Okay, so we are moving on now to the procedures that either the general gastroenterologists or the interventional gastroenterologists perform on a day-to-day basis. So the general gastroenterologists, we are performing upper endoscopy, colonoscopy, and I'm going to talk about some of the basic accessories and tools. Of course, there is also another procedure called enteroscopy, which is kind of an extended version of the upper endoscopy that often general gastroenterologists will perform. And then the major ones, the interventional gastroenterologists will perform the procedures called ERCP, that stands for endoscopic retrograde cholangiopancreatography, or EUS, stands for endoscopic ultrasound. So the upper endoscopy includes the endoscopic examination of the upper GI tract, including esophagus, stomach, and part of the duodenum. It's otherwise called esophago-gastro-duodenoscopy, or EGD in short. You can see the picture. Several indications are available for this EGD procedure, including upper abdominal pain or discomfort, gastroesophageal reflux disease, dysphagia or difficulty in swallowing, iron deficiency anemia, signs of bleeding, either you're vomiting blood or having a black stool or melina, presence of esophageal viruses in a cirrhotic patient or other conditions, foreign body removal or food impactions, feeding tube placements, and also sometimes for people with intractable nausea and vomiting. So as you can see, we insert the upper endoscope under direct visualization. We go through the hypopharynx. Let me see if I can point this. Oh, here it is. So we go through the mouth. You can see the hard palate, soft palate. And then over the tongue, we proceed. And this is what you see. We teach the fellows, actually. You can see the epiglottis, the true and false vocal cords, the piriform sinuses on the side. And this is where you go, actually, where the upper esophageal sphincter is, and gently intubate. And then you move down the esophagus, which is a hollow tube. And usually, as you can see, the gastroesophageal junction is located at 35 to 40 centimeters from the incisors. So the upper esophageal sphincter is sometime somewhere around 15 to 18 centimeters. So you can see the nice change in the color. This is more pinkish. And then you start seeing the orange. And this junction is called the squamo-columna junction, or sometimes people refer to that as Z line, Z standing for zigzag, actually. So you can see it is slightly irregular. So esophageal lining, it's usually a stratified squamous epithelium, or the mucosa. It's a stratified squamous epithelium, whereas the stomach, it's a columnar epithelium. And we also sometimes refer the top of the gastric folds. That's another marking for the beginning of the stomach. Most of the time, what you have is the top of the gastric fold will coincide with the columnar mucosa, right at the squamo-columnar junction. Sometimes you have seen a small or large even hadal hernias that happen, where we see the diaphragmatic pinch down below the squamo-columnar junction, or the Z line. I like to refer to that as squamo-columnar junction, and then you see down below the diaphragmatic pinch. And that difference between these two will be the length of the hadal hernia. So this is what you see when you put the upper endoscope into the esophagus. So that's the lower end of the esophagus. You can see the distinct linings of the esophageal mucosa and the gastric mucosa. Then you slowly proceed through the squamo-columnar junction into the stomach. And then in the bottom, you see mostly as the patients are lying down in the left lateral position, you can see the greater curvature here and the lesser curvature on the top. So we go along the greater curvature and have a good look into the body of the stomach moving on. And then finally, we get into the antrum, which is the lower part of the stomach. And you can see the pyloric opening right here. And then through the pylorus, we go into the duodenum bulb. That's the beginning of the duodenum. Duodenum has four parts, as you just recently heard. It's roughly 25 to 30 centimeters long. Actually, the word duodenum came from the Latin word. It stands for 12 fingers. So it's a 12-finger length, actually. So what we examine is up to the second part. We don't go all the way down into the third or the fourth part most of the time when we do upper endoscopy. So we stop somewhere in the half of the second portion of the duodenum. And as you just recently heard, this is the major papilla, or ampulla, where the common bile duct and the main pancreatic duct, they join and they drain both the bile and the pancreatic juice. So they're flowing from this opening. This is controlled by a sphincter called sphincter of OD, and it's draining into the second part of the duodenum. So after doing that exam, we come back into the stomach, and then we do a maneuver called retroflexion. So