So, here we have a colonoscope, and you can just pause for just a second, Lyle. And you see a lesion here in the rectum, a semi-translucent cap that you see at the periphery of the colonoscope. And right now, we're just trying to assess this lesion, and you can play, please, Lyle. Thank you. So, we're getting a sense of this lesion. Right now, we're injecting a solution containing methylene blue, a little bit of epinephrine, as a submucosal injectate to raise the lesion. And that often takes a number of different injections in order to delineate the full extent of the lesion to get a sense as to the periphery of the lesion where normal mucosa meets the polyp. If you could stop for a moment there, Lyle. And then using standard hot polypectomy or current-based polypectomy resections, we can use an electrocautery-based device and our snares to remove this lesion in a piecemeal fashion. In other words, this lesion is too large to remove on block. It must be removed in a piecemeal fashion. You can play that, Lyle, please. And you can see one piece was taken off. Here's the snare coming out again to remove another section. And again, the blue, the methylene blue in the injectate both shows us the periphery of the lesion. And you can see we're removing segments of it here again in piecemeal fashion. It shows the periphery of the lesion. It'll help us identify at the end if we have achieved what we believe to be a complete endoscopic resection. And it also highlights the submucosa well. So this is done repeatedly in a piecemeal manner until such time that endoscopic resection is achieved. And sometimes if there is a question about residual polyploid tissue at the periphery using a hot biopsy forceps, sometimes with what's called an avulsion technique to pull away some residual tissue to achieve a clean margin. I will say that, and here we're taking off another little island of tissue, again, with the hot biopsy forceps. And we do this until we feel that we've achieved endoscopic. Stop there for a second, Lyle. Complete endoscopic removal. And sometimes there is application of current, in this case, a soft tip coag to coagulate, to burn the periphery of the lesion to make us feel more confident about the complete resection and the ablation of any residual cells. I will say the use of this has been studied. There is debate about it, but it is used by many well-respected practitioners and at least one study out of Australia by Michael Bork down in Australia and Melbourne. Continue there, please, Lyle. I think we're coming to the end of the slide. So that was the soft tip coag here just at the periphery to ablate any residual tissue. And then here we have, you can just stop it there for a second because we're really at the end here of this video. You can see what looks like a very, very nice defect that endoscopically looks excellent. And we come back and survey this at an appropriate interval.

colonoscope

lesion

rectum

methylene blue injection

endoscopic resection