Fortunately, I have the best talk of the morning. It's the most interesting stuff that we do. And I would say that if you talk to most gastroenterologists, what got us interested in this field is the ability to do endoscopy and to see inside the body and therapeutically intervene and do things to keep patients out of the operating room. So there's your disclaimer. I'm not going to give you time to read it, but we'll probably see it again later this morning. So we're going to talk about basic procedures first, upper endoscopy, colonoscopy, and some of the tools and accessories that we use through the scope to accomplish therapy and things we want to do. And then the last two procedures we'll look at are some interventional-type things that have already been alluded to this morning, the ERCP, looking at the bile ducts in the pancreas, and endoscopic ultrasound. So starting with upper endoscopy, this is perhaps one of the most basic procedures we do. This is a procedure that we would do to find eosinophilic esophagitis. The scope passes through the esophagus, the stomach, and duodenum. It's also called esophago-gastroduodenoscopy, or EGD. There are many indications for upper endoscopy. It can be abdominal pain, acid reflux, screening for Barrett's esophagus, trouble swallowing, also called dysphagia, anemia due to blood loss, or acute bleeding, patients vomiting on blood or passing a lot of blood from the other end. We screen for esophageal varices, which is due to portal hypertension, which is pressure on that portal vein that Dr. Martin was just showing to you, which can cause varicose veins of the esophagus that can bleed. We do foreign body removals, which we sometimes see with EOE patients, or food impactions, I guess, as opposed to more foreign bodies. And then we can also do feeding tube placement. The way we do this is we start by passing the scope through the mouth. Let's see here, I think I need to point at this. We go through the mouth and post over the tongue. And then right over the tongue, we're going to encounter the vocal cords here. We always try to tell the first-year fellows that is not the place to put the scope. That's called a bronchoscopy. We are going behind the vocal cords down into the upper esophagus, which sits right there. After we get through that, we're going to pass down the muscular tubular esophagus, and we're going to come to what we call the gastroesophageal junction. This is where the esophagus and the stomach come together. I think we've actually seen some pictures of this already. The important landmark here is this Z line. You see it's kind of shaped like a Z, so it's ingeniously called the Z line. This is the transition between the squamous lining of the esophagus, the pink pearly lining, and the columnar mucosa, or the darker pink lining of the stomach. And the top of the gastric folds here mark the actual transition to the stomach. When you have a hiatal hernia, these gastric folds are oftentimes pulled up into the chest. So I think we'll see some pictures of that in a later lecture. Here again is an up-close of that gastroesophageal junction. The scope anatomically is positioned now. It's come through the tubular esophagus. We're sitting right above that junction. As we advance the scope forward, I think we saw this picture earlier, we're anatomically now located in the upper kind of body of the stomach. And the greater curve is inferiorly oriented, and the lesser curve here is superiorly oriented. And as we move through the stomach, that anatomic relationship continues. We're now down into the lower body of the stomach. Again, you see these rugal folds that we talked about earlier. And now we're going to advance further down into what we call the antrum, which terminates in the pylorus. The pylorus is the small little opening at the end of the stomach that kind of regulates emptying of the stomach contents into the small bowel so that everything doesn't dump all at once. The stomach churns the food into smaller particles, and then those small particles in a regulated fashion empty into the small intestine to start the actual process of digestion. When we pass through that pylorus, we enter the duodenal bulb, so named because it's sort of bulbar-shaped here in the first part of the small intestine. And then we make a sharp right turn, and we end up in the second part of the duodenum down here, or D2, as Dr. Carpenter referred to it earlier. You'll note on the sidewall of this second part of the duodenum is the major papilla. That's the opening to the bile duct and the pancreatic ducts that we will cannulate to do ERCP. Then we talked about this a little earlier, the retroflex view. So once we're done looking at the duodenum, the scope comes back into the stomach, and the scope you'll see in the Sim Lab can retroflex 180 degrees and turn back up on itself, which then allows us to get a really nice view of this top of the fundus and the cardia right here, right where the stomach and esophagus come together. It's a beautiful place to see that Z line, and the retroflex position can sometimes see little dots of barrets or other little abnormalities up here. So it's a very