Our next presenter is Dr. Aaron Shields, who joined Rockford Gastroenterology Associates in 2004, and currently serves as managing partner. He specializes in liver disease and disorders of the biliary system and pancreas. At the University of Illinois College of Medicine at Rockford, Dr. Shields holds the title of Clinical Associate Professor of Medicine. Dr. Shields is a member of the ASGE Reimbursement Committee, and he previously served on the ASGE Health and Public Policy Committee. Aaron, the proverbial floor is all yours. Well, thanks, Jill. You know, I'm once again very glad to be part of this course. APPs, nurse practitioners, they play a critical role in our practice, and we're very involved with education to make sure that they're, you know, having a good role in our practice. We feel that they're essential to the operation of our practice. So again, I'm very happy to be part of this course again. We heard from Dr. Martin about upper endoscopy, and it's going to be my privilege to talk about a couple of specialized upper endoscopic procedures, specifically ERCP and endoscopic ultrasound. I think ERCP, if you were to poll gastroenterologists who do it, a lot of them would say that this is one of their favorite procedures to do because technically it's a challenging procedure, and a lot of the things that we do with ERCP provide quick feedback for the patient. In other words, they feel you get kind of prompt clinical responses with a lot of the things that we do. So ERCP stands for endoscopic retrograde cholangiopancreatography, and it is a technique for both diagnosis and management of pancreatic and biliary diseases. And when this procedure was first developed in the 1980s, it was largely a diagnostic procedure. One of the biggest changes that's occurred is that it has moved to primarily a therapeutic procedure. So there are very few diagnostic ERCPs anymore, which is a good thing because there are some significant risks associated with the ERCP that we'll be discussing. Some of the other tests or procedures that have replaced diagnostic ERCP include endoscopic ultrasound, MRCP, transabdominal ultrasound, CT, or sometimes just an intraoperative cholangiogram during a cholecystectomy. So here's a schematic of how an ERCP is performed. Patients are typically sedated with general anesthesia, although the procedure can be performed with monitored anesthesia with propofol. These patients do require typically a deep level of sedation because of the length and the complexity of the procedure. But the endoscope is inserted through the mouth, advanced through the esophagus and stomach into the duodenum. And the duodenoscope is a modification of a regular gastroscope that is basically a side-viewing scope. So instead of being able to look directly where you're going, you're looking at a 90-degree angle. And I tell my students and APPs that it's much like driving a car looking out the side window. You can't see exactly where you're going. But it's designed this way so that when it reaches the small intestine, the duodenum, it lines up directly across from the major papilla, where the pancreatic duct and the bile duct empty into the intestine. So this is a nice schematic of how ERCP is used for one of the more common indications, which is a common bile duct stone. And so if you look at panel A there, you'll see kind of what the anatomy of the area that we're looking at is. And it's important to have a very good understanding of the anatomy of all these structures, where the bile duct and the pancreatic duct empty into the small intestine. And this is critical for the endoscopist to understand in order to be able to access the correct duct. But as I mentioned, the duodenoscope is a modification of the forward-viewing scope. It looks at a 90-degree angle. And then there's a special operating channel with an elevator that allows deflection of instruments that can be then directed into either the bile duct or the pancreatic duct. And in the case of this patient, who has a stone that's stuck in the bile duct, the goal is to gain access to the bile duct and then allow the stones to be removed. ERCP is performed with fluoroscopy at the same time, because we rely on injection of contrast into the bile duct to be able to visualize the bile duct structures and identify many pathology. In this case, in the right panel there, you can see that there are multiple stones that are kind of stacked up in the bile duct. And ERCP really shines when it comes to procedures like this with being able to remove stones. One of the things that I encourage my APPs to do is, when explaining one of these procedures, is to take a diagram with, because most patients, while they might be able to understand a general anatomy of a stomach or a colon, when it comes to the more complex anatomy of the bile duct or the gallbladder, it's just, it's a lot easier to show them a picture while you're explaining the procedure. So most of my nurse practitioners, they walk around with a little map of the bile duct in their pocket. There are a number of different ERCP indications. We just talked about one of the most common, which is choledocholithiasis, or a common bile duct stone. Some of those patients also have cholangitis from an infection that has developed within the bile duct. Another common indication would be for management of malignant biliary obstruction. And these are your patients who show up with jaundice, dark urine. Most