That's obviously a difficult talk here, because we're trying to bring evidence into endoscopy, which is not really our home in endoscopy, but it's becoming there. So does the data determine which resection method we should use? So we'll see lesions in practice. You'll see lots of lesions. And my goal wasn't to say, what should we do for this lesion? It's to say that every lesion is different. And when we decide how we're going to use evidence, we need to consider the lesion itself. And then we have so many things we can do for it, right? We have a menu of choices now. We have conventional, it doesn't even fit on the menu, right? Conventional EMR all the way down to ESD. So many different things we can choose for each of these lesions. And then beyond that, we have people, right? We have people who have different skills and expertise they're bringing to these lesions. And so when I say, what does the evidence say? I need to think about the lesion, all the choices I can use, and who the people are who are doing the procedures. And that's what makes this a challenging topic, right? So how do I choose the evidence? I have to think about polyp location, polyp morphology, and individual expertise when I say, what should I be doing next? And so this was mentioned earlier in our discussion. The risk of occult malignancy does vary based on the location in the colon. And this is one study from Michael's group, which shows the risk of cancer as you progress towards the cecum. So 11% in the rectum, 17% in the sigmoid, and then it starts to drop down as you go to the right colon. So we think a lot about location when we're thinking about whether or not this polyp may have malignancy or not. And you'll see different numbers, but everyone agrees that left colon, especially the rectum has a higher risk. So everyone loves to sort of say that location, location, location, right? That's what matters. So if I tell you I have a beachfront home, you're like, that's great, but not all beachfront homes are the same, right? And so not all rectal lesions are the same, not all sigmoid lesions are the same. You need to not just be worried about location, but also everything that Tanya spoke so well about in terms of morphology. And she showed very nice slides on features of a malignant colon polyp. I'm not going to go over these again, but try to read some of these papers, try to look at these images over and over and understand that that non-granular polyp is going to have a higher risk of submucosal invasion. Understand when you have a very, you know, homogenous granular polyp, and then all of a sudden there's this big sessile component in the middle of it. There's a reason that's different. And that's because it also has a higher risk of malignancy. And then again, you see that depression in that last image. So keep this in your head, not just location. And this is a very nice paper that came out last year that shows where we talk a lot about location, that location of a polyp in the rectum is a higher risk. Michael's group showed nicely that if you actually just use looking at the polyp and determining in these rectal lesions, whether you think that there's a reasonable risk that this is invasive cancer based on the morphology and the kudopip pattern, those patients can go to ESD, but a majority of the patients actually can get EMR in the rectum and the obviously the technical success and the cancer risk after EMR was very low. Main point being that you can identify patients who can get EMR in the rectum. If you are really, really good at viewing the morphology, which I wouldn't say all of us are, right? This is more of a proof of concept. So with that background, my task is to really summarize the evidence comparing various endoscopic resection techniques with the assumption that we can reliably identify a malignant co-rectal polyp. And again, the caveat being, we're not talking about surgery anymore. We've moved beyond as a field, all knowing that endoscopic resection is superior to surgery for these polyps. So there's a lot of questions because of all the menu choices, right? When you talk about evidence, you could be comparing so many different things. I'm going to talk about conventional EMR versus ESD, cold EMR, underwater EMR, and hybrid ESD in the six minutes I have left. So my favorite cartoon, this is endoscopist discussing ESD. When we say it's not a rocket science, we mean it's something far more complicated. And this is how I think the ESD people like to think about things, right? We can make it very traction with tooth floss, whatever they're doing. They're doing a lot of stuff in there, right? So it seems complicated. This is the current summary of randomized control trials comparing colon EMR and ESD. So as of right now, we don't have any high level data to guide us on this topic. There is some literature out there, and I'm just going to summarize my opinion on this, and we can sort of debate it in the discussion later. My opinion for colon lesions, EMR for nearly all colon polyps. And then if you're really good at looking at morphology, you can use it for select rectal polyps, otherwise ESD for rectal polyps. Obviously the caveats being that EMR requires margin ablation, that ESD complications vary widely by experience. And so if your ESD complications