A lot of this will be overlap, but that's good. Managing recurrence. So, as we talked about, recurrence is not uncommon after EMRs, and meta-analysis showed that it's seen in 14 percent, and late recurrence can be seen in 4 percent, and you have to have a strict surveillance colonoscopy protocol after EMR to be able to detect as well as manage, and high recurrence rate will entail additional cost because you'll have to do more colonoscopies, high morbidity, and the perceived risk of referral to surgery. So what are the risk factors for recurrence after EMR? Larger size of lesions, unfavorable or difficult to access locations, especially if the polyp was at the IC valve or behind folds, sessile depressed morphology, non-lifting areas in the original polyp due to submucosal fibrosis from previous interventions or tattoo injections, interprocedural bleeding, advanced histology, high-grade dysplasia, as well as previous use of APC. So the Australian Michael Burks group has come up with this tool called ASSERT, Sydney EMR recurrence tool, where they had three predictors of recurrence, size greater than equal to 40 millimeters, interprocedural bleeding, and high-grade dysplasia, and they gave two points for size greater than 40 millimeters, one point for bleeding, and one point for high-grade dysplasia, and if your ASSERT score was zero, then the negative predictive value for recurrent adenoma was 91% at the first follow-up colonoscopy. Now there's another complicated scoring system called the SMSA score, which includes size, different sizes given different scores, morphology, pedunculated sessile flat, site left or right, and access. So a little more complicated, but you compile this and you come up with grades, grade one to four, and higher the grade, higher is the recurrence or higher is the risk of recurrence. So if you have SMSA grade three or four, then the risk of finding recurrence or residual adenoma on follow-up is much higher, and this was actually corroborated by the Australian group where they found that the odds of recurrence was much lower when the grade was two or three compared to grade four. So but it's a little more complicated scoring system. So what are the risk factors that have been shown in other studies? The CARE study by Heiko Pohl showed that if the incomplete resection rate was significantly higher for sessile serrated adenoma polyps, as they were called at that time, versus adenomas, and also for larger polyps compared to smaller polyps, and also it varied according to the endoscopies, the risk, incomplete resection rate ranged from 6.5% to 23% between different endoscopies in the study. But a subsequent study showed that the recurrence rate in adenomas was actually higher than in SSLs or SSAs. And over a period of two years, the recurrence was significantly higher for adenomas compared to SSLs. And actually, if you did a subgroup analysis, it showed that there was an eight-fold higher recurrence rate for polyps 20 to 25 millimeters in size when they were adenomas versus SSLs. So contradictory evidence, I think now the current thinking is that if you do a good resection, you look at the margins carefully with a white light and NBI or electronic homoendoscopy, the risk of recurrence with SSLs is lower than adenomas. Now why only blame the polyps? What about the endoscopies? This study from Mayo Clinic showed that with experience, the recurrence rate goes down. As endoscopies become more and more proficient in removing these lesions, there's lower risk of recurrence. And this was shown over a period of time in three endoscopies. And we also know that the experience works because in this study by Dr. Michael Burke, in which they compared, this was a study in which they had SNARE-TIP soft coagulation versus no coagulation, they found that in the control arm where no SNARE-TIP soft coagulation was performed, the recurrence ranged from 0% to 31% between different endoscopies. So we also have to take kind of the blame when we see a higher recurrence rate. And this was further confirmed in a meta-analysis where the recurrence rates differed significantly between expert and non-expert endoscopies between 8% for incomplete resection versus 18% for non-experts. So how do we reduce the recurrence? The main issue here is we should treat the margin. That is standard of care now. This is shown level one evidence that recurrence after SNARE-TIP soft coagulation of the margin was 5% compared to 21% when there was no treatment performed. And this should be done. Technique is pretty simple. You take the tip of the SNARE and use soft coagulation, effect 405, 80 watts, and go around touching the margins to ablate the margin. Now this was again confirmed in a subsequent 1000 Legion study where after complete thermal ablation, which was successful in 95% of the patients, the recurrence rate was only 1.4% at the first surveillance colonoscopy. So I mean, unquestionable data that we should be doing this as a routine after EMR, hot EMR SNARE. So we can also ablate the margin with APC. This is a study from Dr. Raju that showed that with APC, if you ablate the margin, median size of the polyp that was taken out was 35 millimeters. The recurrence rate was very low, around 5%. Then recent meta-analysis has basically confirmed what we have shown here, that the pooled risk difference after SNARE-TIP soft coagulation is minus 0.16 and after APC is minus 0.26. So negative number here means that there's lower recurrence when you ablate the margin compared to no ablation. The pooled recurrence rate after SNARE-TIP soft coagulation was only 4% compared to 9% after APC, significantly better than no treatment of the margin. Now the question