Well, thank you so much, Vivek. It's such a pleasure to be a part of this program, and I think that we have been having very nice programs so far. So my task today is going to be talking about EOS-guided biliary drainage and GJ, when should you do it and how. So I have nothing to disclose. Today I will cover indications, devices and techniques, outcomes and pitfalls, and I will finish with some tips. So the most common indication for EOS-guided biliary drainage is failed ERCP. Some of the indications include inaccessible ampulla in patients with gastric outlet obstruction, tumor infiltration of the ampulla, and surgically altered anatomy when it's difficult to access the ampulla. Contraindications include tumor infiltrating along the luminal surface, or unable to visualize bile duct, massive ascites, severe coagulopathy, and unstable patients. Generally there are two main areas that EOS can access the bile duct. One transduodenal, and the other is transhepatic. For transduodenal, we can access the bile duct from the bulb to place a stent, and that's called choledochoreudinostomy, or EUSCDS. We can also do rendezvous technique when we advance, puncture the bile duct, advance the wire through the ampulla into the duodenum, and exchange the wire into ERCP, and we perform ERCP. We can do that from the bulb or D2. For transhepatic, we can place a stent transmurally, and that's called hepatical gastrostomy, or HGS, and through this hepatical gastrostomy track, we can actually advance the wire across the hilum and put another stent into the right intrahepatic duct. We can also put stent from the left HGS into the duodenum through the ampulla. That's called antigrade stent placement. To do this type of procedures, we're going to need to use linear EUS, CO2, fluoroscopy, electrosurgical unit. We use 19-gauge FNA needle. We also use guide wires. There are several kinds of guide wires that we can choose from, 0.025 or 0.035, dilator. It could be Bougie dilator or Cautery, like Six French Sister Tone, or balloon dilator. Finally, stents, which come in different types, plastic stent, tubular metallic stent, or lumen-opposing metallic stents, known as LAMs. The ESGE has just published the recommendations on stent selection for each therapeutic EUS for malignant obstruction. For EUS-guided CDS, the ESGE recommends using fully-covered tubular biliary metallic stent or lumen-opposing metallic stent. It could be any brand, really. They work very well. For HGS, it's important to understand that for HGS, you're going to have to put the stent in much longer. Therefore, lumen-opposing metallic stent is not recommended. You can use fully-covered tubular metallic stent. The length should be at least 8 centimeters. Generally, we can use 10, or some people use 12, or partially-covered metallic stent with the same length. Now, let's get into the techniques a little bit more. We start off with EUS-HGS. This kind of procedure has multiple steps. I'm going to start from step one. You have to identify the dilated bile duct, puncture it, and then advance up. After you puncture it, then you aspirate bile, inject contrast to perform cholangiogram, then advance the wire, aim it to the direction that you prefer. Mostly, we would like it to come down to the CBD. After wire manipulation, then you dilate the tract. You can use Bougie dilator or French cystotome. After that, we can dilate the tract further using a balloon, but this is optional. Finally, we put a stent in. Here's a video showing how we identify the dilated duct. We puncture, and then we advance the wire. We did not dilate this, or we dilated it with French cystotome, and now we are placing stent. You can see that the tip of stent is right here, and then the distal end of the stent is going to be deployed inside the skull, and then we will push the stent down into the stomach, as you can see here. For anti-grit stent, there are a couple of steps added to the conventional transmural HGS. You can see that after we advance the wire, then we see that stricture right there. What we like to do is to dilate the stricture, and you can use balloon dilation. Some people use six French cystotome to dilate the stricture with cautery, and after you finish dilation, then you want to place the stent. Make sure that the distal end of the stent is located in the duodenum under fluoroscopy, and slowly pull back the stent. The distal end or the upper end of the stent should be placed in the CVD, which is going to be deployed right here. Okay, now the stent is fully deployed. Now here we go. Moving on to EUS-guided CDS, I think it's very important that we know where to puncture and where the direction of the needle should be. For CDS, we want to put transmural stent, therefore the tip of the skull should aim towards the hilum, and the direction of the needle should be aiming towards the hilum as well. Here is a video demonstrating two techniques of EUS-guided CDS. The first one is on the left here. You can see dilated CBD, but less than two centimeters. So for this particular case, we elected to use a multi-step technique. Basically, this is the needle. We identify the dilated bile duct, puncture