for the colon are very low, that may be a reasonable primary option and understand that we can manage all endoscopic recurrences. So what about cold EMR versus conventional EMR? You already saw the debate sort of starting earlier. There is a randomized trial that just completed her enrollment that Dr. Pohl was a PI of, and we should be seeing some of this data coming out going forward. There is a lot of data out there that is sort of prospective pre-post type data. This is another nice study that Michael's group did that showed basically that the risk of cold EMR versus conventional EMR, as well as the unblocked resection rates and recurrence rates. So what this shows is when they switched to cold snare EMR for serrated lesions, specifically serrated lesions, the delayed bruining rate went to 0% from 5%. The deep neural injury went down from 3% to 0%. And the procedure times were roughly similar, showing a very, very low risk of serious adverse events. And the reason we all feel comfortable doing this now is because the rate, the risk of recurrence may be there, but they're very easily managed recurrences, right? So we can, we can always take care of them. And so a lot of people have moved exclusively to cold snare EMR for serrated lesions. I think the data is a little bit more mixed for adenomatous lesions, and that's why I'm looking forward to the trial that just completed. We've seen a higher residual or recurrence rate after cold snare polypeptide for adenomatous lesions. And my personal practice is to actually only use cold snare for serrated lesions and not for adenomatous lesions. But again, we should have higher quality data coming out soon. Underwater EMR is another one that actually has pretty good data out there in terms of randomized controlled trials, but it hasn't shifted practice as much as you might think. This is a nice trial for 10 to 20 millimeter polyps where they compared conventional EMR to underwater EMR. And this is again, as a randomized controlled trial, the R0 resection rate was greater for underwater EMR and the on-block resection rate was greater for underwater EMR. So, and there was similar bleeding rates and no perforation in either group. And this is really going against years of conventional wisdom. And it really probably gives some people on the panel a little bit of anxiety to see this still, but this is good data out there now saying underwater EMR is safe and effective for this intermediate size. And then this other trial has just come out in GIE this year, showing the same thing that underwater EMR actually was safe and effective and the risk of recurrence for conventional EMR was seven times that of underwater EMR. That said, they did not do margin ablation in this study. So that probably impacted their recurrence rate. At the minimum, we have at least a couple of high quality randomized controlled trials that show it's pretty safe, that we're not getting tons of perforations because people are doing underwater EMR. So it's something else to put in your toolbox. Hybrid ESD, you know, this at minimum involves circumferential incision around the polyp may also include some dissection. I think this is something interesting to think about. You know, there's been a couple of trials out there. There's one RCT that just came out from China that basically shows that when you do hybrid ESD, or at least do a circumferential incision around the polyp, you can potentially increase your on block resection rate because it helps you really isolate the polyp a little bit better, adds a few extra minutes of time, but without any increasing complications. So this is the idea that basically you're not just marking the polyp with a cotter, you're actually sort of isolating the polyp with an incision. And this is something that's something reasonable to consider in your practice. But we could use some more data to show whether it's actually adding a lot of advantage. So what's my answer as of today for this, try to put together all the data. So if we look in the colon, if we suspect invasive malignancy, then we think about surgery and then ESD for very select cases, if we can say that we think this is a superficial submucosal invasion. If there's no suspicious features, EMR, conventional EMR is still the gold standard, but we're getting a lot more trials out there that are suggesting that for certain lesions, we need to be thinking about other options for serrated lesions, cold EMR. There's a lot of people who have switched exclusively to that for these lesions. And for ad nominus lesions, we have some pretty good data that underwater EMR is good and might be something you want to consider in your practice or hybrid ESD. For rectal lesions, it's more complicated. If there's suspicious features and you really need to look and you need to be confident that you know how to look, there are lesions out there you could probably remove with no suspicious features you can remove with EMR. If you're not sure, ESD is probably your best bet at this time. So if you're not really sure, I would not do a piecemeal EMR and then have to go back to the patient saying there was invasive cancer and you're going to need some sort of alternative therapy. Thank you for time.

resection method

endoscopy procedures

lesion

occult malignancy

colon polyp