So, we're going to start our second, we're going to start the next lecture. I'd like to introduce Yuto Shimomura, also from Showa University, who is going to talk about his tips and tricks for poem procedures. Welcome. First of all, I'd like to thank Dr. Adam and Dr. Sethi for giving me the opportunity to give a talk in this prestigious course. My name is Yuto Shimomura from Showa University, Koto Toyosu Hospital in Tokyo, Japan. I currently work with Professor Haru Inoue, and I will give a talk on poem procedures including tips and tricks, and will share some essential tips based on our experience. I have no financial relationships with commercial support to disclose. More than anything, the most crucial part of poem is preparation. Preoperative patient assessment is critical, important. The risk of general anesthesia should be thoroughly assessed, and the definite diagnosis of motility disorder should be confirmed as the poem strategy is decided based on the preoperative diagnosis. And fasting is essential before general anesthesia because of the risk of aspiration when positive pressure ventilation is performed with a face mask. Esophageal cleansing should be performed before poem when deemed necessary, especially for patients with sigmoid type. To ensure the safety of poem, preparation should be decided carefully depending on preoperative examinations, including the CT scan. If this is a mild sigmoid type echolacea and there is no fluid residual on the initial endoscopic assessment, in such a case, there is no need for routine preoperative esophageal cleansing. However, if there is fluid residual on preoperative endoscopy, it is preferable to undergo esophageal cleansing beforehand. In your institution, we perform esophageal cleansing one day before poem where there is a high risk of fluid retention in the esophagus. The use of antifungal drugs is recommended in case of esophageal candidiasis. This is important as inflamed mucosa often causes technical difficulties. If fluid residue remains at the time of poem, we need to sufficiently lavish the esophagus to prevent contamination into the immediate science. Now I will share how we prepare for poem in our institution. A knife is a critical device in poem. We use TTJ as a standard knife with a triangle tip and a cutting knife length of 4.5 mm. The TTJ has a watershed function that speeds up the procedure. The cap that we use is a space adjuster super soft hood. This is a transparent distal attachment capable of adjusting its tip to the shape of narrow spaces because of its flexibility. This would adjust its shape into narrow spaces such as the submucosal layer, stabilizing the endoscopic view and providing adequate counter traction while performing dissection. For some mucosal injection, we prepare 500 cc of saline with 5 cc of blue dye for all cases and no epinephrine is required. Coagulation forceps should be ready to use anytime. There are cases when we encounter severe bleeding and coagulation forceps are required to coagulate LERS vessels on the gastric side. Endoclips are required for mucosal closure. Any endoclips are acceptable. However, a repositional clips may be easier for mucosal closure for trainees. This is the image of our operating room. It is essential to have equipment in the proper place for the operator to be comfortable in performing poem. We always use two scopes, one therapeutic scope and one pediatric scope. A second endoscopy system is required to perform a double scope technique. A therapeutic scope that we use is H290T with a 3.2 millimeter channel, which is dedicated to therapeutic endoscopy. A 1200N is a pediatric scope used for the double scope technique. Although in some institutions it may be challenging to prepare an additional endoscopy system, we believe that this technique is one of the most important techniques in poem. And it is essential to use a low flow gas tube to minimize the CO2 leakage to the mediastinum and peritoneal cavity. The main reason for using a low flow gas tube is that the CO2 insufflation systems for poem are different from those used for laparoscopic surgery. They're not made to adjust the flow rate automatically and maintain a constant pressure. The operator and the assistant should regularly check that CO2 is being used and check for evidence of severe pneumoperitoneum. Poem must be performed with CO2 insufflation. Air insufflation should never be used. If poem is performed with air, the risk of gas related complications are higher, which could be fatal. The positioning of the foot pedal is based on the operator's preference. Still, the key point here is that the operator should know the positioning of the pedals without looking down during the procedure. As mentioned previously, these are several devices that must be prepared in poem. And we think some other pieces of equipment are essential to prepare. Lens cleaner and Q-tips are a must tool for our procedure to ensure clear visibility. Maintaining clear visibility is vital to achieving a high quality procedure. This is the list of equipment for poem in our institution. Other equipment are as follows. And the primary generator settings are endocot and spray coagulation mode. For a mucosal incision, we use endocot 2, effect 2, cutting duration 1, and cutting interval 6. For submucosal tunneling, we use