She is a Program Director of Advanced Endoscopy Fellowship, the Department of Gastroenterology at the Cleveland Clinic. She finished her internal medicine, gastroenterology and advanced training in endoscopy at the Mayo Clinic in Rochester. And since then, her main interest has been in ERCP-US and US-directed transluminal ERCP. She's published widely in this area. She's the Chair of several National Societal Committees. And of course, she is an accomplished speaker and does involve many workshops. Thank you so much, Dr. Reddy. And thank you, Dr. Barra and ASG for giving me the opportunity to present this talk. So I think all of us, we have learned the basic and advanced cannulation skills, and now we are ready to tackle the large CBD stone, which is one of the difficult indications for ERCP in my mind. These are my disclosures. So the outline of the talk, I think we'll talk about endoscopic papillary large balloon dilation. We'll spend some time on lithotripsy, including mechanical, electrohydraulic, laser, and finally talk about stents, both fully covered metal stents and plastic stents in dealing with large common bile duct stones. So as we all know that up to 18% of symptomatic gallstones are accompanied with common bile duct stone. And according to ESGE and ASGE, whether the patient is symptomatic or not symptomatic from common bile duct stone, if the patient is able to undergo ERCP, we should strive to remove the common bile duct stones. Why? Because up to 25% of these patients, they can end up with complications like pancreatitis, cholangitis, or jaundice. In the study published by Molar and JAMA Surgery, they showed that the larger the size of the stone, higher are the chances of complications. So they found if stones are less than five millimeter in size, the complication rate are about 5%. And if the stones are more than five millimeter, the risk is almost double to up to 9%. So this begs the question, how do we define a large common bile duct stone? Generally accepted definition is stone that is larger than 1.5 centimeter is considered large. So basically if you're seeing the duodenoscope on fluoro, a little bit larger than the duodenoscope caliber would be a large common bile duct stone. So moving on to the endoscopic papillary balloon dilation, I think this has become the mainstay for management of large common bile duct stones. And if you are dealing with the stone, which is about one to a little bit less than two centimeter in size, you can get away with this technique. This was first reported in 1990s, but then it fell out of favor because there were a lot of studies which showed significantly higher risk of pancreatitis, including severe pancreatitis, if you do papillary balloon dilation of large, of intact sphincter. It was not up until 2003 by Eros where they demonstrated the technique where they did submaximal sphincteratomy in combination with the papillary balloon dilation that it was not only safe, but effective. So since then, we have had about 12 randomized control trials, more than 5,500 patients who have successfully undergone this technique. It is one thing that you have to keep in mind, it's unhelpful if you have patients who have impacted CBD stone, as shown by a video by Mustafa, or a patient with disability stricture, it won't work in that situation. And then while you're using this technique, a couple of things that you have to be mindful are the complications of bleeding and perforation. Most of the times these complications are managed endoscopically, either the method shown by Mustafa earlier, clipping, cauterization, use of fully covered metal stent. So a nice technique to have to know about and to utilize. So some of the practical tips that I want to share with you about this technique is number one, most important is the choice of size of balloon. The most important thing is when you are looking for how much balloon dilation you can perform, look at the size of the common bile duct. So when we are deciding about the size of the balloon, we are looking at the size of the common bile duct. So you can determine the size of the common bile duct again by looking at the duodenoscope. So in this case, the duodenoscope is about 13 millimeter and the bile duct is a little bit larger than that, so approximately 15 millimeters. So you don't want to use a balloon that is larger than 15 millimeter in size because the risk of perforation would be higher. Another thing you want to look at is the appearance of the papilla. Some of the papilla are generous with a large intradudenal segment. So it allows you to use a larger caliber balloon. And on the other hand, some of the papilla are quite petite or they're synodic. So even if the common bile duct is larger in size, you may not be able to use a larger balloon in that situation. So the next is how long should you inflate the balloon? So generally speaking, I personally inflate the balloon till the waste is gone, although some recommend inflating it for about 30 to 60 seconds. The rationale behind that is, you know, it acts as a tamponette and possibly reduces the risk of bleeding. You don't want to keep the balloon inflated more than 60 seconds because you are technically compressing the pancreatic orifice and the risk of pancreatitis may be there. So generally I just inflate once the waste is gone and then you go about to retrieve the stone. You have to be mindful that there's no stone sitting in the distal bile duct. Most of these balloons are about four to five centimeter long so you want to push the stone above before you inflate the balloon. And then obviously this is not going to work if there's a stricture. So when you're performing the sphindrotomy, just