Our first speaker presenting the counterpoint on cold-snare polypectomy for polyps large and small is Charles Kahi, Professor of Medicine from Indiana University. Thank you, Asma, Peter. It's an honor and a privilege to be here. So I have the charge of defending cold-snare polypectomy for a variety of polyp size ranges. And I always start this talk by remembering how I learned polypectomy. I was in fellowship not too long ago, I like to think. And honestly, back then, it was largely based on empirical evidence and what my attendings, largely subjective preference, was very few objective data to support what we were doing or not doing. And now we're in the midst of what we call the cold revolution, which essentially means, Dr. Rastogi, that the indications and situations for which you really need to use electrocautery are shrinking and shrinking and shrinking. And this is not just a trend, it's here to stay. And it's based on very high-quality evidence, at least for some polyp size ranges. I'll just start by saying this. Cold-snare polypectomy is really, probably the single most important and the most commonly used technique that you'll ever need in your practice because the majority of polyps are small, less than 10 millimeter in size. And in that size range, the prevalence of advanced histology is extremely low. And so it follows that using cold-snare polypectomy can be reasonably done because you're not really worried about any submucosal invasion from these types of lesions. And to make a long story short, cold-snare polypectomy has basically an unassailable dominance in this size range for a variety of reasons. Number one, it is effective. And we see that with low incomplete resection rates. Very importantly, it's quite safe. And frankly, this was really the fuel that led to the cold revolution in the first place, the search for a very safe polypectomy method. The fact that you don't use electrocautery by definition means you have very little risk of delayed bleeding and essentially zero risk of perforation. And this also, it's very, very straightforward in every way to apply, to teach your trainees and to learn. So let's review some salient studies that support the statements that I'm giving. When you compare cold-snare polypectomy to cold forceps polypectomy, there's no question that CSP outperforms cold forceps. In fact, cold forceps tends to fail as soon as you get into the larger polyp size ranges within the less than 10 millimeter category. And once you get beyond three millimeters, the incomplete resection rate for cold forceps polypectomy is really high. And it has ranged in series from 10% all the way to 60%. When you look at aggregate data, a systematic review and meta-analysis of three RCTs comparing these two resection methods, you see that incomplete resection relative risk was significantly reduced with cold-snare polypectomy, 0.31. So 69% reduction of risk of leaving polyp tissue behind. And a more recent study, a network meta-analysis comparing a variety of cold resection techniques, including seven studies and 700 patients, showed that cold-snare polypectomy was superior to cold forceps polypectomy for complete eradication. And the odds ratios ranged from 2.5 to four depending on the type of snare or resection approach that was done. What about hot resection techniques? Well, let's start with hot forceps polypectomy, which I'll contend really should not be used in any situation, but this randomized controlled trial compared hot forceps polypectomy in the size range where you could compare them so that the smallest, the most diminutive among diminutive polyps in the three to five millimeter range. And cold-snare polypectomy, again, outperformed hot forceps polypectomy. There was higher on-block resection rate for cold-snare polypectomy, 99% to 80%. Lower incomplete resection rate favoring cold snares again. And the next item really is intuitive, but you have higher severe injury to the tissue specimen when you use hot forceps because by design, you're not just removing the polyp, you're actually obliterating it with the hot forceps. And there were no instances of delayed bleeding or perforation. What about hot-snare polypectomy compared to cold-snare polypectomy in the slightly higher size range within the less than 10 millimeter category? There's an important non-inferiority RCT that actually compared those two approaches, the Crescent randomized trial. And in this study, the incomplete resection rate was 1.8% for cold-snare compared to 2.6% for hot-snare, which was not statistically significant, and that was the primary endpoint. However, importantly, bleeding requiring hemostasis, as you might expect, occurred exclusively only with hot-snare polypectomy, no instances whatsoever with cold snares. What about cold-snare polypectomy versus hot-snare polypectomy in aggregate? And here I'm trying to synthesize significant data in a variety of studies that were very well summarized in the recent update to the Multi-Society Task Force guidelines and in several reviews such as this one and an issue actually edited by Dr. Shaukat. And cold-snare polypectomy really has comparably low incomplete resection rates compared to hot-snare polypectomy for small and diminutive polyps and similar retrieval rates. However, it has advantages in a variety of other domains. There's significantly shorter procedure time with cold-snare polypectomy on aggregate that's about seven minutes for overall, per procedure. There's a lower incidence of delayed polypectomy bleeding with cold-snare polypectomy and virtually no risk of deep neural injury. And you do have instances of immediate bleeding during the procedure with cold-snare polypectomy, but those are rare. And they very rarely actually require any active intervention. This is just a nice illustration of the basics of the technique of cold-snare polypectomy for small polyps where essentially the key is really to get the loop of the wire of the snare around the polyp and resect a generous margin of normal tissue with a quick guillotine transaction of the polyp, intensive lavage of the mucosal defect you left behind because this tamponides any small bleeders. And essentially this entire process, especially with a well-trained endoscopy tech takes only a few minutes. The guidelines support what I just said and this is really which belies the strength of the cold revolution. The Multi-Society Task Force now actually recommends cold-snare polypectomy for diminutive polyps and small polyps due to the high complete resection rates and safety profile. It recommends against cold forceps polypectomy due to high rates of incomplete resection but it does leave some wiggle room for those really pesky, very small lesions that are in areas that may be difficult to access with a cold snare. And in this situation, a standard large capacity forceps or a jumbo forceps can be considered. And it recommends against hot biopsy forceps due to high