My name is Kanika Robinson, I'm a gastroenterologist just down the road at Rush, primarily general GI with an interest in motility. And we're just going to go over some tools of the gastroenterologist, or basically just like a brief introduction to endoscopy. So our objectives, we're going to do some general GI, so we're going to talk about upper endoscopies and colonoscopies, and we'll just go over some of the tools that we use for those. And then briefly we'll talk about some of the tools that we use in the interventional GI suite, like for procedures like ERCPs and endoscopic ultrasounds, or EUSs. So just looking at what we look at for an upper endoscopy, I'm going to try and – you guys are going to have to forgive my technologic deficiencies. So for an upper endoscopy, what we're going to be doing is looking at the upper GI tract. So we look at the esophagus up here, which as we already discussed empties into the stomach, and then the duodenum. So it's the E and the G and the D stand for the esophago-gastro-duodenoscopy. So indications for an upper endoscopy, there are many. Epigastric pain or pain in the upper part of the abdomen is a very common one. Patients who have signs or symptoms that are worrisome for gastroesophageal reflux disease or GERD, also heartburn kind of falls under that umbrella term, dysphagia or difficulty with swallowing or pain with swallowing is a common one. Iron deficiency anemia, as we talked about, is something that always needs to be investigated. Signs of bleeding, so if somebody is having – if they're vomiting blood or if they're passing blood from below or if they're having black stool, which is also a concerning feature, something that we would look at with an upper endoscopy. In our hepatology patients who either have a known history of esophageal varices that we know we need to treat or have a new diagnosis of cirrhosis and we have to go look to see if they have esophageal varices, those are individuals who are often getting EGDs. The bane of the gastroenterologist's existence for our call cases are the foreign body removals and the food impactions, which seem to only come at 3 in the morning, never at 5 p.m., and placement of feeding tubes for patients who are no longer able to tolerate food by mouth. So the first thing that we do is we insert the scope. So this is done under direct visualization. The first thing that we see, and truthfully, we don't spend a ton of time up here, but the first thing that we do see is the upper part of the airway here. So here are the cords, and that's kind of where we know to not go. So we insert the scope down here by the piriformis sinus in the upper esophageal sphincter. So we look at the esophagus, and then when we get to the bottom of the esophagus, the esophagus is about 35 to 40 centimeters in length from the incisors or the teeth. One of the first landmarks that we're going to look at is the Z line or the squamo-columnar junction, also known as the SCJ. And basically what that is is it's this white stuff here is the esophageal mucosa, and then where it gets a little bit pinker is the beginning of the stomach, so gastric mucosa. And so we're seeing this kind of transition zone from the squamous mucosa of the esophagus to the more glandular mucosa of the stomach. The top of the gastric folds right here, it marks the beginning of the stomach, or it also marks the end of the tubular esophagus. This is another picture of the lower esophageal sphincter. This is that Z line that we saw before. This looks pretty regular. So if we were doing a scope here, we would mark that as a regular appearing Z line. Just to the left, we have kind of the schematic of like where the scope is, and then kind of the anatomic area that we're looking at here. So now we move on to the upper stomach. So we look at the J-shaped upper stomach that we were talking about earlier. We have the lesser curvature that is up here, and the greater curvature, which is down at the bottom of the screen. And then this is our endoscopic correlate to look at those two areas. We advance our scope a little bit further, and we go into the body. Still lesser curvature and greater curvature as we kind of move towards the distal part of the stomach. Now we get to the antrum. So the antrum is kind of the most distal part of the stomach. And the important thing in the antrum, there are a couple of important things in the antrum, but the landmark that we're looking for here is the pylorus. So this little hole here marks the end of the stomach. We're going to push our scope through this hole, which is the pylorus, and that's going to be the entryway into the duodenum. So this is our cartoon diagram that's kind of showing the same thing here. So now we've entered the duodenum, and the first part of the duodenum is the duodenal bulb. You can differentiate the duodenal bulb from the stomach by looking at the lining. So I'm just going to try and go back quickly. So you can see the gastric mucosa here. The rugae aren't quite as prominent in the antrum, but the gastric mucosa, I guess it's a little bit hard to appreciate, but it just kind of looks like this. And then you're going to notice the difference when you get to the small intestine. Now you can kind of appreciate those little finger-like projections or the villi, which let you know that you're in small intestine somewhere. For our purposes, we're in the first part, or the duodenal bulb. So we advance our scope a little bit more. We go around the sweep of the duodenum, which is that sharp turn there. And one of the things