Well, I'd like to talk about the effective use of ESD tools. This is my disclosure. As everybody knows, ESD is a kind of multi-step procedure. We should understand the features of necessary devices for ESD procedure. And before talking about ESD tools, I would like to emphasize that the straight endoscope position is the most important key point to have successful result. Because if we bend the endoscope, we cannot transmit our movement of our wrist directly to the tip of the endoscope. Please keep the endoscope straight, in a straight position as far as possible, and try to control both up-down and right-left wheels only with your left hand. Please don't try to control right-left channel using your right hand. You should hold the endoscope all the time. Well, this is the typical case of too much bending or too much twisting with your right hand. We don't have to control too much with our right hand. Just hold gently and keep straight position. And if it is necessary, please one step back from the patient. Then you can easily keep the straight endoscope position throughout the procedure. And key point is that you don't have to torque endoscope shaft by right hand. Just torque your wrist of your left hand, and together with controlling up-down and right-left channel with your left hand, we can easily control the direction of the endoscope tip. I would like to show you the example. I'm just torquing my wrist and using up-down angle. Then we can easily control the direction. I don't twisting right hand too much. Just holding the endoscope and gently torquing my left hand. That's usually good enough to make a circular control of the knife tip. This is really important. I would like to show this video once more again. I don't control too much, but it's effectively smoothly moving around the target region. This is really important for us to keep the stable condition when we conduct mucosal incision and submucosal dissection. Well, and injection itself is also very important. Once we make a puncture, we should pull back the needle as submucosal breadth creating. If you push the injection needle too much, we cannot create a nice submucosal breadth. Therefore, we should pull back the needle slowly, slowly as the submucosal fluid cushion getting bigger. Then we can make a nice submucosal fluid cushion. And we should avoid the gap between the hold and the target region. We should lift up an entire region. And the location of puncture site is also very important. We usually start injection a few millimeters away from the marked area. Because if there is blood vessel beneath the mucosa, sometimes the puncture cause bleeding. Then we should cut there to stop the bleeding. Therefore, puncture site should be located a few millimeter outside the marking dot, which is exactly on the incision line. And to avoid bleeding situation during submucosal injection, I think that RDI, red dichromatic imaging of Olympus new endoscope system, which is X1. I'm sorry it's not commercially available in the United States yet. But it will come into the market very soon within this year. I had a chance to work with the Olympus engineer when we developed this new narrowed band imaging. In this new narrowed band imaging, we use relatively longer length of the wave, which can penetrate to the deep submucosal layer. Like NBI, we can visualize relatively thick blood vessel within the deep submucosal layer. Then we can recognize the location of the thick blood vessel when we make a puncture during the ESD procedure. There is three RDI mode. Mode one is very effective for visualize bleeding point. Mode two is very effective to visualize the blood vessels located deep submucosal layer. And mode three is very effective to visualize the regenerating blood vessel when the mucosa has some inflammation, such as the case of ulcerative colitis. Well, this is the case of esophageal cancer, which I used RDI before giving submucosal injection. We can easily recognize the location of the thick blood vessel. Then we can avoid injury of the blood vessel during submucosal injection. And we should make a second puncture, which already some part lifted up with the previous submucosal injection. Then we can easily give additional submucosal injection, because there is enough submucosal space already. Well, this is another case. This is a relatively big colonic polyp. I did the water pressure method. But by using RDI, we can easily visualize this kind of thick blood vessel, then easily avoid vessel injury. Then quickly start the mucosal incision. But in this particular case, I made a very shallow mucosal incision by hooking the muscular risk mucosa with the disc part of the dual knife. Then we can make a nice mucosal incision without having bleeding. Well, for the mucosal incision, we should fix the knife tip to the submucosal layer. Therefore, I usually make a puncture when I start the mucosal incision. Then keep the white ceramic tip on the surface of the target tissue. Of course, you may use any device. But the good contact to the target tissue is really important to have a nice result for mucosal incision and submucosal dissection. We should keep a good contact. Well, I would like to show you the mucosal incision. This is the pig stomach, but it's nearly the same situation. Making a puncture with the open tip of the dual knife and keep the white ceramic tip on the target tissue. Please don't push too much or please keep the constant pressure to the target region. And if you push too much like this, it is too deep and sometimes it causes massive bleeding by cutting the deep submucosal vessel or even sometimes it causes sudden perforation during the mucosal incision. Therefore, please don't push too much. And of course, if it is very shallow, you cannot continue the smooth mucosal incision. It easily slips away from the target tissue. Therefore, good contact to the target tissue is very important. And please keep a good distance from the target tissue. If the scope position is too far from the target position, we cannot transmit the power to the target