All right, our next speaker will be Dr. John Morris from University of Utah Advanced Endoscopist giving us our talk on therapeutic colonoscopy. Then after this talk, you guys will have a short break, and we'll continue our lectures after that. Dr. John Morris Morning, everybody. I don't have any disclosures to talk about or pertinent, so just a brief overview of what we'll be talking about in this setting, you know, because there's other extensive therapeutic colonoscopy that we won't necessarily cover at this time, but the, you know, first year you're going to do a lot of lower GI bleeding cases, so therapy to stop bleeding. And then you'll get a lot of exposure to polypectomy over the course of your fellowship, and that can be, you know, the whole gamut of polypectomy that we'll cover from a diminutive to large colon polyps. And then something that you'll also see when you're on the inpatient service is primary teams or ICU teams consulting for sick patients who have, who need colonoscopic decompression because they have, you know, significant colon distension, aka Ogilvie's or pseudoobstruction. And then just a brief review of complications that can occur during colonoscopy. So just, you know, we had the definition of upper GI bleed, which is proximal ligament trites. We now kind of also talk about small intestinal bleeding, and then lower GI bleeding is, you know, this is kind of how I think about it, as opposed to distal ligament trites, I don't think about it that way anymore. I think of small bowel bleeding, which may be, you know, a negative upper and lower or positive capsule findings, but we're going to talk distal to the ileocecal valve is lower GI bleeding. And this is acute GI bleeding, which is going to be patients who present with the onset of bleeding in the, you know, we say less than three days. There's subacute bleeding and chronic bleeding. Those are the patients, the acute bleeders are going to be the ones who present most often with hemodynamic instability, changing their vital signs, right? Chronic bleeders tend to have time to compensate physiologically. They may present with anemia, but they're probably not going to have altered vital signs and come in noticing beforehand. This is a pretty comprehensive list, and since we're short on time, I'm not going to go over each of these, but it's what I do recommend is that when you are doing independent study, or if you have a case that's interesting, you look over these things, just try to think of the clinical factors of the differential. And you don't necessarily have to be the person that has the differential of all 20 causes, but that you kind of know what distinguishes one etiology from another so that when a patient presents with something that you kind of can put things higher and lower based upon your experience in your own study. Diverticular bleeding is the most common one. Up higher, ischemic colitis, angioictasia, hemorrhoids are all common causes of lower GI bleeding. So here's just a quick question. 75-year-old woman comes to ED five hours of painless bleeding, bright red blood, toilet bowl every one hour. There's no prior history of GI bleeding, it's the first GI bleed. She's not on any aspirin, NSAIDs or anticoagulants. Blood pressure is 100, vital signs are normal. Hemoglobin is still pretty normal for a woman. Normal platelets, INR. What's the best next step in management? So we're going to go ahead and prep that patient for a colonoscopy, right? So that's pretty straightforward. So the management of lower GI bleeding can change based upon the context. So we're just going to briefly review. In occult bleeding, they may have, you know, that's not going to be a brisk bleed by any means. They may have, you know, it's more of maybe even an outpatient thing, right? But you go ahead and you see this is a pretty common referral for outpatient colonoscopy. Melanin, we often think is predominantly maybe 80% upper GI source, but there is a fair amount of right-sided, slower bleeds in the colon that can present with melanin. So if that EGD is negative, then the next step is to do a colonoscopy. And you may find an angioictasia, for example, in the ascending colon that you're going to go ahead and treat. So there's still, you know, maybe therapeutic colonoscopy there. You know, I found that this is worth mentioning is scant intermittent hematochesia in a young patient without any features that put them higher risk for a malignancy. You can start with a flex sig, and if you don't see something to explain their symptoms, go ahead and do, you know, schedule them for a colonoscopy. Whereas if it's kind of like this person needs a colonoscopy anyways, or like could benefit from unexplained weight loss, or just they're of the age and haven't had one yet, then go ahead and just do a colonoscopy, or prep them and schedule a colonoscopy. And then inpatients with severe hematochesia, what's important, some of the downsides to or the difficulties with colonoscopy is that you want to have good visualizations. You have to prep them. You can't just go right in like, or, you know, maybe get them stabilized, give some erythromycin, and go in for the upper GI bleed in six