important part of completing an upper endoscopy is to retroflex. So moving on into the colon, we've already seen this anatomical diagram. We know that the food leaves the small intestine, the duodenum. It goes through like 20 feet of small bowel, and then it terminates the waste products now terminate in the large intestine, starting with the cecum. The appendix hangs off that cecum. This is in your right lower quadrant of your abdomen. And then the ascending or right side of the colon ascends upward and across. Now the colon comes across the mid-abdomen called the transverse colon. Then it descends down in the descending colon into the S-shaped, so-named sigmoid colon because it's S-shaped, and then down into the rectum and the anus. So when we do colonoscopy, we are retrogradely going through the anus and up through the rectum, the sigmoid, all the way over into the cecum. We can also enter the last part of the small intestine called the ileum. We can see maybe three or four inches of the ileum, more on a really good day, but usually that's about the limit. Now colonoscopy, of course, is not as simple as EGD. EGD patients just come to us with nothing to eat or drink after midnight. There's no real prep involved for that, but for colonoscopy, they need to clean out. So we ask them the day before, they're usually on a liquid diet, and then they start drinking some laxative prep with the goal being that everything is purged out and what's coming out the other end, I tell them it should look like urine with no particles or sediment in it. And that will give us the best view of the mucosa, the lining of the colon, so that we can search for polyps in particular, is the most common reason we're doing this. And any other abnormality will be seen much better if the colon is well-cleansed. So the most common indication for colonoscopy in the United States is screening for colorectal cancer, followed by surveillance. Surveillance means a patient has already had a polyp or something, and now they're coming back at a five-year interval or such to look for new polyps. This is the, we'll see this a little bit later, but this is what we're looking for. They're hoping to find small little polyps early in their growth phase, before they take ten years or so to grow, grow, grow into an invasive carcinoma. Anything up to, here for sure we can remove, oftentimes we can remove this, but when it gets to be an invasive cancer, endoscopically that's much harder to deal with, and frankly here this is going to be a surgical procedure to get that out. So lots of other reasons though for colonoscopy, not just screening and surveillance. We frequently evaluate patients who come in with abdominal pain, rectal bleeding, anemia due to blood loss, iron deficiency, inflammatory bowel diseases like Crohn's disease, ulcerative colitis, lymphocytic colitis, diarrhea, bloody diarrhea, and then sometimes patients come in with an imaging procedure, a CAT scan that was done sometimes for an entirely different reason and something has been seen in the colon that necessitates us go in and take a direct look. There are also therapeutic reasons to do colonoscopies. A common one of course would be a polyp. We have a known polyp that maybe it was too large to be removed by the first person who did the procedure, so they're referring in to have a big polyp removal. We go in and look for bleeding sites, somebody's pouring out blood per rectum, we go in and try to find the site and we can do therapeutic interventions to stop bleeding. There's something called volvulus where the colon literally twists upon itself and the blood vessels become constricted and if it's not un-volvulized or de-twisted, the colon can die from infarction for lack of blood supply, so we can actually go in to usually a very dirty, unprepped colon and go up and find that site of twist and untwist it and make the colon come back so that it can evacuate and decompress the colon. One thing, there's something called Ogilvy's syndrome or colonic pseudo-obstruction where the colon isn't really blocked but it just blows up like a toad, usually in patients who are maybe post-op and laying in bed doing nothing on narcotics, not moving around at all and their colon just gets bigger and bigger and that's another, I like to say, first year fellow procedure because I stand across the room and let them put the scope in and start sucking all the stuff out. It's a very dirty, not fun procedure. For some reason, they always come in at like 5 o'clock on a Friday, but anyway, so that's some of the nastier parts of what we do. So moving on to accessories and tools, the things that we can use through the scope, we're going to look at each one of these and you will get to, again, see all of these in the simulation lab and get your hands on some of these if you want to. First and foremost are biopsy forceps, probably the most common thing we use. These are disposable. They're on a very long catheter with the tip of the catheter having these cups that there is a handle on the upside, outside the scope, that a tech can use to open and close the forceps. These are in the open position and this is directed