Okay, I think our next presentation is going to be on closure and we'll talk about this whole issue of closure. So we just talked about, can we prevent delayed bleeding? So, you know, delayed bleeding is related to a few things. One of them is the size of the lesion. The bigger it is, the greater the risk. The farther it is into the proximal colon, the greater the risk. And of course there are factors like anticoagulation and resumption of plavix and clopidogrel that are associated with a statistically significant increase in bleeding, at least in some studies. So that brought around this whole idea of closure. Now my sense is that based on this trial that we've just been, you know, beating to death that using cutting current, at least with a microprocessor controlled for a generator. And if you're not using one, if you're using an old fixed output generator, you know, that's something that you should be thinking about updating in your next capital expenditures. So cold resection, yes, it definitely works. Now epinephrine, we haven't talked much about epinephrine. There was a question about it. Epinephrine, there are a lot of people that are big enthusiasts about it. And I think Amit was saying that he uses it for cold resection, but not hot resection. Michael Burke always uses epinephrine. When you see these huge blue stained defects that just look perfectly smooth, part of that has to do with the epinephrine because you just get, you know, you get less intraprocedural bleeding with it. If you're using epinephrine for cold resections, there was a question about this, I'm sorry, for resection of large non-pedunculated lesions, you generally want to dilute it. So what we typically do is take a syringe of one to 10,000 epinephrine. And if we have a 10 ml syringe of injectate, then we would add, if you add a half an ml of the one to 10,000 epi, you end up to one with one in 200,000. One in 200,000 will cause very nice blanching, but you can get nice blanching with concentrations of one in 400,000, one in 500,000. Cyrus Paraka, who is at Henry Ford in Detroit, and is kind of the spiritual leader of the cold revolution movement, the cold EMR movement, he uses one in 500,000. So Michael Burke uses one in 100,000. I think the more volume you inject of higher concentration epi, the more post-procedural abdominal discomfort that you get. So we, I abandoned it mostly for that reason, because we process EMR patients in the recovery area, kind of like we do regular colonoscopies. If they wake up, first of all, if I have evaluated the defect and I see no evidence of a muscle injury and the patient wakes up in recovery and feels fine, we would discharge them in about the same timeframe as we would a regular colonoscopy patient. Some people monitor EMR patients for a few hours. And I think part of the reason they end up doing that is because of the epinephrine, because I think it causes some ischemia, abdominal discomfort that wears off usually over two or three hours. But you know, when the patient is in discomfort in the recovery area, you'd like to watch them until the discomfort is better. So that's the reason I've backed off on it. But if I have a very, very large resection, I still sometimes put epinephrine in, but I dilute it quite a bit, usually one in 400,000 to 500,000, but it doesn't prevent delayed bleeding. I have the, just, I wanted to echo, I have the same thoughts you do Doug on all of that regarding epinephrine use, same approach. Thank you. Thanks Tanya. So the implications of delayed bleeding, first of all, it's our most common complication. The average stay in the hospital with a delayed bleed in the U.S. is about three days. I don't think there's a lot of medical legal risk associated with it because the outcome is usually quite good. About two thirds of the time, you know, it stops on its own and the great majority of the time when it stops on its own, it doesn't resume. It's usually not, I've seen it be very scary bleeding. The scariest bleeding that we see in our practices is when you take out big duodenal polyps with electrocautery and there you'll see some really rapid arterial bleeds. These delayed bleeds are also typically arterial, but they're just not as, they just don't involve the same size vessels or bleed as fast. I think that some of us are, I think there's a lot of variability in how comfortable or how much we like complications. I will admit, I don't like having complications. And even if I know that they're going to go well, you know, I just prefer to not have people in the hospital, you know, having to check on them all the time. And I think if you're in a, if you live in a smaller city in the United States or a rural area, you know, it is viewed as kind of reflecting badly on you because people don't understand. I always say, you know, nobody wants, if you live in a town of 50,000 people, nobody wants a high school football coach in the ICU with a post polypectomy