the duct with the needle, aspirate the bile, inject some contrast, and then we advance the wire into the duct. Here you can see the phalangeogram with dilated duct. And once you get the wire inside, you dilate the tract, the cystotome, and after that you exchange the cystotome out and put a stent in. So now you want to make sure that the stent is deployed properly. You can see the tip of the stent is right here, and the other end of the stent is being deployed in the duodenum. But when you have a very dilated CBD, more than two centimeters, you can choose lumenopostal metallic stent, and you can do it freehand, meaning no wire guided. You can see the stent is coming through here, and we're slowly deploying the distal end of the stent. Sorry. Here. The stent is coming in. Okay, now we're opening the distal end of the stent, the first phalange. And once the first phalange is being completely deployed, we want to pull this phalange up against the wall of the CBD, and after that, we can deploy the other side of the stent in the channel, and then we can push that stent outside the channel of the scope, and you can see the other phalange of the stent in the duodenum right here. Okay, so it really depends on the size of your bile duct. You can use different technique. Now moving on to rendezvous. For rendezvous, we can actually access the bile duct through transgastric or D1 or even D2. There are some advantages and disadvantages. For transgastric, the advantage of this is that it's straight, the Y is straight, and the B2, you can access B2 from the esophagus, so it's easier. However, the disadvantage is that you're going to need a dilated intrapartic duct, and it's long distance, and the wire manipulation is more difficult, whereas when you access through D1, D1, the scope is more stable, however, the angle is very difficult because the tip of the scope is sort of aiming towards the hilum in this position, so the needle is going to bend a little bit if we do it from D1. For D2, its short direction is good, but the scope is very unstable, so there are pros and cons of the location of the puncture. You have to look at a patient's anatomy and see which one would work best. Now I want to highlight this a little bit. When we do this type of procedure, especially pedicle gastrostomy, it requires so many steps. Each step can have adverse event. For example, needle puncture might cause bleeding or double puncture, and to make sure you use Doppler and you look at the EUS view closely, make sure you don't see two layers of the gastric wall or the duodenum wall. During wire manipulation, you could have wire shearing that happens a lot, especially if it's difficult to manipulate the wire. When you remove the needle, that can create a little bit of bile leak, not a big deal. During the dilator insertion, sometimes the wire gets displaced, so you've got to make sure that you and your assistant work together well. During dilator removal, there might be a little bit of leakage of the bile. Finally, during stent deployment, the stent can be misdeployed, creating perforation. So all of these things can happen. Just have to remember that you want to do everything, all these steps under EUS image until when you get to the stent deployment, and that's when you turn on your endoscopic view and look at it through the endoscopic view. There are several questions being asked about EUS-guided biliary drainage. Number one, EUS versus ERCP, which one is better? Is EUS going to replace ERCP? Is ERCP retiring? That's a hot issue right now. Number two, EUS-guided HGS versus EUS-guided CDS, which one is better? Can EUS be performed as primary drainage procedure, or what's the role of EUS in high-level law? I'm going to try to give you some evidence to answer these questions. Question number one, EUS versus ERCP, which one is better? Several studies, including RCTs, comparing the performance and the success rate, as well as the adverse events of EUS and ERCP, and it turns out that these two techniques have very similar success rate and adverse event, with an exception of one RCT demonstrating that ERCP has higher complications or adverse events, being acute pancreatitis, when compared to EUS, and all these studies were performed in patients with malignant obstruction. What about EUS versus EUS HGS versus CDS? Several studies have been performed to compare the technical and clinical success of hepatical gastrostomy versus coledocal adrenostomy. Overall, they seem to have comparable technical and clinical success and comparable adverse event, with an exception of a couple of studies demonstrating that coledocal adrenostomy has higher adverse event than hepatical gastrostomy. Now moving on to the question about whether or not EUS biliary drainage can be used as the primary method for distal malignant obstruction. Many RCTs, as well as meta-analysis, have compared the performance and the success rate between EUS, BD, and ERCP in patients with distal malignant obstruction. Both techniques are comparable in terms of technical and clinical success, and also comparable in terms of overall adverse event. However, EUS guided biliary drainage has less