is at the Mayo Clinic in Rochester, Minnesota. He's a prolific therapeutic endoscopist who completed his fellowship at the Mayo Clinic, completed an advanced endoscopy fellowship at Northwestern University, was at Michigan University on faculty, and has recently moved to Mayo Clinic as Associate Professor of Medicine in the Division of Gastroenterology and Hepatology. Dr. Law is gonna talk to us today about ERCP tips for cannulation, including selection of right and left ducts. So thank you, Ryan, for your time, and we look forward to your presentation. Thanks, Todd. So thank you to the ASG and the course directors for the invitation to speak. As Todd mentioned, I'm gonna talk about selective biliary cannulation with some tips and tricks for success. So the objectives for the talk are to discuss the normal anatomical and technical considerations for high-quality biliary cannulation. We'll then work towards alternative techniques when conventional cannulation fails, and then finish up a bit with some tips and tricks for accessing bile ducts of interest after the initial biliary cannulation. Consistent, efficient, safe cannulation is one of the most important, if not the most important ERCP skills. It makes our procedures much more safe to be able to have high-quality techniques. It's certainly a skill that increases with procedural experience, and I would submit that improvement is never ending, even experts with tens of thousands of ERCPs continue to improve in this particular skill. My view is that cannulation begins with visual inspection. I think that's the most important aspect of cannulation from the standpoint that this gives you a plan, helps set your plan forth about how you're going to complete the procedure and considerations would be, is there one orifice versus a separate pancreatic and biliary orifice? Perhaps there's a duodenal diverticulum that may be impactful to your procedure or important pathology such as adenoma or tumor and impacted stone, et cetera. In terms of normal anatomical considerations, there's traditionally a single papillary opening which leads to two ducts. There may be a short common channel versus a long common channel, which again would be impactful in achieving a successful deep cannulation. And I'll show some schematics here on the next slide to discuss that a bit further. There's a septum which runs diagonally between the pancreatic and bile duct. You can imagine with the papilla sectioned into quadrants with a vertical fold at 12 o'clock, the bile duct is most typically in the left upper quadrant and the pancreatic duct in the right lower quadrant, keeping in mind that any abnormal anatomy in this area may alter the position sometimes significantly. Upon entry into the common channel, the bile duct typically runs more superiorly while the pancreatic duct tends to run straight inward. Here is an image. You can see that the bile duct tends to be in this quadrant. So typically when teaching fellows, the goal is to aim high and left in terms of accessing the bile duct versus more low and right or kind of from that one to four position on the right side if the goal is to achieve pancreatic cannulation. And here's an image just describing what we talked about, the bile duct running more superiorly, the pancreatic duct kind of running straight inward towards the center of the patient. These are again in normal patients. So this is the kind of, tends to be a patient-to-patient type situation as we all know, but some important considerations nonetheless. One recent article I wanted to present, it's actually a video, a video GIE last year from Japan. I found this to be incredibly helpful for teaching fellows or new learners to ERCP. And it's called the compact disc method. And again, it goes back to that idea of having a plan with biliary cannulation. And the concept is to imagine three compact discs, even though compact discs are essentially outdated. For those of us who still know what they are, the idea is to imagine three compact discs along the intraduodenal segment of the bile duct. And that helps in terms of what you need to do to achieve deep cannulation. And you can imagine in this particular image where the intraduodenal bile duct is quite straight, this may be a very straightforward cannulation, whereas this one, there tends to be a little bit more movement to it, maybe a little bit trickier. And I've had some of our fellows find this incredibly helpful. So I would recommend that something to consider when teaching for sure. Now, some basic cannulation tips. Again, examine the papilla, keeping in mind that the best examination and the best position potentially for cannulating would be the long position. I think most people tend to begin with a sphincteratome or cannula, some people still use a cannula to cannulate. Preloaded with a guide wire with the goal to aim over the top of the septum to that high left position, leading with the tip of the guide wire and then passing the guide wire with small forward movements or potentially torquing if you're using an angled wire to gain access in deep cannulation. I prefer to use full strength contrast as opposed to half strength. I would submit that we should aim to minimize but not totally eliminate contrast in