So, the last talk in this series right now, I think it's one of the funnest talks, it's sort of one of the fun aspects of why we went to GI, Dr. Diane Snyder from the Mayo Clinic will talk about tools of the gastroenterologist and introduction to endoscopy. Hello, hi everyone, as Dr. Yoon said, I'm Diana Snyder, I'm one of the esophageal specialists at Mayo. So now that we've given you an overview of the process and the natural physiology of the GI tract, we'll show you some more images and how we view it using our endoscopic tools. So as Dr. Yoon said, this is kind of the fun part and then you'll get to apply this when you work in the lab later. So in terms of our objectives, first we'll talk about general GI endoscopy, so that's upper endoscopy, colonoscopy, and then the accessories and tools that we use. And then after that, I'll mention a couple items on interventional GI, so that's endoscopic ultrasound as well as endoscopic retrograde cholangiopancreatography, which is a tongue twister, so we say ERCP for short. And I know you already asked about EUS, so there's a couple images for you there. So first upper endoscopy, some of this will be repetitive from what you've already seen so that you get a sense over and over and help you learn it before you do the hands-on. So here in terms of our upper endoscopy, so this is where we're using the camera through the mouth and we're looking through the pharynx into the esophagus, the stomach, and then as we mentioned before, the first part of the small bowel, so that's the duodenum. And we're really just, with the standard upper endoscopy, we're really just seeing the bulb, that first portion, and then the descending part that we talked about, the second part. The scopes that Dr. Ewan had talked about earlier, special balloon scopes that go deeper into that 20 feet of small bowel is not covered by a standard upper endoscopy. In terms of other names that we use, so technically this is an esophagogastroduodenoscopy. We don't say that. We say EGD because that's a lot easier. So just remember EGD or upper endoscopy. We have a lot of different indications for why these are done. Some are based on symptoms that the patient has, abnormal imaging, other interventions that we're trying to do. So here's some of the basic principles. First abdominal pain or discomfort is a really common one that we'll do this for. Gastroesophageal reflux disease, dysphagia, which for those who are less familiar just means difficulty with swallowing, iron deficiency anemia. The reason why we do this in terms of endoscopy is one, we're looking for bleeding if you're losing iron. But also celiac disease that many of you have heard of, of course, has become quite common in the US. So sometimes that will manifest with iron deficiency alone without any symptoms or in addition to other symptoms. So we like to look at the duodenum and biopsy for that. Signs of bleeding, so if someone's vomiting, bright red blood, or if black tarry stools are coming out, that's what we call melana. So when we think about bleeding the GI tract, when it's happening higher up in the esophagus, stomach, or first portions of the small bowel, those blood cells are getting digested in the many feet of the GI pipe system. So by the time it comes out, it's not going to look like red blood. It's going to look like black tarry digested blood. We also look for abnormal blood vessels in the esophagus. That's what varices are. Just like you've seen varicose veins that people have on their legs, it's the same thing that happens in the esophagus, mainly for our patients that have liver disease. If you have a really scarred off area there, blood flow is going to back up into the wrong places and one of those wrong places is in the bottom of the esophagus. We also take out different items. Unfortunately, a little one sometimes will swallow batteries or even adults will swallow different things that we have to take out or food that gets stuck in the esophagus that we need to remove. And then the last indication here is for placing feeding tubes that can go into the stomach or small bowel. So this is what we initially see. So we're directly visualizing with a camera. One caveat I'll mention here is we work very closely, especially for me as an esophagologist with our ears, nose, and throat doctors. They're the ones that are really in clinic. Some of you may have had these scopes that they do in clinic. They're going while you're awake just with some numbing medicine through the nose. And they're the ones that really want to look at the airway. I like to tell my patients as GI docs, we're doing everything we can to not go in your airway. We're in the pipe system. We're not in the airway. We want to go in the feeding pipe system. So this area that you're seeing here, we're only briefly glancing at this. We're not sticking around in this area. So what you're seeing here is in the back of the throat. So you can see the vocal cords here. And so this is the zone we don't go. And then here is the epiglottis, which is basically protecting the airway. When you're eating, it's going to cover that area so that food's going down the right way. And then down here is the paraform sinus. So you can go in with the scope on either side. And that's where we're diving down into to get into the esophagus. And that first valve that we had already talked about earlier with Dr. Mather, that's the upper esophageal sphincter. That's where we're diving into first to get into the GI tract and doing everything we can to avoid the airway. So once we're in the esophagus, it's essentially the pipe system that you saw. The main landmark that we had already discussed earlier in the first lecture is the gastroesophageal junction. So this is located about 35 to 40 centimeters from the incisors. So you're going to notice that number is a lot longer than what we talked about earlier in terms of the length of the esophagus that's closer to 18 to 25 centimeters. And that's because we're measuring from what we call the incisors, basically the teeth. So there's a lot of distance that's happening here with the mouth and the throat before you actually get in the food pipe. So that's why that number seems longer. In addition, we already talked about the squamo-columnar junction. So we have a lot of different names for where the esophagus meets the stomach. This is a basic overview. I'll tell you, even some GI doctors, we can struggle with finding the exact junction between the stomach and the esophagus because when you think about it, the esophagus, when we're going in, is essentially a flat tube. It's opening up into this cylinder when we're putting carbon dioxide in with the scope. And you'll see that when you practice later. So we're making a flat tube into basically an open pipe system. And it's a moving organ. So depending upon how you put