Welcome back. Thanks for watching the live demonstration. I'm sure you had a great time watching the masters, Dr. Yamamoto and Dr. Toyonaga. Now second part is Dr. Yahagi and me, Norio Fukami. Assistant is Dr. Kato. And my assistant here in the back is Dr. Brijesh Patel. Today I'd like to show you how to use Dual Knife-J because I'm an inventor of Dual Knife-J. That's why I would like to show you basic technique of Dual Knife-J. Basically, Dual Knife is a simple device, but it has much function because even if we close the knife completely, still there is a small metallic part remaining on the surface. We can use this small metallic tip for placing marking dot or hemostasis during the procedure. Most of the minor breathing, we can just use the closed tip of Dual Knife. It's usually good enough. And of course, in case of having severe breathing, we usually switch to coagulasper or some other coagulation forceps. And of course, this has injection capability. Just pressing the foot pedal, we can give additional fluid cushion at any time through the knife. It's one of the great merits. But unfortunately, unlike hybrid knife, it doesn't have high pressure. That's why, at least at the beginning of the procedure, we should use injection needle at the beginning. Well, I would like to introduce the knife to the working channel. And this is isolated pig stomach. Usually, pig stomach has really sick mucosa. So, if you can see here, there is a little bit irregular surface. It means it has really sick mucosa. And if we go here, it becomes a little bit smooth. And this is very nice area to do EST training because of much thinner mucosa here. So, I'm going to put the marking dot as a target region. Usually, for the human procedure, I prefer to use soft coag for pressing marking dot. But this is pig stomach. It is necessary to use much high power coagulation current. That's why I'm going to use post coag for pressing marking dot. And for pressing marking dot, usually, cross tip of dual knife is very good. Just touch to the target tissue and press the foot pedal of coagulation. We can press nice marking dot like this. And control of the endoscope is very simple. I always try to keep the endoscope straight as far as possible. This is very, very important technical tip. Otherwise, we cannot transmit our movement of her right hand to the tip of the endoscope. Therefore, I always try to keep straight position, then try to transmit my movement of right hand directly to the tip of the endoscope. If I talk my wrist to the right side, it goes to right. If I talk my wrist to the left side, endoscope tip also go to the left. This is really convenient. We don't have to control right-left channel so much during the procedure. But of course, I always try to control both up-down and right-left channel together with my left hand. I usually control up-down angle with my thumb, and I usually control right-left channel with my fourth finger like this. So this kind of maneuver is quite important for the precise EST procedure. Okay, back to the marking. I would like to press the marking dot a little bit more, gently touch to the target tissue, and press the foot pedal of coagulation. Then I can make a nice marking as a target region. And of course, we should clean the lumen as far as possible before starting actual procedure. Check the marking dot. Okay. And connect the marking dot here. Now it's nice target region. Then there's another important technical tip. In case of doing actual human procedure, I always press additional marking dot, which we can easily recognize the direction of the resected specimen. I'm keeping retroflex position. Therefore, this is anal side and this is oral side. So if you find this additional marking dot, you can easily recognize that this is anal side of the resected specimen. This kind of additional marking dot is really necessary, and you can give additional information to the pathologist at your institution. Oh, hey, sir. Yeah. You mark inside the marking, but you're not marking on the lesion itself, right? Of course not. Of course not. And I usually keep a few millimeter outside the target region. I mean, I place the marking dot a few millimeter outside. Therefore, usually there's enough space to give additional marking dot in between the target region and the marked area. And of course, if you didn't have enough space, you can put additional marking dot even outside. It's up to you. So what is your plan with this procedure in the retroflex? You're going to be incising from distal closer to you first and create a pocket? That's right. That's right. For the standard dual knife ESD procedure, I usually don't make circumferential mucosal incision at the beginning. Because if we make a circumferential mucosal incision at the beginning, injected solution easily leaks out from the incised area. That's why I usually