It's now my pleasure to introduce Caitlin Cookston. Caitlin is a physician assistant specializing in gastroenterology at UCHealth Digestive Health Center. She's also an instructor at the University of Colorado Medical Campus. Caitlin, the audience is yours. Thank you, Sarah. So today, I will be talking about the approach to ERCP and patients that have undergone Roux-en-Y gastric bypass. The altered anatomy of that procedure presents some unique challenges, so we can get right into it. I was going to review the indication for ERCP and the procedure itself, but Dr. Martin did a wonderful job of that, so you can pass over those slides. We'll review Roux-en-Y gastric bypass anatomy, and then I hope you feel comfortable with understanding the options for approaching ERCP in the setting of Roux-en-Y gastric bypass and undergoing some shared decision making with your patients about which approach may be best for them. Because really, there are some benefits and risks to all of the types of procedures that we have to offer, and it should be a shared process in those decisions. So like I said, I'm just going to glide over these slides. So whether you're in clinic, you're in the hospital setting, you have determined your patient needs an ERCP. The very first question that I want you to ask yourself is, what is their anatomy? Have they undergone any type of surgeries that change how our approach would work for an ERCP? Roux-en-Y gastric bypass is what we'll touch on today. Other common altered anatomy patients that you may see, though, are patients that have had Bilroth 1 or Bilroth 2 procedures, patients that have had a hepatico-jejunostomy, status post-liver transplant, and then patients that have had undergone Whipple procedures. So to quickly review Roux-en-Y gastric bypass anatomy, these surgeons essentially dissect out the stomach, and they leave a small gastric pouch and bring up a limb of jejunum to create a gastrojejunal anastomosis. And then from the excluded stomach, it goes down into the duodenum where your major papilla is with your access to your biliary tree and pancreas, and that comes down and ultimately lands in a jejunal-jejunal anastomosis. In terms of terminology, typically we'll refer to the gastric pouch as just a small pouch, and then the excluded stomach, the limb that is brought up to the gastric pouch is referred to as the roux limb, the alimentary limb, or sometimes the efferent limb, and then the limb that's coming down from the excluded stomach may be referred to as the afferent limb or the biliopancreatic limb. So our approach options, we have three main approach options that can be utilized. A balloon enteroscopy-assisted ERCP, an endoscopic ultrasound directed transgastric ERCP, which is a mouthful, so we call it the EDGE procedure, and then a lap-assisted ERCP with or without G-tube placement. We'll start looking at the balloon enteroscopy assisted. So with this procedure, we traverse the entirety of the bowel there. So we go down through the esophagus, down the roux limb, back up the biliopancreatic limb in an attempt to get to that major papilla. We utilize a single balloon enteroscope to get there. There is a really wide variation in the length of the roux limb as well as the biliopancreatic limb. It can average anywhere from 100 to 200 centimeters. On average, you see about 150 centimeters for the roux limb and about 50 for the biliopancreatic. But it is widely variable. It variables surgeon to surgeon. It can vary depending on when they got their surgery, if it's an older versus newer one, as well as from center to center. Most meta-analyses suggest that the success rate is around 60 to 70 percent for this procedure of successfully completing that ERCP. And I think that wide variation again comes because there's a large variation in the length of those limbs. So advantages of performing the balloon enteroscopy assisted ERCP. When successful, therapy can be accomplished in one procedure. There's no risk of reversing the gastric bypass. It avoids trips to the operating room or coordination with the surgical team and is therefore cost effective. Drawbacks is that it is a technically challenging and lengthy procedure. Usually this is due to ambulations, adhesions, looping of the bowel. Another way to look at it is there's a 30 to 40 percent failure rate of these procedures. And if that happens, this is going to facilitate need for an additional procedure to gain that biliary access. And then depending on the indication for this ERCP, there's a limited amount of ERCP accessories that can be utilized within that single balloon scope. So we may be limited on what we can actually do once we get there. These are just some nice floral images. The image on the left shows a person with standard anatomy. You can see it's a pretty straight shot. And then the picture on the right was a single balloon that was done at our institution for the indication of choledocal lithiasis. You can see the extensive looping and how far they had to get into the bowel to get to the major papilla. They were successful in this procedure, but it took about three hours and our attending that day was rather exhausted by the end of it. Okay, moving on to EDGE. So EDGE is a procedure that utilizes EUS and placement of a lumen-imposing metal stent or a LAMS stent to recreate a gastro-gastric fistula. Typically this procedure is done in two steps. Step one, we go in and place that LAMS and then we just come out. And then step two, usually one to three weeks later, you then go through and you can go through the LAMS to perform the ERCP. This can be a little bit different based on endoscopist and based on centers. Some people will do this in one step. They'll place the LAMS and then they'll proceed directly to ERCP. The risk there is that there's an increased risk for stent migration, which can be a really serious complication and may result in the need for an emergent surgery. But some centers do it where