common would be things like pancreatic cancer, bile duct cancer, or cholangiocarcinoma, or some type of an interhepatic mass, which is compressing the bile duct. We will occasionally see post cholecystectomy bile leaks. This has become less common as surgeons have become more skilled with gallbladder removal. Biliary strictures, either after a gallbladder removal or after transplant, are fairly common, as is with primary sclerosing cholangitis. So far, we've only talked about the biliary diseases that can be managed, but you can also manage pancreatic disease. For example, chronic pancreatitis, where intraductal stones or biliary strictures, which compress the bile duct, can be managed with the ERCP. And pancreatic duct injury or leaks are good for management with the ERCP. This is probably one of the most important things that I review with my nurse practitioners, because of how frequently this specific question comes up. So patients come into, for example, the emergency department with abdominal pain, or they've got increased liver tests, and we get contacted because there's a suspicion that the patient may have a common bile duct stone. These are specific guidelines that were developed by the ASGE, and we use these all the time to make a decision on appropriate management of a patient who may have a common bile duct stone. Again, this is accessible through the ASGE. These are guidelines. But the most common thing that we are using this for is to determine if the patient has a high risk for a common bile duct stone. And that would include direct imaging of a CBD stone on either ultrasound, CT, or MRCP. The patient has a bilirubin of greater than four with a dilated common bile duct, or if they have clear evidence of ascending cholangitis. Those are the patients that don't require any additional imaging and can proceed directly to ERCP. For patients who don't meet those criteria, we look for other ways to try to confirm or eliminate the possibility of a common bile duct stone. And that would include things like MRCP, endoscopic ultrasound, or even the patient going just for a cholecystectomy and performing an intraoperative cholangiogram. But I suspect that the information in this particular slide comes up at least once a week as we're discussing how to manage somebody who has a suspected common bile duct stone. So very useful information here. The pre-procedural assessment is going to be similar to any other endoscopic procedure. You're going to do a review of the preoperative risk assessment, including determining the patient's ASA classification, make a decision on the sedation plan. So as I mentioned, most of these patients are getting their procedure done with general anesthesia, although there are occasional cases where we'll go with MAC, with propofol. Antibiotics are really only needed if the patient has primary sclerosis and cholangitis with a stricture, or if after the procedure you're unable to obtain adequate bile duct drainage. Rectal endomethacin is also something that we will oftentimes give because it's been shown to decrease the risk of post-procedure pancreatitis in high-risk patients. We've already talked a little bit about the management of anticoagulation, so I'll just emphasize some of the important points as they relate to ERCP. Both sphincterotomy and dilation of the biliary sphincter are considered high-risk procedure, and in those cases, anticoagulation and antiplatelet agents need to be held. Again, aspirin does not need to be held for this procedure. For patients on Warfarin, there really isn't a consensus on what the INR should be. I think if you ask different endoscopists, you might get a different answer on what level they're comfortable with. Something less than 1.8, obviously the lower the better. Other procedures can be performed safely on anticoagulation or on antiplatelet agents, and those would include things such as stent placement removal, brushings. If you're just doing a cholangiogram or a pancreatogram, those are considered low-risk and there's no reason to discontinue anticoagulation. This is probably the most important thing for you to understand, is what to do to get ready for an ERCP with regards to informed consent. As with all procedures, you're going to review the procedure itself. Again, diagrams are very helpful in this case. Discuss the goals and the potential alternatives, as well as any personnel that are going to be involved, including the endoscopist that's going to be performing the procedure. Informed consent is important for every procedure, especially with ERCP because of the higher risk profile. Pancreatitis occurs in about 5% of patients, that's usually the number that we quote, but there are certain groups that are higher risk for developing that. Fortunately, most cases of post-procedure pancreatitis are mild, but there are people who can become very ill or even die from the pancreatitis. Perforation and bleeding are less common. Cardiopulmonary complications can occur. There is a reported incidence of death. I think it's useful to discuss a little bit the chance that the ERCP might not be successful. Now, in skilled hands, ERCP should be successful about 95% of the time. There are cases when you anticipate that it could be a particularly difficult procedure, and it's worth letting the patient know ahead of time that we're not always successful with this and sometimes we have to move to a plan B. The post-procedure