Latest / Behind The Knife: The Surgery Podcast / Surgical Endoscopy Series Ep. 3: Per Oral Endoscopic Myotomy
Transcript
- BTK POEM Audio Final === [00:00:00] Welcome back, and thanks for tuning into our third episode in the surgical endoscopy series. In this episode, our focus will be on the various uses of per oral endoscopic myotomy, or poem, technique, and the gastrointestinal tract. For a brief re introduction of our team, I am Elia youSo. I'm the current minimally invasive surgery fellow at Endeavor Health formerly North Shore. Once again, we were lucky enough to be joined by assistant professor and for guide surgeon Dr. Mason Hedberg from Endeavor. Dr. Trevor Krafts again joins us from the Rocky Mountain VA in Denver, where he is also assistant professor at the University of Colorado School of Medicine. And this time we're also lucky enough to be joined by Dr. Michael McCormick from Swedish Hospital here in Chicago. Dr. McCormick previously participated as a, the first fellow at Endeavor Health. So we're lucky to have him today. But Dr. Hedberg, let's start with you and, and kind of dive in. Do you mind providing us with a brief introduction and background about esophageal poem, [00:01:00] how it came to be and then talk a little bit about the technique? Absolutely. Yeah. Thank you. So as the name would suggest, this is a endoscopic means of dividing the lower esophageal sphincter in the case of the esophageal poem. And this is an alternative to the traditional laparoscopic or originally open hell or myotomy. So a poem was first introduced by Dr. Inoa in Japan in 2008 as a means of treating achalasia. Achalasia is diagnosed with high resolution manometry, which must demonstrate that the lower esophageal sphincter does not appropriately relax with a swallow reflex. And this is evident by an elevated integration, integrated relaxation pressure, or IRP. The action of the esophageal body distinguishes the three achalasia subtypes type one. It's absent contractility type two pan esophageal pressurization, and type three where there's spasm present in 20% or more of the swallows. In cases where manometry is inconclusive it is, you can use endo flip or a time barium gram to help clarify the diagnosis. So, P is [00:02:00] now well established to treat Achalasia. There's a randomized trial in the New England Journal of Medicine where POM was non-inferior to Heller Myotomy. In terms of postoperative quality of life and IRP measurement, the number of adverse events was fewer in the PO Group Co. The number of adverse events was fewer in the poem group and poem. Patients recovered more quickly. The main drawback of palm is the incidence of postoperative reflux. Since there is no concurrent anti-reflux procedure per performed, as is typical following Heller myotomy, in this study, the GERD rate was 44% at two years. At our institution, we bring patients back one year after Palm to perform an EGD and pH testing. If it's abnormal, we recommend lifelong PPI use or return to the OR for fund application, but the vast majority of patients choose the medications. Also in our own group we have reduction in ECKHART scores from AM mean of six to 1.5 with clinical efficacy over 95 or 90%, excuse me. And our GERD rates are similar under [00:03:00] 50%. It's worth noting. Poem is a viable option for patients who require a repeat myotomy either after a prior poem or Heller Myotomy. And there is some evidence that P May or a modified version of P may be used to treat other esophageal motility disorders like esophagal, gastric outflow obstruction, or jackhammer esophagus. But these indications are still somewhat experimental and outcomes are not as good as poem for achalasia. So how do we actually perform this operation? We tend to do it under general anesthesia in the or, and first and foremost, foremost safety is a concern. We keep patients on a clear liquid diet for two days prior. I ideally I was just hoping to flush out any residual food particles and decrease the risk of aspiration on intubation. Always identify your appropriate landmarks. We tend to keep the patient's supine as the scope is oriented. Posterior tends to be at six o'clock. You can use some irrigation through the scope to confirm, kinda see where the pooling is with gravity. To confirm your orientation and you [00:04:00] always need to check the GE junction. Do a retro flexion roll out on mass or other cause of pseudo obstruction. There are different kinds of caps you can put on the end of the endoscope. And I, I think of these kind of as the retractor for endoscopic surgery helps push the tissue away a little bit and improves your review. We tend to use the radio frequency ablation cap that's a little bit angled, designed to scrape that sloth off of the tissue, off of the mucosa after RFA. You know, there's also some variability in where people start the mucus otomy and actually perform the myotomy. We tend to go about three o'clock. You know, thinking about that view of the esophagus, six o'clock is posterior, your aorta is gonna be down there. The heart is north at 12 o'clock. And so that three o'clock as the vagus starts to twist around at the GE junction, there really shouldn't be any major landmarks right there. And it's pretty