hours. It takes a lot more work to be able to visualize. And these patients, if they're unstable, then you have to sedate them. So you may not really have the luxury of going in and doing a nice colonoscopy. So that's where I think this massive bleeding, where you may want to consider that we may have to call IR, or recommend that they call IR. So you have an unstable patient, they're pouring out, they have multiple bloody bowel movements, you can't just go in. So stabilize them and get IR. And you know, IR sometimes, depending on the clinical setting, may want to CTA first. Sometimes they may want to go in straight away. But what I've realized over the course of my fellowship is that all bleeding is intermittent. Even these, you know, that's why a non-bleeding visible vessel is essentially almost as high risk as active bleeding, because, and you'll sit there, you'll go in, you'll see a non-bleeding visible vessel, you'll say, go grab a clip, and suddenly it starts spurting. And then you're going, you're trying to play the clip, and then it stops for a couple minutes. And then, you know, so it's, when they do angiography, they have to have active bleeding. The same thing with the CTA. If it's that five minute period where you're not actively bleeding, then they may not see that extravasation, right? So oozing has to be brisk enough. So there's times where these things are negative. The patient stabilizes, maybe the bleeding pauses temporarily. And that's where they're, you know, they're going to ask us to go in and do a colonoscopy. And you have that window to do it. And that's where, you know, I think this is going to be institutional dependent, what protocol you use for, or how frequent, and what the settings. So I think it's something to ask your institution, your upper levels, or your attendings, you know, when you're covering overnight, like, what do we do? Does the patient have to be in the ICU, or do the, you know, for a purge prep? But just looking at these, so it's about four liters for a full prep, right? And if you want to do that in about three hours or so, it ends up being a cup or eight ounces every 10 minutes. And then if they have an NG tube, then you can, you know, sometimes the nurses set it up to a rate that's like consistent with IV fluids, 150, 200, and you have to make sure they know that that's going to take all day, right? And it won't even be effective. So you have to just do the calculation of how much that's going to be. So you know, they go up to 999, but they may have 999 milliliters an hour. They may have to supplement by doing some boluses by hand to push that, to really get it done within a three or two and a half, three hour timeframe. But you do have to be cautious that these patients don't aspirate because that is a lot of fluid and make sure that they're otherwise resuscitated to where they can handle that. So then, you know, that other side there is basically, I think, considering, you know, do you want to do an EGD in these patients with brisk hematochezia to rule out an upper GI bleed? And in that case, do you want to move your timing up and what are some factors, both clinically or maybe bedside assessment, that can help you? And most importantly, that first step is actually getting information, making sure the patient's resuscitated, having the, you know, blood counts in order and IV fluids and everything given. So we talked about the disadvantages of colonoscopies. They need sedation. You need, you really, visualization's key, right? If you go in and you see a poorly prepped colon, a bunch of blood, you may not localize that bleeding source and it's not going to be of any value to you. But the advantages are it's a relatively low complication rate and it has a lower complication rate than angiography and diagnostic yield is variable and some of that is based upon how early potentially you're able to go in with a good view to localize a source. But you're there and you can deliver therapy at the time of it. So it's both, you know, pretty good diagnostic yield and then has a potential for therapy and is relatively low risk procedure. So here's another question. A 55-year-old male who is on Afib or has Afib on Warfarin had a screening colonoscopy five days ago and a cecal pulp was removed, presumably with cautery, presents with painless bright red blood for five episodes. He calls in to the clinic, sent into the ED, vitals are still stable, hemoglobin's down from maybe 14 at the time of the procedure. He's been back on his therapeutic, back on the Warfarin, so you go ahead and do a colonoscopy to evaluate and find a ulcer at the site of the polypectomy with a non-blind visible muscle. What's the next step in management? And I think this doesn't vary significantly from what Dr. Adler just talked about, right? So go ahead and you're going to place a clip to treat that. So what are some options that during colonoscopy? So there's pretty much what you have available to you during upper endoscopy. So you have epinephrine. Things to remember with epinephrine is that if you get closer to the rectum, and for an upper G, I believe, if you get closer to the G junction, you're going to not get as much first