CHRISTOPHER GOSTOUT: Well, good morning, everybody. We're about a minute or so from actually starting the live cases. And I just want to encourage everybody today to speak up. Share your thoughts. If you don't understand something, we'd be happy to explain it. If you don't like what you see, we want to hear that too. Because we want to understand why. And otherwise we want this to be a really, really interactive event. We've got a total of six hours of live cases. We should have at least three hours of lively discussion in-between those cases.

We will try to ask the endoscopist today-- I don't want to say endoscopist. I try to steer away from using the word endoscopy. I prefer to say endoluminal interventions, transluminal interventions. Because that kind of pigeon holes endoscopy into lower reimbursement status. And the kind of stuff we're seeing today is not, obviously, traditional endoscopy.

But at any rate, we'll try to interrupt the endoscopist and ask them questions when we can. Sometimes they prefer to do all the talking themselves. And that's OK. And we'll be polite. And sometimes they're a little too distracted to kind of catch what we're trying to ask them. But we will try to be as interactive as possible.

SPEAKER 1: So just as a show of hands, how many of you are new first time attendees?

Pretty good.

[SIDE CONVERSATION]

[SIDE CONVERSATION]

CHRISTOPHER GOSTOUT: OK. We're starting our first case with Dr. Zhou, master of POEM. And we're getting a glimpse of the lumen. Here comes the clinical scenario.

SPEAKER 2: Morning. We have a POEM here for after a failed Heller for Achalasia with Dr. Zhou.

So we have a 74-year-old gentleman with a past medical history of coronary artery disease, status post drug-eluting stent with subsequent CABG and aortic valve replacement, hypertension, and COPD. Who presents for treatment of Achalasia. Duration of symptoms were 72 months. He's an ASA Class III patient. He was previously treated with a robotic-assisted Heller myotomy with a posterior fundoplication back in 2013.

Presently he has no weight loss or retrosternal pain. But he has dysphagia and regurgitation with each meal, giving him an Eckardt score of six.

So in this esophagram, we see that's a stage two esophagus, 3.2 centimeters in width. And it's a non-sigmoid esophagus.

On high resolution manometry, he's found to have an Achalasia Type II with a basal pressure of 27.6 and an IRP, 19.8.

Two weeks ago, he underwent endoscopy with EndoFlip. And over here you'll see very low distensibility at 0.5.

PING-HONG ZHOU: Good morning. Hello.

CHRISTOPHER GOSTOUT: Good morning.

PING-HONG ZHOU: Yeah. [INAUDIBLE]

So this gentleman was diagnosed as Achalasia Type II. Once had a Heller myotomy with a Toupet fundoplication. Now I put the scope into the patient's esophagus as you can see. The lumen was enlarged.

Push up forward. Forward. This is, I think, the EG junction.

Push. Push. Push. I can feel a little bit of resistance in this area.

And now the scope was in the stomach. So when I reflect the scope, you can see there's surgical changing in the fundus. This is the EG junction.

So the patient's EG junction, through the mouth about 40 centimeters. So the lumen is stretched. Lots of [INAUDIBLE].

Today I will perform the POEM for this patient.

CHRISTOPHER GOSTOUT: And what will you do? Anterior or posterior? How will the postoperative appearance of the fundus guide your decision as to which approach you'll take.

PING-HONG ZHOU: Yeah. For the Heller myotomy, you always cut through the muscle. And make a different foundation in the anterior wall in the EG junction. So now the patient is on the supine position. So I will make a tunnel or cut to the muscle in the posterior wall. So always I make the incision or make a tunnel entrance about 10 centimeters proximal to the EG junction. So I will make an entrance 10 centimeters proximal to the EG junction, this area. In the 6 o'clock is a posterior wall.

This is a HybridKnife T-type from ERBE, Germany. Open the knife, please. The tip of the T-type knife. So the solution I always use is saline. Where is the saline? With a little bit indigo carmine. No nephrine.

And this [INAUDIBLE] setting. For a POEM case, ours use forced coagulation in effect two. And the time interval is 3, 2, 4. So I always use this setting for the whole procedure of the POEM. Make an incision. Cut through the muscle for the hemostasis. No changing. I never change the soft coagulation or swift coagulation. Just the one setting, one mode.

CHRISTOPHER GOSTOUT: Have you always used that setting? Or is this what you've eventually evolved to finding to be the best for you?

PING-HONG ZHOU: So I think such a setting can make the whole procedure very, very easy. So I never change the mode or change a setting.

CHRISTOPHER GOSTOUT: So in the audience, how many folks are using ERBE that can relate to these settings?

PING-HONG ZHOU: So now I use the tip of my part in the mucosal.

It don't work?

OK.

But it don't work.

CHRISTOPHER GOSTOUT: You're trying to use the forced water jet to create your cushion.

PING-HONG ZHOU: Maybe some problem with the pump.

CHRISTOPHER GOSTOUT: Just to kind of review things. The patient had a Heller myotomy. So that's an anterior approach. And then had a wrap, which also will be anterior. And hence the reason to go posterior. It should be pretty wide open.