safe place to do the myotomy. So find your Z line or GE junction. Typically, we come back about seven centimeters to start our submucosal tunnel. So the tunnel is probably the most critical part for all of these [00:05:00] procedures. The major risk of these is a perforation direct, you know, full thickness defect in the, in the organ. So if you have your submucosal tunnel a couple centimeters long, that's gonna protect from a leak as it heals. It'd very, it'd be very hard for something to leak all the way through the tunnel and form a fistula through your, your surgical site. We use this hybrid knife, which lets you inject it, we use a blue solution, so that's saline with Indo indigo Carmine, and this sticks to the proteins in the submucosal tissue. So as you inject under the mucosa, it lifts up and you can see this blue plane with the mucosa on one side and the muscle on the other. The mucus otomy itself needs to be a couple centimeters long, at least twice the length of the scope. Small mucus otomy actually is prone to tearing, which is much harder to close. So it's good to have a long mucus otomy that you're not fighting with the scope as you're doing the procedure. Then the tunneling procedure, you kind of go back and forth kind of hugging the muscle. So remember, the circular fibers are gonna be on the inside of the lumen here. You wanna be traveling perpendicular to the circular fibers, heading straight down towards the [00:06:00] pylorus. It is possible to kind of spiral around the esophagus as you're doing this tunnel. So keeping that orientation just. Perfectly perpendicular is very important. Once you've made your whole tunnel, you, it's really tight. Down at the GE junction you can tell you're approaching the LES that lift, that injection solution has not given you the tunnel that you had higher up, and then you kind of pop through and it opens up again as you get onto the gastric side. We typically go about two centimeters with the tunnel onto the stomach, and then you take the scope out, go into the normal lumen retroflex, and you wanna see some evidence of your tunnel on the gastric side. Then you know that you've done your tunnel long enough. Then we come back and starting, you know, this, this data has been changing a little bit. We used to do long myotomy, like a Heller Myotomy, but we're finding less reflux potentially with shorter, my autotomies really just trying to hit the lower esophageal sphincter. So usually my myotomy are four or three centimeters. And again, you can kind of tell where the LES is. It gets really tight and the appearance is a little bit different. So really just come back and start at the top of the lower esophageal sphincter. [00:07:00] Take that myotomy all the way down onto the stomach and you can confirm the adequacy of your myotomy using endo flip. Once you're satisfied, the myotomy is adequate. Just need to close that. Mucus otomy, we tend to use endoscopic clips. Usually four or five, sometimes six of them will close the entire mucus otomy. If it's a really big hole or something that tore and it's hard to close, you can always get the Apollo over stitch or another closure device to get that closed. That's excellent. Dr. Krafts do you mind kind of chiming in? Dr. Hedberg started to allude to things that. You know, make this easier and appropriate landmarks, but any tips and tricks that you have for people who are trying to perform this procedure for the first time and, you know, maybe some common pitfalls of what you see people you know, perform this that could, could make things easier. Yeah. No, I think Dr. Hedberg covered the vast majority of it. I would say that something that comes to mind is the, probably the most challenging thing when you're learning this is the initial mucosal incision. And you obviously are really hesitant 'cause you're using this knife to burn into the wall of the esophagus and [00:08:00] you don't want to make a full thickness hole right away. So you're really hesitant. But sometimes, especially when patients have. Like longer standing disease, the mucosa can be really thick and sometimes it takes some really intentional pedal work to get into the, through the mucosa, into the submucosal plane. And then one of the other things he mentioned, kind of hugging the muscle and resisting that kind of tendency to spiral as you go down. I think one thing that I try to do and I harp on is periodically with drawing the scope within the tunnel itself and just kind of checking your orientation in the natural plane that the scope wants to travel in, to try to make sure you're as anatomically straight as possible. Then I think finally just generally not estimate or underestimating anatomic variants in these cases. So some people, like any kind of surgery you do, you know, have different anatomy and some people have really thick circular muscle, for instance. And you're kind of hacking through it. And other times people have relatively large caliber submucosal vessels, especially as you move farther distally. And you have to be prepared to address these other, with a knife or with a another coagulation device. Basically, bleeding is kind of the arch nemesis of this [00:09:00] case. Like you can always, almost, always virtually