spray coag 2, 50 watts. And we use soft coag, effect 2, 50 watts for a hemosthesis. Next I will introduce our standard method of poem, anesthesia. Poem is typically performed in the supine position. The reasons for our supine position allow the procedure to reflect data from the preoperative CT. And exposing the upper abdomen during the procedure is needed to monitor the degree of pneumoperitoneum. A general anesthesia with controlled ventilation is required. To prevent aspiration, it is recommended that rapid induction with cricoid pressure is performed with extra care to avoid regurgitation from the esophagus. In our institution, intubation is done in a tilted position to avoid aspiration. And I'll now move on to poem procedure. As everyone knows, poem consists of mucosal incision, submucosal tunneling, myotomy, and mucosal closure. And I will go over tips for each part of the procedure. When performing poem, maintaining orientation is crucial. As you can see here, compression of the left main bronchus is an important landmark. And in this video clip, you can see that the scope is advanced without torquing it, maintaining its orientation. However, we can quickly lose orientation in the case of the dilated or sigmoid esophagus. By flushing water or sailing, we can confirm the fluid pooling at the 6 o'clock position. From there, it is possible to identify the 2 o'clock or 5 o'clock position. Submucosal myotomy should be avoided to prevent the occurrence of a diverticulum. And in addition, anterior myotomy in the upper thoracic esophagus should be avoided as it may lead to esophagotracheal fistula. And I'll move on to mucosal incision. And we use saline with indigo carmine for submucosal injection. 5 cc of saline is injected for initial mucosal cutting. Here I injected saline at the 2 o'clock position. Injection site should be 2 centimeter proximal to the starting point of the myotomy. And in most cases, it is approximately 32 to 35 centimeter from incisors. But it depends on how long the esophageal myotomy should be performed. The mucosal incision is performed with endocuts. First, 1 to 3 cuts are applied using endocuts. And a 2 centimeter longitudinal incision is made to allow the scope to enter the submucosal space. If difficult to get into the submucosal space, it is practical to extend the mucosal incision viscerally or add 1 to 2 cuts laterally to create an L-shaped mucosal myotomy as shown in this video clip. And submucosal dissection is added with spray coagulation to allow the scope to advance into the submucosal space. So now the scope is easily into the submucosal space. And submucosal tunneling, we use spray coagulation mode for submucosal tunneling. It is important to dissect close to the muscle layer to avoid mucosal injury. And to inject additional solution whenever needed. And always keep the submucosal layer colored in blue. The other tips are as follows. Continuous counter traction with the hood should be applied throughout the dissection. And submucosal tunneling should be straight without any deviation. Less than one-third of circumferential dissection is recommended. There is no need to widen the submucosal tunnel. And submucosal tunnels should be created down to gastric cardia at least 2 cm distally from the junction. And spindle vein is characteristic of the submucosal layer at gastric cardia. And this video clip shows that this is the end of the tunnel. And you can see that the scope adds but that the tunnel is not deviated. And this is the submucosal tunneling in the posterior approach. Please note that this hood is flexible and adjusted shape for the scope to advance into the submucosal space. And spray coagulation is very effective in opening up the space by using this spray coagulation mode. It opens up the space to allow the scope to enter deeper. The next step after creating the tunnel is myotomy. And we perform selective myotomy. And we only cut circular muscle and avoid cutting the longitudinal muscle which can act as a safety margin to the mediastinal structure. Longitudinal muscle fiber cannot be identified at the beginning of myotomy. So spray coagulation should be applied carefully to identify longitudinal muscle fibers. Now I was able to see the longitudinal muscle fibers. And the other tips are listed here. The circular muscle should be entirely cut. And spray coagulation should be applied in the intramuscular area to avoid bleeding. And endocut mode is used to cut the circular muscle. And intramuscular space should be identified every time before cutting muscle fibers. And even in Achalicia patients, circuital muscle is not thick at LES. But this thin circular muscle cannot relax during swallowing and should be cut completely. And two centimeter myotomy on the gastric side is recommended. When anatomy becomes unclear on the gastric side, inject blue dye added saline into the intramuscular space. It creates good contrast, which allows good visualization of circular and longitudinal muscle fibers. And this is the end of the myotomy. This is a video clip confirming that myotomy has been completed. Longitudinal muscle fibers are preserved. It is essential to check that there's no area of incomplete myotomy. In addition, there is no active bleeding within the stomacosal space and no big vessels are untreated. This is important to avoid