E145 Masterclass With Rob Bechara On Optical Evaluation Of Colonic Polyps
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Chad Ball 00:06
Welcome to the Cold Steel surgical podcast with your hosts Ameer Farooq and Chad Ball.
Ameer Farooq 00:26
It's a bird. It's a plane. It's a polyp. But what kind of polyp? On this episode we were joined by the master of optical evaluations of polyps, Dr. Rob Bechara. Dr. Bechara is an advanced therapeutic endoscopist at Queen's University in Kingston, Ontario, and he gave us a masterclass on how to look at polyps and assess what kind of polyp it is. This is an essential primer on important macroscopic and microscopic polyp characteristics and evaluation and really is a must listen for anyone who does endoscopy, whether you're a surgeon or a gastroenterologist. Also, don't miss his really unique experience training in Japan, and how we might learn about our own training models in the process. For anyone listening to this as a podcast version, make sure to head over to our YouTube channel www.youtube.com/@coldsteelsurgery to see all of Rob's really neat videos and pictures. And finally, don't forget to check out Rob's YouTube channel. Links, as always, in the description. Dr. Bechara, thank you so much for joining us on the Cold Steel podcast. It's truly an honour to have you on the show. Can you tell our audience a little bit about where you grew up and where you did your training?
Rob Bechara 01:40
So yeah, thanks again for inviting me. It's really a pleasure, and I hope you and our viewers find it useful. So I did my training, in terms of my undergraduate, in medicine in Toronto, and subsequent to that I did my internal medicine training and GI training here in Kingston at Queen's University. I then went to St. [Michael's Hospital] and did therapeutic training for a year, and then I went to Tokyo in Toyosu Hospital at Showa University, did about 14, 15 months of third space training and magnifying endoscopy training. And I came back here in about 2015, and I've been working here since then.
Ameer Farooq 02:28
That's an amazing training pathway. How did you get involved or hear about Japan? Or what was the impetus to go to Japan? Was there a pre-existing connection between Toronto or Queen's and Japan? Or how did that kind of come about? What was that experience like? How is going to Japan different than what you're seeing here in Canada?
Rob Bechara 02:44
So I was actually interested in some of the advanced endoscopy techniques in terms of the optical diagnosis and, kind of, at the time, which was the tissue resection with endoscopic submucosal dissection, since internal medicine. And then when I was doing internal medicine, I had decided to go to some conferences abroad, including some conferences in Korea, some in Japan, and basically found that, you know, a lot of the stuff that was done in advanced endoscopy was kind of initiated in Japan. So I started going to a few more of those conferences, and I met different people. And I met Dr. [inaudible] and, you know, just kind of talked with him and kind of became friends with him. And we subsequently set up my fellowship afterwards, but I just, kind of, just through interest started going to different places. And that's really how I ended up going to Japan for the fellowship training. Yeah, so it's, it's very different. So for multiple reasons. So obviously, it's you know, different language, different culture, and in terms of just endoscopy, just the way endoscopy is practised there, it was extremely different in terms of — the culture kind of makes its way into practice in terms of medicine. So just the attention to detail, and how meticulous they are just with every endoscopic examination, and the ability to detect things that we wouldn't even notice. So, just the, you know, your basic diagnostic exam, I was just amazed at the amount of detail that they would appreciate and that they would examine. And that, as I said, just the culture making its way into endoscopy. And just in terms of, obviously, you know, work culture, it's quite different there. So, similar to, you know, whether they're into, whether it's work or music or just the amount of dedication that there is in that area. So they really, kind of, go all the way, you know, with whatever it is that they decide to do, whether it's, like I said, music, art, literature, medicine, so — and again, that just went — that was the same in endoscopy. So it shows just, kind of, like, the dedication and the amount of work and effort that's, kind of, put into it. It's just a different magnitude, you know, compared to us, even though we all work very hard, but it's just a different level of, kind of, dedication that I found there.
Ameer Farooq 05:43
What was the structure like? Like, what was a typical day like for you when you were doing your training in Japan?
Rob Bechara 05:50
Well, so, in terms of — one of the interesting things in terms of the structure, which I thought was extremely beneficial, was that the services were set up into teams, so we didn't have gastroenterology and surgery in terms of being separate teams. So we had the upper GI team, which consisted of surgeons and gastroenterologists, and it really took me a long time to find out who was a surgeon and who was a gastroenterologist, because we basically rounded together in the morning, so you know, you'd come in early, depending on if there are advanced cases in the morning. So I'd usually come in, you know, anywhere from 5 to 6 and make sure everything's set up. And then we'd go round together as a team. So it would be, for example, the surgeons and gastroenterologists rounding together, seeing the patients, and as I said you wouldn't know who's who. And in that regard, you know, after rounding, you know, we start the procedures. And again, it may be a gastroenterologist or a surgeon in terms of the endoscopic procedures. And, you know, depending on the day, you may have anywhere from ,kind of, 3 to 5 third-space procedures, and then, depending, some diagnostic procedures, kind of interspersed throughout the day. And then at the end of the day, again, kind of rounding with all the patients together as a team. And after that, probably doing a fair bit of work until the evening time. But that's, kind of, the typical day, but I thought one of the amazing things was the structure in terms of, you know, your upper GI team — so a patient comes in with a foregut issue, you have surgeons and gastroenterologists on the same team. And basically, the patient got, kind of, the treatment that they needed very quickly. And it wasn't necessarily based on well, you know, I'm a gastroenterologist so this is what I can do, so this was the way we're going to go, or I'm a surgeon, and doing it that way. It was basically discussed openly between the, you know, the surgeons and gastroenterologists who are on the same team, on the same service. And really, the treatment is kind of decided together, and it happens in a lot more efficient manner and more, kind of, comprehensive manner.
