This week, electrocautery settings for EMR on the ASGE SuTab tip of the week. I'm going to keep these top two blue rows on as we're talking about electrocautery settings because they emphasize that we're in the middle of a cold revolution in endoscopic colorectal resection, and there are many lesions that are definite or potential candidates for cold resection and that the advantage of that is a very low or negligible risk of complications in most instances, and the uncertainty of it is the recurrence rate, at least for larger lesions pending the results of randomized trials. Before I talk about the electrocautery settings that I use for polypectomy and EMR on the colorectal, I want to mention the evolution of generators and concepts about how the type of current that we use affects the type of bleeding that we see. So until recently, the paradigm that was widely discussed was that coagulation current results in less immediate bleeding because it seals vessels better, but more delayed bleeding because it causes a greater depth of injury that you can't appreciate during the procedure, but which results in damage to deeper vessels that then start bleeding after the patient leaves, and that's the worst kind of bleeding to have because it can result in hospitalization, transfusion, repeat procedures. It's better to have bleeding occur during the procedure where you can deal with it. So cutting current would seem to be preferred because it tends to result in more immediate bleeding and less delayed bleeding, less depth of thermal injury, and these concepts are based on older uncontrolled studies that were done with procedures that use fixed output generators. That is, you put them on 17 or 18 watts of coagulation current and that's what you get. As a result of this concept, many experts switched from low power coagulation current, myself included. Incidentally, that was the way I was trained to perform colorectal resections to predominantly cutting current, maybe around 10 years ago, plus or minus a few years, depending on the expert, with the idea that this would limit thermal injury to the semicosa and reduce the risk of delayed hemorrhage. And many of us switched specifically to endocut. Endocut is an alternating cut coagulation current that emphasizes cutting current compared to pure low power coagulation current. So what's different now? Well, we have a randomized trial, and this is, to my knowledge, the first randomized trial to compare current types for any type of endoscopic resection in the colorectum. This was done in more than 900 lesions undergoing EMR, non-pedunculated lesions, 20 millimeters or larger in size in more than 25 centers, mostly in the U.S., and comparing coagulation current to endocut. Now, importantly, the generators were not fixed output, but rather they deliver microprocessor controlled current, meaning that they calculate the tissue resistance and deliver enough power or current to perform the transection. And this is true for both currents. And the results were surprising. For the critical endpoint of delayed bleeding, there was no difference. That's the main result. And it's different than that paradigm we've been believing for a long time. Also, no difference in recurrence rate, but the rate of immediate bleeding was higher with endocut. So what does this result mean? Does it mean that we should trash the entire concept that limiting thermal injury prevents delayed bleeding? Well, we can't do that because the entire cold revolution is based on that. We know that cold resection is associated with a lower risk, but we do need to question, especially if you're using microprocessor controlled currents, that it's necessary to use cutting current compared to coagulation current to limit thermal injury. My bias is, and I'm going to talk about this in the next video tip, that actually what's important is the transection speed. If you come through faster, you have less thermal injury. And we're going to talk about how you can mechanically control that. So as a result of this study, I am now in many instances using microprocessor controlled coagulation current to perform EMR. No real downside in terms of delayed bleeding, less immediate bleeding. And my bias is that there may also be a lower risk of perforation. I have felt for a long time that when you're using coag current and you have muscle trapped in the snare, the tech or you, whoever's doing the snare closure is more likely to feel it than with endocut where there's more of a tendency to go straight through it. So that's not proven. It's a bias, but I suspect it's true. Having stipulated that in many instances, I've gone back to coagulation current for EMR. I also reiterate the caveat that I still strive for fast transection speeds with the goal of reducing thermal injury. For large pedunculated polyps, we'll almost always use standard hot snare polypectomy. I recommend forced coagulation current effect to max 25 watts. I mentioned in an earlier video tip that I like to approach all large pedunculated polyps as if they're potentially malignant. This one's obviously malignant. The head of it is ulcerated, but in general, for any bulky lesion, including a large pedunculated polyp, it's hard to endoscopically predict the presence of cancer. So you want to assume that it could be malignant and shoot for the best oncologic outcome. And to do that, what you want to do is transect the stalk very low, close to the colon wall. About a third of malignant pedunculated polyps have invasion of the stalk. They're haggard level three. And by going low on the stalk, we are maximizing the distance between the resection line and any potential cancer. And if we use forced coagulation current and we follow the basic principles, which is that the snare is actually touching the stalk, it's squeezing the stalk, and then we apply a bit of conditioning current to get the burn started before we transect, we'll almost never see these bleed. I haven't seen one pump for a very long period of time. So we place the emphasis on the quality of the specimen, the length of the stalk, and after the resection is complete, we can clip the site closed. For hot EMR, you have your choice between endocut Q and forced coagulation current, as we've already discussed at length. For endocut Q, the manufacturer recommends the 3-1-3 setting. In our clinical trial that I've already discussed, we use the 2-1-4 setting. It's the first number that ranges from one to four that is most important. The lower you set that number, the more cutting and less coagulation effect you'll see. A massive granular LST in the transverse colon that I took off just a few weeks ago, and I mentioned I've switched back to low-power coagulation current. And despite that, you'll see that the submucosa looks nice and blue. And I just want to make the point here that that's one way we can judge whether or not we're limiting thermal injury, is have we charred the submucosa white, or does it stay nice and blue? Here's a view of the defect later in the resection. You can see this blue color of the submucosa, which again, I believe, indicates less thermal injury compared to a charred white appearance. And again, next week, we'll talk about how, as a principle, speed of transsection, despite the use of coagulation current, or regardless of what current is used, helps to achieve this end and appearance. Avulsion can be performed cold or hot. When it's needed during hot EMR, I prefer to perform it hot. I think you get faster and cleaner resection with hot avulsion. You want to switch the endocut from Q to I. In our paper on hot avulsion, we use the 313 setting, but subsequently I have shifted to almost pure cutting current. So endocut I on the 141 setting. We'll discuss the avulsion technique in detail in later tips, but by way of introduction, it involves grasping fibrotic tissue with a hot forceps, the right amount of tissue, second, placing mechanical tension on it, and third, applying this low voltage endocut I cutting current with very brief pulses on the yellow pedal to separate the fibrotic tissue in the same plane that the snare resection was occurring in. Finally, after piecemeal hot EMR, we want to treat the normal appearing mucosa at the margin of the defect with thermal injury, so-called snare tip on soft coag, as we discussed and demonstrated in detail in tip number one. We use soft coagulation current effect four or five max watts, 80. This is the same current that we'll use for control of bleeding using the snare tip or coag graspers. Thanks, and see you next week on the ASGE SuTab tip of the week.

electrocautery settings

endoscopic mucosal resection

ASGE SuTab tip

current type

delayed bleeding