It's a great pleasure to be here and I thank Ferger and Jason and Doug for inviting me. There is a learning resource for this EMR. We made a comprehensive learning tool for colonic EMR and it's available from the ASGE store, just recently released. So before we get to doing any of this, just the outline of the talk, so I want to talk about the problems in context, lesion selection, serrated lesion considerations, techniques to reduce recurrence, improving safety, and then a summary. It's a huge topic, so I have to sort of be somewhat selective. Just to remind you that in this, in 2016, I don't think there should be any benign lesions going to surgery. There's a suite of publications coming out in GIE in the next couple of months that clearly show that surgery does not offer the patient the best possible outcome. And at least in this study, our own study, multi-center, prospective, 1,000 patients, we only needed to treat 30 patients by EMR to avoid one death when we use two independent, well-validated surgical risk score models. So, and not only that, it's much more cost effective. So when we look at this, not to worry about the busy slide, but just to take account of the fact that we factored everything in, you can save about 10 and a half thousand Australian dollars per patient treated by EMR against surgery, and that's surgery which is complication-free. If there are complications from surgery, which happen at about 20%, then the cost of surgery goes up, the saving goes up to about $20,000. So, what then do we do when we come across a lesion in the colon, a large lesion that we need to excise by a complex technique? Then, first of all, we have to make an accurate assessment of its morphology, and the Paris morphology and surface topography, or whether it's granular or non-granular, really stratifies the risk very conveniently, and this is based on 480 patients from the ACE study that was published in Gastro in 2011, and you can see there's just a gradual step-up in risk from a laterally spreading granular lesion to one that has a nodule, so a 2A plus 1S granular lesion to non-granular lesions, and particularly if there's a depression. And we've extended this observation, which was presented at DDW two years ago, and we haven't sort of submitted the manuscript yet, but it will soon come, and in fact, when we exclude those who obviously have cancer because we can see a 5I or 5N pit pattern, and then we include more lesions, 2,500 prospective multicenter, we can see that these 2A granular lesions, no matter how large, the risk is very low. It's only 0.6% in the proximal colon, and then if it acquires a nodule, the risk goes up quite a bit, but even if it's a 1S granular lesion in the proximal colon, the risk is still very low, 1.4%. Non-granular lesions, particularly in the distal colon, have a much greater risk of around 15 to 20%, so these perhaps might be lesions that we consider for an alternative means of endoscopic resection, perhaps by ESD. Then we need to undertake focused interrogation, and so what you want to do is just have an overview, look at the lesion, and then allow your eye to be drawn to any nodule or depressed area because that's where the major pathology will be, and you can, of course, use a dual focus mode to get fantastic images of the vascular pattern and pit pattern, and I don't think we need chromoendoscopy to understand that. So here we see three different examples in overview, and we can see that there's perhaps a nice type three area in these spots here, and then we look a little bit closer. We see that they're depressed with disrupted pit pattern, and on MBI, we can confirm that there's an absence of the vascular pattern or disruption of the vascular pattern. So this is deep submucosal invasive cancer, and these lesions can't be treated endoscopically. Let's not forget about serrated lesions. Conveniently here, side by side, an adenoma and then a serrated lesion, and what we shouldn't forget is dysplasia within serrated lesions because if we don't appreciate the full extent of the lesion, then we can incompletely resect the lesion, and we take away the dysplastic focus because we think it's just a small adenoma, but in fact, it's a larger lesion, and we leave behind the serrated lesion, and that's at risk for interval cancer, and these are some other examples. I think with using dye in the injectate, which is mandatory in my view, this really allows us to see the marginal lesion and achieve complete excision. So in 2016, it's possible to, of course, perform very extensive resections by EMR, and we can do, of course, full circumferential resection, and this is reproducible, and in surveillance, we see that these patients have perhaps some residual disease at first surveillance, but it's usually diminutive, easily treated, and then long-term follow-up, they're clear. So in summary then, for EMR, what do we know, and I apologize to any of the authors who aren't listed here with their studies, but basically, all the studies sort of more or less show this, most event avoid surgery on an intention-to-treat basis, and this figure is going up all the time. It's over 95% now in our unit. That's all cases referred, so some, of course, are referred with cancer. Mean procedure time is 20 to 25 minutes. There's some bleeding. Post-EMR bleeding's a big problem, 6% to 7%, mainly right colon. Perforation, a very low percentage. We recognize it, treat it. Recurrence is a problem, and then we have invasive disease. We've published extensively on all of this, and I recommend to you the technical review, which is in the April issue of GIE from last year, and in that technical review, where we looked at 2,500 manuscripts looking at polypectomy. It's a full review of polypectomy. We've included technical tips on different type of lesion resection, and for EMR, one key thing is to have the snare parallel to the surface, and to make sure that you push down very firmly so that the tissue bounces up into the snare, and use a staged snare closure. So, snare closure is not a binary thing. It's not open-close. It's a staged thing where you close, look carefully, and then close further, and then check that you've got the tissue and so on. So, I'll show you here. So, this is a circumferential