Choledochal Cyst Podcast

Hi, I'm Dr. Alex Bondock, a pediatric and transplant surgeon at Cincinnati Children's. Today we're going to review a topic you all love, choledocal cysts. Choledocal cysts, or congenital dilation of the biliary tree, is a commonly tested topic. Today we're joined by Dr. Alex Bondock, pediatric and transplant surgeon at Cincinnati Children's. So Dr. Bondock, what is a choledocal cyst? Well, a choledocal cyst ray is a congenital cystic dilation of the biliary tree. How common are choledocal cysts? It actually depends on where you are. In the Western world, the incidence is about 1 in 100,000. But in Asia, specifically Eastern Asia, it's quite a bit more common, 1 in 13,000. It's actually three to four times more likely in females than in males. And while there isn't a genetic predisposition to choledocal cysts, there are some genes that have been identified in limited studies, possibly including PKD1 for type 5 choledocal cysts. So where do choledocal cysts come from and what causes it? First, it's important to realize that the most common classification system was developed by a surgeon named Tadani in Japan. There are five types. And for types 1 and 4, it is likely embryologic, relating to the pancreatic obiliary duct junction, also known as, in this scenario, pancreatic obiliary malunion, which oftentimes creates what's called a long common channel of the pancreatic obiliary duct. In this case, it's thought that reflux of pancreatic enzymes from, obviously, the head of the pancreas back into the biliary tree causes inflammation, degeneration, and epithelial changes. In type 5, as mentioned previously, the genetic mutation might predispose to more diffuse dilation of both the intra- and extrahepatic biliary trees. Can you talk us through the different types of choledocal cysts? Choledocal cysts are categorized by the Tadani classification, and that has identified five. Type 1 is a dilation of the common bile duct only, the extrahepatic common bile duct only, and that can either be fusiform or saccular. Type 2, choledocal cyst, is just a small diverticulum off of the common bile duct. Type 3 is what's called a choledocal seal, so it affects the portion of the common bile duct in the wall of the duodenum. Type 4 is separated into two different types. Type 4a, which is a multitude of cysts, both in the intra- and extrahepatic biliary tree, and type 4b are multiple cysts, but in the extrahepatic biliary tree only. Finally, type 5 is intra-hepatic only and sort of diffusely throughout, called Corolli's disease. This can be diffusely throughout, or it can be limited to one lobe or one heavy liver. Interestingly enough, in the literature, there is a type 6, which is actually cystic dilation of the cystic duct itself, but that's, for the purposes of this discussion, probably unnecessary. So, how do choledocal cysts typically present? Well, it can be different in different age groups. Oftentimes, in younger children, such as infants, it's diagnosed incidentally on axial imaging or ultrasound imaging for other causes. In children, oftentimes, you will get symptoms consistent with cholangitis, such as jaundice or fever. The patients also can have a palpable right upper quadrant mass. Now, as you might remember from general surgery times, this is known as Charcot's triad, but actually, this is incredibly uncommon as far as presentations are concerned. Interestingly enough, sometimes, and also in small children, giant cysts that children are born with can actually perforate and present with biliary ascites. Also, it's important to understand that giant choledocal cysts can be diagnosed prenatally on week 20 ultrasounds. And as a result, these have to be followed very closely. And we often recommend a fetal consultation at a fetal surgery center for establishment of care and counseling. Because once the child is born, there are variants of other apatobiliary disease, most specifically cystic biliary atresia, that has to be ruled out. Because obviously, the treatments and the timing of surgery are incredibly different. There was a recent citation that demonstrated that if a cyst was diagnosed prenatally, and it was larger than four and a half centimeters at the 20 week anatomy scan, there was a higher rate of postnatal symptomatology. And the authors, therefore, made the conclusion that perhaps these patients may benefit from earlier intervention. So if you have a one-year-old who presents with jaundice, what is on your differential diagnosis? Well, Ray, there are a few things that you have to be mindful of. Certainly, any problem with pancreatic or biliary tree, as well as stone disease is possible, such as choledocal lithiasis, choledalithiasis. Depending on the patient's other symptoms, you have to consider gallstone pancreatitis. Certainly, choledocal