Ameer Farooq 08:06
It's such a different way — model, that obviously, like, it's a very comprehensive way of providing care for a patient with a specific — and, you know, a specific problem, as opposed to, you know, exactly who sees who first, right? Which happen so often in Canada, where the treatment gets determined by who you see first. You know, if you have pancreatitis, you'll see a gastroenterologist versus a surgeon first, often, and treatments can be quite different. What was the training, sort of, paradigm? Like in Japan, was that, you know, you talked about the intensity, but was there any differences in terms of training styles for trainees?
Rob Bechara 08:44
Yeah, so I find the, you know, in terms of training there, it's really a stepwise training model. And it goes all the way from, you know, very basic things. So, you know, I had already completed gastroenterology and advanced therapeutic endoscopy at St. [Michael's], which is, you know, one of the leading therapeutic centres in the world. And I was like, oh, I'm going to go there and just start doing cases right away, and they'll be so amazed at how, you know, how good I am, right? But, you know, you kind of have to swallow your pride and really go from the fundamentals. So the first thing I did was really just set up the room. So once I was able to set up the room properly, then, you know, I can start assisting some of the more junior staff. And then once I'm a good assistant, and then I can start assisting, you know, Prof. [inaudible], and then when I can assist him appropriately and I'm a good assistant in that regard, then I can start doing cases. So you really have to know the equipment and in terms of the details of being a good assistant, because part of being a good assistant is basically being able to watch the procedure and predict what the next thing is and what they're going to want and what issues are going to arise, so you can be the most, kind of, efficient assistant. So, you know, doing that was extremely beneficial in terms of, again, just learning the procedures and subsequently, when coming back here, being able to teach our assistants and fellows as well. So you know, after becoming, being able to assist appropriately and efficiently and to a high degree of quality, then I would start doing the cases, whether it's tissue resection, or endoscopic myotomies, that sort of thing, and start doing those. So that was, kind of, the training model. And in terms of its, you know, just the procedure in terms of how we practise here, and, kind of, the traditional modes of tissue resection, the movements and everything is a lot more on a macroscopic scale. So starting there, and doing those procedures, just realizing how slow and how purposeful and controlled everything has to be as compared to what we've traditionally done in therapeutic endoscopy was a adjustment, but it's been extremely useful in, kind of, all my practice. So that's kind of how the training was there, in a nutshell.
Ameer Farooq 11:22
Yeah, one thing I've noticed, obviously, seeing you in the endoscopy suite is that when I come in the morning, you're already there, often, and you're setting up the, checking the equipment, setting things up exactly the way you want.
Rob Bechara 11:34
And one of the things that I actually found extremely, maybe, underappreciated here is that all these little, tiny, incremental benefits and attention to these little things in terms of quality or their procedure; all these little incremental benefits and incremental optimizations, in the end make a very big difference. So whether it's the positioning, in terms of how you hold the scope, in terms of ensuring you clean things appropriately, all these little incremental benefits make a difference in terms of, you know, you may have a procedure that's difficult, that if you have all these optimizations and incremental things that you kind of pay attention to, the procedure ends up being easy. Or, if you have a procedure, that's, you know, instead of it being very difficult, it's moderately difficult, or if it's impossible, or kind of unsuccessful, again, all those little benefits will make it a doable procedure. So all those little incremental benefits and attention to detail, I think, makes a big difference in terms of the outcome. And I think that's something that we traditionally have been, kind of, lacking here in terms of some of those small details and optimizations.
Ameer Farooq 12:51
Well, that's just fantastic, Rob. Rob, you know, the reason why we brought you on the podcast, among many, many reasons, is we wanted to delve into with you in terms of one of the areas of your expertise, which is optical evaluation of polyps. So, if you don't mind just sharing your screen, and for all our audio listeners, I'd really encourage you to kind of check out the YouTube version of this podcast as Dr. Bechara is going to share some slides. And obviously, this is a talk on optical evaluation, so obviously the pictures are going to be helpful here. Dr. Bechara, take it away, and just maybe walk us through some of the basics around optical or endoscopic examination of colonic polyps.
Rob Bechara 13:42
Alright, so I'm really going to go kind of just over some of the fundamentals; it won't be as exhaustive as it can be, but hopefully just some of the basics and fundamentals of optical examination of colonic polyps and lesions. So we're going to go over the macroscopic, microscopic exam, and some of the high-risk gross morphologic features, and the Nice classification, which hopefully some people have heard of, and the JNET classification, which people may not be familiar with, but I'll briefly mention it and knowing why it's there and the advantages of it. So we'll go over some cases, and then the macroscopic exam, the microscopic exam and then some of the — we'll go back to the cases again, and kind of see what we hopefully have learned. So usually, I kind of go over the different classification and see what people are familiar with. This is probably the one that people are most familiar with, but — give me a [second]; we'll kind of skip over this part. So why do we care about optical diagnosis? So this is just a nice study out of the Netherlands that showed about 3500 colonoscopies and about 92 T1 colorectal cancers were diagnosed. So, of the 39% that were correctly recognized as cancer endoscopically, only 11% went on to require surgical resection; however, of the 61% that were not correctly recognized as cancer, 41% went on to have surgical resection, and the vast majority of the surgical resections were due to piecemeal removal and inability to evaluate the margins. So, this just shows what we kind of already know, is that, you know, proper pre-resection diagnosis avoids patients getting unnecessary surgery or, kind of, inappropriately piecemeal removal of superficial cancers. So we'll start with a case. So this is just a lesion seen in the ascending colon, and whatever endoscopy platform you have, all of them have some element of image-enhanced endoscopy, whether it's Olympus, Pentax, Fujifilm, they all have very similar technologies, with slight variation, but they allow you to use various techniques to examine lesions. So we're just kind of getting closer to the lesion and examining it with a bit of magnification, which, again, all platforms at this point have some form of it available. So kind of looking at this lesion, I'll ask you, Ameer, in terms of what do you think. Is this just kind of a low-grade adenoma? Is this something with high-grade or superficial carcinoma, or is it a deep invasive carcinoma?