pass metabolism in the liver. So if you have a visible vessel or something that's right near the, down by the rectum and you inject epinephrine, you may see some significant changes to the vital signs. You may want to opt for saline tamponade in those areas. If you're, say, for example, have a post-sphincterotomy ERCP bleed and inject those, you get really good first pass metabolism in the liver and you get very minimal change in the vital signs. But there was a few troponin leaks that we would see over the course of fellowship where people do get, you know, they end up checking their tropes that are like just from the epinephrine injection. But then you have bipolar therapy, APC, which is really good for angioictasia with kind of more oozing lesions, and then our hemoclips. So what are some things that we can do to kind of help our workup or other things that aren't, regardless of endoscopy? So just want to distinguish between a Tadward blood cell scan, which is a longer study, a little more sensitive, but it doesn't localize. But kind of those for those situations where you have intermittent bleeding, but it's over several hours, it may pick up. The radiologist or nuclear medicine kind of physician will oftentimes try to give some type of localization, but it's not always accurate. So it's kind of based upon which quadrant of the abdomen it may be in and what that's likely to be, you know. But that can, you know, sometimes we don't have other options that additional information can be helpful. The technology with these multihelical CT scans, basically where they can be done very rapidly in time with the contrast bolus, so that you can actually localize the source of bleeding. Sometimes you'll find out it is an upper GI bleed, IR will say have GI come in, right? We should really be, first line should be endoscopy, not angiography for an upper GI bleed. If you see an active colonic bleed in an unprepped unstable patient, then that should go straight to IR. Surgery, you know, these algorithms say consult surgery, but we try to avoid surgery and it's not often that we have to resort to that. Diverticular bleeding, you're going to see a lot of this and it's going to be pretty annoying I think over the course because it's oftentimes recurrent. So if a patient has an episode of a diverticular bleed, their risk of having another one in their lifetime is pretty high. If they've had a couple, then it's even higher than if they've only had one. So you have patients who have recurrent episodes of diverticular bleed over, you know, a course of a couple of years. And oftentimes it'll resolve spontaneously, but it's at risk for recurring even oftentimes within that same hospital admission. And they're actually hard to localize. So, you know, there's a good video here where it shows a diverticular bleed where you can actually see the bleeding from the diverticulum, but that's actually pretty uncommon when you actually go in and do the endoscopy. The earlier you go in, maybe you increase that yield a little bit, but oftentimes you cannot see where it's a presumed diverticular bleed. The treatment is a little bit, you know, based upon the location. You have to keep in mind that this is a thin wall. So you're probably going to not, you know, if it's right in the infundibulum of a large diverticulum, you may not be using a bipolar probe, and it may be a difficult area to deploy a clip. But if it's on the rim, it gives you a little bit more kind of flexibility. A band ligation is something that's also been done if it's, you know, amenable, but clips and banding, and I think mechanical-type therapies is what we go to. There's also the over-the-scope clip, which can be used or thought to be used, depending on if that's going to give you a favorable option. But the problem there is that the over-the-scope clip is a very large device that sits on the top of it, and oftentimes these patients with significant diverticular disease will have stenoses, like extrinsic stenoses from inflammation, chronic inflammation, so it can make it hard to get that scope up there. So here's the, let's see here. Here's the video I wanted to show, but that is a good example of some active diverticular therapy. Here's the video. for diverticular hemorrhage is safe and efficacious in certain cases. Injection therapy, shown here, to treat bleeding at the neck of a diverticulum has been reported with limited success. Due to the lack of muscularis propria at the dome of the diverticulum, therapy at this site using injection or thermal coagulation must be carefully considered. When surveying the colon for the source of the diverticular bleed, it is often difficult to relocate the bleeding site following initial identification. We recommend using an endoscopic clip for marking in order to ensure future endoscopic identification, as well as localization for future radiologic or surgical interventions if necessary. Direct clip application should be applied if a clear bleeding site is visualized. In this case, an actively bleeding large vessel is clearly identified at the neck of the diverticulum. After initially marking the location, direct clip therapy is applied. The clip is carefully