management, so if you see these patients afterwards, most patients can safely start clear liquids after they've recovered from anesthesia, so anywhere from two to four hours after the procedure. Typically, we'll wait till the next day to advance the diet, just mainly because occasionally they'll present with pancreatitis four hours later, and if you've already started feeding the patient, you can have some issues with that. So usually it's appropriate to wait to advance the diet until the following day. As I mentioned, ERCP is a very satisfying procedure because you oftentimes do see a fairly prompt clinical response. For example, if a patient has a common bile duct stone and they have pain and jaundice related to that, when you perform the procedure and remove the stone, oftentimes the next day the patient feels, they feel great and their jaundice is improving and it's a very satisfying outcome. It's also very important to arrange for appropriate follow-up. So for example, if a patient had a common bile duct stone that you dealt with and they need to have a cholecystectomy to prevent another episode, it's important to get that surgical evaluation arranged. And then it's especially important if you've placed a stent for some reason to make sure that that patient has appropriate follow-up for a repeat procedure to remove the stent or replace it. All of us have encountered patients who had an ERCP, this wasn't emphasized, and then they show up a year or two years later with a stent that's clogged and impacted and sometimes infected. And it can be a really, something you definitely want to avoid. So it's always important to have something on the chart and arrangements made for the follow-up procedure. So now we'll move on to the second advanced upper endoscopy procedure. This is endoscopic ultrasound. And unlike ERCP, which has become less common through the years, the indications in the use of EUS has steadily increased. And in most practices, endoscopic ultrasound is much more commonly performed than ERCP. And essentially what it does is it combines endoscopy with high-frequency ultrasonography. So in the image here, which is nicely labeled right in the center where it says EUS, that's the scope itself. This happens to be a radial scope. So you see things in a 360 degree view in a single plane. And in this case, this was actually done to evaluate a mediastinal mass. You can see the esophagus is highlighted, the aortic arch is highlighted, and then there's a large mass adjacent to the aortic arch. So this kind of illustrates the two types of EUS endoscopes that are used for this procedure. So a radial endoscope basically sends out ultrasound in a radial plane. And so you get imaging around the scope. If you just see the scope in the middle of the EUS image, you're typically dealing with the radial image. And it's useful for visualizing structures. You can see in this case here, it's being used to visualize a stone in the common bile duct. The other type of scope, and sometimes both procedures, both scopes are used during the same procedure oftentimes, is it's called a linear scope. And in this case, the plane of the ultrasound waves is parallel to the axis of the scope. And this allows a different type of imaging. And it also allows therapeutics, which I'll give you a couple of images up here in just a moment. So the reason why endoscopic ultrasound is so useful in the GI tract is because the different layers of the GI tract have different echogenicity. So if you, typically we look at five layers in the wall of the intestine, and you can see in this diagram, which layers, which histologic layers those correspond to. And this can be very helpful if you've got, for example, a submucosal mass. If you can identify which layer of the intestinal wall it's coming from, you can get a much better idea of what the likely diagnosis would be. As I mentioned, the number of EUS indications has steadily increased through the years. This is by no means a comprehensive list, but it does include some of the diagnostic indications. And some of the more common things that you'll encounter will be EUS for evaluation of both cystic and solid pancreatic lesions. Many of these are incidentally identified because a patient came in for a CT scan for some other reason, was found to have either a cyst in the pancreas or a solid mass. It's also very useful for subepithelial lesions. So lesions that arise from within the wall of either the stomach or the esophagus or the small intestine. It can be useful for either, even problems outside of the GI tract, like mediastinal masses can be used for staging of lung cancer. Some of the, one of the other indications is for staging purposes. And a number of different types of malignancies can be very accurately staged with endoscopic ultrasound. And those would include things like esophageal and pancreatic cancer, lung cancer and rectal cancer. Dr. Call is going to give you much more detail on some of the therapeutic options for endoscopic ultrasound, but I've included some of those here. And this again, this list just continues to grow as endoscopists become more skilled with this procedure. Here's one of the very useful indications. So I mentioned if a patient comes in and has, doesn't have one of the high risk categories for having a common bile duct stone, we look for other options for trying to identify whether there is a common bile duct stone. And one of those common ways of