cyst is up there. The child you're describing is a little bit old for biliary atresia, and we'd hope we would not miss it. But again, that's usually something you'd consider in an infant. Okay, so if you're thinking it might be a choledocal cyst, how do you work them up? From a physical exam standpoint, two major things to look for would be the presence of jaundice or scleralictris, certainly, as well as younger children may present with a palpable abdominal mass. From a lab standpoint, again, with special attention to the patient's age, labs to check would be liver function tests, specifically with total, direct, and indirect bilirubin levels. Plus minus a CBC to look for evidence of cholangitis or infection. But realistically, the major initial screening imaging test would be an abdominal ultrasound. Is there any role for a liver biopsy in these patients? Not typically, Ray, if the patient's older and you have reliable ultrasound imaging. However, a liver biopsy does become critical if you're talking about a neonate or a newborn. Because again, as discussed earlier, you have to rule out the cystic biliary atresia variant. Cannot miss that. What about the role for an MRCP or an ERCP? Well, oftentimes, Ray, what we'll see is not only an ultrasound, but some form of axial imaging, most specifically CT scan because of the ease with which you can scan young children. However, if there are questions about anatomic details, specifically, I like to use an MRCP if there's high disease, meaning disease that's into the hilum or intrahepatic to sort of get a better sense of how extensive the cystic change is. The other way it helps, oftentimes, is if you're really trying to understand in that scenario where there is hylar disease, if there is variant biliary anatomy. Because remember, probably up to 15 to 20% of patients have some kind of variant biliary tract anatomy. The other option is also from a diagnostic and therapeutic standpoint, some patients will benefit from an ERCP. But again, that oftentimes depends on what you see from prior scans as well as the type of choledocal cyst you're dealing with. So for these patients with choledocal cyst, do we need to operate? Are there any non-surgical treatment options? No. The short answer is no. The first reason I think about is due to the anomalous anatomy related to the cyst, that puts the patient at risk for episodes of cholangitis. So with biliary stasis, super infection, these patients can end up having multiple bouts of cholangitis, which can obviously be life-threatening. The other major consideration with regard to choledocal cysts, specifically type 1 and type 4 cysts that do have evidence of pancreatic obiliary malunion as their etiology, there is, as we can best estimate, about an 8% lifetime risk of hepatobiliary malignancy, most specifically cholangiocarcinoma, which, as we all know, is a very aggressive malignancy and hard-to-treat malignancy, as well as gallbladder cancer. Now, there have been a whole bunch of studies estimating that this lifetime risk is anywhere from 6% to 30%. Of note, though, it is important to mention that even after surgical resection of these cysts, some studies suggest that there is still about a 4% lifetime risk of malignancy, which means that these patients need to be surveilled through their lifetime. What kind of treatment options exist for choledocal cysts? Well, certainly, if a patient presents actively infected with pancreatitis, cholangitis, or in some sort of acute way, your best-case scenario is to cool those patients off and treat their underlying process. And then, as soon as you have an initial presentation like that, what I would call a complicated choledocal cyst, then I would work to getting that patient scheduled for surgery after they've sufficiently recovered. However, as we mentioned before, you know, when patients are incidentally found to have these lesions, usually discuss with families is certainly things to look out for as far as complications are concerned, but scheduling surgery sooner than later. I'll discuss with families doing it when it makes sense for the family schedule, but certainly not waiting too long. So, if you've decided to operate before you proceed, what type of preoperative evaluation should you absolutely do? As we discussed earlier, oftentimes the workup includes a basic set of laboratory values and evaluation to ensure that there's no other disease process occurring, certainly one that would be leading to impaired liver function, so that if the patient had presented jaundice or with cholangitis or hepatitis for some reason, that there wasn't anything else going on that would require some other form of treatment. And in the process of finding the cystic lesion, it's not uncommon that an ultrasound and then even a CT scan are