some tend to delay the ERCP. Of note, this placement of a LAMS or performing an EDGE is contraindicated in the setting of ascites. So advantages of the EDGE, it has a high success rate and a really great safety profile. It avoids the operating room. It is cost effective and it's an excellent option if you anticipate that the patient may need a repeat ERCP or may need an EUS. Drawbacks, it is typically a two-step procedure, which can delay therapeutic intervention. So if this is an emergent ERCP, probably not the best decision. And then it can reverse the effects of weight loss. People see weight gain while the LAMS is in place. This is an area that needs a little bit more research as this is a newer procedure, but about 50% of patients may see a five-pound weight gain and up to 30% may see 10 pounds or greater. The hope would be that once the LAMS is removed, that the gastrogastric fistula heals itself and thus the gastric bypass is kind of back to its typical anatomy where it was. But a gastrogastric fistula may persist in patients up to 31% of the time. And again, there's not a lot of great data on the long-term effects on weight gain if that persists, but it is something that patients should be counseled on and should be aware of. In regards to removal of the LAMS, I wanted to say this as well. Typically that's taken out just at the completion of the final ERCP within the same procedure. And closure of that gastrogastric fistula is also dependent on the endoscopist. Some will try to close it at that time, others will leave it and hope that the body would heal it. And then our last approach is a lap-assisted ERCP. So this approach requires OR coordination with a surgical team, typically either the trauma or bariatric surgery team. The patient goes to the OR with the surgery team, they dissect down and get access to the excluded stomach and they insert a trocar into that excluded stomach. Once they have that access, our team comes in and we insert our scope through the trocar and then navigate our way down to the major papilla. This is really ideal at a patient that requires a one-time intervention, but of course there may be some unforeseen complications that would require future intervention. And if that's the case, the surgery team can place a G-tube into the excluded stomach that we can use to access that excluded stomach in the future in the endoscopy lab. But it should be noted that if that does happen, we need to let that G-tube, that stoma, heal for at least four to six weeks before we can repeat any type of procedure through that. So advantages of this approach, it's an excellent option if your patient needs to go to the OR or requires a cholecystectomy because they can get everything done at once under one anesthesia. And it does have a fairly high success rate between 90 to 100%. Drawbacks include the fact that it does have to be coordinated with a surgical team. It does require a trip to the OR. Sometimes these procedures can be really lengthy and it can be difficult to time this around other patients and difficult from just a scheduling perspective. It is less cost effective and it is technically challenging. It requires two operators, the surgeons holding the trocar while the endoscopist is utilizing the scope. And then based on adhesions, it may be really difficult to get proper angulations as well. So it can be a really technically challenging procedure. I wanted to touch on complication rates and adverse events. Generally speaking, all of these procedures are safe and well tolerated. We see a little bit increase in overall complication rate for the EDGE as well as the lapis lazuli ERCP. The EDGE procedure is quoted a little bit higher, mostly due to stent migration. And again, when we wait to do the ERCP, we see less stent migration. So that can be mitigated to a certain degree, although it is still there. And then the lapis lazuli ERCP also sees a little bit higher complication rate. There's a small increased risk for an intraperitoneal abscess, but most of the adverse events related to the increase in lapis lazuli ERCP are more related to the surgical aspect, not necessarily to the ERCP itself. And this is a flowchart to just kind of start helping you think through when you see a patient that has a rheumatogastric bypass, how should we approach this? My first thought is, are they going to go to the OR anyways? If they are, I think that makes a pretty good argument for a lapis lazuli ERCP. Even if there's a chance they might need a repeat procedure, we can always place a G-tube. But if they're not going to the OR, first I see if I can find the rheumatogastric bypass op report. If you can, and the RULIM is less than 150 centimeters, it's probably reasonable to attempt a balloon-assisted ERCP. If that op report is not available, or if that RULIM is greater than 150 centimeters, an edge is probably going to have a higher chance of success. And then also if they need repeat procedures are anticipated, edge is going to be the best and safest option for the patient. So in conclusion, the best approach is going to depend heavily on local resources as well as your endoscopist expertise. But patient preferences really do need to be taken into consideration, and it needs to be a shared decision-making process. I think especially for the weight gain, we have to respect the fact that these patients underwent a massive surgery to lose weight, so they should be aware of this risk. And if that's not something that they're willing to do, we have to respect that. Urgency of procedure needs to be taken into account as well. So one other note for this is when talking with patients, these can be kind of big ideas for them to digest. So I always utilize drawings to help them really conceptualize what I'm talking about and what they might need. I find that to be very helpful. And then these are my references.

physician assistant

gastroenterology

ERCP

altered anatomy

Roux-en-Y gastric bypass