any postoperative bleeding. There are vessels between circular and longitudinal muscle fibers. That is why we combine spray coagulation and end of cut mode. So when we perform myotomy, we place TTJ in intramuscular space and coagulate between muscles and then cut the circular muscle with end of cut or spray coagulation mode. These are video clips of myotomy in the posterior approach. A spray coagulation is applied to precisely identify the longitudinal muscle fibers. And spray coagulation and end of cut are combined in myotomy. The last step of the procedure is mucosal closure. It is important to deploy the first clip on the distal end of the mucosal incision. And the first clip creates a fold of mucosa, making subsequent clips easier. The cap attached at the tip of the scope helps to apply the proper tension onto tissues for subsequent clippings. Tight closure is required to prevent leakage into the mediastinum. And that should be confirmed after completing the closure. And we are now performing POEM for all types of achalasia and esophageal motility disorders. The length and direction of myotomy are controlled with double scope technique for all patients. The optimal axis in myotomy length are still controversial, but we think an anterior or posterior approach is acceptable and myotomy length should depend on the cases. Next, I will introduce our standard technique, the double scope method. The double scope method has been applied to ensure complete gastric myotomy during POEM. And this was initially reported in 2014. As mentioned, a second endoscopy system is needed for the double scope technique. And to perform this method, a thin gastroscope or second gastroscope is advanced into the stomach and the gastric cardia is observed in a retroflex view while the standard scope is placed at the end of the submucosal tunnel. Transillumination can be used to visualize the scope position. When the main therapeutic scope is in the submucosal tunnel, myotomy can be extended while observing it from the gastric side with the second scope. This technique is crucial in controlling the length of the myotomy. It avoids incomplete myotomy of LES. In this case, if the submucosal tunnel is too short, there may be a risk of an incomplete myotomy. You can see the light of the therapeutic scope at SCJ, squamous colonar junction. Two centimeters into the gastric side is the appropriate length of the submucosal tunnel. This is the anatomy of the muscle layer in the stomach. Sling muscle or oblique muscle are shown here in the yellow line. But when performing anterior approach, the submucosal tunnel does not pass through the sling muscle fibers. And this is the posterior approach to myotomy without preservation of the sling muscle fibers. Note that the yellow arrow is heading towards the fundus. Image on the left shows posterior myotomy without preserving sling muscle fibers. And the image on the right shows one with sling muscle fiber preservation. The direction of the submucosal tunnel can be controlled by guiding the scope into the lesser curvature. Using this technique, it helps in preserving sling muscle fiber and it may subsequently prevent GERD after point. And this is the article published by our center in 2019. The conclusions are that gastric myotomy over 2.5 centimeter increased rates of moderate esophagitis without improving clinical efficacy. And preserving the gastric sling fibers may help reduce acid reflux. This method was used mainly to prevent incomplete myotomy. Then in our experience, we think the double scope method may help reduce the risk of GERD. Two main advantages are as follows. First, the extent of the submucosal tunnel on the gastric side can be confirmed. Secondly, the direction of the tunnel can be checked. These will allow us to avoid short or excessive myotomy and help preserve sling muscle fibers. And can we identify the ideal length of the tunnel in submucosal space? And identifying the two penetrating vessels at the gastric cardia may be helpful in the posterior approach. When creating the tunnel at five o'clock, two thick vessels can be detected at the right edge of the sling muscle fibers. The first located immediately after passing the junction and the second two, three centimeter distally towards the gastric side. The submucosal tunneling should be stopped after identifying the second vessel. Now we'll introduce several tips and tricks for POEM. Number one, the tip of the knife should be used and not the whole length. And to stabilize the knife, the TTJ knife should always be used with a distal transparent hood. And two, the straight tunnel can be obtained by creating it perpendicular to the circular muscle fibers. And to do that, the axis of the scope should be straight. If the scope is twisted outside the patient, you'll likely encounter a deviation during submucosal tunneling. And number three, and do not perform myotomy when the muscle layer and the mucosa is in contact. This prevents delayed preparation of the mucosa. The mucosa tends to come close to the working space when passing through the LES. Delicate maneuvering, spray coagulation onto the intramuscular area is often enough to complete myotomy at the LES. Number four, when performing myotomy on the gastric side, pay attention to the artery from the left gastric artery. This can cause