towards the target tissue. The tech closes the forceps and they yank the tissue away so we get a superficial biopsy of the lining of the intestine. This of course is what is used to obtain tissue to find EOE, so that's where we would be using those in the esophagus. They come in lots of sizes and shapes, some with spikes, some not. It's sort of personal preference and oftentimes related to cost as to which forceps a particular unit is using. There's nothing particularly special otherwise about them. Then we have polypectomy snares. This is like a lasso. It's a smooth, thin wire that comes out of the tip of the catheter. Again, the tech has a handle and we say open and they open up and the snare or the lasso comes out of the tip of the catheter and then we use good technique to sort of maneuver that snare over a polyp or a piece of tissue that we're trying to remove. They also come in lots of different sizes and shapes. The type you pick might depend upon the size of the polyp you're trying to remove or the type of tissue you're trying to grasp. You may need a stiffer snare as opposed to a soft snare. So here's how we do a polypectomy. What we're looking at here is a polyp. This is what we call a pedunculated polyp, meaning it's on a stalk. This stalk is actually normal tissue coming up from the bowel wall, but the polyp itself has grown large enough that it's sort of heavy and it's sort of pulled the tissue away from the bowel wall, hence we get a stalk like this. It's sort of like a grape coming off of a grape stem. So we position this lasso snare across this stalk and we slowly close down on it attempting to get well below the polyp tissue. We want to capture normal tissue down here and then we transect that either with electrocautery or sometimes we do what's called a cold cut, cold snare polypectomy. This is a video. Oh yes, I want to give you time to read this disclaimer. We'll see this again. So this is a polyp. This is a pedunculated polyp as you can see. It's on this stalk that we just saw and the snare has already gone around it. That's the snare closing on the stalk and momentarily there's going to be some cautery applied so it's transected through and now they're going to retrieve the tissue for pathology. They're grasping it with the snare, which is not always how we do that, but that's one way of doing it. Here's a polyp that's not quite as pedunculated. It's a little closer to the bowel wall. The snare has gone around it. They're going to tent it out away from the wall and then cut through it. The tenting is to thin out the wall there so that you're not as likely to burn through and through the outer wall of the colon, so less likely to have a through and through burn or perforation. There's what it looks like after the polyp has been removed and that burn site heals within a couple of weeks and you'll never know that it was there. We need to retrieve tissue. Most of the time when we take off a polyp, if it's not that big, we just suction it through the colonoscope and we have a little trap outside the suction that gets the tissue and then we just take the tissue out and put it in formalin. Sometimes we've removed a lot of tissue, a big polyp, and we can't suck it through the scope so we need a retrieval method and we use a net usually. We also use nets and baskets to retrieve foreign bodies, so a kid or a crazy adult has swallowed a penny or maybe an older person has swallowed their dentures. These are the kind of things we might use to retrieve them. We retrieve all sorts of things. I can't even begin to tell you some crazy things. That will be maybe for cocktail hour tonight we can talk about that. This is an example of using a net. In case you didn't get to read it, maybe you're down to the third line, do not copy or distribute. This is a net. We didn't get to see the beginning of this, but the net has been put around the polyp and it's being pulled out. Here they're going to show it to you again, I believe. There's a polyp that's been removed. That polyp was suctioned through the trap. This polyp is being retrieved with a snare, similar to what we saw in the first video. Here's the net being pushed out. You see multiple pieces of polyp there, so we're going to trap those pieces in that net Then we'll have to bring the whole scope out to get that out and then put the scope back in and resume the procedure. Then we have injection needles. These are used to inject medication or dye or things that we want to use to lift the tissue away from the bowel wall in order to maybe remove it. They're little tiny needles, 25, 22 gays. They're about a quarter of an inch long. Again, they're on a long catheter and the tech has a handle and we will tell them needle out and they'll push the needle out and needle in. The needle retracts to not scratch or damage tissue until you're ready for it to be out. The common indications for this would be bleeding. Maybe we have a bleeding spurting artery and we have a blood bath we can't see very well. We might inject epinephrine into that to cause vasoconstriction and the bleeding will either slow or stop and then we can go back and target that site with a more