Ameer Farooq 16:47
Oh boy, I'm getting put on the spot. Alright, well, to me, looking at it, it doesn't look like it has super, you know, very disorganized features. I must admit, you know, I've read about these Kudo pit patterns, but it's hard sometimes to keep them all straight. But it doesn't look like it's, like, it doesn't look like a cancer or a deeply invasive cancer to me. It looks fairly small — that might be part of the reason why I'm saying that. Now, I don't know that this would, and I can confidently say that this is low-grade dysplasia or high-grade dysplasia, but I'm going to go with low-grade dysplasia. It doesn't look particularly worrisome to my eye.
Rob Bechara 17:35
So I think that's some of the stuff we're going to go over in terms of, you know, a lot of it, you know, is kind of subconscious pattern recognition. And we kind of know that, when we see something, I'm like yeah, this is definitely a cancer, this is definitely a low-grade adenoma, but we can't really explain why. And part of it is just getting that, kind of, conscious competence in, kind of, going through a systematic exam, which we'll go over. And, you know, in the cases where things are not so clear, is really being able to make a more accurate prediction of what those lesions are. Most things are usually at the extremes in terms of, you know, grossly invasive carcinoma or a benign polyp, but we do enough procedures, that there's going to be stuff in the middle where we're not really sure. And it will really help in those instances in terms of making the appropriate choice in those instances. So here's another case. So this is a lesion in the rectum. And again, we go kind of through the same process, examining it grossly, and we do whatever image-enhanced modalities we have, and then we'll kind of go more closely to the lesion and examine it in a bit more detail. [I'll] just skip a bit here in terms of until we get into the finer examination. And now we're just a bit more close, and using a bit of magnification, and trying a bit more —
Ameer Farooq 19:00
Rob, is this level of magnification — because I know you have a scope that really can magnify. You're not using that scope, but this is something that is available on pretty much every platform.
Rob Bechara 19:11
These particular scopes have [inaudible] magnification on them. So the degree of magnification is much higher. But whether, as I said it's, you know, any of the platforms, currently, they have an element of magnification that can be used. There'll be varying degrees of the magnification, but they all have some element of magnification, where you can get, really, the same information, although higher magnification may give you a bit more confidence in some of the instances, but is that all of them have an element of magnification. So, I'll ask you, Ameer. So how about this lesion, in terms of what do you think it is?
Ameer Farooq 19:56
This one, I'm more concerned that this is a deeply invasive carcinoma, for a couple of reasons. One, it's bigger — I'd say at least, kind of, 2 centimeters. So that's one thing. The second thing is that that central depression in the middle, that makes me concerned that this is a cancer. Now, is it more deeply invasive, like a T2? That, I don't know. And sometimes, actually, I have to say, as a colorectal surgeon I rely on my finger for a rectal lesion to try and make that differentiation. But I'd certainly be concerned that this is an invasive cancer. I don't think this is a hybrid dysplasia or low-grade dysplasia; I think this is an invasive cancer.