then is, which is better? This was actually answered by Doug's randomized controlled study where you had three groups, patients randomized to either no treatment or margin ablation APC or with SNARE-TIP soft coagulation. And both APC and SNARE-TIP soft coagulation were better than no treatment in terms of recurrence, although numerically SNARE-TIP soft coagulation was better compared to APC, but this was not statistically significant. The other advantage of SNARE-TIP soft coagulation was less time and less equipment, so less costly. So the conclusion was, although both are superior to no margin treatments, SNARE-TIP soft coagulation should be the preferred strategy given it is faster, more efficient, and less costly. What about margin marking? This was a study from Dennis Yang where he actually marked the margins of the polyp with SNARE-COTRI, and actually the margins were three millimeters away from the margin of the polyp. And what he found compared to historical controls is the recurrence rate was significantly lower on the follow-up colonoscopy at 8.1% compared to 29%. So basically, the aim here is to resect the polyp as well as this normal margin so that the COTRI marks are incorporated in the resection, and that was shown to show lower recurrence rate. However, Michael Burke's study where they resected five millimeters of the normal margin around the polyp did not show any reduced recurrence rate on follow-up. So then the question becomes, if you're resecting five millimeters of normal margin and there is no decrease in the recurrence rate, what is the cause of the recurrence? So let's evaluate this. I mean, the reason for recurrence is that when we are resecting piecemeal, we are leaving behind microscopic amount of adenoma between these areas of sequential SNARE capture. And this can happen at the base or this can happen at the margin. And there was this study that actually they proved this by sampling the margin as well as the base with endorotor. So what they did was they resected the polyp and also five millimeter of the normal mucosa around the margin. And following this, they sampled the base as well as the margin with endorotor. And they found that there was 19% residual adenoma in the margin sample as well as 24% residual adenoma at the base. So we're not only missing adenoma at the margin, but we are also missing at the base. So does ablation of the base help? And so this was a recent publication where prospective data from three multicenter registries was evaluated where polyps were removed with no ablation, only margin ablation by either SNARE tip or hybrid APC, and margin plus base ablation with hybrid APC. And the recurrence rate with combined base plus margin ablation was 0.9%, significantly lower than the other two. And this was also true for lesions more than four centimeters in size where the recurrence rate was only 2.4% when both the margins as well as the base was ablated. Now, the bleeding rate was not significantly different. There was a higher rate of abdominal pain, numerically higher rate of abdominal pain in patients who underwent both margin as well as base ablation, but this was not statistically different. Other way of reducing is by using underwater EMR. We discussed this. The rate in this meta-analysis was with underwater EMR, the recurrence rate was only 6.8% compared to 19% with conventional EMR. Cap-assisted EMR has also been shown to decrease the recurrence rate. This is a special type of a mycosectomy cap where at the distal end of the cap there is a gutter that can accommodate an open SNARE. So basically, after you lift the lesion, you place the cap over the lesion and gently suction the polyp into the cap and close the SNARE. At least in this study, which is a multicenter randomized control study, they showed that the recurrence rate at one year was significantly lower compared to when the cap was not used. Now, how can we reduce the recurrence in our practice? This is actually an outstanding study. I don't know how they accomplished this. It can only be done in Europe, in the Netherlands, where they had 30 hospitals with 59 endoscopies randomized to either going through a two-day training versus no training. So endoscopies either went through a two-day training that included hands-on sessions, lectures, case-based discussions. They were provided with e-learning modules developed by experts on all different aspects of EMR. And the other group just went about doing what they were doing. And what they found was that after the training, the recurrence rate in the group that underwent the training was 13% compared to 25% in the group that did not undergo training. More importantly, the recurrence was unifocal in 92% of the cases where they had undergone the training compared to 76% were in the control group. Complication rates were not different. And the caveat here is this positive impact of training actually did not have an effect on polyps that are more than four centimeters in size. So that was the downside that for polyps that are more than four centimeters, there was still a very high recurrence rate, which was similar in both the groups. But still a fascinating study to show that the impact of training, short training, reduces recurrence. So how do you recognize? The next step is you've had recurrence, everyone will have it in best of hands. How do you recognize it? You have to inspect the site. You have to inspect it with high definition white light and electronic comendoscopy. You should be conversant with the different patterns that we've discussed during this day. And you should be able to differentiate between residual or recurrent adenoma with compared to post