severe bleeding if injured. This is a case of pulsatile bleeding on the gastric side. The bleeding point was located without any difficulties and coagulated with coagulation forceps. But bleeding happens even if you take extra care not to injure the vessels. So we need to be prepared. This is a case of severe bleed during myotomy. Water irrigation helps locate the bleeding point when it bleeds massively like this. And if that fails, compression against the bleeding area with a hood will assist in achieving temporary hemostasis. In this case, we were able to locate the bleeding source, bleeding point and coagulation forceps was used to achieve good hemostasis. And lastly, an abdominal puncture with a needle is important in deep compressing intra-abdominal pressure. This will help in reducing the risk of gas-related complications. An 18-gauge needle is inserted under a sterile condition at the point of the left upper abdominal quadrant, at least five centimeters below the ribcage, and a serine discharges gas in the abdominal cavity. Next, I will present a video case in which we encountered fibrosis and had difficulty entering the semiglottal space. A thick and edematous mucosa can be seen, and the long-standing inflammation likely caused this fibrosis or the thickening. And when the saline is injected into the semiglottal, the mucosa does lift, but not to the extent we see in usual form cases. The mucosal incision is performed, but the semiglottal tunneling is difficult as we don't see sufficient space to enter the semiglottal layer. So what are your following options? One, seek another mucosal incision site. Two, extend the mucosal incision length or create L-shaped mucosal incision. Three, change to another solution, injection solution. Four, continue to advance the scope into the semiglottal, and five, other options. And in this case, we chose four. We tried to try as much as possible to get into the space, but as you can see, we pushed the scope against the semiglottal space to maximize the mucosal traction with transparent hood. In such fibrotic cases, a hard hood is often helpful, and I decided to coagulate the muscle layer as well as the deep layer of the semiglottal. It is better to dissect deeper rather than injure the mucosa. As you can see in this video, I coagulate the muscle layer first and also the deeper layer of the semiglottal. And this was continued until the scope was stabilized in the semiglottal tunnel. Although it was fibrotic throughout the semiglottal tunneling, we managed to create a tunnel without unintentional mucototomy. The next case is another fibrotic one. This case was severely fibrotic, and it was challenging to open up the semiglottal space. At this point, we had already tried mucosal entry in another site, but were unsuccessful. We also tried to extend the mucosal incisal length, but were again unsuccessful, so we opted to perform the snare traction method. Among these options, we opted to go for another option. An endoclip was applied to the distal end of the incision site. And before deploying, we advanced a pre-looped snare around the clip. And once the snare was secured around the clip, the clip was deployed. And by pulling the closed snare, adequate traction was obtained. After applying the traction, we were able to stabilize the scope in the tunnel. Here are some figures of this technique. Endoclip was applied through the working channel. A snare was pre-looped around the distal cap outside the scope channel. And then the scope was intubated. The snare was closed around the clip, and the clip was deployed. This is an effective trick when encountering these problematic situations. This is my last slide. The operator should know what is required to safely and effectively maximize the procedure's quality. Tips and tricks were provided in each part of the appointed procedures. Double scope methods should be applied to control the length and direction of the submucosal tunnel. The operator should be prepared for common difficult situations such as severe fibrosis, abdominal bloating, and bleeding. Thank you for your attention. Thank you. That was excellent. Let's have a little bit of discussion here. Any questions immediately from the audience? So I have a few questions, actually. Let's just start with the question of the double scope technique. It is a beautiful technique. And we had Professor Inouye as well share with us the value. But the reality here in the US is that not many centers have this set up for a double scope technique. So in the absence of that, what do you think are the key factors in identifying the junction? I think the important thing is to see the narrowing at the junction area. There's always a narrowing when passing the junction. So you should feel it while advancing the scope. And the other thing is to identify spindle vein. Spindle vein can be identified in the gastric side. So by identifying that, you can understand that you are around the ileus area. And the other thing is to identify the sling fiber. Sling fiber can be identified in posterior approach. In the anterior approach, it may not be easy to locate the anterior sling fiber. But you may be able to see it. So if you see it, then that will give you an idea of where you are in the ileus area. And how often do you recommend coming in and out of the tunnel