create a nice submucosal fluid cushion, which we are planning to make incision and the initial dissection, then give additional fluid cushion through the knife to the submucosal layer directly, then continue the procedure. Well, I'm going to inject solution at the anal side first. I saw a little bit tag over here. Is that your trick? Sometimes. Yes, yes. This is also a very nice trick. Because sometimes we insert the instruments quickly, then it's go out quickly through the working channel, and it causes some tissue damage. Absolutely. That's a great tip. I mean, trick. So we can easily recognize the length of the insertion with this marking. Okay, now it's coming out. Okay. And if we push out the needle, we should keep it inside the transparent fluid. This is completely safe situation. We don't have to ask our assistant to close the knife all the time. Injection needle always out, but we should keep it inside the transparent fluid. And gently approach to the target area. And it is very important to puncture a few millimeters outside the marking dot, because puncture itself always have some risk causing bleeding in case of puncturing the tissue. That's why I always start injection exactly on the incision line. Okay, now I punctured. Injection, please. Now you start to see the lifting. So that's the sign that you have a good plane to inject in the semicosal layer. Yes, that's right. We should carefully check the nice lifting sign. And my assistant always count the volume of injection. That means, okay, stop it, please. If we inject a few milliliters of solution, but it doesn't lift up, it already penetrates through the muscle layer. So we should check the nice lifting sign all the time. And once we create a nice semicosal fluid cushion, we should puncture at the base of the injection site. We have enough space to give additional fluid cushion by a simple puncture. Okay, it becomes quite easy to give additional fluid cushion. Okay, very good. And check the lifting sign here. And I would like to lift up also here. A few millimeters outside on the incision line. Okay, injection, please. It becomes a little bit tangentially. Oh, okay, it's leaking a little bit. Come close. And because of the undulation, it becomes a little bit difficult to give additional fluid cushion here. In this situation, there is some technical tip. Now, we cannot approach perpendicularly here. But if we suck air a little bit, it comes close and the angle changes. So I'm sucking air a little bit, then we can change the angle. Now it becomes a perpendicular approach, then we can inject additional fluid cushion much effectively. Okay, injection, please. Okay, that's good enough. Needle in. Okay, thank you. That was a really big mound that you created. Was it intentional? Yes, yes. Because DualKnifeJ is very, very effective, we can quickly make a causal incision and sub-causal dissection. Therefore, I usually inject a little bit large amount of fluid cushion at the beginning of the procedure. Then I will use additional, I will give additional fluid cushion through the knife. For the additional injection, we don't have to use viscous agents such as oriase gel or hyaluronic acid. We can use just normal saline, but I prefer to include small amount of blue dye such as indigo carmine or methylene blue. Okay, I'm inserting DualKnifeJ. DualKnifeJ has two different lengths. This is 2 mm DualKnifeJ, which is very good for gastric ESD procedure. And 1.5 mm DualKnifeJ is very good for esophageal, duodenal, and colorectal ESD procedure because of the difference of the mucosal thickness. Okay, and once we insert the DualKnife, we should check the knife tip because if it becomes dirty, it doesn't cut well. Therefore, we need to check the cleanness of the knife before start using it. Now the knife tip is completely clean, and we can recognize the small disc part, and we can see the white ceramic tip and blue band. This is a really good situation. And come close to the rifted area here, and working channel is located at 7 o'clock. Therefore, I'm going to start the mucosal incision from left side and going to right side. As Dr. Yamamoto already mentioned, it is a nice direction because we can see all the marking dots when we come from left side and going to right side like this. We can see all the marking dots. Then come close to the target region, gently touch to the target tissue a few millimeters away from the marking dot, then press the cutting current. Oh, I'm sorry, this is the injection. Yes. I prefer to use dry cut for my procedure, but if you prefer to use end cut, you may use end cut, of course. Now I'm pressing the foot pedal of dry cut. Now metallic tip already go into the submucosal area, and this white ceramic tip should stay on the surface. If you push too much, it's dangerous, so just touch to the target tissue and make metallic tip go into