that carbon dioxide in there and how the pipe system is moving as well as how the stomach is moving, this junction can look a little bit different. But essentially, it's this light pink color that you'll see in the esophagus and then the darker orange color in the stomach. And the other names that we have, as Dr. Mather had mentioned earlier, are based on what we're seeing visually versus what the pathologist is seeing under the microscope. So when it's under the microscope, it's called the squamo-columnar junction. And so what I like to tell my patients is think of the esophagus as an extension of your skin. So the skin has that stratified squamous epithelium, those sheets of lining. And the esophagus is the same thing in the inside. That's a normal esophagus here. However, once you get to the stomach, it's those taller cells that we showed you in the first lecture, the columnar epithelium. And then when you get in the small bowel, we have intestinal lining. So there are different conditions that can happen in the esophagus here. You may have heard of some of those like Barrett's esophagus, where basically the esophagus says, hey, I'm no longer a skin cell. I want to look like the intestine cell because there's a bunch of acid in here that came up with reflux that shouldn't be there, and it tries to mutate. However, when it protects itself, it becomes a precancerous condition. So this is what a normal one looks like, but there's a lot of variance to this. Then we get down. Here's another example here of the junction. So you see the scope coming down right at the bottom here where the esophagus meets the stomach. Just another nice view for you to see a crisp lining here between the two organs. And this is what normal looks like. Then we get into the stomach. So a lot of this is repetition from the earlier lectures with real images. You can see what the endoscope is doing. So here, again, we're getting back into the main body portion of the stomach. You can see the lesser curvature that's here is seen up top. And then the greater curvature that's here is seen on the bottom view when we're physically viewing with the scope. And you can see all those rugae and folds that Dr. Mather had talked about earlier. Again, moving a little bit further into the body of the stomach here, you can see those curves once again. And then we're going to be entering into the antrum. So the antrum is that lower part of the stomach. So we got body, antrum, and then we have the pylorus. That's that muscle that's going to open up into the small bowel. Think about the pylorus as similar to that lower sphincter that was talked about in the esophagus. So we have muscles opening the esophagus into the stomach to let food through. This pylorus is opening the stomach into the small bowel to let the food through. So you can see that muscle here. Then we get into the duodenum that was mentioned before. So this is that first portion, which is called the bulb. In this view, it's a little bit harder to see those finger-like projections, the villi and the bulb. They are there. It's just a little bit harder to see in the photo, depending on how you're looking. And then once we get into the second portion, it's a little bit easier to see some of the villi or carpet-looking appearance. And this is the area that was mentioned earlier with Dr. Mishra, where we're looking at the small bowel entering into this lumpy, bumpy area. That's the major papilla. So that's where we showed you on the photos earlier, and there's a couple later, too, of where the common bowel duct enters in there, as well as the pancreas ducts. So that's when I show you an ERCP later, where the duct is going to be sitting to use x-rays to look into those ducts. And then, as briefly mentioned earlier, a really critical part of our practice is looking back with the scope. We always want to retroflex or look backwards on the scope in the stomach, because as you can imagine, looking straight, there's a lot of stuff behind you that you can miss. So we always turn the scope around to look at the top of the stomach. And so what we're looking at is what's called the fundus and the cardio. So the body is that main part of the stomach we were talking about. Up here is the fundus. That's really the area, in addition to the body, that controls accommodation, meaning allowing more food to sit in there for us when we're eating, and also is part of the reflex for burping and belching. But really what we're looking at here is we want to make sure we're not missing any lesions or pathology or abnormal things that can hang out in this space where the stomach meets the esophagus. And so we always need to look back with the scope. So now we'll shift gears, show you some images of what we see during colonoscopy. This is the photo that you saw earlier of what the colon or large bowel looks like. So as we talked about, there's a lot of different segments here. So in terms of what we're doing, we're going in the reverse direction of traffic, right? Poop's coming out and down. We're going up and in. So we're going to start here in your anus, move up to the rectum. Then we're going to head into that region that's windy, the sigmoid S-shape region. Up here, opposite of flow through the descending, across the transverse, down through the ascending, into the end part of the colon, which is the cecum. And that's where it's going to meet a little valve called an ileocecal valve, which is essentially cecal, meaning cecum, end part of the colon, meets ileum, last part of the small bowel. And someone had asked earlier about how often we go in there. So it depends on the indication for the colonoscopy. So a standard colonoscopy, if we're looking for polyps or cancer for screening, we don't have to go into the terminal ileum, but often we will, mainly to maintain that in our practice, because as everyone knows, sometimes it can be a little tricky to get in there when you're going through a valve in the wrong direction, right? So it can be a little tricky to maneuver through there. So we like to make sure we have that in our practice consistently. But indications where we need to get in there is when we're looking for things like inflammatory bowel disease, like Dr. Mishra and Dr. Yoon are specialists in that. So we need to get into that area to look for things like Crohn's disease. We also will go in if we're looking for other reasons for diarrhea, or if we're concerned that there's GI bleeding going on in that area. So different reasons that will pop in through that valve into the small bowel. And then the little guy sitting here, that's the appendix hanging out right there. So here's a colonoscopy scope, the direction going through from the anus up and over, like we talked about. And as I mentioned, this is an easy way to evaluate the terminal ileum, or last portion of the small