PING-HONG ZHOU: So why we choose a posterior wall? You can find the knife comes from the 6 o'clock. So what are we doing? Just fix the knife. And I touch the mucosa with my right hand to push and to pull the scope. So this would make the whole procedure very fast.

Now we're changing another pump. Another new pump.

Sometimes if the mucosa is very, very thickened, you cannot inject the saline into the submucosal layer. First we just cut the mucosa. Then inject the saline into the submucosal layer. First cut.

SPEAKER 3: I'm going to change the knife.

PING-HONG ZHOU: OK.

CHRISTOPHER GOSTOUT: So he had mentioned that he mixes indigo carmine dye with saline. No epinephrine. And pretty standard solution.

PING-HONG ZHOU: For the incision, in China, we always make a longitudinal incision about 1.5 centimeters. In the past, some do a transverse incision.

For the transverse incision or transverse excess, you can put the scope into the tunnel very, very easier. Put the clip occludes of the suction transverse incision--

CHRISTOPHER GOSTOUT: We're going to switch you. We're going to interrupt you to switch to room 1 with Dr. Stavros while you're getting the irrigation water system in operation.

OK, Stavros. We're with you. You're looking rather casual there, my man, for such serious business.

STAVROS STAVROPOULOS: Long Island Life.

CHRISTOPHER GOSTOUT: Yeah. I see that. So when we're all done, you're going to take the shirt off and show us your tattoo with it?

STAVROS STAVROPOULOS: [LAUGHS]

No tattoos. I'm a traditional guy.

So look I just want to show you briefly, so I can start the POEM going, the EndoFlip 2.0.

You can see the balloon shape, which is what you see on a typical EndoFlip. But now the pressures are being recorded on this time strip, which is moving. Let me show you. So I'm going to move it a little.

And you're going to see there's not much happening. So you cannot tell that this line is moving.

But you see this is like manometry. That down is time 5, 10, 15, 20, 25, 30 seconds, 40 seconds. And then the y-axis has basically the electrode number. And the color shows you the pressure or the distensibility, or the diameter.

So basically you can see now we get this pressure contour that is a bit like manometry. Real-time manometry.

You can see there's a fixed narrowing at the GE junction that is not changing.

This patient, the HRM was a question of whether it's Type II or Type III. This is a very thorny question because about, I'd say, 20% of manometries, the manometries is not sure. There are pressurization ways, but there's also some spasm distally. So it's not clear if it's Type II or Type III. For us surgeons, it's very important. Because Type III needs a long myotomy. Type II needs a short myotomy.

So how do you figure this out? There are alternative ways as you gain experience. The barium on Type III, sometimes you can see this lumen facing very tight contractions in the distal esophagus. You can look down the scope. And sometimes you can see a tremendous amount of activity going on during the beginning as you start cleaning the esophagus for the POEM.

Now we have an extra modality. This was published by Northwestern. Looking at this tracing as it runs across the screen. And you can see here, there are no contractions at all. So that favors Type II.

In a Type III, you would see this retrograde contractions running through the 16 sensors. This endoscopic balloon is longer. The normal one is eight centimeters because it's supposed to record the pressure at the GE junction. This is 16 centimeters long to show you a motility-like profile of the distal esophagus.

So you're going to see no activity really. It's just a fixed pressure. A fixed high pressure and small diameter at the GE junction. No activity in the distal esophagus.

So this is what I wanted to show you. So basically we're going to treat it like a Type II Achalasia. And do a short myotomy as opposed to a long myotomy with a Type III, 15, 16, 17, or longer myotomy.

So now you can move into the other rooms. I'm going to start the tunneling. And you can come back and forth in the rooms to show as the tunneling progresses in the different POEMs. I'll be starting my entry now. Hopefully you will show the entry by Zhou. Or you'll see the entry by Inoue. And then you can see how we all use different knives to extend the tunnel. So--

CHRISTOPHER GOSTOUT: OK. Great.

STAVROS STAVROPOULOS: Thank you.

CHRISTOPHER GOSTOUT: It's a nice demonstration of how EndoFlip can be very useful in any kind of luminal remodeling across the GE junction. Whether you're doing a POEM and you're looking at the before and after. Or if you're doing an anti-reflux procedure, it can really help guide procedures like this.

OK. So I think we'll go back to Dr. Zhou in the first case.

[SIDE CONVERSATION]

SPEAKER 4: Good morning, everyone. I'll go over the case for Dr. Stavropoulos. This is a Per Oral Endoscopic Myotomy for Type II Achalasia, as he went over the EndoFlip tracing. This is a 39-year-old woman with past medical history significant for a class one obesity, who presented for management of her Achalasia. The duration of symptoms was 15 months. ASA Classification II. Prior treatment involved suboptimal bougie dilation with 46 French Maloney in April of 2017.