the submucosal area, but still white ceramic tip staying on the surface. And now we can see white ceramic tip and blue band. This is completely safe situation. And recognizing marking dot, I can make a nice mucosal incision. Always you should recognize the white ceramic tip, and if angle changes, you should pull back the instruments a little bit to avoid a risky situation like this. So always white ceramic tip stays on the surface, and using up angle and torquing my wrist to the right side a little bit, I can make mucosal incision relatively easily. And initially, I usually make half circumferential mucosal incision. Okay, I think it's good enough. We can see the nice mucosal incision. Here's remaining mucosal here, so I can trace here once more again, then it's already open. So once you make a nice mucosal incision, you can see the blue colored submucosal area colored by indigo carmine or Mediterranean blue. Next step is to make submucosal pocket. Dr. Yamamoto already mentioned, we don't have to go deep side. Just tracing inner edge of the incised area using a coagulation current. Because just below the muscular mucosa, there will be rich vascular network, so to avoid bleeding situation, I always use swift coag for the submucosal dissection. This is first time to trace the inner edge. This is second time to trace the inner edge. I'm controlling the length of the device using my left hand. Because I'm keeping straight endoscope position, nothing happens if I release the right hand from the endoscope. Then I can easily control the device itself. So controlling the shaft or controlling the device, we can keep the very safe condition. This is second time. Just tracing the inner edge second time, submucosal area already widely opens. Usually three times initial dissection is usually good enough. This is third time. Now it becomes relatively wide submucosal pocket. I always clean the field of the operation and try to open the submucosal pocket utilizing upper rim of the transparent hood. Adjusting the angle and pull back the endoscope and using upper rim of the transparent hood and slowly using up angle, I can easily open the submucosal space. Now it becomes completely safe situation and we can easily recognize the dissection plane. We have wide area to do submucosal dissection. Please carefully check the submucosal layer. If you can see the little bit dark blue layer, it's a light dissection plane. We can see the little bit whitish area. This is muscle layer side and this is the backside of the target region. So in between the two whitish area, you can see the little bit lucent but bluish area. This is through dissection plane and gently apply the knife tip. Then start the dissection using up angle and the gentle torque of the wrist and come to the edge. Okay, that's good enough. And once more again. And if it is necessary, we can give additional submucosal fluid cushion at any time. But as I mentioned, this knife doesn't have a high pressure. That's why gently touch to the target region, then press the foot pedal of coagulation current and start the injection using pump. Then we can give additional fluid cushion very effectively. Then quickly start the dissection. Now we can see the edge hooking the remaining tissue from inside and go to outside. This is completely safe situation. Hook here and cut here to the edge. Now it completely opened here. It's time to complete circumferential mucosal incision now. Therefore, it is necessary to give additional submucosal fluid cushion through the knife. Gently touch to this area and press the foot pedal of the coagulation current and press the foot pedal of injection. When you did that, was the knife open? Yes, knife open. You may use closed tip of dual knife, but open knife is much effective. But it is necessary to check the safety of the condition. If there is no lifting sign, it's very dangerous to use the open tip. But this area already somehow lifted up. Therefore, we can apply open tip here and create a small hole like this. Then we can give additional fluid cushion very effectively. We don't have to switch back to the injection needle. We can suck the air once more again in order to change the angle here and make a small hole here using coagulation current. Then inject solution directly to the submucosal layer. Otherwise, you can give additional submucosal fluid cushion directly from the submucosal layer like this. Of course, if you prefer to use hybrid knife, you don't have to make a small hole. But this dual knife needs to make a small hole to give additional fluid cushion effectively. I would like to check the direction of the gravity. Now, just rotating my list to the left side, we can see the lower side according to the gravity. This water pool is the gravity side, and this region is located upper side according to the gravity. So, dissected area easily