bowel. As many of you know from personal experience or friends and family, anyone that's had a screening colonoscopy, the best part of the colonoscopy is what? Doing the prep, right? So you guys do all the hard work. We get to do the fun scoping. So when you do the hard work, you're drinking, depending on the volume, sometimes a big guy, they'll go lightly, the big guy, sometimes a smaller amount of liquid or other types of laxatives to clean everything out. Because if it's not clean, we can't see this lining. We just see a bunch of brown in there, right? So it's really important. And it depends on the season too. I mean, during the summer, we'll tell you all how much corn we find in the colon. Because we all talk about fiber, right, and how important it is for our GI tract. However, with fiber, we don't want it the week before the colonoscopy. Inevitably, our patients want to take in fiber at that time. Oh, I'll make my colon look really healthy for my GI doc, right? But that week, when you eat the corn, we'll tell you it's still sitting in there when we go in there, even with the prep, so we can see the little corn in there. So we appreciate the hard work our patients do with the clean-out process. It's as important as the endoscopy itself. So why do we do colonoscopies? Many of these indications you're all familiar with, as I mentioned. The main thing is colorectal cancer screening. You may have heard recently our guidelines change from 50 to 45. There's also patients that will have screening earlier, depending on family history or if they have inflammatory bowel disease or other conditions. In addition, we also use colonoscopy for surveillance. So that just means that we found some kind of pathology, whether it's a polyp or something else. And because of that pathology, then the patient has to get another one in a certain time frame. And here you can see we have an image of what it looks like in terms of polyps that can grow. And these types of polyps that we're showing here, the adenoma, this is the type that is considered a precancerous polyp. We have some that aren't. This is the routine polyp you think about when your family and friends get colonoscopies that are taken out that can produce ultimately an invasive cancer. So our goal is get them out before they become cancer. We of course, though, have other indications for colonoscopies. So it's not just for screening for polyps and cancer. We also do it based on symptoms imaging, similar concept to what I talked about with upper endoscopy. So abdominal pain and discomfort again, rectal bleeding. So this is more when the red blood is coming out, not the black tarry stuff that we talked about that's higher up in the GI tract. This is with red blood. Also anemia, patients losing iron, inflammatory bowel disease, diarrhea, or if we find something else on radiology imaging or other studies that would say, hey, we got to go in and directly visualize and sample an area. We also have therapeutic indications. So different things we do during the colonoscopy. Remove polyps. We'll stop bleeding. That's what's called hemostasis. We will do other procedures where we untwist the ball. So this is something called volvulus. We talked about that windy S-shaped sigmoid. Sometimes that can really get twisted on itself, and we have to go in with the scope and untwist it. In addition, we'll have issues, something called colonic ileus, where the bowel is very large and dilated. Something is preventing it from having the good normal pump action, and we go in and try to suction air out of there and put in tubes to help release that air and support it while it gets moving again. And then also sometimes patients will have physical blockages, either from a cancer or something else or narrowing from inflammatory bowel that sometimes could require other interventions like a stent placed in there to open things up. And we use a lot of different tools here. This is a brief overview of various tools. During the hands-on, you'll have a chance to ask more questions, practice with these, see how these things work. So first one is biopsy forceps, and I'll talk about all of these individually. Polypectomy snares, retrieval baskets and nets, injection needles, clips, electrocautery probes, and band ligators. So this is what the forceps looks like. There's different types, there's different sizes. We have standard, we have jumbo, it depends on what you're taking out. They're all very fun to use. You'll see as GI docs, we love endoscopy, as Dr. Yoon had said, that's really what we're passionate about. So there's different sizes, and you see some of them have different shapes in there too. Some have this pin or spike in there that helps to grab the tissue or stack it. So it just depends on what we're taking out. Sometimes we're using these just to sample the tissue, just a biopsy to try to diagnose some kind of condition. Other times we're taking out really tiny polyps with these. We try to only reserve these for very, very tiny polyps because our goal with taking out polyps is to not leave any polyp behind. So if it's too big, this isn't gonna work and I'll show you what we use for that. So that's what we use a snare for. So a snare, just think of as a lasso. That's really what it is. There's different shapes, different sizes, different thicknesses, different rigidities of it. So in terms of using these, mainly we're taking out polyps but there's different reasons to use them. So here you can see the end of the colonoscope here and then you see the little catheter coming out and then the snare comes out like a lasso. You see what they look like down here and there's the polyp and we're basically putting the lasso over the polyp. And the other thing is besides the shapes and sizes of polyps indicating which one we use, a lot of it's endoscopist preference too. So there's a lot of nuances to this. You'll get to play around with that. Here's another example of what it looks like in terms of removing polyps. So there's different methods that we use. This is a general overview of what that means. So one of the methods here, so this is the type of polyp that we call podunculated which basically just means a mushroom with a stalk. So we take the snare out, put it around the stalk of the mushroom and then remove the polyp. So the snare opens with our technician, closes and then cuts off the polyp at the stalk there. And as mentioned, there's a couple methods. So one is cold. That just means the snare itself is mechanically cutting just like you would cut something with scissors. Whereas hot, we're using different types of electrical current that are cutting in a mixture of coagulating vessels to help with the process of removing the polyp. And those we'll show in the video too. So here's an example here. So this is the polyp that's sitting there and you see the snare