The Eckardt score total is 11, based on the symptomatology of weight loss, dysphasia, retrosternal pain, and regurgitation. This is the esophagram showing Stage I, 2.2 centimeter width of the esophagus. Non-sigmoid orientation. These are the high resolution manometry tracings that Dr. Stavropoulos was referring to. Basal LES pressure of 54.9 and IRP of 29.3.

So we'll go ahead and do the procedure.

CHRISTOPHER GOSTOUT: OK. We're also going to get a patient history for Dr. Inoue. This way we'll have all the patients summarized in our brains as we go back and forth to the different rooms.

So while we're waiting for that patient history to come up, Dr. Zhou-- just for those who don't use ERBE, which looks like the majority of the people here. What he was trying to do was doing a forced water injection across the mucosa without the benefit of a needle injection. Which is the purported value of the ERBE system, which a lot of people like. It's kind of relatively a traumatic

OK. We'll get the clinical scenario behind the pediatric case that doctor Inoue is going to do.

SPEAKER 5: Good morning. This is going to be a pediatric POEM for Achalasia. The case is an 11-year-old girl with Down syndrome, Hashimoto's thyroiditis. Status post repair of complete atrioventricular canal defect and duodenal atresia who presents for treatment of Achalasia. Duration of symptoms are 116 months. She's had self-induced vomiting since two years of age. ASA Classification II. She had a regular manometry in 2009 that showed complete aperistalsis with incomplete LES relaxation and hypertonic LES, consistent with classic Achalasia.

Prior treatment has included pneumatic balloon dilation. Four times, in 2008, 2009, 2011, and 2013. Patient has an Eckardt score of six with no weight loss or retrosternal pain. But has dysphagia with each meal and regurgitation with each meal.

This is the esophagram. You could see Stage II, 4.7 centimeters, non-sigmoid esophagus. And you could see the progression from 2011 to most recently 2018, as it's become more dilated.

This is an EndoFlip that was just done on March 12th. You can see the various readings, including a low distensibility of 2.1.

And this is the high resolution manometry tracing. You could see the Basal LES pressure is 19.8 and the Residual LES pressure is 16.

HARUHIRO INOUE: Hello.

CHRISTOPHER GOSTOUT: Good morning.

HARUHIRO INOUE: CJ, can you hear me?

CHRISTOPHER GOSTOUT: Yes we can.

We can't see you anymore. Now we can. We can both hear you and see you.

HARUHIRO INOUE: Yeah. Thank you. So this is directed at the esophagus as you can see. This is a pediatric patient. Type I Achalasia. Proximal part of the esophagus dilated. And also this patient received several times balloon dilation. So LES looks not so tight. This is a part of the LES. I'm gradually advancing the scope. We can recognize a palisade vessel here. You can see it. OK.

So this is LES. A little bit of pressure, but muscle tight. Junction is generally open at beginning of space of stomach. And then a little flex. Not so tight. So like this. Because it was a patient who received several times balloon dilation. So we back up.

Position of the [INAUDIBLE] junction is 35 centimeters from the patient's teeth. And then back up. So in this case, it's not necessary to put the long myotomy. Proximal fundus are totally dilated. And then back up. And in this case I will put the posterior [INAUDIBLE].

We can choose anterior also. But I think--

CHRISTOPHER GOSTOUT: Yeah. That's what I was going to ask you if having four balloon dilations, does that influence that decision in any way? Do you see more fibrosis from one approach versus the other? Or it's pretty random?

HARUHIRO INOUE: So most of the case of who receives a repeated balloon dilation is the junction, it looks not so tight. So in this case, if you do [INAUDIBLE] or 16 remarkably not so high. But the patient has the stack of the barium in the esophagus. And a repeated symptom of vomiting.

So back up seven centimeters from the junction. In this case, I think a short myotomy is OK. So we also use a saline plus blue dye. So first the injection. OK.

At the time injection, please confirm the lifting of the mucosa. OK. So five or six cc of injection. The most important is the lifting of the mucosa.

So now we are inserting the TTJ.

CHRISTOPHER GOSTOUT: For those who haven't done this yet, you're looking and you're watching this submucosal injection. It's rising. You can never use enough, OK. Because you got to remember this is an intramural method. So it doesn't matter how much of the lumen you're obscuring with your injection. You want to get yourself a nice plane within the submucosal that you could comfortably fit in advance.

HARUHIRO INOUE: So now we cut the mucosa approximately 32 centimeters. OK. Once again. Yes. I think a little bit more. OK. Place the TT knife into the submucosal space. And then cut a little bit more. OK. So that's enough.

And then we have to dissect some submucosal fibers using a splay coagulation. As a cutting current, we use Endo Cut I. For submucosal dissection, we need to dissect the submucosal fibers real good.

And then we will [INAUDIBLE] three uploads to the [INAUDIBLE].

OK. Flush. So flushing the water also creates a submucosal space.

In this case, a little bit fibrosis. But it's OK, I think.

Now I'm trying to back and forth in the scope. And then trying to get in the submucosal space. OK. Once again. OK.