we go into this area here. This is actually where the body meets the antrum, and that inflection point is called the incisora angularis. And from there, we just do the retroflexion so that we can see the lesser curvature better and also examine the valve. It's called the flap valve, the gastroesophageal flap valve, which basically protects the esophagus from the gastric contents most of the time. And we also look for the hernia, the hadal hernia. So that's the examination of the upper endoscopy. Moving on to the colonoscopy. Obviously, we are examining the colon, which you already saw as different segments, starting from cecum, ascending colon, transverse colon, descending colon, sigmoid, rectum, and anus. We examine the whole thing. And obviously, as part of the colonoscopy, we also go into the terminal ilium and examine a portion of the terminal ilium. So as you can see here, we insert the colonoscope through the rectum. We go to the rectosigmoid, sigmoid, descending splenic flexure, transverse hepatic flexure, ascending colon. And we then examine the cecum in depth. This is the appendicial orifice. You can see this appendix. And this is where the, usually in the picture, it'll show you the ileocecal valve with the opening for the terminal ilium. So I like to examine the whole thing and make sure there are no pathologies. The key thing is, I always mentioned that to have a good screening colonoscopy, you need to have a very, very good bowel prep. That's the most, most important. Without a good clean colon, you cannot have a good screening exam. And I emphasize the point, we are talking about screening colonoscopy, not for diagnostic purpose all the time. So here we prepare patients requiring screening colonoscopy with a liquid diet. And also for me, actually, sometimes it's a clear liquid diet the day before. And also bowel preparation, including certain types of laxative agents. So what are we screening for? So this is very important. As you know, we are screening for these asymptomatic and sometimes also the high-risk individuals. So we have an average risk screening and also high-risk screening, but screening for early growth, right? And the one in the colon, we call it polyp. That's the word we use. And we are looking for small to large polyps in these either average risk or asymptomatic or high-risk individuals. So that's the screening part. And then in the surveillance part, we are periodically examining when we obviously identified the presence of these polyps. Now, the word I use is polyp. I mean, the polyps obviously can be two types, mostly for you all. It's an adenomatous type. We here see the word adenoma, which is basically, by definition, it's a pre-cancer, meaning in the sense there is always early mucosal changes, but not a full-blown advanced cancer that you see. So here is the pathophysiology you see from hyperproliferation of the colonic epithelial cells. You start developing these changes at the tip. That's a small adenoma. So by definition, has we call it low-grade changes. And then the large adenoma, the advanced adenoma, they start having more high-grade dysplasia or high-grade changes. And then you start developing cancer which is localized purely in the mucosa, hasn't gone through into the submucosal area. Then you start developing an invasive cancer. And finally, the cancer start invading not only through the submucosa, but it's going through the muscle layer and into the serosa or the outer lining of the colon. So the goal is that obviously doing the colonoscopy, we are trying to identify people at an early stage and we are screening, but it's also only preventive exam in my opinion. There are no other technologies available right now to remove the polyps without performing colonoscopy. So we do these diagnostic procedures too for abdominal discomfort, rectal bleeding, iron deficiency, anemia, inflammatory bowel disease, diarrhea, and abnormal imaging. And I'm pretty sure later part you'll see some of these disease processes in different parts of the GI tract where some of these procedures are done to evaluate. And we also do a therapeutic procedure as I was mentioning for screening exam. We are basically going and removing polyps and that's the best way of preventing any early development of advanced polyps or cancers. Also, we stop bleeding by localizing the bleeding site and performing hemostasis. I'll come to some of the tools that we use later on. We also correct the twist in the bowel. So we reduce the valvulus and then decompress for a gaseous distension of colon called colonic ileus. And then obviously for malignancy and otherwise we place a stent placement to relieve the obstruction in the colon. So now that brings me to the tools that we use and some other accessories. So we'll go down the list starting from the biopsy forceps, polypectomy, snares. We do have different types of retrieval baskets and