terms of cannulation. While I don't believe that seeding the papilla and flooding contrast blindly is a good practice which data would support. I think that sometimes when we're not totally clear where our device is, if our guide wire is superficially engaged, so on and so forth, small flashes of contrast can be incredibly helpful. And I don't believe that that truly increases the risk of pancreatitis to patients in that setting. I think the idea of contrast-free cannulation is a bit overrated using that kind of guide or in that context. It's incredibly important to be gentle when touching the papilla. I learned from Todd way back when the concept of docking the space station where you superficially engage the papilla and then use the tip of the wire to kind of gain access to the bile duct. Keeping gentle touches to the papilla allows you the ability to change your position without creating too much trauma where it becomes more difficult or structures are not easily recognized. And then the other important thing I would state is to have a stepwise approach for the majority of your patients and also be a bit adaptable to that approach throughout your career. So we'll spend a few minutes talking about alternative techniques. When the standard techniques fail or the anatomy is not so straightforward. Typically after a failed primary cannulation there's kind of three ideas to discuss. The first is how long to persist with your initial attempt and your initial setup, what secondary steps you may take to achieve cannulation and then when to institute pre-cut techniques. We'll save the pre-cut techniques for Mustafa Reyn in a subsequent talk. In terms of how long to persist, I think that that's a bit up to the provider. I think there's certain people who are less patient who are moving on to a secondary approach within a few minutes. I think, and certainly there's others who would persist a bit longer. The important thing is to, something has to change if you're not having success whether that's positioning, might be devices, might be a guide wire. And that's kind of the important thing. In terms of the most commonly used secondary steps, many providers would change to a secondary catheter or change the guide wire. Additionally, if you gain access to the pancreatic duct that can be used to facilitate biliary cannulation either over the guide wire or by placing a stent in the pancreatic duct and then cannulating over the stent. And we'll talk a bit more about these techniques in the next few slides. So in terms of an equipment change versus technique change, it really is personal preference. There's certainly more than one way to skin a cat and becoming comfortable with the routine I think is a good approach. However, I would say be open to adaptation meaning that your routine doesn't have to be your routine forever. If you typically go from a sphincteratome to a cannula, perhaps changing the type of cannula to a double lumen or going to a single lumen, maybe something that you adapt to over time. From an equipment perspective, if you start with a cannula, you may consider switching to a sphincteratome where you would gain some benefit from the bow or vice versa. If you start with a sphincteratome and aren't having much success, switching to a cannula may be helpful. You may consider changing the guide wire from either a straight to an angled or an angled to a straight. You may consider a caliber change in the guide wire going from an 035 to an 025 or even an 018. You may prefer a more stiff guide wire or a guide wire that's completely hydrophilic. All of these things can be considered. You may ultimately end up changing both the catheter and the guide wire, but being aware of what options you have certainly will go a long way. This just is meant to represent several of these options. On the top, you can see kind of different guide wires that tend to be used. Certainly not all guide wires are created equal. Some of them here in this image, you can see that there's a shorter segment of hydrophilic tip, whereas these two guide wires are completely hydrophilic. This particular guide wire has a gold tip at the end, which makes it visible as it is an 018 wire, which can be helpful. I'll show a video demonstration for a different purpose here shortly. And then other considerations again would be to switch from a catheter to a sphincteratome or vice versa. A lot of options, definitely stylistic and definitely the take-home point is that providers should use what works for them. So going back to the concept of inadvertent access to the ventral pancreatic duct, there's several beneficial features or proposed beneficial features that may help you with this approach. Getting access to the pancreatic duct can stabilize your position for subsequent cannulation. It may straighten the common channel or the pancreatic duct, which could subsequently allow access to the bile duct. It orients the pancreatic access such that you can then determine from there the most likely position of the bile duct access, which is sometimes surprising from where you expect it to be. It also obstructs the pancreatic duct such that subsequent attempts to get into the pancreatic duct or I'm sorry, to get into the bile duct may not lead to