lesion, which extends over about 12 centimeter in the distal sigmoid in a 50-year-old man who was adamantly didn't want surgery, and this case was done in about 2012, something like that, and so you can see that this is a granular 2A plus 1S lesion, so it's at very low risk of invasive disease. We look carefully. Start the injection before you stab the lesion, and we use a staccato stab, and you instantly find the submucosal plane, and then make sure that you use, you include a margin of normal tissue in the snare resection, and once you, so here we deliberately take normal tissue at the edge and aspirate gas as the snare closes, push down firmly, and then we close the snare all the way, really tight, and virtually cut it off with fractionated current. One or two taps and you're through. Expand out the defect with the water jet, and keep going and work from the edge of the advancing mucosal defect systematically along in a sort of inject and resect technique. You can't elevate all the lesion. It creates too much tension in the submucosa, so if you wanna have good pieces, you just inject and resect, and here we are in retroflex. Excise this portion, and then you'll see the end result. So, and if you work systematically, really it's not so difficult to achieve a completely clean excision and have no visible residual adenoma. We don't use thermal ablation, and this is surveillance for this patient at two years, and you can see that he's got a clean scar. There's no residual adenoma with high definition or white light, narrow band, sorry. What else should we do when we do resection? We must always consider gravity. Use gravity because it optimizes your opportunity, so the fluid pool is over here because if you have a problem like a perforation or bleeding, then of course your working field is away from the point of attachment of the lesion, so you always want to rotate the patient so that the lesion is opposite the fluid pool, and this allows you to manage things. So, there are many questions in EMR and advanced polypectomy, and I think we always need to compare the new therapy against the existing standard, and sometimes we sort of get ahead of ourselves, and there's lots of studies coming out now saying we should be doing ESD for all these lesions, but in fact, I'm sure it has a role, but quite a limited role. So, any of these things, any of these new innovations need to be compared against the existing standard. I can't cover all this, although I have done some of it, but we do need to talk about serrated lesions because I think they require special considerations, and I'd like to talk about recurrence because it's often cited as a limitation, but we should view EMR as a two-stage procedure where the second procedure deals with the 16% incidence of recurrence. In long-term follow-up, we see the first 1,000 cases from the ACE study, there was a risk of recurrence of 16% at first surveillance, SC1, and at second surveillance, there was 4% recurrence. So, if the initial EMR was deemed successful and the EMR specimens didn't have cancer, then 98% of patients were free of recurrence and adenoma-free and avoided surgery at 16 months. So, EMR is a very effective technique for lesions of all sizes, but the main limitation is the very large lesion, greater than 40 millimeter, and of course, we shouldn't be using APC for visible residual, we should excise, and then bleeding is also a risk factor for recurrence. So, nonetheless, can we reduce recurrence? So, here we see, with careful inspection, just a dot of adenoma there, and this is why patients have recurrence, and this paper is in press for gastrointestinal endoscopy, and what we did was this observational cohort study of extra-wide-field EMR where we take a big rim of normal tissue at the margin, and the fellows coming from overseas when they first came to our department and were watching me, they're saying, what are you doing? This is like you're making this giant thing, but unfortunately, it doesn't work. So, the recurrence rate is the same between extra-wide-field and standard EMR, but there is something else that works very, very well, and this will be presented at the late-breaking plenary session tomorrow morning, and this is a snare-tip soft coagulation of the post-EMR margin. It's very easy to do. It's inexpensive. At a time when every new innovation seems to be so much more expensive, this is just using the snare and changing the settings. It's the same setting we use for hemostasis, and you can just sneak around the margin, coagulate it, and it looks like this. So, this is a big lesion, about 11 centimeters long in the distal sigmoid. These are sort of somewhat extreme examples, but these days, we only tend to get very big lesions sent to us. I think the 20 to 30 millimeter lesions have been done outside of our center, and so we excise this. You can see here in a moment, there's some exposed muscle, so we do this technique of topical submucosal chromoendoscopy, just irrigate fluid over the surface to make sure there's no target sign or deep injury, and then if we come to the technique, I'll just show you, you must excise all visible residual, so this is a tiny bit of residual, and now we've got a clean excision, no residual adenoma, and then we do the snare tip soft coagulation like so. So, you just work along the edge. It's very easy to do once you get the hang of it. You just work with the catheter and the scope as one, and then you see the end result here. So, this reduces recurrence from high teens to low single digit, so please come and see that abstract tomorrow morning, and it's easily reproducible. So, a lot of other problems with EMR and polypectomy, so bleeding, perforation, and we've covered recurrence. One of the problems also is incomplete resection. We know from the very excellent care study that this is most common with large serrated lesions, more common with large lesions and much more common with large serrated lesions, and this is an example where this lesion has been incompletely excised, and I think the other problem that I alluded to earlier is this failure to recognize the full extent of the lesion. This is a dysplastic serrated lesion with two foci of dysplasia, better seen under MBI. You can see this tubular pit pattern as