Our next lecture is an ASG endowed lecture, and it's called the Basil Hershowitz Endowed Lecture for the ASG Postgraduate Course. And before I introduce our speaker, just a few words about Basil Hershowitz, truly a principal figure in the field of gastrointestinal endoscopy and related disease. The ASG honors the late Dr. Basil Hershowitz for his leadership and accomplishments through his this annual lectureship. The lectureship is presented by the ASGE Foundation and was established through a generous support of ASG friends, trainees, and colleagues of Dr. Basil Hershowitz. So please join me in welcoming Professor Michael Burke, who is Clinical Professor of Medicine at the University of Sydney, to present the 2022 Basil Hershowitz Endowed Lecture, Approach to a Difficult Polyp, Michael. Thank you very much for the opportunity to honor the memory of Dr. Hershowitz. It's a great honor for me to be here, and so these are my disclosures. So I think EMR is unequivocally the standard of care in 2022, and there's some critical things that we need to do when we approach a large and difficult polyp like this. So Doug's run through them, but six o'clock orientation, use the injection to optimize your access to the lesion, so you want to bring the lesion up and out into the lumen. Resect the nodular component first, if you can, in one single large piece. And then once you expose the submucosa, work sequentially in the submucosal plane. One third of the tissue is submucosal tissue, and the other two thirds is neoplastic tissue. So you follow the plane. If you make an error, I made an error here, immediately re-excise that, because it may be difficult to find that abnormality later, particularly in a large lesion. Take as much normal tissue as you like. Be certain that you get the neoplastic tissue. It's so much easier to take a large piece than it is to just sort of try and finely position the snare and grab that little piece. So aspirate gas, push down firmly, and the lesion bounces up into the snare. And then after each resection, we use the water jet to expand the defect, so that minimizes the number of injections you need to do. And then at the end, carefully inspect. So here we see loss of homogeneity of the defects. So we irrigate with dye, topical submucosal chromoendoscopy. And then we finish with snare tip soft coagulation. This is a light touch technique. So you can gently push along and around the sides. And then you get this nice Mount Fuji effect with three, four, or five millimeters of ablation. So it should all look like that. That's how it should look. And we know now that this is the standard of care. We can get recurrence down to about 1.5%. So what about more difficult polyps? So this is a lateral spreading lesion at the ileocecal valve involving the full circumference, then over onto the lip as well. So you can use a distal cap attachment as we had done here. Patient orientation is also important. So the ICV is on the medial wall. Often it's covered in a fluid pool. So if you have this lesion, maybe roll the patient to the right lateral position so that you can expose the lesion if you want to do it under gas rather than fluid. And then same as always, so we start in the most difficult position. So here we are starting inside the ileum in retroflex, lots of normal tissue. And then we just work our way sequentially across the lesion. First of all, excising the tissue in the ileum. That's normal ileal villi moving out into the cecum as they often do. So they're, again, working in the plane that we've established. Slow movements, stage, snare closure, close a little, make sure the snare bites in, and then close continuously till resistance, and then cut through. And we cut through relatively quickly. So we have a crisp edge you'll see here in a moment. This is the last piece of the ileum to be removed. Difficult position, no doubt, moving from retroflex to forward view almost, and then cut that off. And then you see here a nice, crisp margin in the ileum, which we will later ablate. You can see ileum, nice villi, all of that looks great. And then if we come over here towards the end. Now for intraprocedural bleeding, we use snare tip soft coagulation. This works very, very well. Remember the fan principle? The point of the bleeding spreads out as a fan. So at the apex of the fan, that's where the vessel is. So when you see the fan, the bleeding point is at the apex. And then use the snare tip as a wand, working with the snare and the scope as one. So you're not adjusting the relationship between the snare and the scope. And here's the ileum. And there's back to the beginning. So we can't clip that up. So there is a 10% to 12% risk of delayed bleeding. So we just have to be cognizant of that. This is another example. And there are other examples. And