that we see here is the major papilla, which we just talked about, which is the entryway to the biliary tree. And we still see that we are here with our villus-like projections. And this is usually the extent of the procedure for a standard upper endoscopy. We could go further if we're looking for certain things or if we have a longer scope. But for just a routine upper endoscopy, we usually get to the second portion of the duodenum. And then we start to withdraw the scope. So we come back into the stomach. Oops, you're dizzy. Sorry. So we were over here before. We withdraw our scope back into the stomach. And then what we're going to do is a maneuver called retroflexion, where we actually flip the scope back up on itself to look at the GE junction. So we're actually looking right here, where the esophagus meets the stomach. So we can kind of see the fundus of the stomach, which is the top part of the stomach here, and the GE junction, which is where sometimes there's some pathology that hides there, like some esophageal cancers and things like this. So that's the upper GI tract. Now we'll move on to the colon or the large intestine. So these are just our landmarks that we're going to be looking at here for our colonoscopy that we're going to do now. So colonoscopy is an endoscopic examination of the colon. We can also evaluate the terminal ilium, as we talked about before, which is the very last part of the small intestine that connects to the colon. You do need to prepare for the colonoscopy. So that's the dreaded bowel prep that everyone kind of talks about or, well, I guess that's what people do, complains about it, I don't know. But basically, the preparation involves a full day of a liquid diet and then some sort of formulation of some laxative to kind of get all of the stool out of the colon such that when we go and insert this scopin, we can actually see the lumen and the mucosa. So indications for colonoscopy, far and away, the most common is for colon cancer screening, which is pretty routine. By definition for a screening exam, we're looking at asymptomatic individuals or individuals who are at high risk due to family history or other medical history that puts them at increased risk for colon cancer. Surveillance exams also for colon cancer surveillance for individuals who've had some sort of abnormality or polyp in the past. And then this is just looking at kind of the different types of polyps that we might see on a colonoscopy exam. So small polyps or small adenomas are quite common. Larger adenomas are things that we see as well. This whole pathway is kind of the adenoma to carcinoma pathway. So if we're doing an exam not for screening, so somebody's having some sort of issue, these are the common things that we are ordering a colonoscopy for. Some sort of abdominal discomfort or pain, rectal bleeding definitely needs to be evaluated with a colonoscopy. For iron deficiency anemia, we do do an upper endoscopy and a colonoscopy because that is something that we need to kind of look to see if someone's losing iron from somewhere and it can really happen anywhere in the GI tract. Inflammatory bowel disease, diarrhea of unclear etiology, usually if it's been going on for like six weeks or longer, or some sort of abnormal imaging if someone's had a CT scan or something like this that's showing some abnormal inflammation in the colon. We usually will then like to look at that intraluminally to see what the issue may or may not be. From a therapeutic standpoint, if there is somebody who has a history of polyps that we know we need to go get, they are certainly great candidates for a therapeutic endoscopy. For the bleeding individual, we will do colonoscopies for two reasons. One is for diagnostic purposes to see what is bleeding and also for an attempt at hemostasis or to stop the bleeding. A colonoscopy is very helpful for an individual who has a volvulus, which basically means a part of the colon is kind of twisted on itself. This usually happens in the sigmoid colon on the left. By inserting a scope through that area, you're able to kind of reduce that area that is twisted and oftentimes able to save somebody from surgical intervention. Also from a decompression standpoint, if there is an ileus or basically a functional obstruction, so things are not moving through the colon the way that they should and the patient's getting very distended and dilated and at increased risk for colonic perforation, inserting a scope to kind of decompress liquid stool and air is very helpful. And then in patients who have some sort of obstruction, usually from malignancy, placing a stent across that obstruction is something that we can do via colonoscopy as well. So now we will go into some of our accessories and tools. So we have forceps, we have snares, we have retrieval devices, we have some injection needles. I guess you guys probably know all of this because most of you I'm sure are involved with developing and selling these tools. So we'll go over some of them. Band ligators are on that list as well. So the biopsy forceps basically function to obtain tissue biopsies. They can also remove very small polyps, usually less than like 5 millimeters or so. They're in a couple of different sizes. So typically we have like the standard biopsies and then the jumbo or large capacity biopsies. And then sometimes you'll see that there's a little bit of a difference with whether there are these spikes on the, I guess the two jaws or whether it's a little bit more smooth. So a snare or a polypectomy snare is a device