positioned near the base of the artery in order to entrap the immediately surrounding tissue. The usefulness of the water jet is emphasized for precise clip application. Slight downward pressure is applied, the lumen is collapsed with minimal suction, and the clip is deployed. Although a single clip may be sufficient, we typically place two additional clips in order to ligate the feeding vessel proximally and distally to the bleeding point. This case demonstrates direct clip application to the dome of the diverticulum. An adherent clot is directly visualized in the diverticular dome. Bringing the clip close to the endoscope provides the most controlled technique. The clip is carefully positioned close to the vessel in order to entrap the immediately surrounding tissue. Being cognizant of the thin diverticular wall, a second clip is placed at the opposite side of the defect in order to ensure hemostasis. So another common cause that was on that list is angioictasias, and these can be fun, if you will. You've kind of seen some examples already of the argon plasma coagulation, and you'll see them, and sometimes they won't be, sometimes they'll be oozing and actively bleeding. Other times, you'll see them and you'll don't know, is that incidental, or is it the cause of their lower GI bleeding? And when you go ahead and treat them, some of them will almost kind of like, you know, suddenly start burst bleeding, and that's kind of like, you think, okay, that probably was the cause, and others just, you coagulate them and are much less impressive. There's actually a video showing that where it kind of bursts on them, then they have to go ahead and use clips because the APC wasn't completely eradicating the bleeding. But colonoscopy, again, very good sensitivity at finding these, they're more common in the right. You'll get a sense of which patients are at higher risk for them, and who this is highest in your differential. I commonly use APC, but a bipolar probe is effective as well. And some patients, so pretty commonly, LVAD patients will have these, and they really don't want to stop their blood thinners. So in those patients, I might go ahead and resort to clipping, basically, because like Doug was saying, you don't want to induce an ulcer with thermal therapy, that then is gonna be a subsequent bleed. So you can still go ahead and treat them with mechanical therapy if needed. This case of AVM bleeding shows initially that argon plasma therapy was used. Bleeding, nonetheless, continued, and endoscopic clipping was necessary. Multiple clips were required to achieve primary hemostasis. On follow-up, the patient had no report of re-bleeding. So that video didn't show you at the beginning before they did that first treatment, but it may have been a non-bleeding angioictasia initially, and they treated it, and it suddenly just kind of like opened things up, and you get a lot of oozing. So that's a non-uncommon thing that you'll see. You still can usually continue to apply the coagulation with the APC probe until you get a nice eradication, but in situations like that, where it's persistently bleeding, you now can go ahead and use your clip, or you could go ahead and maybe inject some epi, slow things down, and apply clips. So moving on to polypectomy. So this is like a whole range from diminutive polyps to large polyps that require a piecemeal or endoscopic mucosal resection. It's important to understand the different features that may make one lesion significantly more difficult than another. So does it extend over multiple folds? Is it, where is it located within the lumen? What part of the colon is it in? How stable is your positioning? Like how looped are you? How large is it? But I think size is probably not really what makes a polypectomy difficult. It's really all these other factors. And how flat is it? How, where is it? How does it, in regards to the folds. As far as describing some of the shape, this is the Paris classification, which I think is important to understand. And it's helpful to know what the risk of submucosal invasion is. Those lesions that are more likely depressed or excavated are gonna be more at risk for having early cancer. And therefore, maybe not amenable to a definitive polypectomy. Also, the flatter lesions may be difficult to resect without using a lifting agent. But basically it's, the one lesions are kind of your standard polyps. One P for pedunculated, one SP for either sub or semi-pedunculated, and then one S for a truly sessile lesion, which is raised more than two to three millimeters, basically is what, but does not pedunculate it in shape. And then the two lesions are, I think it makes most sense to go this way. So you have 2A, 2B, 2C, and then three. So you have a flat elevation, and then a truly flat with just a mucosal change. So no elevation, that's your 2B. And then 2C, where you actually get some depression, but not an excavation or an ulceration. That's gonna end up being a three, and that's gonna be very high risk for malignancy. Then you have these 2A plus C or 2A plus 1S that have features of both. And then we often talk, is it granular or non-granular? And then you'll see more examples