definitive method to stop bleeding like a cautery probe. We sometimes inject sclerosing agents into those varices I mentioned earlier that can occur in patients with liver disease and portal hypertension. Probably more commonly, we use it to lift lesions in order to facilitate removal of a flat polyp. So here in this diagram, you see a flat polyp that is being injected with some fluid. This particular fluid has a little blue dye in it, which we really like because it not only outlines the edges of the polyp, but when you remove the polyp, it shows the submucosa underneath so you can get a better feel of how deeply you've gone and whether you've damaged tissue deeper than you really wish to damage. So this is a flat polyp that now we're going to be able to put a snare around much more easily. You can imagine if it's really flat, you put that snare out, it just slips over the top and you can't get it. So lifting is a very, very important part of good polypectomy. So we do things called, bigger polypectomies are called endoscopic mucosal resection or EMR, and sometimes even bigger and deeper polypectomies are called endoscopic submucosal dissection, ESD. That's a very sophisticated procedure that very few people are highly trained to do. It requires a lot of training and skill. There's also something called POEM, peroral endoscopic myotomy, something where we do through the scope to cut that lower esophageal sphincter open in patients who have something called achalasia. Their disease is that their sphincter doesn't open properly and it's too tight so they can't swallow. So we can cut that open and facilitate passage of food through the esophagus. Another more common thing we do is tattoo lesions. So we take India ink, which I think is the kind of ink that they use to do tattoos, but we use black, and we go into a site that we want to mark permanently so we can find it again in the future. So that might be a big polyp that we've removed in the middle of the colon, and we want to put a mark adjacent to it so when I come back six months from now to be sure I've fully removed it, I can go exactly to that site and know that I'm in the right spot. Tattoos are also nice if you've got a lesion that needs to be surgically removed, but maybe it's not big enough to where you know the surgeon will go in with the laparoscope and immediately see it. So we can tattoo spots around the lesion, and those tattoo marks can be seen extra-luminally. While they're looking inside the peritoneal cavity, they'll see those black marks on the outside of the bowel wall, and that'll take them right to the target area for resection. We can also inject Botox, which is another thing that we might do for achalasia with that tight sphincter. There are some people who aren't really fit for surgery or the POEM procedure, and we might inject Botox to relax the muscle just like you would on your face or cosmetically we're relaxing the muscle to decrease wrinkles, we're opening, relaxing the muscle to open it up. We also sometimes do that at the pylorus, that opening at the end of the stomach can sometimes be spastic and cause problems, so we can inject Botox into that and open it up and facilitate drainage. So this is a nice video showing a lift. You can read that again. Be sure you got it. There'll be a test over that later. Okay, so here's the catheter. The needle is going to come out, and what you're seeing is a polyp on a stalk. So this is the big polyp. This is the stalk. The stalk looks like it's got polyp tissue growing down it, so it's not a clean stalk. So it's very important that we get right to the very base of that polyp to resect all the tissue. Hence, they're injecting it to lift it away from the bowel wall. So he's injecting with some solution that has some blue dye in it. It's very faint right now, but you'll see it better in a moment. We're just filling up the submucosa with fluid, fluid, fluid, and it's pushing that polyp tissue away from the bowel wall to make it easier, you'll see in a moment, easier to grasp with the snare. So okay, see, this has got polyp tissue all the way down to the base, so we need to burn deeply below that, and in order to not burn through the whole bowel wall, we're lifting it away from the bowel wall so we can safely get a snare around it. There's the blue dye now, you can see, and it really puts a nice demarcation between polyp tissue and normal tissue. All right, moving on to hemoclips. Clips are something that we can use like staples, like a surgeon uses a staple to close something, we can use them to stop bleeding or to close defects. Maybe we've removed a very large polyp and we have a big open area and we want to close it to prevent bleeding or put a clip on a big vessel that we see there to prevent bleeding later. Sometimes we actually cause perforations in a therapeutic procedure, so we can use these clips to close a perforation as well and keep the patient out of the operating room. Now we have electrocautery probes, so one of the common reasons we do urgent procedures is for GI bleeding. A lot of times ulcers or there's other little things, arteries that spurt out of different areas that we