falling down from the upper side to the lower side. Therefore, it is necessary to cut the mucosa at the lower side first. Otherwise, it becomes a little bit difficult to cut here after making submucosal dissection from the upper side. That's why I would like to make additional fluid cushion here and complete the mucosal incision at the lower side first. Then, one more from here. I need a little bit more here, already lifted up, but need a little bit more. Okay, this is very good. And we can start exactly from here, but we should suck the liquid from the cap, okay? Then you may start from here or any place from the small hole like this, okay? I would like to start from here, okay? Then control, sorry, using dry cut and connect the incision line dot to dot by putting back the endoscope, I can easily go up and connect the dot, okay? And there is no interval for a dry cut or swift crack, therefore it is necessary to step the foot pedal intermittently, and it is very important to keep the constant rhythm. If you step foot pedal irregularly, like that, that, that, it's really bad. It will cause some carbonation or sometimes cause bleeding. If you cut too fast, it will usually cause bleeding. If you go very slowly, it cause carbonation. That's why constant rhythm is very important. So after making part of the mucosal incision, I would like to trace here using coagulation current. It was not opening up, so you need to go down a little more. It is mandatory to open here until blue submucosal layer becomes completely visible. Now we can see the blue submucosal layer, it's good enough. And wash this area using normal saline. There is another important point. Please use normal saline for the irrigation from the endoscope. If you use just distilled water, sometimes it goes to the submucosal tissue, then electric current doesn't work well. Please use normal saline for the irrigation of the endoscope. Okay, catch the edge with the metallic tip, then go to upper side. It is very simple. Just torquing my wrist to the right side, the knife tip also goes to right side. And I'm controlling up angle using thumb. And just holding shaft of the endoscope very gently. I usually don't twist the shaft of the endoscope, just hold gently. It's usually good enough. And the movement of my wrist is minimal, but still we can control direction very well. So we don't have to hurry. Just go slow, precisely, and check the direction. I think for beginners, it's always difficult to understand the speed of the cut. Yeah, yeah. And would you explain what the tips you want to provide? We should carefully check the situation of the cutting. If it doesn't cut well, you should stay a little bit longer, or you should increase the cutting effect. I usually control the endoscope depending on the speed of the cutting. If the knife goes to the right side, I follow the movement of the endoscope. And slowly give a more gentle pressure on the tissue. Yes, that's right, that's right. And usually, only single cut sometimes is not enough, because there is no blue submucosal layer here. So I would like to trace same line once more again. Then we can nicely see the submucosal layer all around the region, like this. Perfect. And the next step is, once more again, trace the inner edge of the incision line using swift quark, because there will be some vascular network here. Now I'm controlling my wrist, gently talking left to right. Then we can control the tip of the endoscope, making circular. It's very simple. Combination with the up angle and the gentle movement of my wrist, I can control it very easily. When you're making a submucosal incision here, I want all the virtual audience to understand the depth, how you're controlling it. Yeah, yeah. The reason why I'm using blue color is to check the depth of the incision and submucosal dissection. As far as we can see this blue color, it's a kind of safe sign. If we can't see the blue color anymore, it becomes very close to the muscle layer. So we should check the color of the submucosal layer. This is a really safe situation. It is important to open the submucosal space again. Of course, you can use the transparent food to open this area, but much more simple technique is to use the water pressure. Just flushing the normal saline to the dissected area, we can easily open. Then gently come to the target region, we can easily go in. This is one of the technical tips. Then the next step is to focus on the edge on both sides. Because if we dissect too much in the middle of the submucosal layer, the final step usually becomes a little bit tricky. Therefore, I would like to recommend you to finish both edges first, catching the remaining tissue from inside and finish into the luminal side. And using up angle, finish into the lumen. It's completely safe manner. And of course, we can recognize the blood vessel if it is existed