CHRISTOPHER GOSTOUT: So the submucosal space is pretty easy to create. You can use a variety of things. You could use a soda straw and blow into it. And you could puff it up and get a nice space. He's using water and you'll see using the endoscope as well to dissect and open up the submucosal space. Works very, very nicely in the esophagus.

HARUHIRO INOUE: So in order to get in the submucosal space is a little bit difficult in this case. So now I'm injecting the distal end of the mucosal flap in order to lift the distal end a little more. OK wait. OK.

CHRISTOPHER GOSTOUT: So why do you think it's tough to get into that submucosal space? You think the mucosa is just too resistant?

HARUHIRO INOUE: Yeah. Some [INAUDIBLE].

OK. Thank you. So once we get in the submucosal space, it's OK.

This part is the most difficult, I think. Generally. So at the time, we tunnel. Turn rotate the endoscope 180 degree with a flush.

CHRISTOPHER GOSTOUT: Yeah. I can see you're using a lot of rotational torque to try to encourage the tip of the scope in there.

HARUHIRO INOUE: A little bit fibrotic. So we have to dissect a little bit more. In a straight position. OK. And then go out.

CHRISTOPHER GOSTOUT: With these difficult entries like this, are you worried about inadvertently injuring the muscle layer unintentionally?

HARUHIRO INOUE: Yeah. That's right. So now, as you mentioned, we are trying to dissect a little bit submucosal fiber across through the muscle layer, southeast.

Hopefully we can get a better space. Wider space. OK. Maybe we can get in. Once we get inside of that, it's OK.

We can see a lift inside of the image. We can recognize the submucosal muscle needle out. OK. So we will dissect here. So a little bit dissection to the muscle layer also.

So this is the submucosal muscle. Splay onto the muscle. I hope we can get in the space.

OK, like this. So now we can recognize our circular muscle. So our top half of the image is a submucosal space.

CHRISTOPHER GOSTOUT: Yeah. It looks like you're finally getting in there now. This is an excellent example of difficult entries. Because your scope winds up coming in perpendicular when you want to really be along the same longitudinal axis. And as you drive in perpendicularly, you're creating some risk. You can inadvertently drive into the muscle layer. You could perforate the muscle layer.

HARUHIRO INOUE: Yeah. Thank you very much.

CHRISTOPHER GOSTOUT: And then you might have to select a different route after that.

HARUHIRO INOUE: Yes. That is the technique we use.

CHRISTOPHER GOSTOUT: This is definitely not your typical entry. Right?

HARUHIRO INOUE: Yeah. So now we are in our submucosal space. And after this, it's very easy. So now the injection.

[SIDE CONVERSATION]

Keep injecting. OK. Move out.

So like this. Now we can recognize very well our submucosal muscle and the submucosal layer. So it's not so difficult.

CHRISTOPHER GOSTOUT: OK. It looks like you've mastered the submucosal space. We're going to EndoFlip to room one right now and join Stavros.

OK. Now you got a radically different view of submucosal space.

STAVROS STAVROPOULOS: This is a posterior POEM. You can see here on this, now Type II we decided, patient. You can see the opening. I do a sort of transverse opening. Because it's easy. And it's easy to get in. And for overstates, it's easier to close a transverse opening without narrowing the lumen. Because he has a very narrow lumen than doing a longitudinal closure. If you use clips, you should do a longitudinal closure because it's easier to close.

You can see those contractions, right? That's for the manometry people. You see what's going on the esophagus. There's continuous contractions here that is very active. You see what's happening there?

CHRISTOPHER GOSTOUT: Right. It's pretty obvious.

STAVROS STAVROPOULOS: But we didn't see it on the end of flip as retrograde contractions. So we are dealing with it as a Type II situation. So the z-line is at about 39 here. So we start the tunnel at about minus 6 or so. Some people start at minus 10. So this is it, posteriorly. These are the landmarks. The spine is on the left. You can see here. Gravity here at 6 o'clock. Spine. And that is what we got. About 5 o'clock.

So then you get in. And then you can see here the muscle in the back. And we're about to enter the cardia. So you begin to see those spindle veins here. Let me do a little near focus. And you can see here the underwater magnification with near focus. You can see the spindle vein very nicely. These are in the areas where the muscle is very tight. You can see the other parts of the GI track too. So these are little aneurysm of dilation.

So you can see the cardia beckoning in the distance there. You see the nice easy, open space that we will get shortly after we pass this sphincter here. And then we'll do 2 centimeters and do the double scope transillumination. We use the I-type HybridKnife. You can see it's straight, very precise. And we inject saline.

And the settings on the cautery is Endo Cut Q, 3, 1, 1. Basically a very intense cutting current. And then we use force when we find vessels. Force is at effect 225. Sometimes I use 240 depending on how the conductance of the individual patient is. And that's how we coagulate the vessels.

And you can see that I show this on my lecture the mark we put to maintain posterior orientation. If you can focus and zoom on this part of the endoscope right here.