incomplete resection rates and the risk of complications. So we talked about small polyps. How far can the cold revolution go? Well, the evidence shows that actually it's going, it can go far and it's still going strong. Next up, the next size range, 10 to 19 millimeters. There's a role for cold-snare polypectomy in that size range as well. A randomized trial comparing cold-snare polypectomy to cold EMR and hot EMR assessed efficacy of these techniques for over 700 polyps all the way up to 20 millimeter from six to 20 millimeters. Now the complete resection rates were actually lower for cold-snare polypectomy, 82% compared to 94 to 95% for the other two techniques. But, and this is an important caveat, most cold-snare polypectomy failures occurred in the 16 to 20 millimeter size range within that big range. So there is a role for them in the slightly smaller size range. And importantly, delayed bleeding favored cold-snare polypectomy again with a very low rate of 0.8%. A very important entry in this field is a very recent non-inferiority randomized trial comparing basically the four major resection techniques, cold-snare, hot-snare, cold EMR, hot EMR for nearly 300 polyps in the six to 15 millimeter size range. The overall incomplete resection rate was 2.4% and all of these occurred in the hot resection techniques, hot EMR or hot-snare polypectomy. The IRR for the cold-snare polypectomy group was essentially zero and there were no adverse, serious adverse events in the cold-snare polypectomy group. And in addition, there was a shorter resection time for cold-snare polypectomy with a mean of 60 seconds compared to at least 100 seconds for the other techniques. The multi-society task force guidelines reflect some uncertainty in the size range. They suggest cold or hot with or without submucosal injection to remove 10 to 19 millimeter non-pedunculated lesions. However, the studies that I showed in the previous slide were published subsequent to these guidelines. So the field is in dynamic evolution and really the limits to cold-snare polypectomy continue to shrink. Let's push the ante a little bit. What if we go beyond 19, 20 millimeters and above? Well, for serrated polyps, and by that I mean sessile serrated lesions and large hyperplastic polyps, honestly, the sky's the limit. You can resect anything with that histology with a cold-snare. Now the caveat here is the literature supporting what I'm saying is quite heterogeneous because studies employ a variety of resection methods and sometimes include adenomas with the lesions that are reported. Some studies use submucosal injection, others do not, but most do. There is a merit to use submucosal injection for serrated lesions once you get higher than the, size range greater than 10 millimeters. That's my personal practice as well. One is you have much better delineation of lesion borders. You ensure a resection margin of at least two millimeters around the polyp and you facilitate transsection and really decrease the risk of immediate bleeding. And as you, I'll show a video here in a second, serrated lesions are not very tightly tethered to the underlying layers of the colon. So when you do a cold-snare polypectomy, the thing just lifts and is removed very straightforward manner. You don't need to use snare-tipped soft coagulation with cold resection, cold EMR in this situation, nor do you need to use clips in the great majority of situations. The technique is very effective. You have very low recurrence rates, from zero to 10%. The immediate bleeding rate ranges from zero to 3%, depending on the series. And again, there is no risk of perforation. So this is a section from IU, see here approaching a serrated lesion in the right colon, starting with a submucosal injection. As you can see, the dye really serves to delineate the borders of the lesion, so you can see what you're doing. And the initial resection, as you saw here, went primarily for a very generous rim of normal tissue. And this is by design, again. You need to get a full hold under the submucosal and make sure that you're resecting the borders very effectively, and then move on sequentially around the lesion, removing piece by piece. We're not doing anything here. We're just doing cold-snare, this is called EMR, but each resection is just like a mini cold-snare polypectomy. And with this submucosal injection, every piece really is very easily engaged into the snare, and the resection is just very straightforward. You see all these little bleeders. Invariably, they are of no significance whatsoever. You pump water into that mucosectomy defect, and that has a tamponading effect, which essentially arrests any bleeding in its tracks. Rarely have I ever needed to use anything additional for hemostasis in this situation. And there you go. The resection is done, and you move on. You don't need to do, you don't need to treat the edges of the polypectomy defect with coagulation, nor do you need to clip this lesion. So caveats. Where can we not, where do we not recommend using cold-snare polypectomy? Well, it's really difficult to transect in one go once you get above the size of 10 millimeters. I think we've all experienced this snare stall phenomenon, where you just, you grab the lesion, and you just can't go through it. So if you get above, in the 10 millimeter and above range, and you need to ensure at least a two millimeter margin of normal tissue, that means you're going to essentially convert to a piecemeal resection. And in that situation, you're advised to actually inject the lesion to make sure you're doing it adequately. Now, I mentioned the sky's the limit for serrated lesions for really large cold-snare polypectomies. That can be done for some large adenomas as well, although the literature is much more sparse with regard to that situation. And we don't, it can be done, but appropriate selecting criteria are not well-defined. And in the case of adenomas, it's not just a matter of size, it's also a matter of bulk. It's very difficult to transect large, bulky adenomas without causing a lot of bleeding, which obscures your field of vision. Of course, we didn't talk about pedunculated polyps. Once you get above the five to six millimeter stock diameter range, it's really not appropriate to use cold resection. You're better advised to use caudary in that situation for hemostasis. And finally, if there's any suspicion of subucosal invasion, cold-snare polypectomy is not recommended due to limited resection depth. So finally, the cold resection revolution, the wrap-up, is best for polyps that are less than 10 millimeters. It's gaining ground for polyps in the 10 to 90 millimeter size range. It's the best for serrated polyps at any size range, I would argue, and it meets all the requirements for high-quality colonoscopy. It's effective, it's safe, it's efficient, and it's practical. Thank you.

cold-snare polypectomy

polyps

technique

complete eradication rates

safety