endoscopically control it. But it really eats up time in the operating room. It shakes your confidence and it distorts all the planes you use. I would say other things just in terms of postoperative management do generally the same practice for myself as you all do there. So this can be performed safely as an outpatient. Don't have to routinely perform a contrast study postoperatively. These patients get a modified diet where they progress from basically. Pureed textures to solids over the course of about a week or so, we, we do routinely place these patients on a daily PPI due to the very high incidence of postoperative reflux. And there's some thought that patients with achalasia may have some impaired sensory function, and so they're at risk of this kind of silent, so to speak, esophagitis. So one option is I think this is what they do at, at endeavor North Shore, is to basically perform an EGD and Bravo after a year or so to see if the patients need to continue on A PPI or can, can just come off. And in a recent study presented at Sage is the use of this protocol reduced the rate of non-routine EGS and dilations.[00:10:00] And then finally, I think it is important for anybody who takes care of Alaia patients to be aware of is that even after treatment, these patients are at risk actually for esophageal squamous carcinoma. And so while there aren't strict guidelines for it, they should probably have an endoscopic screening every about five years or so. So some final thoughts on poem. Some of this actually happened to me and it's alarming and worth mentioning, I think, but the, I think it's because the esophagus has no cirr. Rosa and CO2 is very soluble. You can actually get abdominal insufflation while doing the poem. The gas will leak through the esophageal tissues across the peritoneum and it. You know, accumulate in the lowest pressure space, which is the, the peritoneum. But you can actually get somebody into abdominal compartment syndrome doing that. I was doing a procedure supervised by my glorious mentor, Dr. Yuki, and we failed to notice that the patient's belly was getting bigger as I was struggling to do the palm. And the patient actually started losing her vital signs and we had to stick a needle in her belly and vent the gas very quickly, and she came right back. So it is. Practice. You know, we teach [00:11:00] this, I wasn't doing it at the time, I always do now, but check the belly during the poem. Make sure you're not collecting gas in that space and have a needle or something ready to decompress if you need to. There are some insufflators that can have lower pressures and it's much less likely to happen with that, but the ones we have in the OR are just on. Its a certain setting, and I think the pressure's a little too high. Final thing I was gonna mention, we talked about the circular fibers, which is really what you, you wanna hug and do your myotomy on those longitudinal fibers are sitting right behind the circular fibers and they can split very easily. So there are multiple occasions I'm looking into the mediastinum through the longitudinal fibers, but it's actually not a problem. Once you desufflate, those will heal. And again, that's why we have that mucosal tunnel to avoid a leak after that procedure. Yeah, that's great, Mason. I, and I agree, and I also wanna emphasize that the first time you encounter a bleeding during a poem it can be challenging. And I think it's worthwhile to know that you're, you're working in very limited space and you need to control it. [00:12:00] And the best way is to avoid it to begin with. So if you see vessels, just make sure you're cauterize them well. But if you do encounter bleeding you know, I think it's important to know that you're gonna switch to irrigation and you're gonna try to find the source through just trying to irrigate out the blood so that you can visualize where the bleeding is coming from to try to get it. I think that's an important point too, for people trying to learn this. Yeah, absolutely. I wanna add as well, I mean. I've got a couple bad bleeds with a poem, and you just remember your basic surgical principles, right? First you apply compression, so if it's too bloody to really see where it's coming from, even though the irrigation, you just push the scope into where the bleed is coming from. Wait a couple minutes and then back up and it'll have slowed down a little. But I, I use that whenever I get a bad bleed and it tends to work pretty well. Don't panic, just push. Now, we've officially talked about everything that no one will ever write about in a paper when it comes to poem. This is the Honesty Podcast. Excellent. I think the principles of the poem technique, you know, are very much the [00:13:00] same at each part of the GI tract that we're gonna be talking about. But I think it is worth mentioning, you know, talking about the indications, workup and outcomes for gastro poem or g poem. So Dr. McCormick, do you mind talking to us a little bit about that? Yeah, let's do it. So thanks for having me. So g om this is a treatment option for certain patients with gastroparesis. It stands for gastric per oral endoscopic myotomy, also known as gpop. Per oral, al Myotomy gastroparesis is a syndrome of