CHRISTOPHER GOSTOUT: Stavros, could you give us another little peek into the cardia? I want everybody to just put that in your mind's eye. You can see just kind of a little ridge of muscle.

You see how that submucosa opens up suddenly? Then you kind of know you're finally entering the cardia. It's got a very distinctive appearance after you pass that speed bump.

STAVROS STAVROPOULOS: Can you zoom more? Or that's maxed?

CHRISTOPHER GOSTOUT: OK. So you have your marker on the scope.

STAVROS STAVROPOULOS: That's the green marker here. So you can see with that marker completely at 12 o'clock towards the ceiling, the muscle is exactly at 6 o'clock. So as long as my marker on the scope is up and the muscle is at 6, I know I haven't spiraled. OK.

And now this is the cardia. Even just with insufflation, it opens up. So this is clearly the cardia. So we are continuing now with the dissection. This is the tricky part. Number one is passing through the muscle without injuring the mucosa. But number two is not running into a huge vessel in the cardia. And there are plenty of such penetrators.

Can you go up on the force to 40?

So here I'm going to use increasingly forced current to avoid accidentally cutting. They can be submerged. You can see the vessels there can be tricky to see. And if you cut one of those, these are much bigger than the esophageal body vessel. So that's the other thing that you need the attention. And one is crossing a tight sphincter. The other is not cutting one of the penetrators of the left gastric here. So [INAUDIBLE].

And then if you find a big one, if you can avoid it and deviate around it, this is sometimes better than trying to coagulate. See that's a small one. You can see this vessel here. This vessel is an artery because it has that pale contour around it. But it's small enough that this could be appropriate to coagulate with a knife.

CHRISTOPHER GOSTOUT: Stavros, when do you select between spray and forced? Can you, again, give us a general overview of your decision making in those?

STAVROS STAVROPOULOS: I go back and forth. I'm in a forced period now. Probably if you look at my videos from last year or the year before, I was basically using spray. They're very similar currents. Force is more controllable. But if you get an intense small [INAUDIBLE] from an ill-defined area. And you try with force, again and again. With force you have to be very precise. And you can't get it, then you can switch to spray. Spray is more like ABC. You don't have to be very precise. You just blast a two millimeter area and you get done.

But for the same reasons, you can end up hitting, accidentally sparking the mucosa. And then it gets unpredictably, because it's 4,000 volts. So it will go through the mucosa and then burn the surface where the resistance suddenly goes high. Because of the luminal air and water. So it will then blast the mucosa, having skipped the entire submucosal cushion where conductance is high. So spray is a little more risky. And it tends to clog the HybridKnife much more than forced, which doesn't usually clog. So, yeah, there are minor differences.

CHRISTOPHER GOSTOUT: OK. Thank you. We're going to switch to room two right now, OK?

STAVROS STAVROPOULOS: Thank you.

CHRISTOPHER GOSTOUT: We'll be back.

OK. I see you're well on your way here.

PING-HONG ZHOU: I almost finished the tunnel making. So during the tunnel making, we can sometimes find some vessels penetrating from the muscle layer to the submucosal layer. This is a thick vessel, I think. There's an artery. So for this thick vessel, for beginners it is suggested to use as a Coagrasper to manage it. As we know, the HybridKnife have many, many, functions. One of the functions is hemostasis. So we can use this knife to manage such vessels.

How to manage? So you never use the tip to touch the vessel. We always use arm part of the knife to touch a vessel. Then coagulate it and cut it.

CHRISTOPHER GOSTOUT: Do you ever leave vessels just the way they are now and just avoid them? They're obviously nourishing the mucosa that we've separated. So do you ever leave them in place and just work around a vessel?

PING-HONG ZHOU: I always dissect vessels from surrounding.

I always use the arm part to touch the vessel and to coagulate it. And there is no bleeding.

Here is also the submucosal layer. I just cut it. And this is the end of the tunnel. Here is another vessel. So just with the same technique, touch your vessel in the middle of the vessel. First coagulate, then cut it.

CHRISTOPHER GOSTOUT: So if you keep in mind what you saw with Stavros earlier. You see that appearance of the cardia, how that submucosa just really opens up. It becomes a real gauzy looking area.

PING-HONG ZHOU: So this is the end of the tunnel. Here is another thick vessel. I usually coagulate. Coagulate, not cut.

CHRISTOPHER GOSTOUT: OK. We're going to shift back to Stavros. He's going to show us in contrast the use of a Coagrasper in a similar scenario.

PING-HONG ZHOU: OK.

STAVROS STAVROPOULOS: OK. So this is a vessel penetrating in the cardia. You can see it has a victory sign. It's a V with two vessels penetrating. The left is an artery because of the pale thick wall. This can go either way. So you can use forced starting farther away from it. It's probably an artery and a vein together. The vein is that bulgy, thin wall. The dark red vessel. And the artery is that pale muscular looking one. Wrapped together. There's one next to it.