clipping artifact. Now, this is the study that Dr. Rex had aware, in spite of careful inspection of the scar, when he biopsied the scar, there was a small proportion, about 6% to 7% cases where there was residual adenoma in spite of him not able to identify it visually. So that's the importance of at least doing some random biopsies of the scar. Now, these are the three types of post clipping artifact that we should be aware of. Here is an example of how you identify the scar by distortion of the folds, a little bit of depression here with some nodularity. So this area had been clipped, this lesion had been clipped and you examine with NBI, you see a very bland pattern. This is the type three type of clipping artifact. And if you recognize these under NBI, especially when you focus with near focus, you should not worry about this being residual adenoma and there's no reason to start snaring these out. How do we do this in recognition of residual adenoma? Actually, if you're conversant with the patterns, you do pretty good. This is the study that showed that the sensitivity to identify residual adenoma using high definition white light as well as NBI was 93% with an accuracy of 94%. And what they showed was that it is better to use a combination of white light with NBI compared to only white light alone, where the sensitivity of the combination or combined approach was 93% compared to 67% when you use the white light alone. And another study from Mayo showed similar results that when these scars were assessed by four endoscopists, the sensitivity when they used high definition white light with NBI was greater than 90% with an accuracy of 93%. And when you make a high confidence diagnosis of recurrence with NBI near focus, then the negative predictive value was 100% with a sensitivity of 100%. Now, you have the recurrence, you've examined the scar, now you have to treat it. What are the different ways of treating it? So the stepwise approach that I use is, depending on the size of the recurrence, I always want to try to remove as much as I can, either using the submucosal lift and snare technique, followed by the cap suction technique or underwater EMR. After I've removed whatever I can, then I try to remove whatever is remaining with avulsion. And the different techniques are hot avulsion, cold avulsion with snare tip soft coagulation. And after that, you ablate, and the way to ablate is with snare tip soft coagulation or with APC. And then there are miscellaneous methods, either using the full thickness resection device, which can be tricky with the fibrosis and scarring, or using the endorotum. So let's review a couple of examples, quick videos. This is the scar here, you can see the tattoo mark you examine it with NBI it's at the edge, the residual lesion is at the edge of the recurrence is at the edge of it, you know it's small. You could use different techniques I decided to do float this with water and just try to remove it with underwater EMR technique is not really EMR. It's a very small polypectomy so but nevertheless, it came out very easily with just one. One passage of the snare and using snare cautery and then you look at the area you examine it with white light and NBI to see if there is any residual and if there is then you can treat accordingly. Otherwise, this is pretty much the end of this recurrence, and then you have to keep following them up I bring them back in a year to take a look at that area. This is a little bit of a different challenge here you can see it's more scarred down. Looking at it, I had a feeling this would not float up with underwater and will be difficult so here is the normal inflamed area here, the recurrence, or the recurrence is right here you can see the nice type two pattern. So, too small to snare, so I decided to do hot avulsion, the technique stays the same, as we've discussed, take the hot biopsy forcep, grab the tissue, and then you just avulse it, you peel it, it's like peeling it off using endocut. Pressing the yellow pedal, and you pull the biopsy forcep towards you, or towards the center of the lumen just basically, as the name suggests, avulsing the tissue away from the wall. So, here we are trying to do it, piece by piece, you have to have a little bit of patience work closely, close, you have to be close to the lesion, you grab it, and then you avulse by pulling peeling off, pulling the forcep towards the scope and slowly by slowly you can start, you see that you're getting rid of the remaining adenoma that there was, which was pretty scarred down and would have been very difficult to remove either by snare cautery or by underwater EMR. And then after, as Doug had discussed, after I remove whatever I can with the avulsion, I try to ablate it with the tip of the snare using soft coagulation, which is also very safe because it doesn't go too deep. You can just touch up that area with the tip of the snare to get as much or ablate as much as possible. So here I'm touching up the edges here, and you can also do it at the base to ensure that you've gotten as much, any remaining microscopic adenomatous tissue with this ablation. So that is the whole process. And obviously at the end, this is how it looks. I mean, obviously it doesn't look as pretty as your nice EMR, but that's because of all the scarring here. So this is another example, very similar, very dense fibrotic scarred down tissue there. We remove whatever we could with snare cautery. You can see the nice blue dye, whatever is not amenable to resection by EMR technique. Then you go with hot avulsion. Again, the same process, grabbing the tissue, pressing the yellow pedal and pulling the forcep away towards the scope