ERCP, obviously, and less tumor in growth because the stent doesn't go through the tumor and it doesn't go through the ampulla. Therefore, pancreatitis is going to be less. Also, one meta-analysis demonstrates that EUS biliary drainage has less pre-intervention rate. Finally, is there a role of EUS in hyaluronic block? I think this condition is where EUS guided biliary drainage is gonna help a lot because ERCP is not always successful with hyaluronic block. So, so far, the studies have been small studies with limited number of patients, but if you look at technical and clinical success, they are approaching 100%. However, the adverse events are also kind of high, ranging anywhere from 10% to almost 30%. So with this, I think that EUS BD, especially hepatical gastrostomy has a role in hyaluronic block although as of now, the adverse events is still high, but in expert's hand, the adverse events is actually very acceptable. So before I finish the EUS BD portion, I wanna summarize that EUS biliary drainage should be done as a rescue procedure after failed ERCP in accessible ampulla. The options include EUS rendezvous, EUS hepatical gastrostomy for hyaluronic block and EUS choledical duodenostomy for distal block. Although for the distal block, you have an option of doing HGS or CDS depending on your preference. Can EUS BD be used as primary method in malignant obstruction? Yeah, it probably can, but it's best to use it in a surgically altered anatomy and patients with gastric outlet obstruction, it could be benign or malignant. And for distal malignant obstruction, I think the data is looking very good, but the current recommendation is to try to perform ERCP first. And when that fails, then you do EUS BD. In patients with gastric outlet obstruction, inaccessible ampulla, you have an option of doing hepatical gastrostomy with anti-grit stent placement or a transmural stent placement. And for this type of procedure, you only use tubular metallic stent, not lumen-opposing metallic stent. Now I like to move on to EUS-guided GJ or EUS-guided GE because sometimes, you know, we don't do GJ per se, we do gastroenterogenostomy, so I'm just gonna call it EUS-GE. Well, EUS-GE is one of the treatment modalities for gastric outlet obstruction now. We have intrastent and conventionally surgical therapy, but EUS-guided GE is really something that can be performed in this type of patient. There are five proposed techniques for EUS-GE. The older techniques include anti-grit stent. This is a balloon catheter. You put the balloon across the stomach into the small bowel and then you blow a balloon and you puncture at the balloon. Or a rendezvous technique, or retrograde entero-gastrostomy. These three techniques now, we don't really do it anymore. Currently, we're doing mostly EPAS or direct puncture. I should say that EPAS is a special kind of balloon that is a double balloon. When you do this, you advance this balloon catheter across the obstruction here and then you blow these two balloons. And then you fill up the segment of the bowel with water, mixed with methylene blue. And then once you can see this dilated small bowel segment, then you puncture right here and then you put a stent here. But, you know, EPAS balloon is only available in Japan. So people outside Japan can't really use this. So now we're using direct puncture or direct method, which I will show you in a second. For this type of procedure, we would need linear echo endoscope, LAMs or Luminoplasty Metallic Stent with cautery tip. Guide wire, we used to use it, but now it's not recommended anymore because it can push the small bowel away from the needle. We use saline mixed with 0.5% methylene blue just to make sure that we are in the right bowel loop. Occlusion balloon, this is optional. The alternative of occlusion balloon is a catheter or nasal bleeder tube. As far as the ESGE recommendation, the type of stent being used for EUSGE is Hot Luminoplasty Metallic Stent. And it can be any brand really. Now I want to show you the technique. This video was taken from our unit. So here in this patient, we use aortic balloon and we also use Hot Axios. We did not use the 19 gauge needle punctures because we use direct technique. And here's one thing we have done. This is a DIY aortic balloon combined with the NGV and we attach an NG tube to this aortic balloon. And the purpose of that is that when we do this, this is a case of a patient with benign pyloric stricture. So we dilated the pyloric stricture with the CRE balloon. Then we went inside the small bowel. So here, this is what we do. This catheter is an NG tube attached to a aortic balloon. We advanced this catheter beyond the stricture so then we can actually flush water through the NG tube because a lot of water can go in much better. So here, what we did was that we blew the balloon. So the balloon would block the small bowel loop right here. And the NG tube is right around here. So we flush this loop of small bowel through the NG. And then you can see this loop of the small bowel becomes dilated very nicely. And then you advance the LAM and start deploying distal flange. Once you see the distal flange open, then