Rob Bechara 20:43
Okay. And just go to the last case. So this, again, is a lesion in the rectum. And again, same systematic exam, just like, you know, when you see your patient, you have your history, physical, you know, labs, your endoscopic exam should be approached in the same way in terms of just a systematic exam such that, again, you don't miss things. Just like when you have a patient, and you may see them walking, you know, that's the diagnosis, just based on how they're, kind of, walking, limping, etc. But you still go through your systematic process, and every so often you're surprised and you find something that maybe not — wasn't what you expect. So, just for the sake of time, I won't grill you again about it, but again, kind of look at the different appearance and some of the different areas where we have a bit of a higher magnification and getting those details. So now I'll just briefly move on to some of the [inaudible] examination. So we have the macroscopic assessment, the Paris classification is quite old now. And it's basically just a way in terms of describing the gross morphology of a polyp or anything in the GI tract, because it can also be used for the upper GI tract. But basically you have 3 main categories: protruding type, flat type and excavated type. The protruding type is made essentially of your 1p, so your pedunculated polyps. Your 1S, which are in the colon, are basically the polyps that have an elevation greater than 2.5 millimeters. And this can be estimated based on kind of, you know, roughly, a closed biopsy forceps is about 2.5 millimeters. Then you have your flat polyps. So you're completely flat, which is a 2B lesion. You're slightly elevated, which is a 2A lesion. And you're slightly depressed, which is a 2C lesion. And this classification is generally for superficial GI neoplasia. So excavated lesions we generally don't see in superficial colorectal neoplasia. So generally, if something's excavated in the colon, it's already massively invasive; however, you can sometimes see these lesions that are excavated that are superficial in the upper GI tract. So Rob, one thing that confused me when I first saw this is, why is there the 0 before the — like, what does that mean? It basically has to do with the — it's for the description of superficial neoplasia. So I think there's some of the classifications for, for example, more massively invasive lesions from the surgical literature. And they're like, their classification starts with, like, 1. I think 1 is the — if I'm not mistaken — the Borrmann classification; for example, upper GI cancers, but it's just kind of the convention. And this was, you know, brought to North America in, like, the early 2000s, but it has been used in Japan for years prior to that. And it kind of came together at this meeting in Paris, where it had surgeons, gastroenterologists, pathologists, oncologists all, kind of, meeting and seeing where this classification could potentially be applied in the West, and it really has been, kind of, taking off from there. And it's, again, it's a relatively coarse description, but in an attempt to try to add some objectivity in terms of descriptions of polyps. And, you know, for the most part, really, what it does, it tells us kind of what we already know. 2C lesions, so lesions with depressions, which you already mentioned, you know, you have a higher degree of suspicion of it having carcinoma in it. So even smaller lesions with depressions, you can see, have not an insignificant risk of carcinoma in them. In terms of the the other, more sessile or protruding lesions, again, as they get larger, higher risk of carcinoma. So it's a very coarse, kind of, quick-and-dirty way of getting a rough idea of, kind of, what you're dealing with in terms of pathology. Next, I'll go over the LST classification, which is probably a bit more useful in terms of the ability to predict pathology and in terms of what you're going to do. So an LST — a laterally spreading tumour — is defined as a lesion that's 10 millimeters or greater, but has a predominantly horizontal growth. So these big, protruding, kind of, lesions can't be used in this classification. So it's really only for the lesions that predominantly grow horizontally that are greater than 10 millimeters. So that's important to remember, because this is often an area of confusion. So we have 4 main categories: the laterally spreading tumour that's granular and homogenous; the granular and mixed; non-granular flat; and the non-granular pseudo-depressed. So the granular homogenous has this kind of nice, uniform, lumpy, bumpy, almost cloud-like appearance. The granular and mixed has some element of that, but at least 1 dominant nodule. The non-granular has a smooth appearance, a smooth surface. And the flat is just that — completely flat. So just slightly elevated lesion. And then the pseudo-depressed, it actually has a depression; why it's called pseudo-depressed is just, that's just, again, convention, but it has a slight depression there in the middle. So from this, you know, you can see the granular homogenous, the risk of submucosally invasive cancer is quite low. So 1% or less, even when they get larger. The granular mixed and the non-granular flat, they have an intermediate risk of carcinoma. And the pseudo-depressed have a fairly high risk of having carcinoma in them. And this also, kind of, correlates in terms of fibrosis. So the low or — sorry, the homogenous have a low risk of fibrosis. So even when the lesions are 3, 4 centimeters, they come off quite nicely and fairly easily with traditional EMR. The granular mixed have a bit more fibrosis in them, and they can be a bit more challenging to remove, as well as the non-granular flat. The pseudo-depressed are extremely difficult to remove, even when they're smaller, you know, 2 centimeters or 1.5 centimeters. These can be quite challenging to remove correctly. So these, even when they're smaller, I would think should be managed by someone who has some experience in advanced endoscopy. So lift — again, it correlates quite well. These lift very well. So one of the reasons why is that these granular, homogenous and granular mixed, their muscularis mucosa is actually arranged kind of like an accordion. So when you inject underneath, it really elevates quite nicely. Whereas the non-granulars, their muscularis mucosa is flat. So these are the ones you'll traditionally inject, and then you're like, oh, I injected too much. And now the [inaudible] is sliding off of them constantly. Because the muscularis mucosa is flat and then when you lift, it's not a nice protuberant lift, it's very diffuse. So that's something, again, to be aware of when you're thinking about removing these lesions. And again, that correlates with resection difficulty. And this basically just says that, you know, for the granular mixed type, when they do have submucosally invasive carcinoma, the majority of them have deep invasion, whereas the other lesions, when they have submucosally invasive carcinoma, it's about 50/50 in terms of those having superficial invasion and those having deep invasion. So that's just, again, something that gives you a bit more information in terms of when you're deciding on resection techniques.
Ameer Farooq 28:23
So, say that again. So, Rob, just go back there for a second. So, the granular — you said that the pseudo-depressed ones have a greater —
Rob Bechara 28:32
A higher risk, a higher risk of carcinoma.
Ameer Farooq 28:35
But in this table that you're showing, this one shows the granular mixed have the highest risk of — oh, no. Okay, that's just the numbers. Okay, so it says 20.5% of these pseudo-depressed are going to have a deeper invasion, right?
Rob Bechara 28:54
So it's about 50/50, which is the same for the non-granular flat. Again, 50/50 in terms of superficial versus deep, and as well as the homogenous. But the granular mixed, for whatever reason, when they do have carcinoma, you know, the majority, probably 80+ percent, end up being deeper than the superficial submucosa, which is something that I think surgeons probably know better than us, but this is kind of traditionally what's been taught in terms of the risk of lymph node metastasis. So, you know, up to SM1, so 1000 micrometers, the risk of liftable metastasis generally is quite low, whereas when you get into the deeper submucosa, the risk of lymph node metastasis increases. And those are the patients where, traditionally, warrant formal oncologic resection with lymph node dissection. However, there is, kind of, data that's been coming out over the years, when you correct for the tumour variables in terms of lymphovascular invasion, tumour budding, etc., that the risk of lymph node metastasis, even for deep invasion, may not necessarily be as high as we previously thought. And more recently, this meta-analysis came out, which essentially showed that — so, when you correct for all the variables, just the deep submucosal invasion on its own shows that the risk of lymph node metastasis is not as high as I, kind of, showed previously in that slide, where, you know, those studies didn't necessarily correct for the tumour variables. So I suspect, down the line we may see some changes in the guidelines for curative resection criteria.