and just peeling off the tissue as we go along. It's pretty effective. Just have to have the hot biopsy forcep, which has completely gone out of vogue, has made a resurgence now because of this reason. So you have to have that forcep with you in your toolbox. So here we are almost towards the end of it and looks reasonably okay. You've ablated whatever was remaining with the snare tip soft coagulation and that should be the end of it. Now, recurrence could be bigger. I mean, this was a patient referred to me by a gastroenterologist who had been working on a polyp for a few years. This, as you can see, it's like pseudo depressed in the center. You get a good look with your NBI to make sure there's nothing concerning there. I thought that central portion was a little concerning, but nevertheless I decided to take it out. So this is where you can't just do hot avulsion alone. So here I'm floating it with water, trying to do underwater EMR, get as much of the tissue as I can with snare resection, snare underwater EMR, and then whatever is remaining, if there is, try to use another technique like avulsion or what have you. So you have floated it up. I'm getting my snare around. Again, you have to torque a little bit, pushing the snare. And again, coming to Tanya's point, I mean, this is pretty safe. Obviously the concern here is always that are you grabbing muscle? But I mean, data has shown that the risk of perforation is very low. So here we've gotten a big chunk of it out. You can see the tattoo, which is not helping. It's probably causing more fibrosis, if anything. So here I'm trying to get the second portion. Again, I'm just doing everything underwater. You have to have a good prep. You can't be having a murky prep here because you need good visualization. You want to be sure what you're grabbing is tissue. So here we've almost gotten most of it out. I'm trying to suction a little bit. Very gentle, not too much because it's already floated up, but you can have a little bit of suction. And here we are coming towards the end of it. And let's see what we have remaining. There's a little bit remaining, and this I removed with a hot biopsy forceps. So sometimes you have to use multiple techniques. I mean, you remove the bulk of it by snare, then whatever is remaining, your waltz, and then your blade. So that is the standard way I approach these, depending on how much recurrence or residual there is. Then this was pretty impressive. This was actually a very large polyp that I dealt with on a lady who had been dealing with this polyp for a couple of years. It was circumferential. It was about nine centimeters long in the rectum. I did a two hour EMR to remove as much as I could, and then brought her back in three months. And this is what is remaining. Just at the distal edge, there's already a stricture forming, but I was able to pass the scope through it. I examined the proximal portion, which was devoid of any adenomatous tissue. So everything was condensed at the distal edge. So here, because this is pretty fibrotic, it's the rectum, which is thick-walled, I decided to use the cap suction technique. So I'm opening, I'm staying close to the polyp, opening the snare, suctioning the residual into the cap, and then using snare cautery endocut to cut it. So actually it was pretty effective. Got out big pieces. But I mean, this was an impressive polyp, one of the biggest, if not the biggest one that I had removed from the rectum. So compared to what we dealt with, this recurrence or residual, whatever you call it, wasn't very bad. And we were able to use snare cautery to be able to remove it. Here, I felt there was a little bit of a divot here, but there was no perforation. And slowly and steadily, we worked all around. As you can see, it's all around that area. There's chunks of adenomas remaining, and we were able to kind of get all of it out. And obviously, she's waiting to be scoped back. So I don't know what it will look like, but I have a feeling that whatever is residual will be very small amount, and we should be able to deal with it without any problem. So that's another technique, the cap suction technique that works, especially in the rectum, which is thick walled. You should have good confidence in doing it. So how do they fare? Underwater EMR has been systematically studied and was shown to actually do better than conventional EMR for residual recurrence with higher unblock resection, higher complete resection, and less recurrence, only 10% on second follow-up colonoscopy compared to conventional EMR. Which showed a 39% residual or recurrence on the follow-up. Now, what about CAST? The Australians are big into this. Michael Burke's group has shown that if you use snare cautery followed by cold avulsion snare tip soft coagulation, you have successful treatment in 92%. And the mean number of treatment sessions needed to successfully treat the recurrence was only a little more than one, and 85% required only one session and more importantly, surgery was needed in less than 1%. So the bottom line for these recurrences is that simple cost effective techniques are safe and effective in treating recurrence. Rates of long term remission are more than 90% and the resources and intensive techniques, such as ESD or full thickness resection, or even referral to surgery are necessary in only very selected cases. Now, Dr. Rex talked about FTRD. We know how it works. You have to pull the lesion with this grasper into the cap, deploy the cap, and then you have a pre-opened snare in this rim under the edge of the cap, which closes and cuts through. Initial studies have shown that this is good for scarred down lesions or recurrences with