hemorrhage because everybody thinks you didn't do something right, you know, oh, didn't they cauterize that? Like, no, they cauterized it too much. That's why the patient was bleeding. So because it's common, I think it would be nice to prevent it. And you know, Amit has really emphasized that, you know, we have too many benign polyps going for surgical resection. And I don't really know that we understand the reasons why that is. I can imagine a whole bunch of them, but one of them is, I don't want to take the risk of a complication. I don't want to send it a hundred miles to have some expert do it. My local surgeon, you know, is right here and can do this. And then I don't have to worry about the complications of it. So if you want to show that a method to prevent bleeding works, you have to do it, if you're going to do it, you have to have a control group where there is a high enough rate of bleeding. Anytime you look at a method to prevent bleeding, like clipping, and you have a control group that has a low risk of bleeding, that is they have small polyps, you're not going to be able to demonstrate it, that it works. So these are the studies that have been positive. This is our original study with historical controls, and we had an almost 10% rate of bleeding. Now, you know, that is, I always viewed that as a lot because I do a lot of EMR and I had a, I had somebody in the hospital, I would say half the time, maybe a third of the time with a delayed post polypectomy hemorrhage, or at least a half or a third of the weeks because I do so much EMR. So when we went from clipping from 10% to 2%, that is a wild difference in how you experience EMR. You've reduced the number of people coming in the hospital by 80%. That feels very, very different. Now, this is the HICO-POL multicenter trial. This is the same trial with the yellow versus blue petal. This is the Spanish trial, and then this is Michael Burke's trial. Michael Burke and I used to debate clipping versus not clipping. It seems like every other DDW, and now he's a convert because his own trial showed that it reduced the rate of bleeding. So who does it reduce the rate of bleeding in? Well, it's large lesions in the proximal colon removed by electrocautery. That's the bottom line. I would say that this includes the transverse colon, but it doesn't include the left colon. It doesn't seem to work in the left colon. Now, the risk is lower in the left colon, but the bottom line would be that when you're looking at a lesion and you're asked, one of the things that you're going to ask yourself is, when I'm finished with this resection, should I close this? And secondly, can I close it? And maybe thirdly, how am I going to close it if that need is there? So this is the group of lesions. Now, cost analyses suggest that clipping is cost-effective in these high-risk lesions. There are cost analyses comparing cold resection to hot resection that suggest that cold resection, on average, it's more cost-effective than using electrocautery. Why is that? Because you avoid the clips that we need when we use electrocautery on certain lesions. This study was presented at DDW, and I don't know what to make of this at the present time, but this study has a different result than all of the others. Basically, clipping didn't work. Now, when you're putting clips in, this is a big lesion in the cecum, and it looks like it's too wide to clip. It's perfectly legit to put clips right into the subucosa to pull the edges together. One concept that you can use to some extent is to pull the edges together, closer together with certain clips, and then place clips around that to close the defect. So you can close pretty large defects sometimes. Now, okay, in general, I would say that the best way to orient the clips for most lesions, most lesions that certainly that are on FOSTI, if you're facing the lesion directly on FOS, as you are sometimes in the cecum, for example. Sometimes in retroflexion, you're directly on FOS to the lesion. A lot of the times in the forward view and the right colon, you're relatively tangential in your approach to the lesion. Most of the time, you want the clips to be oriented in the up-down direction, and you're going to use the bottom prong of the clip and then bend the tissue down and turn the lesion toward you. You want to turn it on FOS into the clip, and then you push against the clip to make sure that tissue is completely filling the jaws of the clip. I call this a buried clip, which basically means that when you look at the clip afterwards, you would not prefer to see any gap between the arms. You want this thing to be so that the jaws are absolutely full of tissue. I think when that's the case, the clips adhere better. Now, when we look at these clipping trials, they suggest a couple of things. One, as we've discussed, the risk of bleeding is reduced. There's also a different timing to the bleeding. When you are not clipping, most of