tissue. But if it becomes too close, we cannot see the marking dot or we cannot see the condition of the target region. Therefore, it's sometimes dangerous. Therefore, keeping good distance from the target is always very important. And right after making mucosal incision, I usually make initial submucosal dissection by tracing the inner edge of the incised area. It is not necessary to dissect the deeper part of the submucosa at the beginning. If you try to dissect the deeper part, I mean the outside of the mucosal incision, it's going to be really deep. It is kind of a dangerous situation. Therefore, please try to trace the inner edge of the incised area. Now, I'm tracing just below the mucosal incision at the inner side of the initial mucosal incision. This is the first initial dissection. This is the second submucosal dissection. I'm still tracing the inner edge of the incised area. This is usually good enough. After making initial submucosal dissection two or three times, we can open up the submucosal space. Now, I'm slightly lifting up the edge of the incised area with the tip of the dual knife. Then, we can easily go into the submucosal space, utilizing the upper limb of the transparent food. This is a very important technical tip when we conduct submucosal dissection. Usually, the initial part of the submucosal dissection is very difficult, especially for the beginners. Therefore, please try this technique, tracing the inner edge a few times. Then, you can create a nice submucosal space to go in. After creating a submucosal space, we usually use the limb of the transparent food. It is a very good situation to have a nice visualization of the submucosal layer, and we can give some traction to the target tissue. Then, after making submucosal dissection to some amount, I usually make a mucosal incision for the rest of the remaining mucosa. Now, I'm conducting a mucosal incision from the distal side and connect the incision line to the previous mucosal incision. Then, again, trace the incision line with the coagulation current. This is also very important to make sure the end point of the submucosal dissection. Making a little bit deeper initial dissection at the anal side, we can easily finish our procedure. Otherwise, it becomes a really flappy situation at the end of the submucosal dissection. And the next step is to continue the submucosal dissection. Again, it is very important to open the submucosal space utilizing transparent food. And please try to recognize the edge of the remaining submucosal layer on the left side. Then, we can hook here and continue the submucosal dissection. Otherwise, it becomes a little bit difficult and a flappy situation. But by checking on both sides, we can easily cut the remaining tissue. I always check the edge of the remaining submucosal layer. Then, start submucosal dissection by hooking the remaining tissue. then we can easily finish the procedure. And as previous speaker already mentioned about the importance of control of bleeding, usually we can easily stop minor bleeding by applying closed tip of dual knife. I usually use spray coag 1.2 for the hemostasis using closed tip of dual knife. Just gently touch to the bleeding point with the closed tip of dual knife. We can easily stop it. But of course, in case of fine, of course, after the hemostasis, usually knife tip becomes dirty like this. In case of having carbonated tissue on the tip of dual knife, it doesn't work well. Therefore, clean condition of the knife tip is always very important. You should clean the tip all the time when we conduct hemostasis using closed tip of dual knife. And in case of finding active bleeding from artery, we should use coagulaspar. This is such a case. If you find this kind of pulsation, we should use coagulaspar. And in this particular case, bleeding point is quite obvious. Therefore, we don't have to use RDI. But if you feel it very difficult to find the bleeding point, we can use RDI. It is also very helpful. And when we use monopolar forceps such as coagulaspar, it is very important to have dry condition. If there is massive water, electric current doesn't work well. Therefore, we should suck all the liquid before activating RF current. And also, it is very important to grasp the bleeding point precisely and pull back a little bit in order to concentrate the electric current to the target point. Otherwise, electric currents go deep. Therefore, it becomes a little bit dangerous situation if you don't pull back the grasped target tissue. I always try to visualize the bleeding point and gently catch the target tissue and pull back a little bit, then activate the soft coagulation. This is the best way to avoid some damage to the surrounding tissue. Of course, if you can use bipolar hemostatic forceps, you don't have to care about the underwater condition. And you don't have to pull back the forceps because electric current goes in between the two forceps. And we can coagulate it very easily using lower setting of soft coagulation. It is much better solution in case of doing aggressive procedure for the bigger region, which has multiple vascular networks. Well, when we found thick blood vessel like this, we can seal it before cutting there by using open tip of dual knife. I usually use very low setting of forced coag, which is 0.3. Now you can see the bundle of very thick blood vessel. I already dissected the surrounding tissue and hooked the main trunk of the blood vessel, then applied the 0.3 of forced coag. Now it completely shrinked. Then it is possible to cut through there using swift coag or precise sect. This is one of the example of successful vessel sealing technique. And of course, in case of having actual bleeding, RDI1 is very effective to visualize the bleeding point. And from the psychological point of view, actually we can reduce our stress during the hemostasis. Because red color is a kind of warning color, it can give us a lot of pressure. Actually, from the color psychology, blue color give us calm condition. But in case of looking at the red