of that in C, but non-granular is another higher risk for high-grade dysplasia or early malignancy. So cold biopsy really should be used for truly diminutive lesions that you can fully engulf with the forceps, one or two millimeters. We've really expanded in the past few years cold snaring. So smaller polyps, we're going to the cold snare more often to get a true single, and you can actually get a margin of normal tissue around it. And even piecemeal cold snaring of large sessile polyps has become more and more. So we've realized we can actually use this a lot more. We don't need to use as much cautery even in large polyps. So cold snare is becoming quite the tool to really the whole spectrum of polypectomy at this point. But the hot snare, either for endoscopic mucosal resection or just certain large polyps, pedunculated polyps is still going to be your go-to there. Hot biopsy really has fallen out of favor for standard polypectomy. The one situation where you may use it is if there's been a prior intervention, there's some fibrosis and you want to target it, you're usually going to grab it, pull it away from the lumen, and then apply some to help you like remove small pieces of a stubborn polyp that has underlying fibrosis from a tattoo or a polypectomy attempt prior to you trying. Here we see an indigo carmine stain colon in which we're using a really large capacity needle forceps to make small polyps and simply pull them off. The advantages of the cold forceps technique include that it's devoid of complications because we're producing only a mucosal injury. And also it's very efficient because it's easier to place forceps on small lesions than it is to place snares on them. And also you'll notice that these lesions are so flat that they would be very difficult to snare. In addition, this technique can be performed in patients who are therapeutically anti-coagulated and the risk of bleeding is extremely minimal to none. All right, so when I do a colonoscopy and it's say a screening colonoscopy, you want to make sure that you are set up to do whatever you think you might have to do. There's been times where I haven't been ready like that and the electrocardiogram machine that you want is in a different room, the snare box is in a different room and I might've just assumed that the technician would have known that, hey, well, we should be ready to do whatever we might need to do. So you wanna have all those things there in case you have a difficult polyp that's large that you wanna have your specialized snares readily at hand. The settings are like, make sure your technician knows how to quickly find the setting because you might be in a position that you don't wanna move away from to help them set it up and make sure they feel comfortable knowing those things. So just having that sense that assessing that your technician skills, your team that's in the room. So you wanna have a variety of snares, you wanna know your generated settings that we talked about yesterday and what your preferable settings are. You wanna make sure the pedal is easily at hand that it can be put in place. I like to make sure before I am ready to do the polypectomy that I have my foot like right near where I'm gonna go ahead and use it so that I don't have to look away to then cross the pedal. You wanna have a polyp trap on hand so you can retain the specimen before the tech knows that they should go ahead and set that up. And then you need to make sure you have your clips available, a bipolar probe potentially, all readily available in case you do encounter a complication that you need to treat. It's very important. So all colonoscopes have the instrument channel at five o'clock. If you're ever using a therapeutic scope for a sigmoidoscopy, that's gonna come out at seven o'clock. So getting these at five or six o'clock, the lesion is the easiest way to facilitate a polypectomy. If you try as you may and all you can do is get that lesion to three o'clock, you can still potentially maneuver the snare to be able to do it. Sometimes if you can only get it to be in that 12 to three o'clock, you can also kind of move it a further way and kind of approach it where you get in the lower part of the screen. But really, it's almost impossible to snare it if it's at nine o'clock or between nine to 12 o'clock because you have just your devices coming out here. It's on the opposite side. You'll lose your visualization trying to get over there. So positioning and stability of your scope are really key. If it's a pedunculated polyp, you wanna basically cut it basically about half. You wanna leave enough distance between the abnormal portion of the polyp along the stock that there is some early cancer. You know, you've resected it with leaving at least two millimeters ideally so that that can be curative. I like to leave, the reason why I maybe do it about halfway is that if there is bleeding afterwards, these stocks will kind of, they'll shrink up after you've cut them. And if you're too close to the base, like the base of the lumen, then it may be more difficult to treat the bleeding afterwards than if you leave some of that stock. Cold snaring has been shown to be effective