go 50% of the maximal sphindrotomy. You don't want to do a full maximal sphindrotomy and then do the balloon dilation because the risk of perforation will be there. And finally, this technique comes in handy if a patient is on anticoagulation, they are unable to stop it, or in patients with altered anatomy like Biliroth 2, if you don't have B2 sphincter tome or if you are not comfortable with a pre-cut technique. You have to be mindful of using the safeguards like paracetamol, indomethacin, load them up with lactate or ringer peri-procedurally and put a pancreatic stent where indicated if you are doing balloon sphindroplasty of intact papilla. Another point I would like to make is there was a recent randomized control study published by Japanese group, which showed that eight millimeter balloon dilation of the intact papilla was safe and effective, but the balloon diameter was just eight millimeter. You don't want to be using balloon diameter 12 or 15 for intact papilla, because needless to say there are numerous studies which show risk of pancreatitis is much higher if you go on to that size. So what's the data behind this recommendation? According to the ASG guidelines published in 2019, the recommendation is if you have somebody with large common bile duct stone, you do submaximal biliroth sphincterotomy, then papillary balloon dilation. This recommendation is based on nine randomized control trials. And so according to the data from this nine randomized control trials, when they compared the combination of endoscopic papillary balloon dilation with endoscopic sphincterotomy versus sphincterotomy alone, the overall stone clearance was significantly higher with the combination group. The need for mechanical lithotripsy was much less and the adverse events were fewer. So this is the data systematic review from nine RCT, which led to the guidelines from ASGE. So if you have stone, which is larger than two centimeter in size, or if the stones are above the stricture, or if you are dealing with patients with mritzi, this is where you have to proceed on with intraductal lithotripsy some form or fashion. The first tool that we pull out of the bag is mechanical lithotripsy. But do you have other options like electrohydraulic lithotripsy, laser lithotripsy, and if the technique and expertise available as well in some centers and countries. So mechanical lithotripsy has been around with us since 1982. It was first introduced as a salvage technique. And since then, number of manufacturers, they have come out with number of devices, which all of us who perform ERCP and tackle with large common bite duck stone, it's an important tool to have in your kit, not only for treatment, but helps us with the salvage as well. Mechanical lithotripsy is successful in over 90% of the patients. Some of the pros are it's readily available, it's cost effective, it's largely a very simple procedure to learn and do. However, there are some cases where it may not be successful. And the one most important point is if you have stone which is getting closer to three centimeter in size, that is a higher likelihood of failure of mechanical lithotripsy. So you probably in those cases should consider about cholangioscopy guided EHL or laser lithotripsy. You can also fail if the bite duct size is smaller, if there's not enough space for the basket to open and wrap around the stone, or in some cases not common, you can see the bite duct stones, which are so calcified on x-ray, you're unlikely to break this stone just with a mechanical lithotriptor alone. So these are the ones you should contemplate on either laser or electrohydraulic from the get-go. There are some complications that you have to be mindful of. And I think the most dreaded one is the basket impaction or fracture of the wires. All of us, we have come across this when you do enough of these or patients refer to you with these complications. You can have problem with a broken handle, problems with perforation of the bite duct, hemobilia or cholangitis. So I'll share with you a couple of the basket impaction cases that happened. So this was a lady, 23 year old. And as you see on the first picture on fluoroscopy, this is a large common bite duct stone. So it's a little bit larger than the duodenoscope, approximately 15 millimeter. In fact, she had couple. So we did 15 millimeter balloon sphindroplasty and then went on to retrieve the stone with a basket, which got impacted. One of the first thing that we do in this situation is, you want to make sure that the papilla is dilated. You can try the balloon sphindroplasty. In this case, it was already done. Next option would be going with the mechanical Sohendra lithotriptor. It comes in tubes in 14 French, the older version. You have to remove the duodenoscope out. You have to cut the wires of the basket near the handle and then take the duodenoscope out. Then the mechanical lithotriptor with the metal sheet is threaded over the wires. And the sheet is advanced right to the hub of the basket, right till here. And then the handle is slowly cranked, one rotation at a time. You don't want to go too fast because that's how the wires, they tend to break. And you can try that as a salvage maneuver works for majority of the patients. Well, in this case, that also didn't work and that got trapped. And finally, and I think few things you can do in this situation is one, if there is space, you can drop a stent in, leave the wires, cut the wires, leave the wires in there, bring the patient back, let the edema settle down. And sometimes it's just the time that is needed and the baskets are easier, easily come out if you wait a few days. Alternatively, you can do