Ameer Farooq 30:34
In other words, like, for the malignant polyp, that's a T1 lesion, maybe, perhaps, this is going to go away. The depth of vision is going to go away as an indication to just go for formal resection.
Rob Bechara 30:49
Yeah, or at least, you know, having certain criteria where, you know, say, an SM2 lesion, so, greater than 1000 micrometers of invasion, but otherwise, you know, good tumour variables, and depending on the size of the actual carcinoma, we may not necessarily automatically say you have to have a surgical resection. So, that's still not, kind of, formally recommended at this time.
Ameer Farooq 31:13
Yeah. So, I think, for the general surgery residents listening to this, this is a classic exam question that comes up all the time, is malignant polyps and criteria for considering formal resection, so I think that was great.
Rob Bechara 31:27
So we'll, kind of, review this lesion together. So, you know, again, we have, kind of, the 4 main categories for these predominantly laterally spreading lesions. And we, kind of, grossly look at it first, and we say, well, is it smooth? Or is it kind of lumpy, bumpy? And this, as you can see, has these little bumps on it. So we say, well, it's a granular lesion. And then, is it kind of homogenous? Or is it heterogeneous, where you have, kind of, mixed morphology? So this, going just based on gross morphology here, you see has these dominant nodules. So we'd say it's an LST-G mixed type. And we'd say it probably has an intermediate risk of having some element of carcinoma in it just based on the gross examination. In this particular lesion, after we did a more detailed exam, we kind of thought, again, the risk of carcinoma was significant, and it ended up being an SM1 carcinoma, and it ended up being in the dominant nodule. So the granular mixed type, when they do have carcinoma, it tends to be in the dominant nodule. So that's an important thing to be aware of, as well. So this was a superficial carcinoma, otherwise good tumour variables, and it was a curative resection.
Ameer Farooq 32:41
Sorry, not to interrupt your flow here. But when you see a lesion like that, that probably changes your approach in terms of how you're going to endoscopically — like, does that make you more likely to do an ESD? And can you just, for, perhaps the junior trainees, can you define some of these basic terms like EMR and ESD?
Rob Bechara 33:01
Yeah, so essentially, ESD is a bit more, you know, similar to, for example, you guys do your surgical resections, you're removing the lesion in 1 piece. The difference is that we're not removing, kind of, the wall. So we're just removing the epithelium. So for ESD, we basically use a tiny needle knife, and essentially we incise around the lesion. And then we get between the mucosal lesion, or the superficially submucosal lesion, and the muscularis propria. And then we slowly peel off, fiber by fiber, the lesion in 1 piece. So we get a much better, kind of, oncologic specimen in terms of if it's something we think there's cancer, whereas EMR, you know, like that previous lesion that we saw, if you removed it via EMR endoscopic mucosal resection, it's something where we would have removed in multiple pieces with a snare and injection. So we basically inject under the the lesion to, kind of, lift it up, and then I'd use a snare and cautery and I'd remove it in multiple pieces. So that's, kind of, the 2 main tissue resection techniques that we have. So this was a cecal lesion. And again, just grossly looking at it, it looks pretty smooth, and it's, again, predominantly spreading laterally. So this is a non-granular lesion. And then it's a bit subtle and difficult to appreciate, but probably on this view, you can see that there's a slight depression in the middle. So this was a non-granular, pseudo-depressed lesion. And again, we did a bit more of a detailed exam, which I'm not showing here, but again, had some high-risk features on the microscopic exam, as well. So this lesion, again, we decided to remove in 1 piece via ESD. And again, this ended up having superficial carcinoma. And you can see here, it's going just past the muscularis mucosa into the superficial submucosa. So this way, we're able to be confident of the vertical and lateral margins, the pathologist can tell us things quite accurately, and otherwise it had no high-risk features and was a curative resection. If we removed it via piecemeal EMR, some of the worry is that if your specimen ends up having, kind of, the area of carcinoma bisected, which may not be uncommon, especially if you're moving it in pieces, suctioning it up through the scope, things get fragmented further, it's very difficult or impossible for them to tell you the margins. And these patients, like that study I mentioned the beginning, often go to surgery unnecessarily. So I'll move on to just some of the gross morphologic features that, again, usually indicates something more advanced is there, and I think most of these, everyone's aware of subconsciously, but it's just a matter of kind of explicitly stating them or seeing them. So there's fold convergence, a demarcated, depressed area, [inaudible] swelling, spontaneous bleeding and, kind of, this chicken skin mucosa. So fold convergence is just that. So you see these folds here, there's 3 folds that all of a sudden converge and come together at this lesion. And this ended up being a massively submucosally invasive carcinoma that was resected surgically. This was a case — actually, one of our colleagues, Sunil, removed for me. So, it was referred to me for resection, and we saw it and, you know, again, 3 folds converging here. This ended up being a T3N1 cancer that Sunil resected. Demarcated depressed area. So this is a lesion in the rectum that, again, it was depressed, but within the depressed area, there was a clear demarcation area. And this was an SM3 mucinous adenocarcinoma with lymphovascular. And this, here, is, again, depressed lesion with a demarcated area. It was the lesion on the previous slide that was resected, surgically T3 and 0.