in polyp. Moving on to cold snaring. Again, try to remove a thin strip of normal mucosa. Normal mucosa is important. That is not recommended with electrocautery use. Cold snaring is devoid of bleeding complications in patients with normal clotting. Immediate bleeding is typical with cold snaring, but is of no clinical significance. The technique is to grasp the tissue around the polyp, including a bit of normal tissue, and then mechanically transect it. Tenting is not necessary with cold snaring since there is no risk of injury to the deep layers of the colon wall. I currently use this technique for about 80% of the polyps that I remove during colonoscopy. Here you see the removal of a sessile polyp. We can grasp some normal tissue at the base and cut it off. It will stay in place as long as we don't tent. And after removal, we move the biopsy channel up to the site and suck the polyp back into a trap. So you'll commonly see some oozing, and sometimes a fair amount of oozing after you use the cold snare, but usually if you just wait a little bit, that will clot off, and I think a significant bleeding is extremely rare. Usually, even though you see a defect, and I rarely, rarely ever, if ever, deploy clips to a cold snare polypectomy, even if the defect's quite large because I've done piecemealing of that area, and it's significantly lower delayed bleeding rate than hot snare polypectomy. Here we see a pedunculated polyp that we're going to grasp by the stalk of the polyp, and then lift or tent into the lumen. Please notice that we see a white cautery burn on the polyp before we begin the actual mechanical transection. Thus, we instruct the assistant to hold off on transecting the polyp until we see that white coagulum. Now we've got a sessile polyp about a centimeter in size. Notice that we're grasping right at the edges of the polyp, which is different from what we discussed with cold snaring. Again, before we begin the mechanical transection, we want to see a little bit of coagulum near the snare. That's the whitish color, and then we'll begin the mechanical transection, and then we're going to inspect the polypectomy site. Some people prefer to photograph the polypectomy site, but I don't think the standard of care requires that. Something to notice during that video is you can really tell that you're not grabbing too deep based upon moving the polyp away from the lumen base, and you can see that it's basically just grabbing mucosa, submucosa. There's no appropriate because it's not pulling the wall with it. You can even kind of move your snare catheter in and out, and you should see that independent movement from the wall because you're going to be applying cautery there. It's very difficult with a cold snare to cut through muscular as appropriate, but when you have cautery, then you can, so you have to be cognizant of that. This is kind of that inspection. You'll learn over experiences how do you distinguish cautery effect from the surrounding area, getting to know the pit pattern of the polyp so you know that you didn't leave any residual, and then trying to, before you even apply the cautery, make sure that you have a good grasp of the full polyp. So this is just, again, things that we talked about. Getting the polyp at six o'clock, making sure you're in a stable position. A clear cap sometimes where you have it passing over multiple folds or if it's on the proximal side of a fold can be very helpful to move it into position or give you just a little bit of space to where you're not. It's difficult with just the tip of the scope to do that and still have some area to maneuver. Non-lifting sign is something where you go ahead and you apply some lifting and it doesn't lift, so it's a marker of submucosal invasion. We really have moved away from fulgurating residual polypoid tissue just because the recurrence rate's so high, but sometimes we have no other options. It's something you might want to try before referring the patient to surgery. And then clip closure. I really like to use clips when I do a large EMR greater than two centimeters, especially in the right colon or if the patient's on anticoagulation, but if it doesn't meet those criteria, we may be tempted to close the defects, but there's not evidence that we're lowering their bleeding risk on, say, a left-sided lesion. That's 15 millimeters or even large left-sided lesions. We're gonna see a video of the submucosal injection for both tattooing and for EMR. It is a skill that does take some time to learn. Dynamic injections, you don't just inject, puncture and inject. You actually use the scope and catheter and kind of move the polyp as you're doing it, as you're injecting to expose, to optimize your exposure of the lesion. And then I'll just mention that the first attempt is your best attempt because after, if you're not able to complete it and you have to refer it on or you want to try again, you're now dealing with scarring, which makes it significantly more difficult to remove. Here's an example of injection. While we're watching this, we don't cover it in this presentation, but I will say that complete underwater immersion, where you remove all air and fill it with liquid, will have a buoyancy effect and will actually thicken your submucosal layer because of that. And it will round out and thicken the muscularis propria. It's essentially a type of lifting where you don't actually have to do an injection. And even very large bites, large lesions can be removed with what's called an underwater EMR, underwater endoscopic mucosal resection. So that's an alternative form of pseudo lifting, if you will, using the buoyancy of the water. And I really like to use that technique, so this is where you're actually creating a buffer by lifting and also exposing the polyp so that when you'd snare it, you're separating the plane of the mucosa, submucosa and the underlying muscle. 