dealing with this is to set the patient up for a combined EUS slash ERCP. And basically what you do is you sedate the patient, you perform the endoscopic ultrasound. In this case, you can see there's a stone within the common bile duct. And then immediately while the patient is still sedated, you can change out the scope, pull the endoscopic ultrasound scope, put down the ERCP scope and perform a sphincter odomy and remove the stone at the same time. So everything can be dealt with all at the same time. Here's another very useful indication for endoscopic ultrasound. This is a pancreatic mass. And you can see that there's a needle that's been passed out of the scope, basically through the wall of the, either the stomach or the duodenum, depending on where it's located and directly into the tumor itself. The sampling can be performed oftentimes with a cytologist in the room and you can oftentimes make a diagnosis right there at the time. At the same time of getting a tissue diagnosis, you can perform staging, look for lymph nodes, things like that. So this is another very common indication for endoscopic ultrasound. Pre-procedural assessment, it's similar to what it is for other procedures. Again, a preoperative risk assessment and then a decision on sedation plan. Most of the time, this procedure does not require general anesthesia. It can be performed with MAC, propofol. You can even perform this procedure, especially if it's something like a rectal ultrasound with minimal sedation. Anticoagulation should be managed. Typically, if FNA is anticipated, so if you plan on taking biopsies, passing the needle through the wall of the intestine into organs, you're likely going to be holding anticoagulation. Antibiotics are really only needed if fine needle aspiration is being performed of cystic lesions in the mediastinum or for some types of therapeutic endoscopic ultrasound. And of course, informed consent should be obtained. Again, we've talked a lot about anticoagulation because it is such an important issue to address prior to the procedure. If a therapeutic procedure or fine needle aspiration is anticipated, then again, anticoagulation, antiplatelet agent should be held. Again, there is no clear consensus, but the lower that you can get the INR, the better. If it's just a diagnostic or a staging EUS without the anticipation of fine needle aspiration, that may safely be performed on anticoagulation or antiplatelet agents. The informed consent process, again, same as with ERCP, review the procedure and the goals, the alternatives, who's going to be performing the procedure, who'll be in the room. This is generally a much safer procedure than ERCP. The risk of pancreatitis is much, much smaller. It's really only if there's a pancreatic procedure, if you're going to be doing a biopsy of the pancreas, and even then, the risk is quite low. Perforation, bleeding, cardiopulmonary complications, death, or again, unsuccessful procedure is also a possibility. So in summary, ERCP and endoscopic ultrasound are really essential procedures for the management of both GI and non-GI diseases. The most important thing for the APP to know is selecting which patients are appropriate for each procedure. Whenever possible, you should perform less risky tests, and this really applies to ERCP. Management of anticoagulation, operative risk is key. And of course, as with any procedure, early recognition and management of complications is essential. So I'm going to wrap up with just a few polling questions here to hopefully reinforce some of the important things that we've touched on. So which of the following is most appropriate for evaluation of a patient who has a low suspicion for choledocal lithiasis? ERCP, endoscopic ultrasound, MRCP, or abdominal CT? Okay, so this is very interesting. Perhaps the question should clarify a little bit further that we are specifically looking for a common bile duct stone. Ultrasound is a good initial test if you're interested in cholelithiasis, which is a stone in the gallbladder. But if you really want to identify if somebody has a stone in the common bile duct, you should look at the ultrasound. If somebody has a stone in the common bile duct, ultrasound is really not very sensitive. Only about 30% of patients with a common bile duct stone will have a positive ultrasound. And abdominal CT is even worse. So if you really suspect that somebody might have a common bile duct stone and you're trying to confirm or disprove that, then MRCP is the way to go. So which of the following are complications of ERCP? Pancreatitis, bleeding, perforation, hypoxia, or all of the above? Okay, so it's all of the above. Pancreatitis is the kind of the most feared complication of ERCP, but certainly bleeding, perforation, and respiratory complications such as hypoxia are also possible. And then I believe I have one more question here. So EUS is indicated for which of the following? Diagnosis and staging of pancreatic cancer, endoscopic pancreatic pseudocyst strainage, FNA of mediastinal lymphadenopathy, evaluation of common bile duct dilation, or all of the above? All right, very good. So all of these are accepted and good reasons to perform endoscopic ultrasound. Okay, so thanks for your attention. I will now pass the floor to Dr. Call who will talk about therapeutic endoscopy.

ERCP

EUS

pancreatic and biliary diseases

common bile duct stones

high-frequency ultrasonography

patient selection