Ameer Farooq 36:55
Can you go back? What do you mean by demarcated?
Rob Bechara 36:58
So, for example, you see the centre is depressed.
Ameer Farooq 37:01
Yeah.
Rob Bechara 37:02
So, and then when you just look at it here, you see there's a demarcation between here, like, this area. So it not only has a depression, but there's a difference in the appearance. There's a demarcation area. And same here. You can kind of appreciate that, yes, this area in the middle is depressed, but there's a difference in terms of a demarcation between those areas. So that's, again, a feature that makes you think that something more advanced is there. And stalk or base swelling is just that. You know, you have these lesions with a very thick base or stalk that looks like it's swollen, and it's from tumour infiltration. This was an SM3 lesion that was detected on bit. It was removed via just EMR in 1 piece, but nonetheless was SM3, so deep submucosal invasion, and had a surgical resection subsequently, but there was nothing remaining. And spontaneous bleeding; kind of self-explanatory. Again, a lesion here in the rectum prior to any manipulation, just spontaneously bleeding. This was a mucinous adenocarcinoma. That was a T2 that was removed surgically. So the chicken skin appearance is kind of this whitish kind of skin you see around lesions, and this just has to do with macrophages — lipid-laden macrophages and lamina propria. And they're not neoplastic. So this chicken skin mucosa is not neoplastic epithelium, but can often be seen in, kind of, higher risk lesions. So this was a rectal lesion that was removed, and it was just high-grade dysplasia, but nonetheless, it's something that makes you think if you see this, there may be something more advanced. So now we'll kind of go into the microscopic part. But this basically tells you, you know, from a systematic review of about 30,000 lesions, when you just use the gross morphologic features on their own, they have a much lower accuracy in terms of predicting superficial carcinoma, as compared to using magnifying endoscopy or NBI, BLI, optical enhancement, any of these image-enhanced modalities that you have. So when you do your systematic exam, and you see some of these high-risk gross features, it's important that you then do a very careful, detailed inspection with your image-enhanced modalities that you have available. So very briefly, I'm just going to go over what NBI is. And that's the same with the different technologies — BLI, optical enhancement. But NBI was the first platform — Olympus was the first platform to, kind of, add it, so that's why I'm presenting it. So basically, NBI means, kind of, 2 wavelengths of light: 415 and 540. The reason why they use them is that they're more readily absorbed by hemoglobin and, as such, blood vessels. So 415 wavelength; that penetrates more superficially, and it gets absorbed by the capillaries, so the capillaries appeared dark on endoscopic exam. The 540 wavelength penetrates more deeply because it's a higher energy, and then you get absorption of, a little bit by the capillaries by then, as well as the veins. So that's why you get the, kind of, dark appearance in the blood vessels up here; kind of brown, brownish or greenish for the deeper vessels. And this just shows you that again in a schematic. 415, 540, this is where it penetrates, and this is what you see. And this is the same area, but just with different isolated wavelengths. This is, for example, showing you a longer wavelength. It goes more deeply the deeper veins are highlighted. Why is it called narrowband? The reason is, so you have your 415 and 540 wavelengths, and then they also filter out the superfluous wavelengths kind of at the margins. And that just improves the contrast, and hence, it's called narrowband imaging. So with the, kind of, narrowband imaging, a bunch of classifications came out. There are tons of them that came out, and they look at the vessels and then the surface, and it became very confusing, especially for North American endoscopists. So that's where the nice classification came in and said — try to make something a bit more practical and easy to, kind of, understand. So now we'll go into the microscopic examination, and I'm going to really focus on the Nice classification. So this is the Nice classification. So nice and simple, 3 main categories. So your type 1, which corresponds to your sessile, serrated lesions, or your hyperplastic polyps; and then your type 2, which correlates to your typical adenoma; and type 3, which correlates with your invasive carcinoma. So when you see your lesion, you look at it grossly. And then you can see, well, grossly, is it lighter than the background, is it darker than the background, or is it patchy? So type 1 typically looks lighter than the background when examined with NBI. And then you're going to do your detailed examination. So you're going to look at the microvasculature. So for these type 1 lesions, you may not see any vessels at all, or you may see some of these lacy vessels like this, for example; kind of these lacy, branching, dilated vessels. And that's going to correlate with a sessile, serrated lesion or hyperplastic lesion. And then, when we talk about the surface, we're talking about the white area. So the white areas, the epithelium, so that's what we are talking about when we're talking about the surface. So you may see some, kind of, dark areas or spots with these serrated lesions. And we'll go over a couple of practice lesions in a bit. And then your adenoma, your typical adenoma, you're going see it's darker than the background. And then when you look at the vessels, you see their regular caliber distribution throughout the lesion. And then when you look at the white part, you'll see the same thing in terms of regular width and distribution of the white part, so the