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. So when you're removing these polyps and you may have multiple polyps in different locations and with a Rothnet or a snare, if it's too large to come through your trap, you have to basically withdraw the scope. So you wanna think about how can I do this most efficiently but also at the same time, make sure that I'm correctly labeling and sending the pathologist the location of which polyp you may have removed in that site so that if there is a finding of high-grade dysplasia or cancer, you've correctly identified and marked that area. But again, you don't wanna necessarily go, you know, it can take a lot of time if you're removing right side lesions and have to go back and do more. So there are different ways, but just thinking ahead, okay, how can I do that? I think the main point here is don't bite off more than you can chew, because then it is a lot more difficult. So if there's a lesion or a polyp that you're not sure you're comfortable removing or you're running behind. So there's actually a study that, you know, if you have your normal block time, say even if you're like very competent at removing large polyps with EMR, you're probably better off at rescheduling that patient into a slot where you're prepared to do the therapeutic EMR than trying to just go ahead and fit it in like a 30 minute or 45 minute screening or surveillance slot. So even if you're capable of it, just know what you're dealing with in that situation or if you're not, you know, what resources do you have as far as referring and don't bite off more than you chew and then do a suboptimal resection. Tattooing is helpful. Key points here is that you generally wanna be distal to the site and do a couple or a few areas in case, you know, one may be adequate for an endoscopic marking, but if that lesion eventually needs to go to surgery, having a couple sites so that during laparoscopy you're facilitating the identification. So that's why two or three. You wanna clearly document that you did do distal so that the surgeon that's reading your report kind of knows, okay, where's this tattoo relative to the lesion. And then endoscopically, I like to photo document the tattoo relative to either the defect or the polyps so that when someone goes back in, if you're yourself and you're looking for that scar, you can kind of refer back to your photo. The other thing too, and there's a video showing the proper technique for doing this is if you inject too deep, like just poke the needle as deeply as it goes and inject, you may actually kind of be spraying tattoo within other sites of the peritoneum and that can make it very difficult for the surgeon to know like there's a bunch of tattoo everywhere. So being very precise is important with tattooing. The other thing I see a lot is I'll get referred to remove a difficult polyp and the tattoo can kind of spread. And so they didn't initially tattoo under the polyp, but they tattooed too close to the polyp and maybe they tattooed a significant amount and it will spread. And essentially you'll have a fair amount of tattoo underneath the lesion, which is suboptimal because sometimes it can lead to fibrosis and make the resection more difficult. Notice that we strive to get the needle tangential to the mucosa. Then we need to get the needle tip through the mucosa into the submucosa. And a good way to check that is to see that we have just a couple of millimeters of needle in the tissue. Then if we lift the needle toward the lumen, you actually see the impression of the needle in the submucosa right there. And that's a good indication that we're in the submucosa and we can start the injection. We must immediately see fluid starting to collect in the submucosa or we stop. We're going to inject one to several cc's into each site. If we have a mound of saline already in the submucosa, then it's easy for us to reinsert the needle into that same mound and inject ink. Here you see in this next injection that we'll poke right into the submucosal cushion and inject again. So like, I like that technique of like say tinting where you first get in, you can kind of lift and deflect the tip up and make sure that you're really as superficial as you need to be. Some fluid there either from the previous submucosal injection for the polypectomy, a very easy way to find the submucosal space. So bleeding is the most common post polypectomy complication. Perforation, if the technique is done