coming out. And so the snare is wrapped around the polyp and we're trying to get it down and tighten it there along the stalk. And this is hot snare. So once it's there, we pull it away from the tissue because we don't want the heat to go into the wall of the colon and put a hole in it. And so this is pulling off the polyp. And then here's another example. And so snare's around, then snare's closing. And then we're closing, closing, closing to cut it and pulling it away. See how we're pulling the mushroom away from the wall of the colon so that we don't get a deep burn deep in that wall. And then slowly you're gonna see it come off here with that electrical current. And that's a really nice, what we call a defect. So that's the site after we take it out that looks really good. That's exactly what we want. We don't want a hole through the colon. So we do everything we can to keep that as superficial as possible while making sure all of the polyp is gone. So next we'll talk about baskets and nets. So this is a fun thing. I do like to think of myself as a human plumber, especially as an esophagologist, right? Because a lot of what I'm doing is opening up pipes and taking stuff out. So that's really what it is. So we pick up and remove different objects. So sometimes we'll take out polyps and there's a video of that too. If the polyp is too big to suction it in, there's a little channel that's in our scope that can suction out if we're suctioning water or fluid in the GI tract or different things. But sometimes the polyp is bigger than the channel. So that's when we take a little net, wrap it around the polyp and physically drag it and pull it out of the ball. We also take out food. So that's one of the things that I do quite a bit because we have patients that have narrowings or strictures in their esophagus or they have motility conditions that prevent that lower sphincter from opening, something called achalasia. So food can build up in there. So we use these nets to take that out. In addition, as you know, with eosinophilic esophagitis, food impaction is one of the big presentations for that. So often we'll take food out and then we have to biopsy the esophagus right then and there to make sure we find the EOE. And then foreign bodies. So sometimes patients will swallow different things that we have to take out. And we have to be careful, especially with things, for example, like batteries. Those have to come out right away or they can hurt the lining of the esophagus or the GI tract. Polyps that are too large to suction through the scope. If a large polyp is removed in one piece, we pick up the resected polyp with the snare and drag it behind us. If we have one large piece and multiple small pieces, we suck the small pieces through the channel and then pick up the large one with the snare and drag it a few centimeters behind so we can continue examining. So you saw it. So remember on these endoscopic views, this is 30 times normal life, right? So that polyp looks huge. But in real life, you know, that polyp is probably a centimeter or less. It's really not that big. It's just we magnify our screen so that we can see everything. But when it's that big, we have to use the net to get it out. So next item are injection needles. So there's a lot that we can do with these and I'll show you coming up in the slides. These can be used to inject medications, dyes, sometimes saline. We're doing different things with the submucosa and I'll show you that. There's different types of needles, so different sizes here. Usually they come out from the end of the scope about five millimeters. So here's our endoscope. You can see the little catheter coming out and then the little needle sticking out here and here it is magnified. So initially through that channel that we're talking about where we can put different devices through the scope, we'll put this catheter and stick it out and the needle is inside here and then we ask our nurse or tech to basically push the needle portion out when we're ready to actually inject the solution and then it can go back in right after. So here's different reasons that we use these. So one is for hemostasis. As I mentioned earlier, that's essentially just to stop bleeding. So one thing that we use is epinephrine. So when we have patients, you've heard of different people that come in where they have bleeding ulcers. So they come in, the bleeding ulcer can have a vessel in there that's bleeding. So what we do is initially take the little needle and inject around it with epinephrine that helps to stop the blood flow there and then later I'll show you, then we'll place a little clip that basically closes off the vessel and so between the epinephrine and the clip, that combination of treatments helps to control the bleeding of the ulcer. In addition, we have these other agents. So funky name, but it's called ethanolamine. So there's a few variants of this. But as I mentioned for mainly our liver patients, but other reasons too, they get those dilated varicose veins in the bottom of their esophagus. I'll show you that later. And there's different ways we can treat it sometimes by putting rubber bands around it. And then sometimes those dilated blood vessels will be in the stomach where we may not necessarily put rubber bands around it. So instead we use a little needle, basically glue is really what it is that goes into the varics and that glue forms a scar in there and helps to stop the bleeding. We also use these to help us with taking out polyps. So there's different ways that we do that. Here's a general example in this photo. So here again, here's our scope. There's the little catheter. There's the little needle. So sometimes polyps are not gonna be that little mushroom with the stalk like I showed you. Sometimes they're very flat. They don't have the stalk. And if they're smaller, we can just take them out that way. But sometimes if they're a little bit bigger or very flat, then we need to inject a solution, either a blue dye with saline solution or just saline underneath there that lifts up the little carpeted area so that we can reach it with that lasso snare that I showed you without putting a hole in the deep walls of the colon. So that's what the needle is doing here. You can see that blue solution here that's lifting up and here's the physical polyp. Here's all the normal colon wall here. Here's the polyp. And so that's lifting it up so that we can get the little snare right here without putting a hole through this muscle portion here. There's other fancy techniques that advanced endoscopists do. This one's called endoscopic mucosal resection. That's basically a technique that's used with lifting and using different types of snares to remove multiple types of lesions, but most often polyps, but there's other things that we do for that. In addition, there's