sufficient to go to the operating room. And once again, if there's any question of what the patient's anatomy is, or if the patient has a very proximal choledocal cyst or dilation into the hepatic ducts, then I would probably recommend more advanced imaging such as an MRCP. What are the surgical goals for choledocal cyst repair and what options do you have to achieve them? Realistically, the surgical goals in general are complete excision of the cyst for the reasons we discussed earlier. However, they do depend on the types we discussed. For type 1 and type 4, because of what we discussed regarding the anomalies of the pancreatic obiliary anatomy, the goals here are to remove as much of the duct as possible. And when I say that, that always takes you behind the head of the pancreas or into the head of the pancreas, because the key here is to take the duct all the way down to where it tapers into very little, so as not to leave remnant cyst. For type 1 and type 4 cysts, you also have to reconstruct the biliary drainage system. Oftentimes, this will include a RU and Y hepatico-jaginostomy, but a hepatico-duodenostomy is also an option that has been described. A type 2 can be simply just removal of the diverticulum at its neck with repair of the common bile duct. Type 3 can be done in a couple ways. If it's just a limited choledococele, actually an ERCP with sphincterotomy can be performed. However, if it gets more complicated and involves the wall of duodenum, sometimes there are also transduodenal options to resect as well. We should also be mindful that biopsy of the mucosa of the choledococele here is important, because if it is biliary epithelium and it's constantly exposed to intestinal secretions, that could become malignant as well. Now, type 5 is probably the most complicated, because it all depends on how diffuse the disease is, because if it's limited to anatomic part of the liver, that may lend itself to a resection. However, if it's diffusely throughout and resection wouldn't leave any functional liver remnant, appropriate amount of functional liver remnant, these patients may have to be considered for transplantation. Let's move on to surgical technique. If you're in the operating room with a diffusive form assist, where do you begin? From an approach standpoint, in a younger child, let's say less than 2, I would either make probably a transverse incision or maybe even a subcostal. I actually prefer right subcostal incisions. For a child a little bit older than that, an upper midline certainly may also still be a viable option for good exposure. Once you identify the porta and reflect the liver superiorly, you should be able to note the cyst. Depending on how the patient's presented, number of episodes of pancreatitis or cholangitis, there may be some level of inflammation in the area. And so it's critical to expose the structures appropriately, knowing that hepatic arteries will be medial to you and the portal vein will be posterior to you. Once you're able to mobilize the cyst sufficiently from the remainder of the hylar structures, I typically like to identify how high the cyst goes and understand where my proximal cut margin will be. And even consider cutting, resecting the superior aspect of the cyst, and then dissecting inferiorly towards the pancreas. Because I find that once the cyst is dissected from its more proximal aspect, it's easier to manipulate the area. Once the proximal aspect of the cyst is transected, it's easier to manipulate the distal portion towards the pancreas. And in that regard, I do find it easier to circumferentially dissect down low enough. Now, in my own personal practice, I always do an intraoperative cholangiogram through the gallbladder so that I try to truly understand where the tapering of the distal cyst occurs so that we're not leaving anything extra. That said, obviously, transecting the cyst proximally can make it a little bit more messy. So I think it's certainly to the surgeon's discretion when they wish to transect the cyst. And so once you get down and you feel like you've adequately and circumferentially dissected the distal cyst towards its taper, then what I like to do is partially transect almost like a tracheoesophageal fistula and identify lumen and make sure I haven't compromised anything and sequentially close proximal end of the common bile duct or the intraepatic common bile duct so that, you know, I'm being very careful and methodical about not just cutting straight through it. Once the cyst is resected, then we work towards reconstructing the biliary outflow. I personally like to do RUINY hepaticojejunostomies. I construct those in my practices. I usually go about 15 to 20 centimeters distal from the ligament of trice or whatever you think will be comfortable and allow reach of the RUINY