nets, injection needles, clips, hemoclips, electrocautery probes and band ligators. This is just a short list. Obviously you know there are more but we can talk about that in a Q&A session later. So forceps, the biopsy forceps over the years evolved. As you can see the main purpose you know it's obtaining mucosal tissue and sometimes we remove small, when I say small, sometimes less than four millimeters polyps in one piece or sometimes in multiple pieces if it is slightly larger. So the key thing is that we do the biopsies because I feel that you know the word tissue is the issue because under a microscope the pathologist can tell us what's exactly the pathology behind. We have various sizes of these biopsy forceps. Usually we use this jumbo or large and then they can have this spike in the center or not. You can see this spike sometimes helps to do multiple bites and then keep the tissue removed in place so that we don't lose the fragment. So then we have the polypectomy snares. You know obviously the purpose is to remove the polyps. It comes in various shapes and sizes. It can be either stiff or non-stiff as you know features and you can see there are different shapes. I mean you know some are oblong type. Sometimes I've seen the trapezoid type. It can be braided, rotatable. It can have spiral or you can see this spiral or barbed features. Different types of snares but the technique is pretty much the same. You pass it over the polyp around the stock or if there is no stock sometimes we create a stock by injecting fluid or even without the stock sometimes some of these we call it sessile polyps. We just go around the polyp and try to be at the base as much as we can. We can also remove some of the normal tissue. It's okay and after we pass it around then you tighten the grip and so push the snare and then do the cutting. Most of the time we are doing nowadays what we call is a cold cut meaning you just cut the stock and remove the polyp and rarely if the stock is too thick mostly for longer pedunculated polyps we call it where we use the electric current which helps to cut the polyp much easier as you can see here. So this is an example of the hot snare polypectomy I think. And now you can see the electricity current passed and then the polyp removed and you can see the base which has that whitish color which is after the electrocoagulation. And of course after removing these polyps which are slightly larger in size we have to if it doesn't come through the channel most of the time not and sometimes what happens if it comes through our biopsy or channel it gets fragmented. I don't like it always so it's better to preserve the whole architecture so we remove with these retrieval baskets especially the larger ones as I said and you can see there are different types of these retrieval baskets or nets call it and not only to remove polyps but it's also helpful for food impaction cases where we remove food and different types of foreign bodies and that list is long. Moving on to polyps that are too large to suction through the scope. If a large polyp is removed in one piece and 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. Okay when we remove the polyp sometimes with the snare we don't close it too tight because you don't want to cut it this you know polyp into pieces but just enough to kind of keep it stable and intact so that we can pull it through the colon and then put it in the formalin jar so for the pathologist to evaluate. Okay moving on now to the next injection needles. So we use for a variety of purposes we can inject medication, we can inject dye or sometimes simple things like saline into the submucosa to lift it up and examine the polyp more carefully. 22 to 25 gauge needles available and it protrudes like five millimeter from the end of the catheter and some of these indications including for hemostasis we inject epinephrine when you have ulcer bleeding to control actually the bleeding per se and especially cutting off the blood supply route around the ulcer. So it's very helpful so you can have a better view some of these injection needle nowadays catheters also comes with the electrocautery probe so you'll see that. Also we do injection of ethanolamine for the varices. It's not very common nowadays as part of the we call it injection sclerotherapy. When I was trained we used to do that and did a lot of studies comparing with the ben ligation but nowadays it's mostly ben ligation rather than this injection technique used. We also use this injection needle for, as I said, creating these submucosal lifts, or kind of a cushion, so which will help us to do polypectomies, used for endoscopic mucosal resection, or EMR, for endoscopic submucosal dissection, or ESD, and then also for oral endoscopic myotomy, POM, whether it's in the esophagus or now, we do it in the stomach, too, for the gastric G-POM, we call it, in the