be putting a bunch of air in it. Vinay and Lillian. Yeah. So there's also a question from the audience just asking about what kind of, what materials, what kind of setup do you need to use APC? Okay. So for APC, you basically need a generator that, that is capable of delivering APC. So there's some generators that don't have APC capability. Number two, you need an Argon tank. We have a tank here built into the system that we just turned on. Number three is you need a device that runs down the channel for, for delivering APC. So again, as Lillian had mentioned, you have a device that's the conduit. You have the Argon gas again, which is an, which is an inert gas that helps conduct the energy from the device to your tissue in a non-contact modality. And so the optimal distance that I tell people between the device and your tissue is anywhere between three to five millimeters. So it's not, you can't be a centimeter away and expect to coagulate. You need to be fairly close between the, between the, the device and the tissue. The other thing is the companies used to tell you that you need to see their whole logo and this black box, this black bar here. This was the right setting, this distance for APC. That is not true. In fact, my personal bias is, so you may have some attendings tell you, advance it to the black mark and then you know, you're, you're, you're fine. The risk is, you know, you're conducting, you're, you're basically having a lot of conductive heat. You can potentially damage the tip of your endoscope, so you don't want that heat to be so close to you that, that you may potentially damage the tip of your endoscope. You're still fine if you work around this, around this far away. So I like to work around this far away at Lillian kind of demonstrate the actual technique here. So we've got many different things to talk about with APC, APC, APC is not a one and done sort of deal. All right. There's multiple different APC devices, there's forward viewing, there's circumferential, there's angled APC. That's that's the device. Number two, there's multiple different generator settings for APC. Now in your institution, you probably have something like APC stomach, APC colon, APC a small bowel. Now in this, in this situation, we are now on APC, we're on a pulsed APC on our generator and we can, we can focus on the generator here in a minute, but I just want to, I want you to see this here and I'll answer the question that I see that's popped up here in a second. So Lillian, why don't you go ahead and demonstrate this technique of pulsed APC. She's already got her foot where she wants near the pedal. She's going to take a look. She's touching the mucosa and then she's backing away. Yeah, while you guys are doing that, there is one question about should you be doing APC if there's a poor preparation, like a poor bowel preparation? Yeah, good question. So APC is not recommended in poor bowel preps if you're doing APC in the colon. The reason is you always want to do a bowel prep, even if you're just doing a flex sig and doing radiation proctitis. Go ahead, keep going, keep treating, keep painting that area. Try not to touch the mucosa, but just demonstrate the other technique where you just kind of go from and you just kind of just paint it. Yep. So as she's doing that, so the reason why you want to prep the patient is because the methane gas and the gases from the colon can theoretically also conduct the energy. And you can have what's very, very rare, but has occurred is a, what's something called a bowel explosion. Basically the whole bowel is full of methane gas. You've got, you've got the energy and all of a sudden you got a combustion where you just kind of, you just delivered energy to the whole colon. And that's a very serious and traumatic event. So in order to avoid that theoretical risk, you want to give a full bowel prep. Now if someone has a bowel prep and it's not perfect, what I do is I just go in and I just suction all the, all the air out and I put in my CO2 and then I'm comfortable proceeding. But you have to do some sort of bowel prep. And what you can see, Dr. Wang is here demonstrating is the technique of painting. Okay. So she's just going over slowly over the fold and painting the whole area. Now this is pulsed APC. So let's stop here for a second. What I want to show you now is I want to see if I can change this from a pulsed APC to what something is called precise APC. So I'm going to press precise APC now. Okay. So go ahead and... Ready? Yep. So you can see that beam is very small and precise. And it's, you can see it's straight. It's not pulsating like it was before, right? So you can see it's a very thin, controlled, precise delivery of energy. Okay. Now just to show you what it was before, let's go back to pulsed. Go ahead and show the same fold and now do pulsed. That's pulsed. You can see the difference there, right? Same settings. Anything else? Just changing the type of APC here. Now finally, I'm going to choose forced APC. So forced APC is just one big beam of energy. It's not pulsating at all. It's just like a lightsaber. And there's another kind of more of a clinical question about what clinical situations would you use this type of therapy, APC, versus when you were using like the bipolar probe? Yeah, good question. So APC is, I think Dr. Wang had mentioned her indications for bipolar, right? But when would you use APC? Great question. So APC for GAVE or radiation proctitis, this is much more of a superficial type of burn. So usually the indications we use are for GAVE and angioecutaneous there. Yeah. So any superficial vascular structures, like she said, that's exactly right. It's often used in therapeutic maneuvers. So when we're trying to, it was mentioned briefly in the lecture this morning, if you're trying to denude an area and you want to close it and close a fistula or an opening, you can denude the mucosa so that you then suture it closed or close it so that the tissue then sticks together. Because if you have mucosa and mucosa and you close it, it's not going to fully heal and form one layer anymore. So that's a rare but therapeutic example that we're commonly using it for. But for treatment of bleeding, it's usually for superficial angioectasias, GAVE, watermelon stomach. You can see CECL AVMs or AVMs in anywhere in the small bowel or in the colon most commonly. And then for radiation related proctopathy, where you have inflammation and neovascularity. That's really the most common causes that most general gastroenterologists use it for. So I just want to take a moment to come back to this VIO3 unit here. And so I personally have not played with this unit much, but this is the latest generator from Irby. This is a VIO3. And so basically here on this, your institution, if they have something like this or a VIO300 or another generator setting, it usually will say APC stomach, APC, like I said, small bowel, APC colon. What you can do here is you can take a look and see, well, what are my settings? What am I actually using here? So this here is forced. We're going to switch it back to pulse. So here you can see forced APC, pulsed APC, precise APC. So pulsed APC is what you have is what the default is for most generator settings, okay? Number two