and looking in the gastric side? Thank you for the great question. We don't really come out that often because we have this experience of knowing where you are in the submucosal tunnel. But in case of sigmoid case, sigmoid-type achalasia, we have to come out and check where you are or to check if the tunnel is not being deviated. That we do frequently in a difficult case. Would you say for beginners that that is something, a good way to look at orientation? I'm sorry. I think for the beginners, it is important to come out and check where you are and to know where you are. So I recommend pulling out the scope into the lumen and then know where you are and then go back to the, go into the submucosal space and have a sense of where you're going to approach. So I recommend doing that. We have a question. Vani? Yes. That was a lovely demonstration of the snare and clip traction technique for difficult entry. Are you placing that clip then as your most distal clip for then the closure as well? Or are you doing something different between the entry and the closure? Thank you for the question. It is a very important question. Whenever we have difficulty closing because of severe fibrosis or severely thick mucosa, we use this traction technique. So we apply traction with the snare and clip at the distal end of the incision site and then close from there. So we use it for the mucosal opening and also for the mucosal closure. And then another question I have is, when you do the L technique, do you have any additional tips then for the closure, which then might be a little bit off and less linear? Yes, the important thing is that when you apply L mucosotomy, L-shaped mucosotomy, don't cut too much to the transverse. Just cut, just place one or two cuts. So just a little cut is enough. And it's because if you apply, say, 2 centimeter horizontal incision, and the closure becomes more difficult. So the goal really is just to, you're widening the opening a little bit. Also, would you say important is to dissect underneath the mucosa, the mucosal edges? Yeah, that's true. It's very important to dissect the mucosal area to get the smooth bleeding. Go ahead. What is your center's experience in managing delayed bleeding in the myotomy, like two to three days after the procedure? Do you mean postoperative bleeding? That's correct, sir. Yes, delayed two to three days post-procedure. Yes, we have experienced that. It's very rare, but we experience that. Most of the time, if it's just hematoma, we see it conservatively without any intervention. But when we see contrast extravasation on CT scan, we look for the bleeding point. So in that case, it has to be done under general anesthesia. Yes, go ahead. In your practice, what do you follow? Do you follow the same day discharge protocol or admit the patient overnight for observation? And how do you manage the postoperative pain in these patients? Thank you for the question. In our hospital, we keep the patient several days. So five-day hospitalization in total, which is quite long. But in our country, it is allowed in Japan. So what we do is we do second look endoscopy the following day, the next day. And also, we do a contrast barium swallow. And then if there's no leakage, we start on clear fluids from the next day, postoperative day 1. And they advance diet from postoperative day 2. For painkillers, actually, we only use NSAIDs and acetaminophen. We don't use narcotics. So you're not having any difficulties with bleeding using the NSAIDs postpone procedure? You are not experiencing delayed bleeding with the nonsteroidals for pain? No, we haven't. But the first one is the acetaminophen. OK, go ahead. I had a couple of quick questions for you. I'm an esophagologist. I don't do poems. But my question is, how do you recommend the patients eat, or what do they eat, building up to the day of the procedure? And if you go in on the day of the procedure and find food in the esophagus, do you postpone, or do you clear the food? Another question is, how do you approach the risk of infecting the tunnel? Is there any chance that a patient gets infection within the tunnel if there is stasis in the esophagus? And how do you prevent that? Thank you for your question. Regarding the food restriction, we ask the patients to avoid something hard or vegetable from two, three days prior to the procedure. And then we only allow very soft, good food the day before the procedure. And as I presented, in suspected case of food residual, we perform endoscopy the previous day just to see if there's any no food residual or not. And if you see it, food residual, on the day of the procedure, we try to clean as much as possible. And it's a very rare case, but if we encounter, it takes about 30 minutes to clear out the esophagus. So I think it's very important to advise the patient of what to eat prior to the procedure. And regarding infection, actually, we haven't experienced any infection within the tunnel because of food stasis. Or maybe candidiasis can happen because of the food stasis. During POEM or post-operative management, we give antibiotics for three days. Thank you. Just as a follow-up to the double-scope technique question, have you used indigo carmine or any other kind of dye-based to kind of identify that you're down in the gastric side? Yes, thank you for