an R0 recurrence rate of 79%, perforation rate of 2%, and bleeding of 5%, but this is a mixed match of lesions which were difficult to remove, not necessarily just recurrences, but definitely an option for small recurrences that we should have in our armamentarium. The new kid on the block is this endorotor, which we who do therapeutic endoscopy, USERCP work, we've been using this for necrosectomy, and this is a kind of a newer option for these scarred down lesions where you have two cannulas, and the inner cannula is rotating inside the outer cannula, and both of them have an opening. You apply suction, and you place the cannula over the lesion, and it sucks the lesion into the cannula, and the inner rotating cannula basically shaves or cuts the lesion. And all this is suctioned into a trap. So initial case series showed good success rates, but this was tempered by a recent publication that I just found that has shown that although they felt that the technical success rate of dealing or treating the recurrence was 83%, there was still, in half the cases, there was persistent lesion seen on follow-up, and there was one perforation and four bleeding. So something to think about, but still not ready for prime time. That would be my take on this. So, in conclusion, recurrence is not uncommon after EMR of large polyps. You should anticipate recurrence when you deal with these polyps and their risk factors that have been identified. You should try to reduce the risk of recurrence by applying good technique during EMR, which we've talked along during this day, and also to treat the margin and whether we have to treat the base. There's more data to come out on that. We'll have to have good randomized control studies to show whether that is effective also. We have shown that good experienced endoscopists have lower recurrence rate, and not only that, training can improve your technique as well as decrease the recurrence. When you're dealing with recurrence, you should be able to recognize it and should be able to differentiate it from post-clipping artifacts. You should always biopsy the scar. I would do that even if I don't recognize any recurrence. And then treat with appropriate methods that we discussed, and always follow up for late recurrence. And the bottom line is that majority of these recurrence are successfully treated by endoscopy and therefore surgery is avoided. I think that's it. Thank you. Okay, that was another fabulous talk, Amit. Thank you very much. Let's see. Um, you know, they're, they're just some maybe general questions I think we've gotten through most of them. And, you know, I really like the approach you take, which for the most part is to use basic tools that are available, you know, to all of us. I sort of think that for the most part for recurrences, we don't need fancy stuff like FTRD or like the endorotor. I think we can take care of the overwhelming majority of them with a snare and with some kind of an avulsion technique. So that was, so that was great. I'm trying to think if there's any other questions that somebody was asking whether we can ever use a cold snare for treating a recurrence. Yeah, so I avoid, I tried it initially when I was trying to start doing the cap suction technique just because of the, the level of comfort that okay if I get the muscular spropria I might, I won't probably cut through the cold snare but then once I got comfortable with the cap suction technique. I haven't used the cold snare at all because I feel, you know, because of the scarring and the fibrosis, as it is the cutting capacity of the cold snare is superficial. And with scarring, it's sometimes very tough to cut through the recurrent adenomatous tissue. I mean, so I don't use cold snare anymore. I don't know what your practice is. I would, sorry I have my camera off there. I basically agree with that. I think that when you've got a recurrence that's on a large EMR scar that the snare has a tendency to, it seems like it bounces off of the scar tissue and you just, you just can't cut through it again. Oftentimes, as well. I think there are times I noticed this even when I'm doing screening and surveillance exams. You know you people have been scoped at a variety of different places. You can see, for example, a very small serrated lesion with a scar next to it, and you know it's a place that somebody has previously taken off a serrated lesion, and I will sometimes I just deflate a little bit so that this that the cold snare can dig in. And if I can capture that a very small recurrence that I think was on kind of a small scar and get a rim of normal mucosa around it in the same way that I would any other kind of diminutive polyp, then I will do it but I agree with you entirely that for the most part, with these recurrences I found it more reliable to to, you know, snare or a vulse the tissue off and I, I like hot evulsion over over cold evulsion but we still do not have a direct comparison of hot versus cold evulsion. Tonya any comments. No, I agree that I approach recurrences with cautery. Okay, for all the reasons described like technically that capture what you're potentially treating. I think even if you get it into the cold snare by suctioning into the cap sometimes it doesn't cut through the fibrotic tissue. And then either you start pulling at it and I mean it's just, it's not. Yeah, and and then at that point too it's, you're going after a recurrence so I feel like the intent is then to not have recurrence on that one right I mean I'm just in the sense of burning versus. Yeah.

endoscopic mucosal resection

recurrence

risk factors

ASSERT score

SMSA score

treatment techniques

follow-up colonoscopies