well and you inspect the site afterwards, there is a risk of perforation, but the key is if you identify it and you can close it, then the risk of surgery after the perforation can be maintained actually pretty low with the clips or suturing and other things that we have available to us. You know, less commonly, you'll see things like retroperitoneal abscess or subcutaneous emphysema. And then there's this post, obviously post polypectomy hemorrhage we've talked about and when you should close them even if there's not bleeding to lower the risk of delayed bleeding. But I just wanted to mention this post polypectomy coagulation syndrome, which you'll see, you actually won't see it that much, but it mimics almost like peritonitis, but there's no perforation. They may have some leukocytosis, have, you know, peritoneal type symptoms, but there's no free air on CT. And the management is just about bowel rest. We give antibiotics out of caution and then you basically kind of monitor the patient supportively until they improve their symptoms. Take it easy on the air during. Let me just pause this really quickly. So I'm going to go ahead and skip the decompression stuff due to time, but I just, these are complications that you may see. So moving on from therapy, but it's important to identify and minimize the risk of complication from colonoscopy and then to identify it. But these are some descriptions and videos of how, you know, perforations can occur during colonoscopy. Take it easy on the air during insertion. Enough air should be insufflated so that the lumen can be clearly identified, but additional air insufflation will lengthen the colon and make insertion more difficult, as well as increasing some risk and discomfort for the patient. Be particularly careful about air insufflation after passing a tight stricture or angulation in a patient with severe diverticular disease. In such a patient, air may not be able to escape around the colonoscope in order to exit through the anus. If the ileocecal valve is competent to air, a closed system can develop. So this is always a little disconcerting where you'll see barotrauma that doesn't cause a perforation and you're like, you know, even sometimes where you don't have a difficult colonoscopy for whatever reason, potentially the hepatic flexure is quite angulated and, you know, air will get in, like create almost like a one-way valve and you'll go and you'll see just some, just mucosal changes that you're like, I haven't even been here yet, what happened? So that's something that should be. Fortunately, CO2 I think has helped some degree with some of that. And so we use CO2 for all of our colonoscopies. There are two basic mechanisms of perforation during insertion. The first of these is mechanical rupture by the colonoscope, which usually occurs when the side of the colonoscope ruptures the colon in the vicinity of the rectosigmoid junction. The most important step in avoiding this type of perforation is to not continue to push the instrument when fixed resistance is palpated by the hand on the insertion tube. Fixed resistance is the sensation that the colon will not stretch further as pressure is applied. No matter whether the lumen is in view or not, you must stop when you feel fixed resistance. So this is something you'll gain experience over time, but patients who have prior surgeries or diverticular disease, oftentimes we'll have this feeling that they, their adhesions and other things become quite fixed. And so knowing when to significantly adjust your technique, change positioning, convert to water insufflation, water immersion versus, you know, can help you to decrease that fixed resistance that you shouldn't be pushing against. Mechanical perforations may also occur when the colonoscope tip is forcefully pushed against the diverticulum. Remember that not all diverticula are small and occasionally diverticula will mimic the lumen, even for an experienced examiner. Mechanical perforations occur more rarely when the colonoscope tip is pushed against a stricture that is too tight to allow passage of the scope. Continued pushing can cause the tip to forcefully slip off the side of the stricture and dissect the normal colonic wall. This type of perforation can be avoided by either first balloon dilating the stricture or by passing a guide wire through the stricture before attempting passage as shown in the animation. The guide wire will prevent the scope tip from slipping off the side of the stricture. All right, let me just go to the end. So just remember, colonoscopy is the chest of choice for acute lower GI bleeding, but there are some limitations and an unstable patient with massive bleeding angiography is an option to expedite treatment. And then just reviewing polypectomy from simple diminutive polyps to larger polyps and knowing how to minimize and avoid the complications of colonoscopy. All right, I'm just gonna go ahead and write and I'll just take any questions. All right. Thank you.

therapeutic colonoscopy

lower GI bleeding

polypectomy

colonoscopic decompression

complications during colonoscopy

proper positioning

tattooing for polyp location

post-polypectomy bleeding