You can try to use force. That's a bit of a gamble. Because first of all, the arterial lumen can be difficult to co-opt. Because of the heat sink effect. And number two, it's under tension. See, it's stretched. Which means if you injure the wall even a little without eliminating the lumen, it's going to tear. And then you have two bleeding ends of a one millimeter, 0.6 millimeter artery. So I'd better not gamble and use the Coagrasper.

CHRISTOPHER GOSTOUT: Stavros, I'm going to ask you the same question we asked Dr. Zhou. Do you sometimes just leave them? If they're not going to be in the way of your myotomy, why fuss?

STAVROS STAVROPOULOS: Right. But the z-line is at 39 and about 40.5. And the most common reason for a failed POEM is an inadequate cardia myotomy. So I have to go through there. And they're right in the middle of my field. So if you try to avoid them, which I do when at the edges. But the scope is closed. The cap could avulse them. Without even you seeing it. On withdrawing the cap, you just rip one of those. And then you have a problem. So this I cannot divert around. So I think they have to go. They are just in the middle of my field.

There's a Japanese study, interestingly, that describes a very predictable v-sign of vessels that should tell you that you need to stop there. So that's not quite that. But it's definitely something before its publication, for years we are calling them the stop sign. Because once you start seeing these multiple penetrators branching out of the muscle, you have probably got within a centimeter of being at an adequate cardiac extension of the tunnel. But I think I need another centimeter or so before I do the transillumination to confirm another [INAUDIBLE]. I'm just going to get them.

You can try to get both of them at the root. But if you rip there and it's bleeding, that's going to be right in the muscle layer. So that's a little more difficult to deal with. So you should go to the middle of it. And for arteries, you should do what the surgeons do. Like do two points even. Because they can be very pesky. The Olympus Coagrasper is a little hollow. Not as much as the hot forceps. But these are a little hollow. So you'll see what happens. You can leave a lumen. So let's see. Close. So I'm going to do the left bundle first.

And then after you finish, it's ripping already. See? Because it's under tension. And it ripped before these heads was coagulated. See there's a bit of oozing. So let go. So now we need to cut both the other vessels, but also the root of the first vessel, with a little bit of muscle to make sure we have everything controlled there.

CHRISTOPHER GOSTOUT: Stavros, do you make a specific effort to stay fairly distant from the mucosa?

STAVROS STAVROPOULOS: Absolutely. Because you can see the current already traveled along the pathway of the vessel. So this is probably maybe the most common cause of cardia mucosal injuries by experts. Is difficult vessels, maybe vessels that were accidentally cut and they're bleeding massively. Where things get a little bit chaotic and then you end up burning the mucosa.

See now we have two ends. This is coagulated. You need to see at least a millimeter of coagulum. If you just did the tip, the minute the cap squeezes the lumen, it could pop the coagulum and it could start bleeding. And this is the other half, which looks pretty good. Open. Now if it doesn't get unstuck like this, you may end up ripping the vessel. So you can do a little pulse of Endo Cut to get rid of it. OK.

CHRISTOPHER GOSTOUT: Great. That's great. It was real nice demonstration of preventive hemostasis. We're going to room three now with Dr. Inoue.

HARUHIRO INOUE: OK.

CHRISTOPHER GOSTOUT: OK. So where are you?

HARUHIRO INOUE: I will explain this. We are dissecting the lower esophageal sphincter but via backup. So we have already created the submucosal tunnel and started myotomy.

CHRISTOPHER GOSTOUT: Have you run into any surprises from the prior dilations? Did that alter your appearance or challenge your entry?

HARUHIRO INOUE: Yeah. In this case, we found lots of fibrosis. So it looks easy beforehand. But when we start the procedure of the [INAUDIBLE], the patient have lots of fibrosis in the submucosal layer. So a little bit difficult.

So we have already created the submucosal tunnel. And then this is our starting point of the myotomy. You can literally, hopefully, recognize the circular muscle bundle, that the muscle fibers lands horizontally. And then a longitudinal muscle behind. We have already dissected the circular muscle. And then we continue the dissection toward the GE junction. And the muscle fiber a little bit torturous.

But this originally be longitudinal vessel. And then we dissect the circular. And then we create some widths. So widen the space then our longitudinal muscle separate. And it looks like oblique. But this is a longitudinal muscle.

And then go down to the junction. So we have already dissected the circular muscle. A little bit of resistance. And then maybe this is behind a longitudinal muscle behind it. This must be a diaphragmatic crus. So then it's very difficult to pass through it, because she's a pediatric patient. So spaces are very narrow.

CHRISTOPHER GOSTOUT: Is it your intent to do a full thickness myotomy at this level?

HARUHIRO INOUE: Yes. Still, I'm trying to do a circular myotomy. Partial myotomy not a full.

So in this patient, the problem is the diaphragmatic crus. You can see it behind this [INAUDIBLE] one. Behind the longitudinal muscle layer is a diaphragmatic crus.

CHRISTOPHER GOSTOUT: Is that up at the 12 o'clock?