is you have, what is the max voltage that you are delivering? And here it's, you can see the default was four. If for some reason you're not getting the effect you want, in theory, you could just dial this up. And you can see as you do this, this graphic shows bigger and bigger injury. What did I start out at 4.2, four? I think it's four. Yeah. So if you're getting too much injury, you can dial it down. So this is in theory what you can adjust. Now the third thing you should look at is the flow rate of the argon gas. And so this is something that most people do not pay attention to. If you look here and if you can do it, if you can zoom in on this, this is all the argon gas that we have already put in, and you can see how much gas there is in this stomach. This was just, we didn't do a whole lot of APC, but this is set to one liter a minute. So even if we did 30 seconds of argon gas, we now have put in 500 CCs of argon gas into the stomach over a 30 second period. And that is something you need to remember because what you need to do is take this out and periodically clean the tip and then take while your tech or nurse is cleaning the tip of this, then the endoscopist has to clean. You see that smoke there on that screen on the, on the endoscopy screen, we have to clean out all that smoke and argon. And now when you look back at the pig stomach here, this is what it should look like. So this is exactly what, what happens to your patients. So you need to be very aware of the fact that you're, even though you're, you're putting in APC and argon, that, that this is what's happening. So go ahead and put this back in. So even if it's not conducting, you're still delivering that amount of argon gas in. So you have to be mindful to periodically desufflate and suction all that, that fluid. Right. And then I just want to emphasize when you have this catheter and you won't be able to use your suction that well too, so you have to physically take out the catheter. Yeah. So it's important to take out the catheter because you have a better suction channel. And oftentimes in real, in realistic, in real practice, you have, you have a lot of char on the APC probe, so you'll want to take that probe out to clean it out and use that time to, to suction. You can suction with the probe in, but it's just very weak. So go ahead and demonstrate a little bit more APC here. So checking my foot position and then finding a fold and then not touching it. And you kind of swing with, by twerking and the small dials a little bit so you can paint like a paintbrush over your target. If you're too far away, for example, here, you won't see the actual gas. Well, you won't actually see, you can tell nothing's really coming if you're too far away. Yeah. So, so energy is not conducting. It's not burning that argon gas and it's not conducting because there's no return mechanism. Right. And if you're too close, for example, here, you're touching it, you're going to see, it's going to start burning and look like. Yeah, you don't want to do that. So the reason you don't want to do that is, is two things. Number one, it's easy to get a perforation. Two, what happens is you can get submucosal delivery of the argon gas. So the argon, you get a pocket of argon gas that's, that is charged into the submucosa and then you touch it with energy. All of a sudden that pocket of argon with that, with that, uh, that conductive mechanism will then deliver heat deep into the muscle and you'll get, um, you'll get a post polypectomy burn syndrome or a transmural burn syndrome where the patient will wake up in pain because you've burned the muscle below. So you don't want to ever touch the probe to the mucosa because if you deliver that argon gas into the submucosa and then ignite it, it'll cause a deeper injury. So why don't we stop there? Let's switch out probes. I've got another probe from the same company and I don't even know if Lillian's seen this probe before, but I'm going to give it to her and let her, let her use it maybe for the first time ever. So go ahead and take it, pass it down a little bit of a surprise. I like to, to, to, uh, surprise people with a little bit of trial by fire. I'm just suctioning out before I put in the probe, um, here we go. Now the one thing, um, you know, prior generators you had to, what you have to do is again, the argon gas is important for conducting the energy. So what you had to do was do something called a purge of the, of the, of the device. What that means is rinsing the instrument with argon gas from this channel here all the way to the tip of the, all the way to the tip of the catheter so that when you step on the pedal, you're immediately delivering energy here with these newer generators. You don't have to do that. So before you start stepping on it, what do you think you have here? So you, these newer generators, you don't have to do that. It'll automatically rinse as soon as you plug it in. So it primes the whole catheter with argon gas. What do you got in your hands? So I'm guessing some other type of APC probe, I'm guessing, but I've never used this one before. Yep. I know. Cause we don't have it in our institution. So this is a circumferential APC probe. So basically it delivered, it's the same exact thing except for it's got an insulated tip on there, like a porcelain tip. You cannot injure this with that tip. What this does is it delivers argon gas around the tip. So it diffuses slowly around that tip. So go ahead and treat something here and take a look and see what you got. So you can see it's more circumferential. So you see there it's coming out to the right because on the right side is where you have the tissue. Now swing over to the left or the bottom. Yeah, fine. Now it's firing on the left side. If you swing down, it'll go down. If you swing up, it'll be up. So it's a circumferential probe that delivers it more, I would say not exactly tangentially, but it's better for coagulating tangentially. And the insulated tip protects you so that if you touch the mucosa, it's not gonna burn that area right in front of you. So you can see it's burning the area to the sides as you move around. So this is called a circumferential APC probe. Very neat. You wanna show one more on the bottom there? Yeah, sure. I'll come over here. And you see Lillian's technique is to touch and then go. I think that's good for when you're learning. If you're doing that, you wanna touch not the vessel that's bleeding, but you wanna touch maybe the mucosa that's right next to the bleeding vessel and then swing over to the bleeding area. You don't wanna touch the bleeding area or the AVM and then burn it because you may cause it to ooze and bleed. So that's something that if you do that method where you touch it and then pull back a millimeter or two, then you don't wanna touch the area where there's a bleeding area. Okay, good. I think we've had a really good demonstration of APC. APC's a lot of fun. If you get a chance, please try to use APC at another hands-on course because that's better to learn. It's just easier to learn without having to have the pressure of a patient who's bleeding in front of you.

energy devices

endoscopy

gold probe

argon plasma coagulation

bipolar device

hemostasis

generator settings