that's primarily used to remove polyps although sometimes we use it for some other things as well. It's basically like an endoscopic lasso. So I think we go into this on one of the other slides. But basically what you're doing is you have this device here that you're going to insert over a polyp and then once it's snug around the base of the polyp you're able to cut that polyp out of the colon. Our snares come in various shapes and sizes. And there are also different features to snares which can be helpful depending on the type of polyp that you're trying to remove. So some of them are braided. Some of them you can spin around. Some of them are spiral snares and it all just kind of depends on A, the preference of the endoscopist and B, again, the type of lesion that you're working with. So this is a schematic of our endoscopic lasso or snare. Basically what we do is we insert the snare through the device channel of the endoscope and then once it's out there, right here, which you guys will actually have a chance to I think do in our skills lab, we're going to place the snare around the base of the polyp or the stalk there with a pedunculated polyp. Once you have this in good position then you're going to tighten the loop of the snare to get a good kind of purchase around the base of the polyp and then you're able to cut the polyp away from the wall of the colon. And there are two different ways that you can do this depending on the characteristics of your polyp. You can either just kind of take it without any electrocautery, so that's what we call a cold snare polypectomy, or you can use electric currents to kind of to cut the polyp while you are pulling it out with a snare. This is a little video of a hot snare polypectomy. So we see the snare going around the base of the polyp there and then it gets tightened. We tent it away from the mucosa and then you're going to see the burn. There you go. And then... Oh, and it doesn't look all right. And then that's the defect that you'll see after a polypectomy. So retrieval baskets and or nets are very helpful for removing large objects. So on the scope, there's the device channel. There's also an air and water channel where we're able to kind of irrigate the colon or whichever lumen that we're kind of working with. And there's also a suction channel, which we can use when we're trying to clean things up so that we can see better. Or if we're trying to retrieve something. So small polyps are very easy to retrieve through the suction channel, and then they kind of get collected in like a little trap so that they don't go into the big suction canister that's destined for waste. But things that are a little bit bigger than that or things that need to be sent out to pathology or things that are foreign bodies and are not supposed to be in the GI tract often will need some sort of retrieval device. So that's kind of where these baskets and nets come in. So they look like this. They get inserted through the device channel. They're very helpful for the retrieval of large polyps. So most of those polyps that we just looked at on our movie there for the hot snare polypectomies are too big to fit through the suction channel and into the trap that's kind of attached to the suction channel there. And what we usually want to do, especially with these larger polyps, is we want to get them to pathology as intact as possible. So we don't want to start cutting things up. So using a retrieval device like this allows you to kind of use this net. You kind of, it's almost like a fishing net, I guess. You kind of put your polyp or whatever the object that you're trying to retrieve is, and then you can kind of cinch it up, and then you can kind of pull the whole scope out. So we use that a lot for food impactions. We use that a lot for foreign body cases as well. So this is a polypectomy. So we've got this polyp that is too large to, oh, I thought it was too large. Apparently it was fine. So this probably wouldn't fit through our suction device. So what you can do is you can, there we go. So we have a net that we can kind of go lay over the polyp, and then we kind of cinch it up so it stays in there, and then we kind of pull the whole thing, not kind of, we pull the whole thing out together. So injection needles serve many different purposes. Endoscopically, we can inject medication, we can inject dye, or we can inject saline all into the submucosa, and there are a couple of different reasons for which we might need to be injecting things into the colon or the upper GI tract. The needles are usually very small, and they will protrude out from the end of the catheter here. So this is the end of the scope. This white thing here, I'm not sure how well that's projecting, is the catheter. And then you have your needle right here that's projecting off of the end of the catheter. So reasons that we would need to use injection needles. If somebody is bleeding, we can inject epinephrine into some ulcers. We can also inject ethanolamine into esophageal varices. If there is a large polyp or a flat polyp, we can often inject saline or some sort of compound into the submucosa so that we can lift that polyp off of the muscular layer so that we can remove it more safely. Injection needles are used all of the time for endoscopic mucosal resections and for endoscopic submucosal dissections, used very often for POAMs. We also will use injection needles if we need to inject a little bit of dye or a tattoo for an area where there's a polyp that we need to kind of go back to later or if we're