a deeper way essentially of doing that. That's what's called endoscopic submucosal dissection. So this can be to remove lesions like polyps or tumors, either benign or cancerous. And so basically they go deeper into the layers under the mucosa into the submucosa to take out lesions that are a little farther down in those layers. Another thing that this is used for is peroral endoscopic myotomy or POAM. So as I mentioned, there are patients that can get motility disorders in the esophagus. So they basically lose the normal peristalsis or pump action of the esophagus, and then they lose the motion of that lower esophageal sphincter. So that trap door doesn't want to open into the stomach. So POAM is a procedure. So traditionally for achalasia, it was treated with surgery where the surgeon goes in and opens the lower sphincter through the skin. However, over the last 10 years or so, an endoscopic treatment was created called POAM, where basically an advanced endoscopist goes in with the same scope I've been talking about through the mouth, but then basically buries a little tunnel into the muscle by using this injection device that lifts up the tissue and helps them bury into those deep muscle layers in the bottom of the esophagus and open them up. And then gravity is our friend. So we open up the trap door muscle and then food gets through with gravity. Another thing we use this for are tattoos. So for example, if we see a colon cancer that we find, we'll want to inject dye near it on a couple sides of the wall so that when the surgeon goes in, they have marks to know which part of the colon or large bowel to take out. Or if we take out a complex polyp that needs close follow-up with another colonoscopy soon, then we'll put a tattoo nearby so the next endoscopist can easily find the area because it'll be scarred off. And sometimes you can see the scar, sometimes it's harder to see. And so the tattoo will allow them to have a landmark, hey, this is the area you really got to pay attention to. And then Botox. So everyone's heard of Botox in the skin. So we do use Botox mainly into the lower esophageal sphincter or the body of the esophagus to help relax it in some of those motility conditions I was talking about. We also will use it in the pylorus, that muscle I showed you at the bottom of the stomach to help it empty into the small bowel. So here's another video. This is showing how we lift up the polyp with that injection that I showed you. And so there's the needle coming out with the catheter. You see that big bubble popping up. So that's the injection going in, in the lower layers there of the colon to lift up the polyp that looks like it's in, the polyp's in the bottom right right now. So you'll see it a little bit better in a second. So there's all the lifting, lifting, lifting, forming that big bubble. So you can see we use quite a bit sometimes depending on the location and size and shape of the polyp. And you can see that the saline's mixed with blue dye there. That helps us to see, to visualize. So now you can see that raised area there, how nicely we can see the borders of the polyp here with the blue around it and the blues underneath too. And you can see that the saline's mixed with blue dye so more lifting, lifting, lifting, lifting, all that blue's getting in there. And so you see how nicely we can find the edge of that polyp because our goal is to not cause a hole in the colon as well as to make sure we get everything. So that's why we need to lift it up. Did you have a question? Yeah, does the blue dye the different tissues differently like the polyp tissue versus just a normal mucosa? As far as would it look different on the camera? It looks pretty similar. Basically we look at it here beforehand. So what you're seeing it here is normal mucosa. It's not really, so it's going into the submucosa. So it's not really gonna be in the polyp itself. Sometimes there's indications to do that in the middle of it, depending on how the polyp's situated. But mainly we're just injecting into the normal tissue next door and underneath to lift it up. And then, I don't know if they have it in here, but once, you saw a little bit earlier when I showed the defect after they took out that polyp, you saw that little circle flat disc. When you inject the blue solution like this, you'll see that circle flat disc where the polyp was removed is blue. And it helps us see a little bit better to make sure we didn't cause a perforation or hole in there. We'll see things like a little target sign where you'll see a little cross in there if we went too far in. So the dye helps us with that. So it's really in the normal tissue that we're using it mainly. So next we'll talk about CLPS. This is something I mentioned earlier that we'll use for ulcers that are bleeding. So there's different types of bleeding that we treat with this. So first, as I mentioned, peptic ulcer disease. So mainly ulcers that are happening in the stomach and the small bowel. And so we inject that epinephrine, shut down a little bit of the blood flow there, and then place the clip on the blood vessel. So two different ways to get that bleeding to stop. We also use them after taking out polyps. So for instance, that polyp that I just showed you in that video, when that one comes out, there's gonna be a larger area there that has the defect or opening after taking it out. So we'll use little clips in a row, almost like a zipper. Boom, boom, boom. Put them in a row to close that area to try to reduce the risk of bleeding afterward. In addition, there's other types of vessels that we'll treat. So dilaphose lesion. Basically, this is a blood vessel that will bleed without an ulcer. So it's a little guy, a little arterial that pops in, out, in, out. It'll bleed really bad, then stop. Sometimes they're really hard to find because there's no ulcer sitting next door. And those, when we do find them, put a little clip on to get them to stop bleeding. And then as I mentioned, closing mucosal defects. So that's, for instance, taking out a big polyp, or I mentioned that POEM procedure where they open up layers with a tunnel and then go into the muscle, and they'll close off that little tunnel that they injected with these clips afterward. There's different sizes. Some rotate, some don't. Just depends on what you're doing. The next item we'll talk about are the electrocautery probes. So these are mainly used for, again, hemostasis, so stopping bleeding. And so there's different techniques for this. I'll show you the main one that we have on the next slide. But essentially, it's heat that's being generated by an electrical current. And so this is cauterizing, or essentially burning tissue to stop bleeding. And this is one of the main ones we use. So it's called argon plasma coagulation, or APC for short. And so this is to treat different