within the submucosal layer. Now I'm focusing on the upper side. Then go back to the lower side. Our lower side is quite good. I already dissected nicely. Again, hooking the tissue from inside and finish into the luminal side. This is quite nice. And as I mentioned, the gravity goes to the left side. Therefore, I would like to dissect from the right side. Then it will come down to the gravity side. Now I talk my list a little bit. Then dissection plane goes to 6 o'clock to 12 o'clock. Therefore, simply using up angle and adjusting the knife length, I can easily control the direction and conduct submucosal dissection. It's quite simple and very effective. Now still we can see nice blue colored submucosal layer. It is good enough. And check the remaining tissue here. And hook the remaining central part. And dissect like this. And come close by pulling back the endoscope and dissect tissue once more again. And focus on the upper side. Then dissect the tissue falling down a little bit more. And if it is necessary, you can give additional fluid cushion at any time. I think you're going to finish in two seconds. But would you show them the different tissue effect comparing with the dry cut and sweet Oh, OK. dry cut and sweet quag. OK. The sweet quag has a much more robust energy delivery so that it kind of goes around much wider area. Faster when it cuts with some bursting effect. Yeah. The dry cut is much more focused cutting. Yeah, yeah, that's right. That's right. So if there is no vascular network, we can use dry cut even for the submucosal dissection. Or sometimes I use endocut even for submucosal dissection. Therefore, we should carefully check the condition of the submucosal layer. Now I switch to the precise sect. Precise sect is also very nice. It can cut very well with minimal tissue damage. It almost acts like a dry cut. Ah, yes, that's right. But you saw when it goes a little far away, it starts to spark. Yes, that's right. Increase the voltage, so it's almost like a spray quag. That's right. Therefore, it is necessary to have good contact to the target tissue. If we cannot contact well, it always causes some spark. But if it goes to the tissue nicely, it doesn't cause any big spark. Still, there is some spark, but the tissue damage is minimal. And of course, we should move a little bit slowly, slowly. And I'm pressing the foot pedal intermittently. Can you show the cut current next? OK. I will conduct dissection using... Oh, this is the endocut. I go back to the dry cut. So dry cut cuts very well. Dry cut is what you touch is what you cut. Yeah. Of course, this is an isolated pig stomach, no bleeding or gas. But in case of having bleeding, for example, if this is a blood vessel, we can apply a closed tip of a DR knife. Close it, please. And switch to the spray quag 1.2. It is very effective. Close it and gently touch to the bleeding point. Only the central part of the white ceramic tip has electrode. It's just 0.65 millimeter small disc remaining on the surface. But usually, it is very good enough. Just touch and step the foot pedal of spray quag. We cannot see any... Oh, spray quag, spray 1.2. 1.2 is how much wattage? I don't know the wattage. It shows up here. Yeah, 1.2 spray quag is usually very good. 14 watts. 14 watts, very low, very low. OK, let's finish the procedure. Switch back to the... Oh, there's no... By the way, for the audience, you can always ask questions. We can see your questions. And Dr. Yamamoto and Dr. Toyonaga is here as well. So you can ask them questions if you have something. Thank you. Now, dissected specimen hanging down because of the gravity effect. It becomes completely safe and easy situation. Just hooking the remaining tissue and control lists little by little and adjust the length of device. I can easily finish it. And usually check the resection bed, feather visible vessel existing on the surface of the resection bed. If there is existing blood vessel, I usually apply close tip of DR knife and use spray quag 1.2. And if the knife tip becomes dirty, it sometimes happens after hemostasis. Then I usually ask my assistant, open, close, open, close the knife. Open, close, open, close. Then flush the liquid through the knife. Then we can clean the knife tip. It's almost the same situation for the flash knife, which Professor Toyonaga invented. We should clean that tip all the time. And still, if there is sticky material remaining on the metallic part, we should pull out the instruments. Then we can clean it by manually. Okay. Thank you very much. No question yet. Oh, there. Thank you. All right. Question. Does any of the electrosurgical setting need to be changed for duodenum or colon? Usually, we use a little bit lower setting for duodenum and colon. Because of the sickness of the mucosa, we use a little bit lower setting for duodenum and colon. Because of the sickness