marking a mass for the surgeons. Botox comes in handy, especially with a lot of my patients, for injecting into the lower esophageal sphincter for individuals with motility disorders. This is, we're going to look at a polypectomy where we're going to be inject... There's our needle there. We're going to inject either saline or some other compound into the submucosa. You can see how things lift up very nicely. That allows you to better visualize the edges of your polyp and it also allows you to kind of have that area of separation between the polyp and the muscular layer of the colon. That blue that you see is just part of the compound that's being injected. So there are a couple of different options there on the market that will usually have some sort of contrasting color so that you can see a little bit better. So CLIPS, super helpful for treating focal areas of bleeding. Often things that we will, we'll often use a CLIP for bleeding ulcers. If there was a polypectomy or a polyp that was removed and then there was some oozing or bleeding after removal of the polyp, putting a CLIP over the polypectomy site is very helpful or if there's a mucosal defect after a polypectomy, closing that site with CLIPS is something that is also a helpful thing to do or I guess kind of necessary thing to do. For our bleeding patients, if there's a dullifois lesion, which are these kind of lesions that are bleeding without like an obvious ulcer underneath, putting a CLIP over those lesions will usually result in hemostasis or stopping of the bleeding as well. The electrocautery probe is used for also stopping bleeding or stopping bleeding of lesions that are actually bleeding and it works by generating heat by the passage of current through the probe here. You can use direct contact to create a hemostatic bond and stop bleeding. So you're basically kind of like cauterizing and cooking tissue. And similarly, argon plasma coagulation is also one of the thermal therapies that we have that is available to us, also very helpful for bleeding lesions. These are usually more superficial lesions, so not like a big, you know, vessel that you would maybe use the bipolar cautery for, but things like an angio-dysplasia, which are these abnormal blood vessels which have a propensity to bleed, or GAVE, or gastric anterovascular ectasia, which you can see in the stomach in certain populations. Radiation proctitis, which is common in individuals who've had some sort of radiation therapy to the pelvis. Basically what this involves is passage of electric current through a jet of ionized argon gas. And you can actually coagulate a lesion without actually touching the mucosa. And this is the bander. This is used for band ligation. Primarily we use it for the banding of esophageal varices, although it does have a role in endoscopic mucosal resection as well. Basically what you do, and I think we have a cartoon of this after, is you're going to suction the mucosa into this plastic cap here. And what you can see here, or I hope you can see, are these little rubber bands. So there are usually five of these rubber bands, and then you've got this white band here, which lets you know that you have one more, because it's a six-shooter bander. And then you've got your last band here. So you're going to suction whatever mucosa needs to be suctioned, or whichever varix needs to be suctioned, into this cap. And then you are able to use this device here, which is the deployer. You turn that, and it deploys a band over your lesion that is in the cap. So this is our schematic of the banding of esophageal varices. So you have these dilated columns of blood vessels, which are your varices. So you're going to suction up part of the varix into that plastic cap there. And then you can see that this then gets sucked up into here. You deploy your band. So now we have this black rubber band that's at the base of the varix. And what you notice then is that there is going to be nice decompression of this entire column here. So the ERCP, or endoscopic retrograde cholangiopancreatography, sorry, we've moved on to our interventional GI devices now. This is used for endoscopic examination of both the bile ducts and the pancreas. And all of these procedures use fluoro or x-rays. So indications for an ERCP, if there is concern that there is a stone somewhere in the biliary tree, removal of said stones, you need an ERCP to do that, at least endoscopically. Dilation of biliary strictures, placement of stents, again, in the biliary tree, or obtaining biopsies or other samples if there's concern for malignancy. The main difference between, I guess there are several differences between an EGD and an ERCP, but the scope is one of the big ones. So this is our EGD scope, and we've got a couple of different channels here. So we have our device channel, we have the camera, we've got our air and water, and then we have a little light so that we can see. This is a forward viewing, oopsies, sorry. This is a, the EGD scope is a forward viewing scope. The Duodenoscope, or the ERCP scope, is a side viewing scope. And so it has some of the same channels that you'll see on the EGD scope, although it has an elevator device here that also allows you to have an instrument that goes through an instrument channel here, and then you can kind of manipulate this elevator to kind of manipulate the angle of this instrument here so that you can cannulate the bile ducts through the major or minor papilla. This is a schematic of an ERCP, we've already seen the liver and the biliary tree and their