the important question. Yes, when we take out the scope to assess where you are in the submucosal tunnel, indigo carmine really helps. So if we are not sure if we have gone past the LES or not, we do inject saline and to see if we have passed LES or not. So I think it's very important to identify where you are. So you retroflex in the stomach and inject on the gastric side? Actually, during double-scope technique, we don't need to do that because we have the transillumination. No, but if you're going to use the indigo carmine, then you retroflex. Yeah, yeah. I see. I have a question actually about any tips for patients who've had Botox or pneumatic balloon dilation, one, two, sometimes three times. I don't know what the experience is there in Japan. Actually, Botox is not available in Japan, so we don't routinely use it. Regarding pneumatic balloon dilation, we do have a patient who do repeated balloon dilation. And if that doesn't work, we proceed with POEM. No, but are there tips for performing POEM in patients who have had these treatments before? Sorry, yes. Regarding the patient who had previous balloon dilation, we carefully assess if there's any fibrosis or not while we are in the esophagus. Sometimes we encounter fibrosis due to repeated pneumatic dilation. But most of the time, it's OK. We can manage to go deep into the submucosa. And in terms of identifying the muscle orientation in those patients, that can oftentimes be tricky because they have split and then are reforming and kind of go in all types of directions. What's your guidance there? I think we have to go back to the basics, like follow the circular muscle while doing the submucosal tunneling as much as possible. And when we are doing myotomy, I think we should identify the intramuscular area of the circular and longitudinal muscle and follow the longitudinal muscle as much as possible. There are cases where it's difficult to follow because of this previous balloon dilation. But in that case, we just have to do as much as we can. Oftentimes, full thickness, yes? Yeah, full thickness, it happens, I think. And I think full thickness at the LES area is not a big issue. Even when we aim for selective myotomy, we still have this full thickness myotomy at the LES area. So yes, and also in those cases with fibrosis, it usually causes full thickness myotomy. This might sound like an unusual question, but sometimes when you do EMR in the esophagus, you can see duplication of the MM layer. And when you're doing a mucosotomy incision, have you ever encountered where maybe you might think that you're actually just trying to get through the MM layer, but you're worried that you're actually cutting the muscular aspropria layer? I don't know if my question is making sense, but. Did you hear that? Yeah, thank you for your question. I think the orientation is very difficult within the esophageal mucosa. So when we inject blue dye with saline with blue dye, we try to identify the submucosa precisely and not to inject into the muscular area. So I think the very important thing is to locate or identify submucosal layer and then inject into that layer and don't inject to the muscular area. Yeah, I think the times that it becomes difficult are the severely when the submucosa is fibrotic and you do not get the beautiful blue color that we have seen in these videos. And oftentimes, it can be opaque, and it can even look like muscle. And in those cases is often when we have the thickest muscularis mucosa. So that's where it's important to use an injection needle and not the jet knife to make your initial bleb and really go feel for that pop. Because it is a distinct pop, particularly when the muscularis mucosa is thick. And you should open at least into some form of more open space. So yeah, it can be tricky, particularly in those cases. I think one final question I have for you is have you ever experienced when the LES is so tight that you are having difficulty making the tunnel? And can it even get down to the cardia? And what do you do in those situations? Thank you for this question. We do encounter some difficulty going through that tight junction area. But if we do, we start cutting myotomy from the oral side of the junction and to release the pressure while we are dancing. Excellent. So usually, I mean, in our cases, I think we have not had failed case of not being able to pass through the junction. Yeah. And in some situations, we've used relaxation medications, for example, calcium channel blockers. But you have to obviously look at other situations like the blood pressure and other medical conditions for the patient. But I think that is the key, is that sometimes you do have to deviate from the order and cut a little bit of muscle. But remember to continue the tunnel. You're not ending the myotomy or starting myotomy there. Yes. I agree. I really agree with your opinion. Excellent. Well, I think that was a really wonderful session. Any other final questions? Thank you so much for joining us. I think it's late there. And we're going to see you a little bit later, very early in the morning. So thank you so much. Thank you very much. So see you later.

Yuto Shimomura

Showa University

poem procedures

preoperative patient assessment

general anesthesia

esophageal cleansing

mucosal incision

double scope technique