constellation of symptoms including abdominal pain, nausea, vomiting, early satiety, bloating. It's usually due to either impair maity of the stomach or relaxation of this Polaris or combination of both. It has a wide array of different etiologies. The most common though, being idiopathic, but I think it's important to remember that because these [00:14:00] patients, you have to do a very thorough history and chart review to sort of tease out what components might be contributing to. They're delayed gastric emptying 'cause some of these can be either reversed or ameliorated. So if they're diabetic, for example with diabetic neuropathy, you can make sure that they have good glycemic control if there aren't certain medications that are contributing to delayed gastric emptying including such as recreational with marijuana opioids, benzodiazepines. The newer GLP one analogs you wanna make sure that they're off dose to see if they have symptom improvement. And then for diagnostic testing, the gold standard is still the gastric empty study, which is a nuclear medicine scan. But I think it's also important that you either perform or they have had performed an upper endoscopy just to rule out any intraluminal lesions that might be contributing to. [00:15:00] Oftentimes these patients will come to the Cerner's office having already done a lot of this workup. First line therapy for these patients in this condition is medical treatment. So they usually already have tried or are on medication trying to help them. First line, the most common one being reg gland. So a lot of times they already come with sort of the workup and the diagnosis and the treatments in effect. Sent to the surgeon's office for alternative treatment. So GPO is essentially like a poem, but it's further dist in, in gastrointestinal tracts. You create a mucus sodomy in a semi mucosal tunnel and divided Polaris to help with gastric empty. Typically in our practice, we do it for patients with either idiopathic or diabetic or iatrogenic injury. So a previous forge surgery where. The vagal innervation has been damaged and they have to have pretty severe delayed gastric emptying. So, it's [00:16:00] defined as greater than 20% retention of food at a four hour after consumption. So, for these patients, we can offer g ppor. It has a equivalent outcome in terms of gastric emptying as compared to traditional surgery For this. So laparoscopic pal myotomy uroplasty but it has a shorter length of stay, shorter quicker recovery less healthcare associated costs. So there's definitely some benefits with this third space endoscopy procedure for this. If the patient has a borderline workup on their gastric emptying and they don't meet those criteria I just mentioned. We can trial an injection of botulinum toxin endoscopically, typically a hundred or 200 units divided into four segments around the Polaris within two centimeters. And then we can see if that relaxes the Polaris enough that they have symptom improvement. [00:17:00] If they do, then we will offer them a gpo. Other possible treatment options include gastric stimulators. And then surgery in our review of our patients almost two thirds of them report complete symptom improvement following g om and nearly all patients report some form of symptom improvement. Excellent. And I think it, it should be noted that, you know, abnormal would be defined as greater than 10% retention at four hours. However in that kind of, you know, 10 to 20% range sometimes we trial, you know, other things like medications obviously before we turn to performing a pop or a G problem. But Dr. Pepper, do you mind kind of touching on technique? Briefly. Absolutely. So, you know, principles are the same as the esophageal poem. You still want a mucosal tunnel and then you perform your myotomy and close the mucosal or the mucus otomy. I was taught to start the mucus otomy on the greater curve [00:18:00] and. I guess it was maybe last year I was at, I was faculty on the Sage's Fellows flexible Endoscopy course and I learned how to do the lesser curve approach. So I've been kind of going back and forth now at my hunch or my general approach is if the scope seems to lie nicely, kind of on that lesser curve area where you would start the Myotomy, then it's probably gonna be easy doing it that way. And I do think it's a little bit faster. But if it feels awkward and the scope doesn't stay there nicely, then you're gonna really struggle. And I just go to the greater curve 'cause it tends to be a little bit easier. One thing to keep in mind as you're getting your, kind of choosing your site and you start your myotomy or your mucus otomy if there's a lot of peristalsis in the stomach, it makes it really hard. So you have a millimeter or milligram of glucagon ready and you give the patient that you know that the diabetics tend not to have that kinda overactive gastric motility. But if this is cytogenic from a vagus nerve injury or some other, you know, idiopathic pathology, they may still have pretty aggressive peristalsis. As soon as you, you hit [00:19:00] the stomach with any cautery. But in general, same principle, a greater curve. We tend to do that longitudinal myotomy still at least two, three centimeters on the lesser