types of superficial blood vessels. So one is called angio-dysplasias. These are little, tiny, wavy blood vessels. They almost look like little branches on a tree, little red branches on a tree that we see in the lining of the bowel. We can also see gastric anterovascular actase, or GAVE. So this is when we're in the stomach and we see these big red stripes in there. We call it watermelon stomach. So it looks just like the stripes on a watermelon. They're just red, and we can treat those. And then radiation proctitis. So for our patients that have had prostate cancer, they get radiation. Prostate is next door to the rectum. That's what we mean by proctitis, or inflammation in the rectum. So the rectum is basically an innocent bystander that gets irritated after the radiation. So little blood vessels appear in there and can bleed. So we go in to cauterize those. So what we're doing with this technique that you can see in the picture. So what's really important with APC is it's non-contact. So this is electrical current that's going through this argon gas. So we're not actually putting the probe on the tissue. We're just putting it next door, a couple millimeters away, and that current is flowing through right into it there. So we don't actually touch the tissue. We just get close enough for it to go through that plasma. And as I mentioned earlier, another thing we do is band ligation. So this literally is like little tiny rubber bands, just like you would use at home or at the office. So we have this device you can see here. So this is the end or tip of the endoscopy scope. There's a little plastic catheter tunnel, essentially, that's put physically onto the end of the scope. And it has these layered rubber bands here. So typically there's about six on there so that we can treat different vessels or different polyp lesions. And also what you can see here is, so this is where we're physically holding the scope. So where we have our hands, there's a little attachment that goes on for the rubber band device that has essentially a turning wheel. And so what we do is we activate the system. We turn a little wheel and a rubber band shoots off on the tissue. And I'll show you that in a second. It's pretty fun to do. So essentially what we're doing is we're bringing in, whether it's a blood vessel or tissue, we're bringing it inside this little cap here on the end of the scope. And then we turn the dial and the rubber band shoots around it. And so here you can see it a little bit better. So this is an example of what we use the most for this technique. So this is when we're dealing with those varicose veins or varices in the esophagus. So you can see that you have the vein down here. Remember, we're looking down the pipe system towards the stomach here at the bottom. And so at the bottom of the esophagus, there's a blood vessel here. Here's that little plastic cap at the end of the scope that I just showed you. And so we use the suction button on the scope, put that dilated blood vessel into the little plastic cap, and then we turn the handle and we get a rubber band around it here. So it's basically cutting off the blood flow there. This can be a very dangerous bleed for our patients, particularly with liver disease. They can get very sick with these bleeds. So it's really important for us to basically strangle that little blood vessel with a rubber band. So in the last couple of minutes, I'll talk a little bit about ERCP and EUS. So this is something, as I mentioned, that our advanced endoscopists do. So after three years of GI fellowship, they do an extra year of advanced fellowship to learn how to do these techniques since they're very complicated. And you already had an overview with Dr. Mishra earlier on the anatomy here. So this is a review of that. So essentially with ERCP, we're really looking at two main areas, the bile ducts and then the pancreas and its ducts. And so what we're doing is the scope is going through the stomach into that duodenum that we showed you earlier. And it's a side-viewing scope, and I'll show you a zoomed-in version of that later in a minute where they're looking towards that lump, that little bump that I showed you in the duodenum, and basically putting dye through that area into the system of the bile ducts and pancreas and using x-rays to see that dye. So the scope here, at least, is not physically going in the bile ducts. It's sitting next door in the small bowel, and the x-rays are visualizing the bile ducts. So here you can see a little bit more where the scope has instrumentation that we use that can come out and go in to the bile ducts. So mainly what they're doing here is most commonly taking out stones. So you've all heard of gallstones. Well, gallstones can get stuck in the bile ducts. So that's when we go in with these instruments to get rid of the stones. Also, they can dilate, treat strictures. There's different ways that they treat the bile ducts there. So as I mentioned, stone removal is the big one, dilate stricture. Sometimes they'll put stents in too to help keep things open, and then biopsying. So here, this is the x-rays that I'm talking about. It's called fluoroscopy. So this is the actual endoscopy scope here. So here's the actual scope that you can see under the x-rays. So that's what's sitting in the duodenum in the small bowel. And then they're shooting the dye through. There's a wire here, but they're shooting the dye through into the bile ducts. So you see this whole tree-like area? Those are the bile ducts. You've got the common bile duct moving up into the common hepatic, into all the different little branches in the gallbladder. So they're not actually physically in there other than the instruments. The actual scope is in the small bowel. And this is what it looks like. So this is the standard upper endoscopy scope that we've talked about, where it has different channels in it. So this is where all our instruments go through. When I'm showing you the injection needle, I'm showing you the snare, I'm showing you the forceps. Those are all going through that channel there. There's a light and a camera, and then there's air, carbon dioxide, that we're putting through. Whereas with the ERCP scope, it's a little different, because as you visualize it, we're going through the small bowel and kind of looking to the left there. So the actual camera's on the side of the scope. So it's a special technique just to be able to put that scope through. So again, here's our bile ducts in a little bit more zoomed-in fashion. So under the x-rays, you can see what they're visualizing there. In addition, you can also see the ducts in the pancreas. So remember, the pancreas here is sitting, so here's our small bowel again. The pancreas is sitting here behind, so it's closer to your back, behind the stomach there. And here you can see the