relation to the small intestine. Basically as we have our scope up here that's going through the stomach and entering into the first part, the bulb, and the second portion of the duodenum, and then what you're able to do is have your device go through your device channel, because we're using that side viewing scope so that we can access the ampulla, and then you can insert your device through the ampulla here, and then you can access the biliary tree. Over here we have a calandrogram, which is just basically an X-ray representation of the same thing that we're looking at here. Similarly, you can do an ERCP to access the pancreatic ducts, and then this is how that would look, and then this is the same X-ray schematic of what we're looking at on the left. Endoscopic ultrasound, or EUS, combines endoscopy and ultrasound capability. Endoscopic ultrasound is very nice because it can actually distinguish between all the five layers of the GI wall. Very helpful for examination of the bile duct and the pancreas, the upper GI tract, and there are also some use in the rectum as well. So we will often use endoscopic ultrasound for diagnosis and staging of cancers. Esophageal is super common, pancreatic is super common. There's also a role in gastric and rectal cancer staging. Staging tissue samples or fluid samples from tissue and cysts within these same areas. Evaluation of lesions that are submucosal that we can't access with a standard upper endoscopy or colonoscopy. Gallstone disease and then drainage of pancreatic pseudocysts, which are a complication of acute pancreatitis, especially if it's been severe. So the two different scopes that we'll use for an endoscopic ultrasound are a radial scope and a linear scope, and these are demonstrated here. They look a little bit different than the duodenoscope, which we use for the ERCPs, which looks different than the standard forward-viewing scope that we use for an upper endoscopy. This is a schematic of our radial scope and how this will look on the ultrasound pictures or under ultrasonography. This is looking at esophageal cancer here at the G-junction, and then the linear scope, which is particularly helpful for looking at some of these vascular structures here. Okay. I think that's all we've got. Do we have any questions? I think we have a break next if there are no questions. If I am correct. I have a quick question. Oh. Yep. Do you have any experience with the AI-guided colonoscopy devices? And if so, what's that been like? And then how do you see that potentially advancing care in the space? That's a really good question. So in our GI lab, we do use AI detection for our screening colonoscopies. It's helpful. I think it's helpful for our trainees who haven't necessarily trained their eye to kind of notice subtle polyps yet. I think it's helpful for identifying polyps that are in, I wouldn't say in hard-to-see spots, because basically the AI can only see what you see, right? So it's not like it's finding things for me behind some corner or something like that. If I don't show the scope, if it can't see the mucosa, then we're not going to see the polyps. So there is still a role for humans, thankfully. But it's helpful for identifying subtle lesions. It's helpful for when there's a polyp there and you know it's there, and for some reason the scope moved a little bit and you can't find it again, having that little green box becomes a little bit of a lifesaver. I think it's really helpful with differentiating mucosa that looks just a little bit abnormal and you're not sure why. You're trying to see, well, is this an adenoma? Do I need to take this out, or is this something that I can leave? I think having the AI photo detection there is also very helpful. That's primarily the use that we use in our lab. I know that there are some other uses that are being developed, like using heat maps and things like this for identifying barrets. But for us, we're primarily using the polyp detection device, which I think has been helpful in my practice anyway. Any other questions? So I'm glad you brought up the AI visualization, because just from different panels I've watched and journals I've read, it seems like there's a lot of new EMR tools and techniques being introduced, from cold snaring to underwater EMR to we just talked about AI. So I'm just really curious where you kind of see the future of EMR going with all of these new techniques and tools being brought to the field. So truthfully, in my practice anyway, I use AI primarily for polyp detection. So I use it for all of my screening colonoscopies. I don't necessarily use it that much for a therapeutic colonoscopy, where I know that there's something that I'm looking for. If there's an IBD patient or something like this, it's just going to light up the whole thing. So for my general healthy screeners, I use the AI all the time. I don't know if it's quite as helpful, at least not yet, for an endoscopic mucosal resection, which is where we're taking out a known polyp that's usually very large. Usually you don't need the AI to show you that polyp, because it's pretty evident, usually. Or if someone's already seen it, it's been marked with a tattoo, so you kind of know where you need to go. So I think it becomes a little bit less useful in those cases right now. That certainly may change and probably will change in the upcoming, probably, years. Any other questions? Okay. I will no longer stand in the way of your coffee break.

gastroenterologist

upper endoscopy

colonoscopy

GERD

polypectomy

AI-assisted colonoscopy

EMR