can treat. So this is a cautery probe, it's called a bipolar or multipolar probe. We also call it the gold probe because it's covered with a spiral tip of gold on the end. And what we do is push that up against the lesion, push it hard up against the lesion to coapt the vessel together and then we apply the foot pedal, which sends heat and cautery into the lesion and it seals the wall of the vessel together and stops bleeding. This is another type of cautery, I guess it's really not cautery exactly, it's coagulation. This is called an argon plasma coagulator. This is like a blowtorch, so it's a non-contact mode of treating lesions or stopping bleeding. So we position it right above the lesion and then we step on a foot pedal and a stream of argon gas comes out the tip of the catheter that's ignited by a spark and it turns into this blowtorch. It's very commonly used for superficial bleeding lesions like what we call angiotisplasias, little red spots where some people get radiation damage from radiation in the rectum for prostate cancer and it can cause constant bleeding. So we can go in and ablate those superficial vascular changes with this argon plasma coagulator. Then we have rubber band ligation. This is adapted, if you will, from the rubber band ligator that's been used for maybe 100 years to ligate hemorrhoids. Maybe you've heard of rubber band ligation of hemorrhoids. Well, we have big juicy veins sometimes in the esophagus that can bleed, which are similar to hemorrhoids. They're big, juicy, swollen veins. In the esophagus, they're called varices. I alluded to those earlier. They tend to happen in people who have liver disease or obstruction of their portal vein and they become very swollen in the lining of the esophagus and can cause massive bleeding, torrential bleeding, in fact, sometimes. So we have ways to treat them. For years, we injected them with sclerotherapy agents so we sclerosed the inside of the vein, but that caused a lot of tissue damage. A guy named Greg Van Stigman, he's a surgeon from Colorado, who had been doing banding of hemorrhoids, thought, why don't I put this on the tip of an endoscope, a long flexible endoscope, and maybe we can band varices. I was actually involved in the initial trial before this was FDA approved. We used single bands loaded one at a time, but now we have devices that have eight bands or so on the tip of one little cup that comes out from the end of the scope so we can release multiple bands with one pass of the scope. So you see here, the little black things, they're just like rubber bands you used on your braces, one stacked on top of the other and there's a cap on the end that we suck the tissue into and then we trip a trigger wire that pops the first rubber band off that strangulates the tissue. And this is what we use to trigger the release of the band. This is on the outside of the scope that we have our hands on. So this is what schematically that looks like. The cap and the scope are here in the esophagus. These orange things are the varices we've positioned right on top. We're going to use very strong suction to pull that vein up into that cap and then we're going to release the band and now we have this strangulated vein that no longer has blood flow going through it. And in a week or two, that's going to fall off and leave a shallow ulcer and then heal and then we come back every so often and keep treating. So we put however many number of bands are needed in one session, usually more in the beginning and then we go every eight weeks or so until they're obliterated. Okay, I'm going to switch over now to some of our two more interventional procedures. Doing ERCP and EUS, both of these procedures take an extra year of training and your fellowship to learn how to do. So most trainees and GI fellows go through three years of endoscopic training and such to learn how to do all these basic things and more than what I just talked about, but we learn a lot. And then if you want to do interventional endoscopy, you have to do an extra year of training so that's four years now after you've finished your residency in internal medicine in order to be able to do these. So ERCP allows us to examine the bile duct and the pancreas duct and it uses x-rays to take photographs of those ducts once we inject them with dye. So what we have here is the scope is passed into the duodenum and we have the major ampulla or major papilla. I mentioned that earlier and I think we've seen it in some of the other slides before. It's like a little nipple sticking out of the second portion of the duodenum or D2. The scope here is positioned in front of it and a catheter is put out into a tiny little pinhole opening. It requires a lot of skill to successfully get that pinhole cannulated and then the catheter is up now inside the bile duct. This is the pancreas duct which we also cannulate separately and then dye is usually pushed up into the duct retrogradely, hence retrograde cholangiopancreatography. And then we take x-rays and here you see there's a stone sitting in this bile duct which is one of the major indications for doing ERCP to remove stones. So we can cut this little