curve. It seems easier to do a transverse, and then you kind of pull down the edge, and then you're almost looking at the pylorus right there. But again, you're, you can still have these circular fibers and you wanna be running perpendicular to them. As you're following the fibers, you kind of see the, the. The color becomes a little more pale. The character of the muscle changes a little bit, and that's kind of the first sign you're getting onto the pylorus and then all of a sudden the muscle just stops. It's kind of like, it just, there's a cliff where the muscle ends. And that's that, you know, distal portion of the pylorus. So at that point, you put your needle right above the muscle or below the muscle into the submucosal space, depending on your approach, and inject real good. And then you're pushing the mucosa of the pyloric channel away. So you have the duodenal mucosa on the distal side, gastric mucosa on the proximal. You don't wanna put a hole in that, right in the Pric channel. Once [00:20:00] you have a good buffer there, you're, I take all that, those you know, fluffy submucosal fibers off the edge of the muscle, so I can see it very clearly. And then you kind of start chipping away at it using the T knife. So hook the edge of it, pull towards you a little bit, and activate the current, and you keep chipping away at it until you've, you're satisfied. You've gotta complete myotomy. Just like the esophageal poem, there is some data suggesting you can kind of tell when your myotomy may be adequate using endo flip. Endof flip's really hard to get through the pylorus. You usually gotta snare it and kind of drive it in there and try to wiggle the scope back without pulling the, the balloon out. And ho honestly, I think the, if the scope passes through the pori with no hangup, you know, it is kind of glides in and out. Even with the caps still on, I'm satisfied. I have a adequate myotomy, so I kind of use that as my, my guide. Now, if I feel something getting hung up, I go in and take another look and there's usually a couple other fibers that I missed that I can get the. Yeah, again, on this adequacy of the myotomy early in my experience, I did have to [00:21:00] take one or two patients back and repeat the myotomy in a different place because we didn't get the symptomatic effect we were looking for. And the pylori still looked kind of tight on endoscopy. There are some people who will do two myotomy in one go. So you kind of cut the muscle in two places or you do a wide myotomy and just really take out a good chunk of the muscle as you go. I'm kind of doing the wide myotomy while I'll take a couple, you know, clips of the muscle on one side, then I turn over a little bit and take it on the other side. So I end up with a really good complete myotomy. And then the same deal, you know, the closure can be a little more difficult because the mucosa and the stomach's thicker than the esophagus. So having some extra wide clips is useful. You know, a couple different companies make these ultra wide clips and that can be helpful. Trying to get the mucosa well, approximated. I think, you know, to turn to the last poem that we're gonna talk about I'll start it off with Akers Diverticulum. And so this is a, a so-called Z poem procedure. To start though, Akers Diverticulum is a, it's a false diverticulum that occurs in the cervical esophagus and it's due to failure to relaxation of the [00:22:00] cricopharyngeal muscle. So in order to treat that, you have to incise the muscle so that it can relax and help with patient symptoms. So how do patients present in clinic? Typically with things such as dysphagia difficulty swallowing localized in the cervical esophagus. Also, things like aspiration, forcedness pneumonias a lot of time are frequent and weight loss. So many of these patients have seen speech therapy and been worked out by an ET or a pulmonologist prior to presentation. It's not uncommon for us to see patients who have been hospitalized frequently with you know, aspiration pneumonias that are thought to be related to this. So workup consists of an esophagus and or endoscopy to localize and describe how big the lesion is. And then in a recent publication actually by our group so we looked at the efficacy of endoscopically suturing larger diverticula. So diverticula are greater than four centimeters. In addition to performing the myotomy. The thought here is that if you close off that space using [00:23:00] endoscopic suturing then patients will have better clinical outcomes. In particular in the, in the larger diverticula. In an international study using ZPOM which our group contributed to, there is a 92% clinical success rate. With clinical success being defined as complete or near complete relief of dysphagia without reintervention. These are very satisfying cases to perform just because in, in terms of the degree of anatomy that you're performing, it's a much smaller space. And these patients usually do, you know quite well in that study that I was referring to, there was an adverse rate of 6.7% with four perforations in 75. Patient. Obviously when you're closing the mucus sodomy, just like, in the other types of poem, it's important to make sure that you have good apposition of the