pancreatic duct. So that's this little skinny duct that's going through here that you can visualize. And then finally, endoscopic ultrasound that you were asking about earlier. So basically, it's an upper endoscopy-type scope mixed with an ultrasound, because when we put an ultrasound on the outside of your body, sometimes it's hard to see deep organs. So that's why we go into the inside, and we can actually look at organs better using the ultrasound from the inside. And so this is handy, because it looks at all of the layers of the GI tract, the mucosa, the muscularis submucosa, muscularis properis serosa. So we can't see all of that when we're just looking with the camera. We're only looking at the mucosa. And so we can examine the upper GI tract. We can go into the esophagus and stomach. They can also see the bile ducts and pancreas next door to look for cancers or cysts. And then also, this can be used the other direction through the rectum too. And so we use this for different things, so diagnosis of cancer, esophagus, stomach, pancreas, rectum. We also will use it to sample tissue, so they can put actual needles through to sample things in the stomach or pancreas, et cetera. And then look at other lesions, as I mentioned, that are in the deeper muscle layers of the esophagus or stomach that we can't see visually with just the camera. Look for gallstones. And then some patients that have inflammation in the pancreas can develop fluid collections in there. And this ultrasound can guide advanced doctors for going in and draining those collections if they're causing symptoms. And here's an example of two different types of scopes that are used for EOS. So this one is essentially looking in this circular plane here, whereas there's another one called the linear scope, where they're looking over on one side there. So zoomed in to here's the radial scope. So this tends to be used more in the esophagus or in a pipe, right? So we want to look along the whole border of the pipe in a circular fashion to look for cancers or other lesions that can happen in there. So that's why we get this circular view in there with the radial EOS. And then the linear one tends to be used a little bit more in the stomach, where you're trying to visualize a specific side spot and to sample either a tumor or a lymph node or something that's sitting in there that needs to be sampled. So conclusions to this. This was a brief overview. You'll get a good example of this hands-on this afternoon with the sessions. But this was to give us a basic overview of upper endoscopy, colonoscopy, ERCP, and EOS, as well as some of the fun tools that we use that are really a rewarding part of our practice. Any questions? Yeah. Yeah, I had a question. When you were talking about the patients with LES and that sphincter that stays relaxed, I guess two-part. How prevalent is that? And is there a correlation between those patients and having additional inflammation in their body? Or the GI tract specifically? Yeah. So the major motility disorder you're referring to is called achalasia. So we don't know what causes it. Something affects the nerves that control the muscle motion within the esophagus, including that trapdoor at the bottom, the lower esophageal sphincter that you mentioned. So basically, that trapdoor muscle is an opening. So we use different ways. We use deep dilators, that Pohn technique I talked about, or surgery to physically open it up. It can cause inflammation in there. Because if you think about it, you have this pipe where the bottom won't open. So all the food and all the stuff is sitting in there and fermenting. And when that's sitting there, there is an association that it can cause cancer, squamous cell carcinoma. It's rare. Achalasia itself, I see a lot of it because we're a referral center for that. But in general, it's rare. I mean, it's about 1 in 100,000 patients. So it's not a super common condition. I just see it a lot because they come to us. And then cancer, and it's pretty rare too. But we do check for that periodically. In terms of achalasia and its associations with other portions of the GI tract, that's not well understood. And that's mainly because we don't even know what causes achalasia. So we don't cure it. We just try to manage it and let gravity do the rest. There we go. One thing that we didn't really discuss is dilation, which is obviously really key to the disease that we're treating. When it comes to the preference of what type of dilator you guys use, is it based on which disease you're looking at? Or is it cost? What are the key drivers in what you're using? Excellent question too. So we'll talk about that more. I'll give you an overview, but we'll talk about it more in lectures upcoming. So we have two main types of dilators that we use. One are balloons that we inflate that looks just like you would think it would as a balloon. The other type are called bougies. They're basically these long tubes. And so it really depends on what type of narrowing we're treating, where it's located, how long it is, and how narrow it is that determines which type that I use. In addition, some of it is based on the endoscopist's preferences or skillset. So most endoscopists are comfortable with doing balloon dilation. Some may or may not be comfortable with the bougie tube dilators, it just depends. So that really guides us. We'll talk more about that specifically in EOE. In EOE, both are safe to use. With balloon, you're really getting radial forces outward, whereas theoretically with the tube type, you're getting the longitudinal forces and the radial forces both directions. So we want to be able to get enough of that scarring in there open to help our patients, whether it's EOE or something else, swallow, but we don't want to cause a hole or a perforation too deep. So it's this fine balance. So that's why we go very slowly, and sometimes they need multiple endoscopies to get them to where we need them. So basically it comes down to what you're treating, what it looks like, and who the endoscopist is that's doing it. Cost, it depends on what practice you're in. For me, I don't worry about what it costs. So I use what's best for my patient to help them, and I let the powers that be figure out the cost on the back end. As you should. Yeah. Thank you. Yeah. Can you hear me? Yeah. Okay. So going back to the akalasia, I had a physician very recently, actually, say he heard that many EOE diagnoses are actually just mis- or undiagnosed akalasia. Can you tell me, you're making a face, just say the words, whatever you're thinking there. It's a really good question. So there's more we're trying to understand with that, and it's kind of the chicken and the egg. So I think Dr. Gonsalves might have looked at this too, but I know one of the docs, Dr. Speckler, who's in Texas, he's looked at some of