clingoscopy guided lithotripsy and break the stone and release the baskets. So this is a case which was actually the first one that I encountered and is seared in my memory. I was an advanced fellow. Dr. Barron was my mentor. This was a 63-year-old patient with symptomatic common bile duct stones. So as you saw, this was, it's a tiny, relatively tiny stone, had a full maximal sphincterotomy, got the stone basket in, which got impacted. And so it doesn't necessarily have to be large stones. So it was a petite papilla. Then multiple methods were tried, including taking the basket out with the balloon, rat tooth, the mechanical Sohandra lithotriptor. So the lithotriptor wire, they broke actually outside patient's mouth. So you don't have enough wire left to do the mechanical lithotripties. So the stent was placed in this patient, wires were grasped and they were dropped into the stomach and patient was brought back 10, 14 days later. The edema had settled down and the baskets, they have spontaneously fallen out and were removed. So don't panic. So multiple options to salvage the situation, including time. So these are the pictures again. Please strongly consider keeping one of those in your tool basket. This was the 14 French outside the scope that I was talking about. And this is the newer version, eight and a half French through the scope. If you have this particular lithotriptor, they are generally more compatible with the baskets that are made by the same manufacturer and they may not work really well with the baskets from the other manufacturers. So moving on to EHL. I think if you have stones, as I mentioned earlier, larger than three centimeters size or stones above stricture or merites, this is where you will need cholangioscopy guided lithotripsy, either EHL or laser lithotripsy. The reported success rate in breaking the stone down is extremely high. You have to be mindful of the adverse event, which can happen in up to close to 10%, including hemobilia, cholangitis, air embolism, pancreatitis, and bile duct injury. So most of these patients, we use CO2. If I anticipate there are multiple large stones and if it's gonna take me a long time with a large volume of saline infusion, we always intubate these patients. And of course, peri-procedural antibiotics is imperative in these patients. So laser lithotripsy is very similar to EHL. Again, we use holmium laser with a different power setting success rate, very similar to EHL. And the adverse event profile is also similar. So for most of the centers, including ours, we have both the laser, holmium laser and EHL. Generally speaking, overall, the efficacy is quite similar. So it's quite comparable, EHL versus laser. However, for all of us who have used both, we find that laser is a little bit more effective in the sense getting the job done in fewer number of ERCP sessions and in a shorter time. And this was also demonstrated by this large multicenter study where they compared laser lithotripsy with electrohydraulic lithotripsy. And they found the technical success was higher with laser, procedure time was shorter, and the number of sessions required for complete duct clearance was also fewer with laser lithotripsy. And some of the factors responsible for failed lithotripsy on multivariate analysis were altered anatomy or papilla associated with diverticulum, which is not a surprise. So what about cholangioscopy compared to conventional methods like mechanical lithotripsy? So this was a randomized trial published by James Buxbaum. They looked at laser lithotripsy versus conventional methods including mechanical lithotripsy for large common bile duct stone. And they found that endoscopic stone clearance was significantly higher with laser. Again, not a surprise. The adverse events were similar. However, the procedure time was longer with the laser, which often can happen if you're dealing with large stones or multiple stacked stones. So some of the practical tips, if you're using cholangioscopy guided laser lithotripsy is sometimes there may be challenge getting the probe out. So if you already have the duodenoscope closer to the papilla, you can just leave it there, wet the probe really well before introducing through the cholangioscope. Alternatively, you can preload the probe before going down with the duodenoscope. Continuous saline inclusion is imperative because these they work best under the aqueous medium. And you want to keep the probe about five millimeter out from the scope tip and about a millimeter from the stone. You don't want to be touching the stone and you don't want to be too far away from the stone. The maximum efficacy is just about closer, one to two millimeter from the stone. And as we talked earlier, intubate the patient. If you anticipate it's going to be a longer procedure, use CO2 to prevent air embolism. And I personally, if I'm using EHL or laser, I start with a lower power because it's hard to predict how dense the stone is. You don't want to be starting with the, for example, in EHL power of 120 shots. You would want to start with about half the power, start with 50. You may want to start with 10 shots and then gradually build up. And once you get an idea how dense the stone is. And again, periprocedural antibiotic in these patients. So just sharing a couple more cases. This was a 36 year old male. He had a factor 13 deficiency presented with a common bile duct stone, which was located above the stricture. So it's not necessarily the large stones. Stones above the stricture are equally difficult to treat, even if they are small in size. And here you see on the cholangiogram, a tiny stone which is estimated to be about seven to eight millimeter in