pylorus. We also use the needles for tattooing, so we put this dye called SPART, or India ink, and then we also use it to inject medications like botulinum toxin, or Botox, to relax the smooth muscles. So, that's the, you can see these different types of these injector needles. Now, this is a polyp, you can see that, there's a pretty large one, and injection being done using that injector needle, it just came out, five millimeter out, you can see the submucosal bleb being formed, and that'll help us to lift the polyp, polyp, and also do the polypectomy much better. You can create a big bleb, no issues, and nothing to get so worried about. So, sometimes saline, sometimes different types of dye, mixed with saline, or just dye alone. Now, you can see the one edge of the polyp much better, so obviously, keep going around injecting, so you get a nice demarcation of the abnormal mucosa, and the normal mucosa, it's very, very important, because without that good margin, if you do not remove the polyp well, then there's a high chance of recurrence. So, when I teach the fellows, I always make sure that you get a good, complete resection, and even extra margin, it's fine, of the normal tissue. So, anyway, so that's all done. Moving on now to the hemoclips, so after you do that type of resection, and sometimes that's called endoscopic mucosal resection, you have to put some of these clips to oppose the mucosa, or close the mucosal defects. So, you can see that, here, you can put a bunch of clips, as long as you can close it nicely. It's also used to treat some focal areas of bleeding, like in the case of different types of peptic ulcer diseases, postpolypectomy bleeding, or even Dullafoy's lesion. So, what is a Dullafoy's lesion? It's a caliber persistent vessel, which is exposed on the mucosa, on the lining, it can be anywhere in the GI tract, actually, I've seen it, and can start profusely bleeding, and there is no ulcer base, so let me be very clear, there is no ulcer base, you just have a visible vessel, just bleeding profusely, and it's not easy to stop, and it's also sometimes not easy to identify these lesions, but once you have identified, you can actually treat it, and sometimes, this hemoclip placement really helps. So, moving on to those electrocautery probes I was mentioning about, so these are used to, again, treat these different types of bleeding lesions, and performs hemostasis, the way it does is, it generates heat by passage of the electric current through the probe, so electric current is converted now into heat energy, and it causes what we call is thermocoagulation, or the word we use is coaptive coagulation, that's the exact word, because also, you actually use those cautery probes, and it's a touch technique, so you basically, in a coaptive manner, cause this coagulative type of hemostasis, so it cauterizes the tissue, and it stops the bleeding, now, some of these electrocautery probes also comes with an injector needle, so you can do both at the same time, so you can inject epinephrine, control the bleeding, at least get the field now more visible, what you want to treat with the probe. So then, there is a non-touch technique, which is normally used by this argon plasma coagulator probes, so uses this, it's again, to treat mostly the superficial bleeding, lesions, as you can see, for angioectasias, I don't like the word angio-dysplasias, it's basically, these are all abnormal superficial vessels in the lining of the GI tract, and you can, and they can time to time bleed, and you can treat that. There's another condition called gastric enteral vascular ectasias, which happens mostly in the stomach, in the entrum part, the end part of the stomach, where these abnormal vessels, they line up, sometimes in stripes, and you can see, they have different other characteristics, and they can bleed time to time, give rise to anemia, iron deficiency anemia, mostly, and you can treat that, and also sometimes for the radiation proctitis, we use this argon plasma coagulation technique. So what it does is, is basically, through a jet of ionized argon gas, which is an inert gas, as you know, electric current is passed, and it's like, as you can see, in a non-touch technique, this, the plasma, this ionized form, now helps in coagulating the bleeding lesion without the contact, so it's the same concept, this, it's obviously, it's also the heat generated by this ionized plasma, it's another state, you know, there's a solid liquid gas, and plasma is the fourth state, so physical state, so. Then, lastly, we get to this band ligation technique, where, obviously, we use these, it's like rubber bands, basically, small rubber bands, and you help in, kind of, squeezing out these esophageal varices. It's also used for endoscopic mucosal resection, where you can take a big piece of tissue that you want to resect, and then put a band at the base. So you, the way