of the mucosa of the stomach, I usually use a little bit higher setting for the gastric ESD procedure. But for the duodenum ESD, we should reduce the power of the cutting and dissection. Thank you. Any more questions? So far, none. Okay. Wonderful. This is a resected specimen. And the backside is completely clean. And we usually place this kind of a resected specimen on the rubber board or cork board and pin it. Then check all the margin, whether it is completely clean or not. And check the additional marking dot, which we can recognize the direction of the resected specimen. And if there is certain irregularity on the surface of the resected specimen, we usually describe the schema and give some additional information to our pathologist. This is the most suspicious area having some mucosal invasion. Those kind of communication is very effective to get precise final pathological result. So, thank you so much for your questions. First question we had is, could you go over the hand control for coming around right and left of the lesion? So, now Hisao. Yeah, it's very simple. Once more again, we should keep the straight endoscope position as far as possible. Then come close to the target area. You can see all the marking dot here. So, going to the left, just talk our wrist. This is straight position. Therefore, it's a little bit different. In case of having straight endoscope position, we should use the down angle and talk my wrist to the right side. Then it goes to left side like this and push forward. And if I talk my wrist to the left side, it goes to the right side. Then pull back endoscope and talk it again. This is simple movement. And it is totally different when we keep the retroflex position. If we talk my wrist to the right, it goes to right. If I talk my wrist to the left, it goes to the left. And of course, we should control the up-down angle together. Then we can trace the line very precisely like this. The control of my wrist is minimal. And the control of the wheel is very minimum. But still, we can control it very precisely, effectively. We don't have to move too much. Of course, you don't have to twist the shaft at all. Just keep straight position. Leave your hand free. Then hold the endoscope gently. Then come close and using up angle, talk your wrist to the right side gently. And up-down angle, release gently. Releasing, releasing, releasing. And talk the wrist to the left side. This is a retroflex position. And this is a straight position. Again, come to the marked area. Here is the marking dot. Distort to the right. The bottom? Or no? I cannot see the marking dot. Where is the marking dot? Strange. I cannot see the marking. But anyway, in case of how... So this is marking dot. And in case I have a straight position, just using down angle. And talk my wrist to the right side. Tip of the endoscope goes to the left side. Like this. So it's quite simple. You don't have to twist so much. Great. Okay. The next question. Excellent demonstrations. I noticed that in the demonstration, the preferred resection plane was in an up-down direction. Or vertical, so to say. Is this favored plane or direction to perform the dissection? It's completely depending on the situation. If we can change the direction to 6 o'clock to 12 o'clock side, we can just simply use up-down channel. It's the most simple way to do smooth movement. That's why I try to find that direction. But if it is impossible, I just keep the target region on a flat plane. Then talk my wrist from left to right, right to left, like this. This vertical movement is also very effective to do some causal dissection. But it's completely depending on the situation. If we can keep it straight, we can just use up-down angle. Okay. Last question. When you're in retroflexion, how do you do the dissection in the fundus? Oh, this is the most challenging part to the ESD procedure. Because the approach becomes completely perpendicular. Therefore, I usually try to approach this area from both lateral sides. Initially, starting from the anterior side and dissect here a little bit. Coming from the posterior side, going to the upper side. Utilizing the gravity, we can dissect the upper side first. Even though it is perpendicular approach, we can do the subcausal dissection utilizing the gravity. But the rest of the subcausal dissection usually becomes very difficult. Therefore, I usually apply creep and line traction technique. Then we can open the subcausal space and safely finish the procedure. But it really requires high skill. Therefore, if you don't have enough experience, please don't touch it. And the traction is more effective as well. Yes, that's right, that's right. Great, thank you very much.

Dual Knife-J

endoscopic submucosal dissection

ESD procedures

marking dots

hemostasis

fluid cushion

straight endoscope position

precise hand control