inadvertent access of the pancreatic duct. And then it can direct pre-cut sphincterotomy if necessary. The most recent ESG guidelines from 2016 actually recommend using pancreatic guidewire assisted cannulation in patients where biliary cannulation is difficult and repeated access to the main pancreatic duct occurs. And this is determined to be a strong recommendation by ESG. And I would second that. I think that this is a good approach if you're having difficulty and are able to get into the pancreas. So this is a panel of images from schematic to fluoroscopy demonstrating the double guidewire approach. After achieving access to the pancreatic duct, the sphincterotome or cannula is reinserted alongside, preloaded with a second wire with the goal to access the bile duct. And I think one important consideration that I try to keep in mind and try to teach is when you re-engage the papilla, the trajectory of your catheter, at some point in almost every case, not every one, but in almost every one, it crosses the wire for the pancreatic duct. So kind of aiming across the wire tends to be more successful than going simply above it or potentially in the same trajectory. I try to envision making an X with the pancreatic guidewire and the sphincterotome or cannula. The second but similar approach is cannulation over a pancreatic duct stent. The same approach is used in that you would try to change your trajectory to create kind of an X over the pancreatic duct stent. Benefit of this approach is that if you had a difficult attempt to cannulate, leaving a stent in the pancreas to prevent post ERCP pancreatitis is obviously good practice as well. So finally, we're gonna talk about some tools and techniques for accessing the bile ducts after the initial biliary cannulation. And I'm just gonna show three short demonstration videos of techniques that I tend to use and I find helpful. So the first is using a small caliber torqueable guidewire. This is an 018 gold-tipped guidewire. You can see we're having difficulty here initially getting into the left hepatic duct, subsequently gain access and then gain very deep access into the left bile duct right there. This is a very useful device. Using an 018 wire will get you where you need to go, but ultimately you may need to switch to a larger wire once you get a catheter device into the left duct or right duct or wherever you happen to need to go to be a bit more stable. But I have found that to be incredibly successful, particularly with the torqueability aspects. So the next thing I wanted to talk about is a steerable cannula. This is a device that has the ability to turn in two different directions based on the hand movements of the endoscopist or the tech or nurse happens to be working with you. If for example, your guidewire won't go into the left hepatic duct, continues to go into the right hepatic duct, you can change the catheter to point in the opposite direction to obtain access to the duct of interest. This is again, a particularly useful device, which may be helpful when you're trying to get to a particular area. And then finally, what I call the duct occlusion technique. Basically, if you're trying to get to a particular duct and it only goes in the duct that you don't wanna be in, for example, in this case, the guidewire continually goes in the left or the right hepatic duct. And I'm trying to get into the cystic duct in this case. What you can do is leave this guidewire in the duct, remove the cannula or balloon catheter, I'm sorry, get a second wire and then inflate the balloon above the area that you're trying to get into, essentially occluding where you don't wanna go. In this case, we were successful in bouncing the guidewire off the balloon. So it didn't go into the intra-hepatics, but instead goes into the cystic duct where it's coiled and then a trans-papillary gallbladder stent can be placed. This can be used to get in the right or the left. It can be used to get in the gallbladder. I find it particularly useful in those situations. Kind of in summary, some important things I would say are take-home messages. We should all be aware of available equipment, both in our unit or available by our industry partners that may help us with improved cannulation. I think it's important to develop a routine and use what works for you. Remembering that there's no evidence of superiority for any particular guidewire, catheter, sphincter or tome in regards to cannulation. And then always keeping an open mind to try new things and adapt a new routine. Also keeping in mind that the value of fluoroscopy is much beyond contrast injection. It helps to define your guidewire passage. It also helps to visualize device trajectory for cannulation and duct selection. And the importance of angles in achieving what you want to for that particular procedure is incredibly important. And fluoroscopy helps in a very meaningful way. And I thought it was a very apt quote by Thomas Edison, especially regarding biliary cannulation. The most certain way to succeed is to try just one more time. So with that, I will conclude. Again, I appreciate the invitation by the course directors and ASG. Thank you.

ERCP tips

cannulation

anatomical considerations

guide wires

papilla

fluoroscopy