when we apply these techniques, cast technique, snare tip, and so on, we get recurrence down to very acceptable levels, around about 4.8% for these lesions. What about previously attempted non-lifting or scarred lesions? These are the most difficult lesions you will encounter. And they can be very extensive. These are three separate examples. We previously reported on this technique of cold avulsion followed by snare tip soft coagulation. And now we call this technique cast. And it's very effective. So we'll watch this video in full. So this is an extensively scarred lesion. So start in an area that is normal, even if it's normal tissue, to find the plane. And then here where it's tacked down, we don't have to inject. We can just irrigate. Just put the catheter there so you get some lifting. So you don't want to inject extramurally because it creates a compression situation. It's hard to get the lifting in the submucosal plane. And as we approach the scarred area, so again, we're just irrigating, not injecting, but just pushing in and using the catheter to fill that up. This is just with gel effusion. And you see careful snare closure, adjusting the orientation of the scope to the lesion. And as we approach the scarred area, then we get ready. We're still working as much as we can with the snare, excising as much as we can. But now we're going to get stuck. And so now we can still remove this bit. So aspirate gas, push down, smaller snare, 10 millimeter. And then we're just left with this little area that we have to treat by avulsion. So you take a normal forcep with a serrated cup. And because the tissue is no longer attached laterally, it's only attached underneath, you'd be amazed how quickly it tears off and how easily it tears off. It creates a little bit of bleeding, so you've got to use the water jet to follow your resection. And then at the very end, now we've got completely removed tissue. So we'll change now to snare tip soft coagulation of the avulsion bed. Very simple. So we just start with the bleeding points, again, remembering the fan principle. So the blood is coming from up the top there, so just coagulate where the bleeding's happening. And then you coagulate the entire avulsion bed. And this then leaves us with what we term as DMI type 2, deep mural injury type 2. Because we have extensive submucosal fibrosis, we can't tell if there's been any thermal injury to the muscle layer. So we're obligated to close the area of thermal ablation or the scarring. We can see elsewhere there's no injury to the muscle layer, but here we can't be certain, so we close this up with clips. Very easily done. And then finally, we finish with snare tip to the margin. And this lesion is not coming back, 100%. This is not coming back. It's very easy to do just using simple principles. Look at this crazy lesion, right? So easily done, same again. This is another one on the anastomosis. Really difficult situation, but easily done. And then we close this up. And we know that the results between naive and previously attempted lesions are the same. Big study, this published in American Journal. And when we use snare tip and thermal ablation, the results are even better, zero recurrence. What about large serrated lesions? These should all be done by cold snare now if they don't have dysplasia. So this is a circumferential serrated lesion removed cold. Same principles that Ali demonstrated in his excellent demonstration. And then at follow-up at 12 months, we think, could this be recurrence? In fact, it's not. Sometimes you just see nodular tissue and scars. But don't take a biopsy. Just remove it cold, hot or cold, preferably cold. So here you must push down very firmly. We excise that. And then I excise the margins of the excision. Not for sport, but just to be certain that there's nothing left. Because I want to be 100% certain that I can say to the patient, you don't need to come back for three years or whatever it is. I mean, in this case, probably has to come back at 12 months because probably there's underlying serrated polyposis. This is the technique. You see pushing down very firmly with the up-down wheel. And then if the tissue's stuck, you can amputate against the tip of the scope. This is very safe in the colon. We have had just the one perforation with a scarred lesion. So you must use the water jet to interrogate the defect. Make sure it all lifts up and you don't see any target sign or any evidence of that. But I think overall, extremely safe and zero bleeding risk. And we see here this big study, outcomes of cold for serrated lesions. And you see no bleeding and recurrence very low. So I'll leave you with that. Thank you.

difficult polyps

endoscopic mucosal resection (EMR)

lesion orientation

submucosal plane

intraprocedural bleeding management