up to the hepatic hilum. Then perform a jejunojejunostomy if the child size allows it in two layers and then do a hepaticojejunostomy with interrupted absorbable suture, usually 5-0 or 6-0 maxon. Other considerations that I usually will do, I usually do my RUINY retrocolic and I do close the small bowel mesentery. How would you change your operative approach if you had a type 2 cyst? Same incisional approach depending on the child's age. But in this regard, hopefully the cyst itself is a little easier to deal with depending on which direction it comes off of the common bile duct. Similarly, as before, if there have been episodes of cholangitis and there's inflammation, the cyst may be a little more difficult to free from the surrounding structures. But once you get it down tapered to the common bile duct, then you're able to just simply resect the neck of it and then repair the common bile duct. I have not typically left a T-tube or anything for future cholangiogram. I think it's sufficient to simply repair with interrupted absorbable suture. As far as a type 3 cyst is concerned, depending on its overall anatomy, type 3 cyst can be approached endoscopically with an ERCP and sphincterotomy. However, if the lesion is large and obstructing the common duct, you oftentimes have to go transduodenal and carefully identify, sometimes even with preoperative stents that can be inserted from an ERCP standpoint, in order to separate it from the duodenum and subsequently reconstruct the outflow. Management of type 5 choledococis or Corolli's disease just depends upon how extensive the cystic burden is. If the cystic burden is limited to one side of the hemi liver or would allow for resection and residual adequate liver remnant, as well as preserved biliary outflow, you can address it surgically with a liver resection. However, if it's cystic disease is diffuse and throughout the liver, you may have to consider having that patient evaluated for liver transplantation. Now that we've removed this choledocal cyst, what should we be doing postoperatively? Certain postoperative considerations, Ray, include enteric drainage and awaiting return of bowel function. Some people will place NG tubes. I typically will because of the new jejuno-jejunostomy, but I try to remove the NG tube the day after. Additionally, we do place drains to assess for any biliary leaks from our new hepatoenteric anastomosis. And typically we like to remove them once the patient is tolerating a regular diet. From a long-term sort of prophylaxis standpoint, institutionally we've oftentimes placed our patients on a choleretic like Actagol, as well as a cholangitis prophylaxis, oftentimes daily backroom for a short period, usually three to six months after surgery. As far as long-term outcome is concerned, generally there's very good outcomes. Patients do relatively well. Certain even short-term to long-term surgical complications can include an anastomotic stricture, small bowel obstruction from intra-abdominal surgery, as well as reflux gastritis. Other things that can occur as discussed above would be recurrent cholangitis due to having a direct connection between the biliary tree and the anteric system. The one thing I do want to mention is the need for lifelong follow-up for these patients because of the possibility of developing, albeit small, the thought is there still is a very real possibility for future malignancy even after resection of the cyst itself. Now that you've worked through choledocal cysts with us, what would you say are your key clinical takeaways? Choledocal cysts are congenital cystic dilations of the biliary tree thought to have an embryologic origin of an anomalous pancreaticobiliary duct junction. These patients often present with cholangitis or pancreatitis, but choledocal cysts can be found incidentally. It's important to have a broad differential diagnosis that includes cystic biliary atresia, as well as other causes for cholangitis or pancreatitis. Workups should involve LFTs, liver ultrasound, and potentially a liver biopsy to rule out biliary atresia. CT, ERCP, and MRCP could be helpful to further delineate any anatomical differences. All of these patients necessitate surgical intervention, which varies based on the type of the choledocal cyst. Postoperatively, patients generally tend to do well, but do keep an eye out for anastomotic stricture, cholangitis, or pancreatitis. These patients also necessitate lifelong follow-up due to the risk of development of biliary stricture or malignant transformation. This episode was created and edited by Ray Hanke, Alex Bondock, Zach Korb, Todd Ponsky, and myself, Rod Gerardo. What else do you want to hear about? Let us know in the Stay Current app, our Twitter, Facebook, or Instagram accounts. And remember, knowledge should be free. .