tissue which is mostly done with clips in order to prevent a leak. Trev do you wanna touch on kind of technique for a Z poem? Yeah, absolutely. I was just gonna say, as an aside, and you were talking about the, the data on placating, the diverticula one other thing that [00:24:00] works. Nicely is doing a sep otomy. I've done that before. That's something that's described out of Europe and it kinda leaves you with a rather alarming hole in the esophagus for a second, but it closes really nicely. It can be a good way to approximate things. And I think that actual, that Plication paper is, is from Chris Roa and he's I just needed his help. Like a month ago. I called him on the phone about, with an endo flip troubleshooting question. He's great. So excited that that's gonna come out. I would say for, for ZPO and how we, how we do this, first of all, I think most of us would agree that this is an extremely rewarding case to do because it's relatively quick in the operating room and patients get so much immediate relief. Plus if you're kind of more familiar with third space dissection, it's relatively straightforward compared to the other myotomy in certain ways. So, as with other procedures we do this with general anesthesia, the ET tube taped away from the gastroscope insertion. And typically use that RFA cap to to assist with visualization and kind of manipulating the tissue. Typically at the beginning you can obtain your endoscopic [00:25:00] measurements of the diverticulum ensure kind of correct orientation. I suppose there's no correct way to do this, so to speak, but usually conventionally we use the true lumen on the right side. Some people use an NG tube to kinda. Even stent this open. And then the diverticulum itself on the left. If you use Endof flip in your practice you would do your pre myotomy endo flip at this time as well. And it started the procedure itself. We use use an eye knife. So as opposed to a t knife for the other procedures. You don't have to hook the muscle like you do in an esophageal or gastric myotomy as much. So you can use a straight knife. Then make a longitudinal mucus otomy on kind of the, the robust part of the muscle right in the center. Careful not to go too anterior or posterior so that you can clip it closed. However, you can be fairly aggressive here compared to the other myotomy procedures because really on the backside of that mucosa is just the muscle that you're gonna be ultimately cutting. So you in, in this procedure, you inject to lift the esophageal and the mucosal, or the, excuse me, the diverticular mucosa away from the muscle. So you effectively create a [00:26:00] tunnel on both sides of the muscle. And then you cut the muscle in a transverse fashion kind of straight down until the Crico pharyngeal kind of tapers out and becomes. Generally fairly evident when you're at the end of your myotomy. And then you can clip it closed in a vertical orientation. If you don't close it adequately, they can leak just like anywhere else, and it can unfortunately leak into the mediastinum. And may be counterintuitive, but this is actually more difficult in smaller diverticula because in larger diverticula there's typically much more space to maneuver and the smaller diverticula can, sometimes you can have very little working room and so. Really, you kind of burn the bridge initially if you make your mucus sodomy too large upfront. When you, if you do use the plication technique, if you have a diverticula, you know, greater than four centimeters, you can basically suture, placate that using a U-shaped pattern much like a endoscopic sleeve. Postoperatively. Similar to other cases, we don't routinely get contrast studies for these patients. They can go home the same day and they get placed on an accelerated esophageal diet that finishes up the different types of poem that we're gonna discuss today. Now, McCormick, [00:27:00] you want to give a, a quick hits of the things that we talked about. So Peral, endoscopic myotomy or poem can be performed in different parts of our gastrointestinal tract, as we've seen, including the esophagus, the stomach, and the al syringes. Poem involves the creation of a submucosal lift, so separate the mucosa from the underlying muscle so that the muscle can be safely incised. Poem is as effective in treating achalasia as Heller myotomy, albeit with a higher rate of reflux afterwards. GPO is one method of treating gastroparesis in patients who are refractory to medical management. Other methods include uroplasty and gastric stimulation, electrical stimulation in patients who have a zenker's. Diverticulum, z OM is an effective method for providing symptom relief. Endoscopic suturing might serve as an effective adjunct in zenker's that are larger than four centimeters. [00:28:00] Awesome. Thank you guys so much for listening to this episode, which is the third episode in our surgical endoscopy series. And make sure to tune in for our next episode in the series, which will be on managing complications in the s skeptically. Make sure to check out our videos that will accompany this episode on the BTK website. And for now this is your BTK surgical endoscopy team from Endeavor Health, reminding you to dominate today. Thanks so much.