We move on to our third and final lecture before the cases, and Dave Katska is professor of medicine at Columbia University and recently led the ASG consensus conference on endoscopic approach to eosinophilic esophagitis. Dave, welcome. Thank you so much, Prateek. I'd like to thank Dr. Fisher, Dr. Sethi, and of course Prateek for allowing me to speak to you today, and the ASG for performing this consensus conference. These are my disclosures. So this process was one in which we assembled a group of experts to ask the questions, what's the role of endoscopy in eosinophilic esophagitis? And this group was comprised not only of adult gastroenterologists, but pediatric gastroenterologists, as well as quality experts to try to make sure we did this right. Now one question is why would we want to do this? And the reason, of course, is that there really is no document that guides us as far as endoscopic use within eosinophilic esophagitis. Part of the problem is as a new disease, we do not have the longitudinal data, let alone enough randomized data to really come up with a guideline, but nevertheless we thought advice, if you will, would be important from this committee. So this process consisted of a standard Delphi process where first we identified nine experts who formulated questions, discussed questions, voted on the questions, and then rewrote them, followed by the addition of other members to the core group to give a much larger group to evaluate these questions. And then finally, of course, after the addition of this group, to eventually come up with formulated statements. Now as with any consensus document, many of the recommendations will be obvious, some will be intuitive, and some will be provocative. And there's no question there may be change in terms of what we recommend. This is the first time we're doing this, but at least we feel it's the best advice we can give at the present day for endoscopic use in eosinophilic esophagitis. So we divided the areas of discussion into four categories. First was endoscopic diagnosis with biopsy and grading, assessing response to therapy with endoscopy, endoscopic dilation, and then monitoring disease. With endoscopic diagnoses, these were the first three statements we came up with, and that is something well known already, for the diagnosis of EOE, at least six biopsies should be taken from the esophagus for a diagnosis of eosinophilic esophagitis. They should be taken from the distal and mid-deproximal esophagus, and in a patient with suspected EOE, biopsies should be obtained from the esophagus regardless of endoscopic appearance. And I think one subtle point here is you'll notice it doesn't mention whether to go into one jar or two jars. At this point, I don't think there's consensus over which one is right. And the third one you'll note, too, that it underscores the fact that approximately 5%, if not more, depending on your expertise of patients with dysphagia, will have a normal endoscopic appearance, hence the need to biopsy in these patients. We also noted that after index endoscopy, multiple biopsies should be taken from the stomach and duodenum in patients with compatible symptoms and or endoscopic abnormalities. In other words, concurrent eosinophilic gastroenteritis may certainly occur in these patients, is more common, but the yield of doing it in asymptomatic patients other than dysphagia is not high. And now one that's a little bit provocative, and that is that biopsies should be taken at the time of food impaction. Having been on the other end of the scope, I grant you that it is difficult sometimes technically and may not always be possible, but in the chance that we could spare a patient an additional endoscopy, we thought this was worthwhile. For endoscopic grading, of course, the EREF score should be used, but we decided that the best place to do this was in the highest scoring area as opposed to a general impression of endoscopic appearance. And we further divide these features into inflammatory versus fibrotic features with the concept that fibrotic features may not improve in the short term, let alone at all, whereas inflammatory features such as furrows, exudates, and edema should improve with short-term medical therapy and therefore may be more worthwhile to monitor in your assessment. The next broad category was response to therapy. And we felt very strongly that endoscopy and biopsy, and not symptoms alone, are needed to assess EOE activity before and after any change in dietary elimination therapy or pharmacologic therapy. So if a patient's on twice daily PPI, you reduce them to one daily PPI, this requires another endoscopy. With food elimination, it's similar. And we felt this was very important because the data, I think, is quite clear at this point from multiple randomized trials and observational studies that symptoms are a very poor judge, or at least indicator, of endoscopic and histologic activity in EOE. So yes, this involves a lot of endoscopies, but nevertheless, we felt that upfront objective assessment of what could be their treatment for the next 50 years is worthwhile for these number of endoscopies. For endoscopic dilation, of course, we should do dilation in all patients. Dilation should be a consideration. And the immediate end point should be the appearance of a mucosal disruption. In other words, you have to go back and look. One question was, what should that end point be? And in adults and adolescent patients with EOE, the gold luminal diameter that relieves dysphagia and food impaction, typically at least 16 millimeters, should be achieved over one or more sessions based on the initial caliber. And therefore, the upfront warning that we give to patients to get you where we need to be may require several sessions. And to lower the risk, achieving a diameter of 16 millimeters may necessitate gradual dilation. Certainly, there are some patients who will go by with 13 or 14, but 16 seems to be the number where most patients will feel better without needing to go further. Effective management of inflammation attenuates the need for future endoscopic dilation, important to make sure they're on steroids or PPIs or diets, whatever you choose. And that different dilation techniques are acceptable depending on your comfort and the length and degree of stricture. It should occur in junction with medical therapy, as mentioned, although some people advocate for dilation therapy alone. That was not the recommendation of this panel. And of course, we feel that dilation is very safe in these patients as opposed to earlier reports. In patients who have dysphagia without a stricture, we do feel that empiric dilation is worthwhile because of the very high misrate of subtle strictures in EOE as demonstrated on radiography. And then most patients with radiographically or endoscopically demonstrated perforation will respond to conservative therapy. Stenting, let alone surgery, is very rare in these patients and fortunately not required. For monitoring disease, we did make the strong recommendation that patients with EOE and remission should be continued to be monitored for symptoms and consideration should be given to periodic endoscopy and biopsy. Although I can't tell you what that interval should be, whether it's one year or three years, so it's a little bit vague on that, but certainly no more than one year just to make sure their treatment is maintaining the efficacy we think it should. Certainly studies from Evendellin show that unfortunately even on therapy which shows remission with acute treatment, many patients will still relapse even on similar treatment. So anyway, so I think that's basically what we covered in this guideline. So again, I think it's important to consider that we've standardized at least what we think is the endoscopic approach at this point. I think we do have to be open to change to more randomized trials without question, but I think at this point for the next few years until that data comes, it's the best we can do. And obviously we're open to discussion. Thank you very much for this opportunity.

ASG consensus conference

endoscopic approach

eosinophilic esophagitis

diagnosis and monitoring

endoscopic grading