epithelium. And this will be your typical adenoma, your type 3 lesion. So it maybe darker in some areas, it may be lighter in some areas, and that will correspond to a vascular area. So when you look at the microvasculature, you're going to see, again, very irregular vessels. You can see some large neoplastic vessels, you're going see avascular areas, and then when you look at the surface, so looking for those white epithelial areas, you generally will see nothing, just kind of amorphous. And this correlates to submucosally invasive carcinoma. So for the most part, this is fairly accurate, and it allows you, kind of, to stratify things based on your treatment strategy. So, you know, the criticism is that you can't distinguish between serrated and hyperplastic, but that's the, kind of, other topic. But type 2, your typical adenoma, is going to be resected endoscopically. And then your deeply invasive [is] generally surgically resected. So these are just some practice lesions. So here, you can look at the lesion with white light, then NBI. So regular, repeating vascular patterns, so the dark areas, and then in terms of the white areas, again, regular repeating in terms of the caliber, the width. This is your Nice 2 lesion, and it's a typical adenoma. Here is a lesion where you see, again, it's a bit lighter than the background. All you see is, kind of, these dark spots, essentially, and you don't see any vessels. And this is a Nice 1 lesion. So, this ended up being a hyperplastic polyp. And then here, you start seeing, again, in terms of some avascular areas, some hypervascular areas, large abnormal vessels, and then some small, little, kind of branching or blindly branching vessels, and then the white in terms of the surface, again, completely amorphous and irregular, but a deeply invasive carcinoma. In terms of the shortcomings of the Nice classification, like any classification we make, none of them are perfect, but the studies they include have larger lesions and lesions that had high-grade or superficial carcinoma, the accuracy of the prediction drops a fair bit to about 75%, and the high confidence rate of the endoscopist drops to about 60% or so. And the criticism of the Nice classification, as well, we can't really distinguish between low-grade and high-grade SM1, which, clinically, is obviously quite important. And we can't distinguish between hyperplastic and serrated lesions. So that's kind of where this JNET classification came in. So I'll just quickly go over it, but basically it broke down the type 2 category into 2 subcategories: 2A and 2B. So 2A [is] still the same; [it] kind of, correlates to your typical adenoma. The surface is regular and repeating, the vasculature is regular and repeating, no variance in the caliber or distribution. And then 2B, you start seeing some variation in those things; in terms of the surface and the vasculature, there's some irregularity in it. And essentially, then, what 2B correlates to is high-grade–to–superficial submucosally invasive carcinoma. And then you can argue that, you know, it helps decide in terms of what you do treatment-wise. The 2A lesions, whether it's traditional polypectomy or EMR, is adequate; 2B, generally, should be removed on block in terms of regardless of the technique. And this is just a short video to show you, kind of, the difference between the 2. So this is a small adenoma, probably less than a centimeter, but then when you look at it closely, you're going see the difference between the periphery and the centre. And this kind of really helps you distinguish between the 2A and the 2B. So this is the 2B area, whereas there's some variability, but it doesn't quite necessarily look like a type 3 lesion, where the vessels are completely abnormal, there's avascular areas, and then the periphery is, kind of, your typical adenoma. So the benefits of JNET are, overall, the high confidence rate is higher, you can differentiate your pathology a bit better in terms of low-grade versus high-grade–to–SM1, but it does require magnification. However, now, in North America, we do have access to magnification on all platforms, so it's not as big a drawback. And we don't have access to, kind of, the chromoendoscopy. But chromoendoscopy, again, is another topic on its own. And as you mentioned earlier about pit pattern. For pit pattern to be done, you need chromoendoscopy. So that's the the issue in North America, here, where we don't have access to it. In terms of our experience here, in the JNET classification, and this is kind of specifically for those 2B lesions, so the lesions that are in the middle, where it's not obvious adenoma or obviously invasive carcinoma, so our accuracy's about 80% in terms of predicting high-grade–to–SM1. So these are the lesions that we've removed with ESD that had this categorization, and about 10% of them end up just being low-grade adenomas. So, you can argue that, basically, those were overtreated with ESD. And then, 56 are high-grade, 22 SM1, and about 10% are SM2 or greater. So, in the vast majority of patients, you know, you chose correctly. And the lesions that end up being SM2 or greater, if they have high-risk features, and again, in discussion, you know, with you in our tumour boards, we decide what the next treatment option is. The other important thing that I want to mention is that you probably have heard a lot about biopsies. So, among the lesions that had biopsies — so about 87 of them — based on the biopsy, 70% are upstaged based on the final pathology. So that means the biopsies were really only accurate in about 30%, which is obviously far less than the classification up here, where it's at about 80% accurate. So it really shows that, you know, the biopsies are not particularly helpful when it's something that's, you know, not a deeply invasive carcinoma, that you're just going to take the surgery.