this. So basically there's this question of, okay, so do you have a motility issue like akalasia where I told you you're getting stasis? All the stuff that you're eating is just piling up in that esophagus, sitting in there, churning, fermenting, doing all this stuff. So then you get the eosinophils that end up in there because there's inflammation going on. And so is that just akalasia with eosinophils, or then do they actually have EOE after that? And then there's this other concept of, well, you already have EOE, so all those white blood cells or eosinophils cause the allergy reaction in there. And then because the allergy condition's been there for a while, you get scarring in the deeper layers and rigid muscles in there, so then you get a motility disorder. And sometimes it can look like akalasia, sometimes it can look like other motility disorders. We have all different ones. So it's kind of the chicken and the egg, and there's a lot of theories on it. There's some data. They've taken some of the surgical specimens of akalasia patients, because the traditional treatment for akalasia is called a hellermyotomy, where basically the surgeons go in and open up that lower sphincter. And so they've taken some deep tissues from that that they've looked at and seen some of the eosinophils in there. So we don't quite know the exact process of the chicken and the egg. So the short answer is not clear, but we're trying to understand more about that. But they can overlap. Okay. And is there like a differential diagnosis, or is that kind of what you guys are working on to decide between the two, is does the patient's history or symptoms come into play in deciding when that question's up in the air for a physician? Yeah. So, I mean, you know, in terms of EOE, and we'll talk more about this, it's a clinical pathologic diagnosis, right, meaning symptoms, clinic, path, biopsies. So patients with EOE, at least for adults, I should say, are mainly coming in with solid food dysphagia or difficulty with swallowing food, food stuck in their impactions. With motility disorders, it's usually an issue of swallowing solids and liquids. So because you don't have the muscle movement, so both have trouble getting through, rather than just a structural inflammatory process. So we try to tease that out a little bit. But ultimately, we have to use our tools. We use barium x-rays to look at the esophagus and see if there's features of EOE or achalasia. We use endoscopy to directly visualize. We take biopsies. We use motility procedures. So you may see the words esophageal manometry. That's a catheter that goes through the nose into the esophagus and measures the pucker power of those muscles to diagnose achalasia or other motility disorders. And then the newer kid on the block that you'll see is that you've seen even in some of your trials that have been used is endoflip, or functional lumen imaging probe, where we're going in during the endoscopy and putting a catheter in there that's measuring the pucker power of the muscles. So basically, we use all of these tools to try to delineate what process is going on. Good questions. Yeah. To follow up on that, do we know, or is there, how often that maybe an EOE and a motility disorder coexist? Or is that rare, or do we even know? Yeah. So again, there is some data on that. Some of that has come from the Northwestern group, too. We do see some overlap. So there's different types. So we've seen some overlap with achalasia and EOE. We've also seen some overlap more commonly, actually, with what we call ineffective esophageal motility, just because that's more common. So like I said, with the esophagus, even though I love the esophagus, it's kind of a lazy organ. I'll admit that. So when we say ineffective motility, it just means we did one of those motility studies with the catheter, and the pump action is not quite as strong as the average person. But we have gravity on Earth, right? So unless you're going to outer space, you don't need full pump action of the esophagus. Gravity helps us a lot. So that's IAM, or ineffective motility, is what we see the most in association with EOE. Part of that might be related to the EOE direct pathway. Part of that might be because ineffective esophageal motility is associated with acid reflux. Because you have that acid coming up, it stuns the lining, and then it doesn't pump as well. And acid reflux itself overlaps with EOE. So you can see how we have this tangled web of trying to understand which entity or which overlap of several entities is happening. So more and more is being studied in that area. So yeah, that's a good question, too. Do we have time for one more? I have another one, too. Go for it. You go. So really quickly. So we use, you know, it's established that biopsies are a good diagnostic tool for EOE, but there seem to be a lot of static among GIs in terms of, like, where you take the biopsies and how many biopsies you should take, and that's one of the challenging conversations that we do have. You know, why is there so much gray area around that? That's the first part. And the second part is around guidelines, if you have any, like, inside information as to when we're going to be having any kind of guidelines around EOE. Yeah. So I know there's, well, there's guidelines that are in process. I'm not writing the guidelines, but some of my mentors are writing the guidelines right now that'll be coming up for one of our GI societies that they're in process now because they're a little over 10 years old. And then, you know, the most recent guidelines would really be the AGA Joint Task Force from 2020. But ASGE came out with the guidelines as well for endoscopic follow-up, which I thought was super helpful. You know, there's a lot of variation with endoscopists with this, and it's a critical issue you're bringing up, and I don't have a great answer to the solution. A lot of it depends on where you train, who you train with, how you're taught with things, and what education you have. And it's not just elsewhere. It's every institution within the group. There'll be different ways people do things. But really, it's important, two important things to do. One, look for the features of EOE and target those. As you all know, it's a patchy condition. You need to target those features, target the furrow, the ring. We'll show you all that later to get the max eosinophil count. And usually, you should be doing at least six biopsies over two different segments. So we need to work more to get more consistency in the GI practice in the U.S. for that. I think it sounds like we got to wrap up. We're happy to answer all questions in between and breaks. Whenever you have more questions, we're happy to take them. Thank you.

endoscopy

gastroenterology

upper endoscopy

colonoscopy

GI tract

biopsy forceps

ERCP

EUS

hemostasis