HARUHIRO INOUE: Yeah, 12 o'clock. That's right.

CHRISTOPHER GOSTOUT: Do you see that little pink area?

HARUHIRO INOUE: Yes. 5 o'clock also same. This is the diaphragmatic crus. And then now I'm trying to pass through it but it's very difficult. So we can easily confirm the diaphragmatic crus like this. Diaphragmatic crus make a contraction.

Keep it closed.

This is a easy demonstration. So this is the level over. Now close the--

CHRISTOPHER GOSTOUT: Kind of an electrical stimulation of the crus.

HARUHIRO INOUE: Yeah, electrical stimulation. But no reaction. Still this is not the diaphragm. Diaphragm will contract when we stimulate it. So this part is very tight and fibrotic.

Now the level of incision length of the endoscope is 35. So I will come back to a recent lumen and then check it. OK.

CHRISTOPHER GOSTOUT: So the concern here is whether or not he's really passed into the stomach. Because of the amount of fibrosis. And it's really important to take a look at the cardia to see if you can identify some dye that has now passed into the cardia. And if you've dissected down into the cardia, the overlying mucosa should start to look pale. So you'll see kind of a blue coloration and overlying pale mucosa, and you know you're in there.

HARUHIRO INOUE: That's right. And now we are placing the endoscope 35 centimeters from the patient's teeth. So this must be a junction. But we have not yet reached this area. So we have to continue step by step carefully.

CHRISTOPHER GOSTOUT: It is very tight in there.

HARUHIRO INOUE: Yeah, tight and a hard compact body. That makes the procedure a little bit difficult. But anyway, we will continue. Once again, getting a submucosal space a flush a little bit. OK.

So this part is well done. And then as you recommended, we have to do the full layer dissection at the level of the junction.

So in this image, left hand side is the mucosa, back side of the mucosa. Right hand side is the muscle layer surface. But the endoscope is a little stuck here.

CHRISTOPHER GOSTOUT: Yeah. So it's really, extraordinarily tight. And you're running a high risk of inadvertently injuring the mucosa. And getting a tear at that pinch is a real mess to try to handle. So I think you're going to try to cut the muscle to open it up and to give you a better path. So that's also a technique that can work in a tight scenario. Start the myotomy in a localized area.

We are going to switch to Stavros real quickly. OK? We'll be back.

STAVROS STAVROPOULOS: So we've finished the tunnel in the cardia. And this is what I was talking about, the two scope transillumination. Dr. Inoue showed in his lecture, too described by this Portuguese group, [INAUDIBLE], back in 2013. Very useful in difficult POEMs to make sure that you extend the tunnel appropriately. Because you see it's two centimeters into the cardia. I left the dissecting gastroscope at the end of the tunnel. And I put a pediatric scope next to it in the stomach just to show the transillumination.

And you can see we kept the orientation perfectly. This is where a posterior POEM lies behind the scope. An anterior POEM lies at the bottom at 6 o'clock in this retroflex view. So this is useful when I do the anterior randomized trial. And I believe [INAUDIBLE] randomized to posterior. It's important to make sure that what you call anterior and posterior do not become the opposite during spiraling of the tunnel.

So this is all good. So now we're ready to start the myotomy. But before doing that, let me show you the real stop sign. Very similar to what the Japanese have described as a sign to stop, a big bifurcating red tree penetrating from the muscles. I'm removing the XP scope. And now we switch to the other one. This takes five minutes.

Haruhiro described the randomized trial where he took 70 minutes for this extra transillumination. But it depends on whether you have a second tower or not. Here we bring our portable tower. Sweet. That allows to also record the image from the XP. And then we switch back. It takes less than five minutes.

So here, now I'm back on the dissecting gastroscope. And you can see this big branching tree entering from there and supplying all these mucosa here. And I'm already at 42, and you see the tunnel is adequate on transillumination. So now I'm ready to start the myotomy.

So this is the sphincter. If it's very tight, sometimes I'll start cutting distal to proximal. Because in a very tight sphincter, if you start the myotomy here, when you reach the sphincter it can be very difficult to get back into the cardia. Because the scope is bulging into the mediastinum.

But here it's not so tight. So I'm going to start the regular way, proximal to distal, about two centimeters below the opening. So this is the opening. We're going to go two centimeters and then start the myotomy. If you want you can see the start of the myotomy or move to Dr. Zhou to see what he has.

CHRISTOPHER GOSTOUT: Yeah, we're going to move to room two.

OK. We're here.

PING-HONG ZHOU: OK.

CHRISTOPHER GOSTOUT: Yeah.

PING-HONG ZHOU: Now I begin to cut the circular muscle. For the myotomy, I always use a technique named push and pull technique. So I just fix the knife. Put the knife between the space between the circular muscle and the longitudinal muscle. And put the scope forward. So what do you do? Just push on the left so that the muscle can be cut. Then we'll be making the procedure very faster.

CHRISTOPHER GOSTOUT: Do you think for beginners this might be a little risky, inadvertently jumping up and hitting the mucosa?