Ameer Farooq 49:14
Basically what you're saying is, like, how it looks to you is going to be much more helpful than necessarily biopsy. So, you just might miss it, or —
Rob Bechara 49:25
Yeah. So for example, you have an apple, right? And you have like 1 area that's bruised, right? And we just take some random samples of the apple. You know, the vast majority, these little tiny 4-millimeter samples are going to be normal. But if you examine the apple carefully, you'll see, oh, there's a bruised area; this apple is bad. So it's kind of like an analogy to kind of give you an idea that biopsies aren't particularly useful. And even when they do have, say, carcinoma, the biopsies are so superficial, they can't tell you the depth. Alright? So really, the endoscopic examination and good photo documentation is extremely important. Alright. So, I'm going to skip over some of this, but basically, this just shows you what I talked about. These are the vessels in the lesions, and the white part is the epithelium. So when we say the surface, this is what we're talking about. So the dark part here is the vessels that we see here in the lesion. And the white part — so, there is these areas. That's just, kind of — just, when you compare histology, and you kind of help frame it better in your mind. I'm just going skip over the rest of that. And then we'll just come back to our case. This is a lesion in the ascending colon. So we're examining it, kind of, in retroflexion with white light. So now I'll kind of go through my exam systematically. So, grossly looking at it, white light, then I'm going to change — in this particular platform is LCI. We're going to go a bit more closely, and then I'll start examining the surface and the vessels again in a bit more detail, with a little bit of magnification. And then I do it — each one of them separately. So in my mind, I'm going to say, I'm just looking at the vessels, the microvasculature; I'm not paying attention to any of the white, the epithelium — so just the microvasculature. And then after I do that on the entire lesion, I'll go back and do the microsurface and do the same thing. For those interested, this is, kind of, indigo carmine and this just, when we talk about pit pattern, again, for interest's sake, the pit is the area where the contrast pools in the middle, and this is, for interest, is a type 4 pit pattern and generally corresponds to a tubulovillous adenoma. But this is just showing you — this, for example, doesn't fall into the LST classification. So it basically is a protuberant lesion. It's a Paris 1S lesion, and then we just do our systematic review. So this would be a Nice 2 lesion. So the surface, the vasculature, is regular, repeating, no variation, JNET 2A. And this just was a tubulovillous adenoma removed via piecemeal EMR. We'll go back to the cases that we did in the beginning. That small adenoma — oh, I told you the answer — the small lesion in the beginning. So again, it's slightly elevated. So, again, for interest, it's a Paris 2A lesion. We look at it with a bit of magnification with NDI or BLI. So the vessels are regular and repeating, the caliber doesn't change very much, the distribution is fairly equal around, and then we look at the surface — so the white part, the marginal, the epithelium — the caliber stays the same. There's not a high degree of variability or amorphous areas. So this was a Nice 2, JNET 2A regular low-grade adenoma. So this lesion here, which we went over, grossly, there's a couple of high-risk gross features. [The] periphery has that white chicken skin mucosa, which you can kind of appreciate. There's spontaneous bleeding of the lesion, as well. Just with washing, it started bleeding spontaneously. There's a depressed area in the middle, as well. So those are, kind of, all high-risk features, which we chatted about. And then when you look in more detail, with magnification, this is in the area of the depression. So let's just look at the surface, the surface is very difficult to really make out any sort of pattern, and some areas it's completely lost. But you can see some of the — here, the white, kind of, lines, that's the epithelium, but in other areas, you see it's completely amorphous and lost. And the vasculature, as well, is completely, kind of, irregular and some areas are avascular. And if you look at it grossly, if you remember the type 3, some areas are darker, some areas are lighter. Again, all those features kind of tell you that this is an invasive carcinoma. This ended up being an SM3 carcinoma with lymphovascular invasion. And this last lesion also helps, kind of, show you the importance of a detailed exam. So this is the lesion grossly examined here. And these arrows just show you in terms of the areas with higher magnification. So here, if you look at it closely, it looks fairly normal. Nice 2, JNET 2A. This area over here, again, nice and normal. JNET 2A, Nice 2A, and same with this area. And I didn't mention it's an LST-G mixed type. So it's that, kind of, intermediate-risk lesion. However, if you notice, there's this area here that's just subtly different from the surrounding areas — slightly depressed, so it's a demarcated depressed area. And then when you look at that area in more detail with magnification, you start seeing some irregularity compared to what we saw on the last slide. So definitely, in terms of the surface, some areas where the surface is actually lost, and some areas where the epithelium is, again, quite irregular. And then you look at the vasculature; same in terms of there's a fair bit of irregularity in it here. So some of the vessels are sparse, some areas are slightly avascular, so this is kind of a borderline lesion. So, based on the total examination, we thought, probably, I thought it was going to have a superficial carcinoma in it, to be honest. And the distinction between high-grade and superficial carcinoma is — there's no real easy way to make that delineation. But I thought it was likely going to have superficial carcinoma, as it was an LST-G mixed type, JNET 2B, and we removed it in 1 piece via ESD, and it ended up being only high-grade dysplasia, but nonetheless completely removed. So those are, kind of, the cases I wanted to go over. I'll just briefly, kind of, go to the end in terms of our overall examination of lesions, just a summary. So we do our macroscopic exam. So you estimate the size, Paris classification. You're going to do your LST subtypes, if it's applicable, and look for high-risk gross morphologic features. Then you're going to do your microscopic examination, whether you have access to magnification or not, but, at least, the Nice classification is kind of the bare minimum, I think, for the microscopic exam. And then you decide on, kind of, your treatment algorithm. So is it something that you're going to remove? Are you going to remove it today? Another time? Are you going to refer it on to someone else? And you go from there. So how can it help you in your examination, whether you do therapeutics or not? It's going to help you characterize lesions better and tailor your therapeutic strategy. So, do I think this is a deeply invasive carcinoma? Am I going to biopsy it and send it to surgery? Is it something that I can remove via endoscopic mucosal resection (so, a low-grade adenoma)? Is it something that has high-grade or superficial carcinoma or something I'm not sure of? Send it for potential endoscopic submucosal dissection. And it'll allow you to predict difficulties. So as I mentioned, those non-granular lesions, even when they're small, tend to be more difficult in terms of resection. So adjusting your booking times appropriately, if it's something that you're going to think you're going to tackle, or saying, well, this person needs to come back because this is going to take a fair bit of time, even though it may not necessarily be a very large lesion.
Ameer Farooq 57:52
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Posted June 6, 2023