size. Stricture, balloon dilation was done, maximal sphendrotomy performed, but unable to retrieve the stone out. So in order to treat the stricture, we placed a fully covered metal stand. Patient was asymptomatic. So a patient was not cholangitic. So it was thought that patient can wait few days or weeks and not before coming back for the procedure. However, he came back sooner than expected, five days later with cholangitis. And as I went down, there's a large clot sitting at the papilla. Snare removed the clot, the fully covered metal stand. Again, on fluoro, you see even after five days, the waste was still there. So scent was removed. The bleeding site was identified. It was at the apex of sphendrotomy, which is most of the time where they bleed from, it's at the apex. And once the bleeding was controlled, we go on to take care of the stone. And as you can see, the dense vibrating nature of the stricture, despite maximum balloon dilation, the waste never effaced. And this is where you would want to, you know, go with something like a cholangioscopy in these patients. So advance the cholangioscope. So you can visualize the stone. As I mentioned, the probe is about five to six millimeter from the cholangioscope. You have a good view of the stone and stone. Cholangioscope is kept about a millimeter from the stone itself and the shocks are delivered. And once you start breaking the stone, you know, it becomes like driving in a snowstorm. You want to be continuously irrigating and you want to be continuously suctioning in order to maintain a clear visualization. Don't try to deliver the shock if the visualization is poor. Take your time to get the visualization again before you continue to deliver the shock. In this case, it needed few before the stone was completely fragmented and the fragments removed. Again, another example of a really difficult situation, post-transplant, patient transplanted with boatloads of stone in the donor liver, a tight anastomotic stricture with the high up anastomosis, not the cover stent were left below it or they migrated or they were not long enough. And this is where cholangioscopy guided lithotripsy really helps in managing these situations. So what are the role of stents, both fully covered and plastic? So both ASG and ESG guidelines, they recommend that we should always leave stent in somebody where we have failed to completely clear the bile duct out of the stone. This is to prevent complications like cholangitis. Stent can be used as a permanent therapy in somebody who has multiple comorbidities and they are not fit enough to undergo repeat ERCP procedures. And they have been shown to be effective in taking care of stones in difficult situations like stricture, diverticulum, altered anatomy with success rates in high 80s. You have to be mindful of complications like cholangitis, migration of stent, cholecystitis, especially with fully covered metal stent, pancreatitis and perforation. And oftentimes if we are resorting to stent as one of the modality for treatment of stones, they are used in combination with chlorhetic agent like or sodioxycolic acid, which works best for soft cholesterol type stones. So what's the data on fully covered metal stent? This was a study published in GI in 2017. They looked at 44 patients with a difficult stone defined as large stones. They achieved success rate in managing these large stones in about 82% of the patient. The median stent to dwell time was two months and not surprisingly in up to 22% of the patient they noted incidental migration of the covered stent on follow-up ERCP. What about plastic stent? This was a study published in 2010 by the Japanese group. They randomized 40 patients with large stone, which they defined at more than two centimeter in size or multiple large stones to either no stenting or a seven French double pigtail stent at the index ERCP. And a follow-up ERCP at two months showed patients who received seven French double pigtail, they had significantly fewer number of stones and also a decrease in the size of the stone. So keep this in mind as a salvage therapy. So wrapping up, I think we've discussed all these different modality. Each of these, they have their pros and cons and they can be used in different situations. So to summarize everything, if you are dealing with the patient who has stone, I would say between one to two centimeter in size, you can get away with endoscopic sphenotomy submaximal with endoscopic papillary balloon dilation based on the appearance of the papilla and the size of the common bile duct. If that fails, the next tool you should reach out for is mechanical lithodripsy. About 90% chance that you will be able to take care of the stone. If the stone is more than two centimeter in size, between two to three, these are the ones unlikely to be tackled with just papillary balloon dilation alone and they will need something like mechanical lithodripsy. However, if the stones are larger than three centimeter in size or if they're above stricture or meritses, as we saw in couple examples, you want to directly start with intraductal therapy with cholangioscopy like EHL or laser lithodripsy. Both are equally effective. And keep in mind the role of stent, either fully covered metal stent or temporary plastic stent as a salvage maneuver. If you're leaving the stent same, leave them in for about two to three months and you'll be surprised to find fewer number of stones or at least smaller size of the stones that you need to tackle. And I think with that, I conclude. Thank you so much.

common bile duct stones

endoscopic papillary balloon dilation

mechanical lithotripsy

electrohydraulic lithotripsy

laser lithotripsy

stents