opposed to the serrated cloud-like surface here with the open pits, and if you don't appreciate that, then you'll incompletely resect, and even in our large multicenter group where we all sort of self-professed experts, we were frequently getting this wrong when there were lesions with dysplasia. We predicted that these were adenomas, but in fact, they were dysplastic serrated lesions, but when it was just a nondysplastic lesion, the prediction was often, much more often correct, and what happens if you fail to resect? This patient had an adenoma resected from the base of cecum six months ago and then was referred to us because they found another large lesion. In fact, the patient had serrated polyposis. We went back and checked the records, but this is an invasive cancer. It's a T2N1 serrated pathway cancer at the site of the previous adenoma resection, and the endoscopist failed to appreciate that this is a serrated lesion, and a cancer has developed there because of incomplete resection. So this is this concept of incomplete resection and the triple threat for interval cancer. So if you see a serrated lesion in the right colon, if you see an adenoma in the right colon, always consider that maybe it could be part of a serrated lesion with dysplasia and look for any evidence of serrated lesion around. So serrated lesions can be effectively removed, and in fact, with very high technical success and low risk of recurrence below that of adenomas. This is data on 150 large serrated lesions, and I think the key thing is to use dye in the submucosal injectate, like so, and then you can see the margin. This one has dysplasia, and so on. But one of the problems with the sort of intermediate size 10 to 20 millimeter lesion is the trade-up in risk with EMR in terms of bleeding risk and also perforation. So I think we're now doing a study looking at the role of cold snare versus EMR in these intermediate size lesions. So you see a subtle serrated lesion here, and you can actually remove this by piecemeal cold snare, and if you're in doubt whether you've got it all, so here maybe there's a little bit of serrated lesion in the margin, you can just extend the excision, and this is reproducible. This one has dysplasia, so we can excise very widely, and these patients don't have a risk of bleeding. It's very safe, and I think it's a fantastic technique for these intermediate size lesions. Just quickly to cover perforation, I think everyone knows about the target sign. There's a range of things that you can see, but effective intervention really means detection. This subtle thing here is an excision of muscle, and if you don't recognize it, then the patient will come back with a delayed perforation. There's a range of things you can see. Bland blue matt is what we like to see. Visible muscle, don't worry. Unstained mucosa, you need to do topical submucosal chromatoscopy. Visible vessels, don't worry. Don't treat them, that doesn't help, and then a subtle target here. These are other examples of targets, and the risk factors, this is a paper in press, transverse colon location with an odds ratio of four to five, high-grade early cancer because it sticks things together, and attempted on-block, so if you want to avoid having deep mural injury or a target sign, don't do an on-block excision of high-grade dysplastic lesion in the transverse colon, because that's got all the risk factors, and of course, the other risk is submucosal spot or repeated intervention. Here, this is a case done by one of our fellows when he just wasn't quite thinking and was quite aggressive, and then we end up with this hole, but we can clip this up, and you don't need to close the whole defect. You can just close up that aspect of the defect and then continue the excision. In the era of CO2, it's very safe to do that, so here you see, and you must evert the edges of the wound into the clip, so you have this sort of cirrhosis to cirrhosis apposition. If there's fibrosis and you're worried or the patient's at risk of bleeding, then you can close the defect, but I think this only really works for small and particularly elliptical defects, so two to three centimeter. Once it gets four, four centimeter and above and oval or larger, you can't really close a defect, and finally, sorry to overrun just a bit, but intraprocedural bleeding, snare tip soft coagulation, so here we see vigorous bleeding in a patient with renal failure, and you can use the same setting, 80 watts, effect four, irrigate, and use a snare tip. You don't have to use a new device. Don't use clips because they often can't bring together that tiny focus of bleeding. Here we have more massive bleeding. In about one in five cases, we have to use coagulating forceps. If you don't have exposure, what we've done, we've rolled the patient so we can see the bleeding point and then we can easily grasp it. The key thing when you're using coagulating forceps, same setting, is grab the bleeding point, confirm that you've actually got it because the bleeding stops, and then coagulate. Tent away and then coagulate, and this is a fantastic technique and it's very safe. I haven't had time to touch on ESD, but we do do it for select high-risk cases in the left colon and rectum, but I think as a universal thing, it has a very limited role. Only about 3% of all patients in our large cohort can benefit from ESD in terms of cure of low-risk submucosal invasive cancer, and the recurrence rate after EMR is coming down all the time, and I think that once we invoke this snare-tip soft coagulation as a standard, then the recurrence rate will be below 5% in most large series. So scheduled surveillance, very important. EMR is the technique for large, laterally spreading polyps. Better lesion selection, I think we have to have bespoke lesion selection, different techniques for different types of lesions. Serrated lesions, I think for the nondisplastic, smaller lesion, piecemeal cold snare. Inspection of the post-EMR defect, very important, and I think thermal ablation of visible residual is not effective, but thermal ablation of the margin as an adjuvant technique will become the standard of care in the future. Thank you.

EMR

endoscopic mucosal resection

colonic lesions

lesion selection

risk assessment