the bleeds occur in the first couple of days. When you are clipping, most of the bleeds occur about seven to eight days after the resection, which I think means they are occurring when the clips are falling off. We want the clips to stay on there. We know that most of them are off by six months or a year. And once you've committed to it, I try to close the whole site. Here we're demonstrating that you can use the scope and the cap on the end of the scope to actually bend the clips down to get access to the defect, as long as you don't pull back too far with the scope. So you can actually manipulate clips that you've already placed. Here we're doing it again. You see we're bending these clips down. But once I've committed to clipping, I generally want to close the entire site and people say complete closure means that there is less than a centimeter between the clips. I usually am even trying to get I think a little bit less than a centimeter between the individual clips. We showed an example of if you have a perforation or a thermal injury, I literally put the clips right next to each other. Not so much for prevention of bleeding. Now here we're using, this is the Cook Instinct Clip. It opens very widely. It's a big clip and it's pretty stiff. And so we can again use this clip. We take the bottom prong of the clip, put it against the tissue, and then start to bend the tissue down and turn that defect so that it's unfossed to us. Then push the clip in and close it and fire it. And notice how those clips are buried right up to the hub. And I think that that, again, that's an important goal. So it's not just a matter of clipping versus no clipping, I don't think. I think it's a matter of how effectively you clip, whether you're able to get sites closed. There are times when we can't get the whole site closed because we can't access part of the defect well enough. Sometimes you do have to clip it in retroflexion. When I do that, sometimes you have to come out of retroflexion, push the clip down the scope, get it right to the tip, then go back into retroflexion, put the clip on, and then repeat the whole process. You've got to come out of retroflexion because sometimes the clips or other devices don't want to go around the thing that is longer in the longitudinal axis than it is wide in the right left axis. Sorry about that. So I was saying that this is oriented, it's longer in the longitudinal axis, but I direction, I would generally still try to clip with a clip oriented up down. And the reason is it's easier to bury the clip. The shape of the semicostal injection mound is usually such that if you orient the clip transversely, it's just harder to get the tissue all the way up into the clip. So even in this case, I would usually keep the clips oriented in the up down direction. So we have now a couple of clips that are called closure clips. And these have some special feature. There's a dual action clip and there is this mantis clip. And this mantis clip has these jaws on it that allow you to pick tissue up and move it. So this is the way it was originally described was to, you pick up one side of the defect, carry it over. And then if you keep a little rightward pressure in that instance, when you reopen that left jaw will stay dug into the tissue and the tissue won't flip back. So it's those spikes on the end of the clip that allow that. So here, most of the time when I do this, I actually don't use that technique. Rather, I open the clip and again, oriented in the up down direction. And then we're just going to dig into the normal mucosa on the rectal side of the thing and then drive the scope forward. We're literally driving the scope forward and then turn down into the defect. And then you can, here we go again. There's got another clip we're going to pick up with the jaw and then lift up and go over the top. Now that would be a hard distance to cover with a regular clip. And then once you get the edges pulled together with one or two of these clips, then you can fill in the gaps with just your regular clips that are not as expensive as these specialty clips. I talked earlier about the value of oncologic resection of pedunculated polyps, but my preference for this reason is to not use endo loops, take them off with forced coagulation current low on the stock, and then put the clip right across the stock. Now, we now have, so we have these suturing devices. The one that we have traditionally used is the overstitch device, which is now owned by Boston Scientific. That one, I think many people did not pick that up because it's a little bit complex to use and it requires coming out, getting the gastroscope ready, loading the device on, and so on. Now we have this through the scope clip, which is called the X-Tac. It's a tacking procedure. It comes in a little package. It has four tacks in it with a suture threaded through them, and you screw these tacks in and you go back and forth across the