it does, you do it, you suction, this is the cap, it's a very clear cap, you can see, so you suction the mucosa into the plastic cap, and you place a rubber band at the base. So that's what the endoscopic mucosal resection, similar technique for the varices, same, you see these dilated veins, you see in the lower end of the esophagus, you suction with this clear cap, make sure that the varice has gone into the cap, and then you fire, I call it, the band, which will go and ligate the base of the varice, and over the time, this band will fall off, and there'll be just a small ulcer, which eventually heals at the base of the varice. You have to do at least two or three sessions to completely eradicate all the esophageal varices, mostly. We don't do this for the gastric as much, we have a different technique. So this is the way, as I was mentioning, we do the banding of the esophageal varices, and you can see this, finally we put a cap at the base, and the cap will fall off, usually after 48 hours or so. So moving on now to the more interventional techniques, and the tools we use for those. So we have endoscopic retrograde cholangiopancreatography, or ERCP, you already saw the anatomy, you can see we examine the bile duct and the pancreas, and at the same time, we do it under fluoroscopy, so you can use the x-rays. So here is the bile duct, you can see a stone in the bile duct, and this is where the main pancreatic duct is. So both draining into the ampulla where we go through. So we use this ERCP technique for removal of the stones, we dilate the stricture and narrowing, sorry, in the bile duct, we also then place stents to have a good drainage of the bile, and often we do biopsies for any suspicious-looking lesions. So this is the eudenoscope, or the side-viewing scope, you can see through this, we inject the dye and it fills up the duct, and you can see a nice filling defect, and that's where the stone is that has to be removed. So this is the difference in the scopes, the upper endoscope, which is a forward-viewing scope, you can see that's our biopsy of the instrument channel, this is where the camera is, this is the ear, and this is the light source, and also there is a, I call it windshield wiper, there is a jet of water which cleans the lens that comes through that, another channel, and then here we have ERCP scope, where you see this, it's slightly different, this is a side-viewing eudenoscope, where you have the light source and this is a portion called elevator, and that's where the instrument channel is, and that's where most of the tools actually come out. So you already saw the anatomy before, it's the same thing, so here you have the gallbladder, you have the cystic duct, this is the common hepatic duct, common bile duct, you have the intrahepatic right-left system, and then the common bile duct now joins the main pancreatic duct, and this is where the ampulla, you can see the side-viewing scope is accessing the ampulla and then we inject dye under fluoroscopy, or this is called the cholangiogram, and you can nicely see the whole anatomy. Pancreatic cannulation, not always we are doing it, inadvertently sometimes, but for certain pathologies we do actually inject dye into the pancreas and look into the entire main pancreatic duct, and you can see any pathologies, so that's called the pancreatogram. And then moving on to the next procedure, it's an interventional procedure called endoscopic ultrasound, where we are combining the upper endoscopy essentially with ultrasound capability. So here we are sending sound waves through the water and you can see, visualize actually the layers or any other pathologies in the upper GI or even some of the lower GI tracts. So we normally see five layers, so it's a superficial mucosa, lamina propria mostly, and then you see the muscularis mucosa, submucosa, muscularis propria are the true muscle layer actually, and serosa, and you can, based on these five layers, there are different pathologies we can identify. You can see the probe in the center here, and we are looking through these five layers. So we examine the upper GI tract, bile ducts and pancreas now also very commonly used, and in the lower GI I was mentioning, it's mostly the rectum, that's where we use the endoscopic ultrasound. Indications, we use it for diagnosis and staging for esophageal, gastric, pancreatic, and rectal mass or concern about cancer. We do final aspiration of tissue and cysts, and nowadays we are also doing actually biopsies, so it's a little more than just having cells around, and we evaluate epithelial submucosal lesions. We also have a whole different field of interventional endoscopic ultrasound where we treat gallstone disease and drainage of the pancreatic pseudocyst. So two different types of US scopes normally used. One is a radial scope. As you can see, it scans in the plane which is perpendicular to the