PING-HONG ZHOU: In the sphincter area, especially in the EG junction, you feel sometimes if you push on the left of the knife, the tip of the knife will touch the mucosa. So the mucosa would be easier if you touch it. So sometimes on the strict side, I always put the knife on the muscle and I pull back.

CHRISTOPHER GOSTOUT: And when do you do full thickness? Do you do it across the EG junction, and then switch to circular only up into the esophagus? What's your preference?

PING-HONG ZHOU: I always make a [INAUDIBLE] sectional myotomy around the EG junction. Or with two centimeters proximal to the EG junction.

So here is a longitudinal muscle. You see the longitudinal muscle is very, very thin. Sometimes if the cap touches the longitudinal muscle, the longitudinal muscle will split automatically.

CHRISTOPHER GOSTOUT: Yeah, this is a very nice demonstration of the longitudinal muscle.

PING-HONG ZHOU: For the [INAUDIBLE] sectional myotomy, I always put the knife outside of the longitudinal muscle.

Then push your scope forward.

Push. Push. And this is four seconds.

This are is the EG junction area.

CHRISTOPHER GOSTOUT: So for the audience, you can see there's no longer any muscle fibers there. You're just seeing kind of the bland looking perijunctional tissues.

PING-HONG ZHOU: So we always use this technique, push and pull technique, to make the myotomy so that the average procedure time for POEM only 30 minutes in our center.

And this is a [INAUDIBLE] muscle.

CHRISTOPHER GOSTOUT: Now that push and pull technique, is that something that you could use with other needle knives? Or you think it's just specific for the one you use?

PING-HONG ZHOU: Only one knife. No specific knife.

And now I've finished the myotomy. So I can use this knife-- I'm going to use this knife to manage the [INAUDIBLE] vessels within the tunnel. So for the [INAUDIBLE], there is no change or exchange some other instruments either we make the core procedure very, very convenient--

CHRISTOPHER GOSTOUT: So you can see how that space is opening. So--

PING-HONG ZHOU: Yeah.

CHRISTOPHER GOSTOUT: --you don't even need to do an EndoFLIP. You can just kind of see how loosening--

[INTERPOSING VOICES]

--that muscle really opens that whole diameter--

[INTERPOSING VOICES]

PING-HONG ZHOU: And now you can see the stomach is open. I reflex the scope to check-- [INAUDIBLE] to check the EG junction. It's very difficult.

CHRISTOPHER GOSTOUT: So as you're inspecting from the mucosal side, you're also looking for inadvertent coagulation marks, right?

[INAUDIBLE]

If you see a coagulation mark on the mucosa overlying your tunnel, do you do anything? Do you put a clip on it? Or do you just kind of acknowledge it's there, and we just keep an eye on it?

PING-HONG ZHOU: So I always use a clip to close those injuries, you know, on the mucosal side. So now I check there was any bleeding within the tunnel that could-- the tunnel seems very clear.

CHRISTOPHER GOSTOUT: Yeah, it looks really good.

PING-HONG ZHOU: No bleeding, so this is a result of the circular muscle in the outside of the tunnel.

OK, I finished the myotomy, the main procedure of the POEM procedure. And next I will use a clip to close the entrance. So during a core procedure, we must now check on the patient to see if there's any [INAUDIBLE] that is tightening, if there's any, subcutaneous emphysema, and so on.

CHRISTOPHER GOSTOUT: Right. So we're looking for extravasated gas that may have tracked outside through longitudinal muscle layer or through that full-thickness portion of the cut. And you have to do an abdominal decompression.

And otherwise, you need to let your procedure room staff not get shocked when the patient wakes up and their face is all puffy from the subcutaneous emphysema that can happen. It resolves pretty quickly.

PING-HONG ZHOU: So this clip comes from the [INAUDIBLE] scientific. So we can rotate this clip by myself, by my right hand.

CHRISTOPHER GOSTOUT: Are you very compulsive placing clips? Do you want like one clip exactly next to the other? Or just generally closing the opening is fine with any number of clips? Or do you really try to stack them?

PING-HONG ZHOU: Yeah, the first clip, it suggests to close to the normal mucosa. Close, please.

SPEAKER 1: Close.

PING-HONG ZHOU: Fire.

[CLICK]

OK, and this is the first clip. Its place-- you put across a normal mucosa, you see? You see?

CHRISTOPHER GOSTOUT: Right. You've placed it across the normal mucosa, kind of pinch it and kind of-- and close-- make it a little easier to start to close the actual incision.

[INAUDIBLE], rotate, rotate, rotate. OK, stop. We just put the arms of the clip across the incision, across the incision. Then we suction. Close, fire.

[CLICK]

That's OK. One more, please. One more, please. OK. [INAUDIBLE], please.

So I will put on clip between these two clips. I think it's the distance it needs to be.

Close, please.

SPEAKER 1: Close.

PING-HONG ZHOU: Fire.

[CLICK]

Yeah. One more, please. One more, please.