defect, and then you cinch the suture closed. The cinch is the same cinch that is used for the overstitch device. I think there's some thought that this device is another closure device. We don't have a controlled trial with it yet. We do have multiple published observational experiences that would suggest it. It looks like it could be pretty effective. I think it's nice when you have, like in this case, this lesion is draped over this fold. It's a little bit hard to access with clips the portion of the defect that's on the sacral side of this fold. You can go over with the scope, put a tack in on the sacral side, and then come back to the rectal side of the lesion, put another tack in, and then you go back to the sacral side, and then back to the rectal side, and then pull the whole thing together. Now if you try to cover too much ground with this, you try to get too wide an area, it doesn't work well. Sometimes you will end up putting one of these on, and then putting some clips on to close the rest of the defect, or using two of these devices with a really wide defect. We don't have randomized data yet. I think there's some thought that the problem with clips in the left colon is that the clips get knocked off, because the luminal caliber is smaller, and there's more solid stool, whereas with these sutures, you've got a better chance of the device staying on there. I just briefly mentioned artifact. I talked about this in the quiz, so I don't think I need to cover too much more that you need to be able to recognize the artifacts that these clips make. Our basic rules for closure then, 20 millimeters or larger, removed with electrocautery, and non-penunculated lesions, and proximal to the splenic flexure. If it's in the distal colon, there's no randomized controlled data that say that you have to close the defect at all. There may be some portion of the defect where you think there's a muscle injury that you want to close. Yes, close that for sure. There may be some place where you had significant amount of arterial bleeding, and you feel like you should close that. Perfectly legit to put clips directly onto the submucosa, not touching any normal mucosa. That is a safe thing after EMR, but you don't necessarily have to close left-sided defects. I'll stop there. Anything we should talk about with regard? You guys have comments about that? I think I answered most of the questions. Let's see. There's some questions that are coming up in the chat box. We talked about this. Please send all your questions to the Q&A box if you can. Let's see. This X-tach, what is your initial sense with the X-tach? I have a feeling, I mean, this is what I feel is like, you know, there are two aspects to clipping. One is you're approximating the edges of the defect together, and the second one is the compression of that base with the clip. What do you feel? Is there enough compression? I know the X-tach can bring the edges together, but is there enough compression of the base of the defect where there could be an impending blood vessel ready to bleed? Well, I mean, I think that's what we don't know. I mean, there's, you know, the people who are real enthusiasts of overstitch like the fact, first of all, that it's a full thickness suture, right? So you do have the compression that you're talking about. When you're using X-tach, you're basically putting these tacks into the submucosa and pulling the edges together. So we don't have a randomized controlled trial yet, but, you know, we've got these series where there seem to be very low rates of bleeding, where we would sort of expect the rate of bleeding to be higher. I don't know, Amit, we don't, I don't know that we know that we have to get compression, you know, maybe pulling the edges together over the top of the vessels, you know, if there's bleeding starts, a clot forms underneath that hood or that tent and it stops. I do think that there are skeptics about the whole idea of X-tach. I will say my own experience with it has been good with, I don't think I've seen somebody bleed yet after closing something with X-tach, not that I've done tons and tons of them. And I, but I do think what you're saying is that we may just be opposing the edges. And I think, you know, one thing that's come up, for example, if you had a very large defect, you know, that what might require overstitch, but you don't know how to use it, could you use X-tach to bring the edges close enough together that you could then close it with clips? It's initially too big to close with clips, but after pulling the edges together with X-tach, now you could close it with clips. There might be some value for initial, you know, opposition of the edges and then another form of closure. So I don't know, we're awaiting, I think we're awaiting more data about it. I think the Mantis technology is good to grabbing the edge and taking it to the other side and then opening the clip. And so I've been able to