you pull it all the way back against this wall. Here we go. And then you start to deploy the distal flange inside the stomach. Yes, and then if you're in the right area, you will see the methylene blue, which is mixed with water coming out through the gastric side. And here is the barium study, which was done a week later. So that's the way we did it. We also created complications, obviously, and I wanna share with you this video. As you can see here, this is a loop of small bowel. You can see it's not as well distended as the first video I show you. And as we were performing this, as we were starting to open the first flange, we kind of lost the vision a little bit. See that, that the vision was gone, but we thought, well, maybe we got it. We open the, we deploy the first flange. And then after we deploy the second flange, if you can see this, here we go. You see fat, you see some yellow stuff, which is not a good sign. And we did not see any blue water coming through. So obviously we were outside of the small bowel, but don't worry. What we did was that, you know, because we were lucky that the gastric, the flange inside the stomach is still there. So we just removed this flange with a red tooth forceps, and then we closed that defect with a clip. We admitted the patient for a couple of days. The patient did well. We came and made PO and placed it into tube. And we brought the patient back a couple of weeks later. And now you can see a nicely distended loop of small bowel. This time we used freehand technique, meaning no guide wire. The first time we used guide wire, this time we decided not to use guide wire. And we went in with a freehand technique and the procedure was performed successfully. And this time you can see, see, you see the blue water coming out. So that means that you're in the right place. So pitfalls always happen, especially with the stent deployment. Several pitfalls can occur. You may miss puncture. If that happens, it's probably because the small bowel was inadequate distended or maybe too much mobility. So if that happens, then make sure that you retract the device back and repuncture with a better visualization. What else could happen? The first flange is deployed outside the small bowel. And I think that's what happened to us on the video that I show you. So it could be that the stent may have slipped during the stent deployment, or it may have been outside the small bowel right from the beginning. And if we recognize that right away, like the patient that we did, then we could resheathe and then pull the stent back. Or if, and we can stop the procedure just like we did, and then reattempt. But if the second flange is deployed outside the stomach, and that's bad, that means that during the deployment, we pushed the stent outside the scope too much. So the stent basically migrated into the small bowel or in the peritoneum. When that happened, a lot of times we need surgery for that. So if you actually do a wire cannulation through the puncture side, inside the deployed stent, you can rescue that stent and put a new stent in. So that is something that can happen. As far as clinical success, more than 90% technical success, also more than 90% that have been studied, assessing the effectiveness of EOS-guided GE versus duodenal stent versus laparoscopic gastrointestinal. It seems that with the laparoscopic surgery, it takes the longest time. With the EOS-guided procedure, it takes, it had a shorter hospital stay and the patients seem to have better quality of life. And therefore EOS-GE right now can be done in patients with advanced malignancy and not surgical candidate. And, but it requires expertise and it can be performed in both malignant condition and benign conditions. So finally, I would like to conclude by giving you some tips on EOS-BD and EOS-GE. For EOS-BD, I think scope position is very important. If you want to do transmural stent, the tip of the scope should be aiming to hilum. But if you're doing rendezvous, the tip of the scope should be aiming to the ampulla. Guide wire. Soft wire is very easy to manipulate, but it can shear very easily. Therefore, once you get your wire into where you want it to be, then you can exchange your guide wire to something that's more stiffer. After you inject contrast, make sure you flush the needle with saline. Otherwise the wire is going to be very difficult to manipulate. During the tract dilation, you can use Boogey dilator or Six French Sister Tone, but avoid using needle knife because it is associated with higher rate of perforation. Proper stent selection is key for EOS-BD and EOS-GJ as well. For EOS-GJ, direct puncture is preferred now over wire guided technique. And you should at least instill saline mixed with the methylene brew for about 500 CCs, no more than one liter. Otherwise your patient may be aspirating. And I generally do this type of procedure under general anesthesia, but some of the institutes, they do it just under deep sedation. And so with that, I'd like to thank you very much.

EOS-guided biliary drainage

gastroenterostomy

transduodenal access

transhepatic access

choledochoduodenostomy

rendezvous technique