papilla open and reach up inside with a balloon above that stone and we can sweep it out and clear the bile duct. This is what a cholangiogram looks like, the scope, the side view coming out, the cannula going into the papilla and then retrogradely the dye now is in the common bile duct, the left hepatic, the right hepatic and all of those intrahepatic ducts that Dr. Martin pointed out earlier, sort of like arborization like a tree, the tree trunk and the limbs coming out at the top. The scope now to do ERCP, as you think about it, I said we're looking at the papilla which is on the side wall of the duodenum. So if you're down there with a forward viewing scope like a regular upper scope, we look right out the end, it can be very difficult. Sometimes you just don't see the papilla at all or other times you may see it but you cannot orient on it to cannulate it or to do therapy. Hence we have an ERCP scope which is a side viewer. So you see the visualization optics and the working channel are coming out at the side of the scope at a 90 degree angle compared to the regular scope. And then we have a lifter inside the scope that allows us to fine tune, manipulate the catheter that's coming out the tip. So again, here's just a schematic of the bile duct being cannulated with the side viewing scope and then the resultant cholangiogram. And this is a pancreatogram, so the catheter here has been now repositioned slightly differently to go into the pancreas and we can take a nice picture here of the pancreas. This is something we would use to look for pancreatic tumors, bile duct tumors, removed stones, stent strictures from tumors. We can put plastic stents or metal stents up in there to open up and give better drainage to the bile duct in patients who are jaundiced or obstructed. Moving on to EUS, endoscopic ultrasound, we've seen I think this same picture maybe earlier. So this combines endoscopy with an ultrasound probe that's on the tip of the scope that allows you to visualize the layers of the bowel wall. So you remember earlier we talked about the five layers of the bowel wall and this is how they're going to look when you put an ultrasound probe down. You see very distinct lining, dark, light, dark again, that's all those different layers of the bowel wall. You can also see, I don't, John is that abnormal or is that just, is that a little tumor or a polyp or is that just a rugal fold or something, I don't know. Looks like mucosa, okay. I don't do EUS so give me a little break on that one. So I do know what it is though so. So it allows us to examine the upper tract like the esophagus, we'll do esophageal lesions to stage tumors. We can look at lesions in the stomach or outside the luminal GI tract which is really what's wonderful about this that you can access things in the pancreas or lymph nodes outside the bowel wall that you couldn't reach any other way. You can use this ultrasound scope to penetrate and put a needle through and get tissue. So again, it's used to stage cancer, it's used to get tissue. We can drain fluid collections like in the pancreas, people who've had pancreatitis sometimes get big fluid collections, sometimes they can get infected or necrotic. They can go in through the stomach wall and cut into that and put stents into the cyst directly but they do that using endoscopic ultrasound under direct vision. This is the two different scopes that are used for this. This is a radial scope, this is the one used for tumor staging and then this is a linear scope which is used for tissue acquisition. Again it kind of looks out the side view and allows you to put that needle out under direct vision, under direct ultrasound vision, the ultrasound's coming out just below the needle. This is what a radial scan looks like. This is, I am told, this is a T1 tumor. I presume we're in the esophagus because it looks like a fairly narrow lumen. So this is the tumor coming out here and you see the layers of the bowel wall here and they become very indistinct here. So the endosynographer is going to tell you that this lesion is at least through the mucosa but it's not penetrating any deeper than that. So it's a wonderful way to stage even more sophisticated and more visual, if you will, than a CAT scan which is what we've used for years to stage tumors. We can get in there and really get a better feel for whether this is a resectable lesion or not. Is it maybe even resectable through the scope as opposed to an operation? And this is how the linear scope works. So here you see, this is a lymph node that is in question. Is it abnormal? Does it have tumor or lymphoma in it or not? It's right next to the aorta. It's behind the stomach, really an impossible area to reach for a surgeon or even sometimes radiologically with a percutaneous needle. So the beauty of this linear scope is that we can position it right in front of the abnormal area and put a needle out there directly through the stomach and catch tissue. So I ended right on time. Thank you. And we'll look at all this stuff in the lab, like I said. Okay.

gastroenterology procedures

upper endoscopy

colonoscopy

ERCP

EUS

endoscopy tools

tumor staging