close reasonably wide defects, but yeah, there are some defects that with clips it's impossible to close. I mean, if they're like five, seven, eight centimeters in size. Yeah. A couple of questions on cold snare EMR. Everyone's asking, a few folks are asking, do you do snare tip soft coagulation after cold snare EMR? Is that recommended or not? So yeah, that's, this is a very common question. I think everybody's, everybody has this on their, on their mind. I think that Daniel, you know, Rintel in Montreal has, has started doing this. He's, he like thinks of every, of every variation of EMR and testing it early, but we don't have evidence to support it. So I I'm not doing it. And, and it gets at the fundamental issue of why is the recurrence rate for large adenomas higher than it is with, with cold EMR than it is with electrocautery. I suspect that the problem is that the, the level of the reception is superficial. Now here's, here's the deal. You know, we, there's actually a paper in this in, in I, I think it was endoscopy just in the last week or two from Michael Burke's group about unrecognized incomplete resection of the muscularis mucosa. And I, I do think that there, you know, there's a, when you're doing hot EMR, you know, sometimes we cut the polyp in the wrong plane. We skim along the muscularis mucosa instead of being in the in the submucosa. And you can actually see that muscularis mucosa. It's a very thin layer of white muscle. It's not the muscularis appropriate, but it's, it's visible. And you know, a clue to it during hot EMR is when you see a lot of vascular oozing, because the submucosa doesn't ooze the same way that the, you know, when you transect through the polyp the way it oozes. I think you can see that sometimes during cold EMR. You can see that you basically have not really gotten into the submucosa. You've left some muscularis mucosa there. And if we inspect carefully, you know, we, we may be able to re-resect that area and get down into the level that, that we want anyway, but I right now, I wouldn't be burning the edges of cold EMR sites. I think it has to be the base because, you know, we are reasonably okay with shaving off the margin, normal margin, normal mucosa. So, I mean, there are two ways you'll have recurrence, either the base or the margin, right? If you've cleaned up the margin pretty well, it has to be the base. And the reason for it being at the basis, your depth of resection is very superficial. And that's why maybe all these initial studies that had flat, less bulky polyps showed good, very low recurrence rates. And then when you have unselected polyps, where you have bulky SSI lesions, I feel in those cold doesn't work that well. Yeah. It's also, I think it's always a question because it's, it's completely inconsistent because we have on the hot side, the, the EMR site, whether it's conventional or such, you have like now the movement and data to show you have to burn the edges. This is already in a in a specimen that's been burned. Right. And then you have on the cold side saying we don't need to, so it's, it's just, it's very confusing, I think, because it's completely two opposite positions and rationales that conflict with each other. Right. Not only about safety, but I'm saying like, if you're like about recurrence and it's, it's, it's, I think the question always arises because it's a bit, it's a bit contradictory. I agree. It's contradictory. You know, even the data is contradictory because if you, if you'll remember, Michael Burke did a study not a controlled trial, but a historically controlled trial where he did he did EMRs and then he resected the entire margin and that did not reduce the recurrence rate. Why should that not reduce the recurrence rate when thermal injury to the margin is the recurrence rate? So I think there's, I think there's some things about it that, that we don't understand. And I, I guess you could also argue, well, there's no evidence that snare tip soft coagulation to the margin increases the complication rate. So, you know, maybe, maybe, you know, maybe it would be safe to do it. I myself, I would await, I would await a controlled trial before I start, you know, systematically burning the margin of cold EMR sites. I just think there's not enough evidence that it will help. And I, I agree with Amit. It's probably that we're not consistently deep enough to get every cell, at least with adenomas seems to work with serrated, but you know, we all don't yet don't should have the feeling that serrated lesions just. They cut so much easier. Yeah. The middle of the resection and the next area, it looks like it's already loose and it's like, it's not in the sub mucosa. Yeah. You don't see that with adenomas. Now, even when you lift serrated, the lift is so different than with your adenomas.

Endoscopic resection procedures

Closure techniques

Delayed bleeding

Clipping

Suturing

Anticoagulation

Lesion size and location