axis of the scope, so this is where the radial, so you can see the lining, the layers much better, whereas the linear one which is parallel to the axis, it scans and you can do this linear for doing variety of diagnostic procedures. So you can see that. So here, using the radial US, this is a suspicious-looking area, and you're looking for early cancer. This is the probe. You can see here the center of the probe. So in this case, it says T1. It just hasn't gone through the submucosal layer. So this is the linear US. So here, you can see the needle coming out for the lesion. So here, this needle tip is coming out, and there's a question here whether this is a malignant lymph node or not. So you can put the needle, get some cells, and examine under a microscope and see for any neoplastic changes. So it's a very good tool. It's a fine needle aspiration. Nowadays, as I said, we also have needle biopsies. So in conclusion, so you saw this intro to the variety of GI endoscopic procedures. Hopefully, you got a basic understanding of upper gastrointestinal endoscopy, or EGD in short, and also colonoscopy, and a flavor for the interventional procedures including ERCP and EUS. Also, we use a variety of accessories and tools to help us not only diagnosing, but also with different types of therapeutics. I think that's it. Questions? Yes, sir. Are all follicles a precursor to cancer, or are there follicles that have no heartworms? Yeah, good question. So that's why I said there are two tests. I only mentioned about the adenomatous, which is the precursor, whereas there is the other one, the hyperplastic, which is mostly inflammation-induced. Rarely, rarely, unless until there's some genetic conditions will evolve into a cancer. So to answer your questions, not all polyps are going to form cancers. Yes? There is a lot of information in the press right now that there's an increase of colon cancer amongst young people. Are you seeing that in your practice? Yes. Yeah, good. Yeah, that's why I think we changed the guidelines recently from screening age 50 to 45. So that's our new 50. And the reason being that we have started seeing, we call it young-onset colon cancers now. Even at the age of 40. However, we are not recommending to start earlier than 45 yet. The data so far analyzed has shown that if we start at 45, we are able to detect even early adenomatous lesions much earlier to the point that if we remove, we will prevent the progression because by the time they come to screening at the age of 50, they might have had advanced adenomas. So that's why we decided on 45. But it's again, sometimes case-to-case basis. If someone has a strong family history, we obviously will start earlier based on the age the index cancer in the family has been diagnosed. So, but this is an important thing. I think we need to get the message around. We are seeing people coming earlier, but there is still quite a bit of hesitancy for younger folks to come and get a colonoscopy starting at the age of 45. Often they prefer sometimes non-invasive type, but I keep telling that this is the only preventive exam. We have enough of, you know, quite a few good screening tools now available, but this is the only preventive. Yes. So most of the devices that you show right now looks like they're made of surgical grade stainless steel or something like that. So how would it affect future procedures like getting an MRI or something like that? So, no, good question again. So we do have quite a few now MRI compatible, like some of these hemoclips, we have MRI compatible. So need to know, so there are, there's a lot of advancement in the material science now. So in the sense that it's not just all stainless steel. So we do have, you know, now capabilities where we don't use ferromagnetic particles. So it's all MRI compatible. So just like the pacemakers. So, you know, our hemoclips are also well advanced now. Yeah. So actually I write it in my report. Because these questions keep coming back, especially for the hemoclips. Yes, good. Yes, ma'am. For EMS, you said that the scanning angle is different from the original linear scope. What would make you determine which one to choose? Which ones, yeah, good question. No, so when we are, you know, again, if you're doing for staging and all that purpose, then obviously you go with the radial, right? You want to see what are the layers and all that. If you're thinking that, okay, I need to, target certain lesions and you want a snippet of that lesion, like cells or a tissue, then you go with the linear. So we sometimes use both. I mean, you know, it all depends. But you examine first and then you, if you need one, then you go for the other. So always have to have two handy though. Yeah. Any other questions? Comments? No, it's all clear? Okay, good.

gastroenterology

endoscopy

colonoscopy

ERCP

EUS

biopsy

cancer screening

early-onset colon cancer