color, our blood pressure increases and our pulse rate increases. But by looking at the yellowish color, we can calm down during the stressful, long-lasting ESA procedure. And actually, our psychological stress reduced when we used RDI for hemostasis. And my young colleague conducted a nice study which proved the efficacy of RDI using eye tracking system. As you can see here, when we use RDI, we can find the bleeding point much quicker. So we could reduce the total procedure time by using RDI. And basic strategy is completely different depending on the device. In case of using IT knife or IT knife 2, we should make a circumferential mucosal incision at the beginning. And because of the nature of IT knife, it doesn't cut well from the proximal side to the distal side. Usually, we should make a small hole at the distal side and make a mucosal incision by pulling back manner. Then we can make a nice mucosal incision. But when we use the short needle type device, such as dual knife or a flash knife, usually we make a mucosal incision from the proximal side to distal side. Then we can make a very nice mucosal incision in a safe manner. Now this is a relatively difficult situation, which is a perpendicular approach. And unfortunately, it becomes a strange movement when we try to keep a tangential position. Therefore, I decided to perform ESD in a perpendicular position. Now I'm giving initial submucosal fluid cushion to the distal side and try to keep a tangential position. But it was unable to have a tangential position. Therefore, I started the initial mucosal incision in a perpendicular position. Made a small hole and fixed a knife tip to the small hole and keep white ceramic tip on the surface of the target tissue and control the direction gently by twisting my left hand and trace the inner edge of the incised area using coagulation current because there will be some bleed blood vessel within the deep submucosal layer. Therefore, I usually use the coagulation current when I trace the incision line and extend the mucosal incision. Then again, started the submucosal dissection by tracing the inner edge. Then give additional submucosal fluid cushion for the rest of the target tissue. Then complete the circumferential mucosal incision. Always, it is very important to keep the constant pressure to the target tissue. After connecting the mucosal incision, I trace the inner edge of the incised area using coagulation current and gradually open the submucosal space. And usually, we try to go into the submucosal space from the proximal side using the limb of the transparent hood. But in this particular situation, it was very difficult to go into the submucosal space because of the perpendicular approach. I tried to open it and utilize the water pressure to open the space. And fortunately, I could open the submucosal space, but it was really unstable condition. Therefore, I decided to approach from different area. That means from the side, especially in this particular case, from the right side, it is much easier to go into the submucosal space rather than approaching from the lower side. Therefore, I tried to open the space from the lateral side. And by utilizing the water pressure method, I could easily open the submucosal space and approaching from the right side, it becomes quite easy situation to continue the submucosal dissection. Therefore, please try to find the best way to approach to the submucosal area. If you feel it very difficult to approach to the submucosal area from the proximal side, you have better to check the other direction, such as right side or left side, or even from the proximal oral side. In this particular situation, lateral approach was quite effective. I could easily open this submucosal layer and continue the submucosal dissection. This kind of strategy is very, very helpful, especially for the difficult situation. Please try to check the other possibility and try to keep safe situation. Well, in case of having really difficult situation, some of the traction technique is very useful. Now, you can find a lot of traction device provided by the industry. Or you can use a very simple string clips traction method. This is one of the difficult case because the lesion was located gastric pharynx and extending to the greater curvature side. Initial submucosal dissection was quite easy. Utilizing the gravity, dissected area easily came down. That's why I could make a nice submucosal dissection even though it was perpendicular approach. But the final part became really difficult. That's why I applied clip and line to give traction for the remaining submucosal tissue. Then it was really smoothly done. And in case of doing colorectal ESD procedure, pocket creation method is one of the best way to clear the difficult situation because you can stabilize the movement of the endoscope tip and you can change the direction of the submucosal dissection using this technique. And also, the water pressure method is quite useful because we can easily open the submucosal space. As I mentioned before, initial step of the submucosal dissection is the most challenging part, especially for the beginners. If you cause deep, if you cause muscle damage at the beginning, you should stop the procedure. Or if you cause massive bleeding at the beginning of the procedure, it will become disaster. But by using the water pressure method, we can easily open the submucosal space by giving active pressure of the normal saline to the incised area. We can easily open the submucosal space. This is very useful, not only for duodenal region, but also for the colorectal ESD procedure. This is the second time dissection. By using the water pressure method, we can easily open the submucosal area. And this is the third time to do submucosal dissection. By hooking the tissue, we can easily open the submucosal area. This is the beauty of the water pressure method. Well, thank you very much for your kind attention. Thank you.

ESD tools

endoscope position

injection technique

RDI imaging

mucosal incision

hemostatic forceps