Benign Biliary Strictures and Choledochal Cysts

the podcast about I'm your host, Amanda Nicolley. Let's get started with our team timeout.

Our patient today is still the hepatobiliary module from the general surgical curriculum. And the operation or topics we'll be covering today are benign biliary strictures and collidochal cysts. In general, benign biliary strictures are a difficult problem to manage and work up as it's often difficult to exclude a malignant cause.

Benign biliary strictures typically affect the extrahepatic biliary tree, but as we'll discuss some of these conditions also affect the intrahepatic bile ducts. Any inflammatory process that occurs along the length of the bile duct can cause stricturing.

So talking a little bit about the potential causes of benign biliary strictures, I like to split these up into iatrogenic, gallstone-related, inflammatory and congenital causes.

So iatrogenic biliary injuries can occur post-collecystectomy most commonly, but also after trauma or other surgeries such as liver transplant. and biliary reconstructions such as a hepaticogeginostomy for whatever cause. gallstone related essentially relates to maritzi syndrome inflammatory causes of benign biliary stricturing include recurrent pyogenic cholangitis parasitic infections primary sclerosing cholangitis or PSC, HIV or AIDS cholangiopathy, pancreatitis and IgG4 related diseases.

And congenital problems include biliary atresia and collidochal cysts. So let's take some time to talk about a few of these different causes of benign bilir restrictions. the first we talked about was iatrogenic injury 95% of injuries to the bile duct are related to cholecystectomy and there's about a 1 in 500 risk of bile duct injury or about 0.2%. Other causes of iatrogenic injury include trauma, radiotherapy and scolicidal agents used for hydatid cysts.

Bile duct injury is a pretty big topic and really what we're talking about when we're talking about benign biliary strictures are injuries that aren't identified at the time and present later with jaundice due to strictures which form from partial injuries, local inflammation or ischemic insults to the bowel The risk factors for bile duct injury can in general be split up into patient factors such as previous abdominal surgery or cirrhosis.

Pathology related, so if patients have Maritzi syndrome or acute cholecystitis, they have an increased risk of bile duct injury. anatomy. So there's variations such as a short cystic duct or variable right posterior sectoral duct anatomy. And surgical factors, which is something that we could potentially improve upon. So these are perceptual illusions where the common bile duct is mistaken for the cystic duct or the right hepatic artery for the cystic artery.

poor or too much retraction, surgeon experience, equipment availability and use of intraoperative cholangiogram. In addition, a fundus first approach is associated with higher rates of bile duct injury.

So of course if a bile duct injury occurs there is a classification system for talking about these. This is the Strasberg classification that splits up bile duct injuries into type A, B, C, D and E. with the type E being split up into E1 to 5, which correlate with the bismuth classification of hyaloccalantiocarcinoma we talked about in the last episode.

So type A is a minor duct injury or such as the duct of Lushka or the cystic duct. Type B is where the right posterior duct is clipped off or occluded. Type C is a leak from the right posterior duct. Type D is where there's a small nick into the duct with leakage of bile but not a full circumferential injury and no major tissue loss. Type E, as I mentioned, is the Bithmus classification, which basically involves full circumferential damage

to the bile duct, but it relates to the distance from the confluence which determines each subtype. So E1 is where the injury is more than two centimetres from the left and right hepatic duct confluence. A2 is where it's less than 2cm. A3 is where there's an injury to the confluence, but the confluence is still intact. E4 is above the confluence with destruction of the confluence and E5 is an injury to the main bile duct plus an injury to the right posterior sexual duct.

It's important to note that the stress burst classification only considers the bile duct injury and often biliary tree injuries are associated with a vascular injury. It also doesn't talk about the cause of the injury such as whether it's from sharp dissection or from diathermy. also doesn't talk about the timing of the detection of the injury which also are important things to consider when managing bile duct injuries.

Saying that, only about a third of bile duct injuries are recognised intraoperatively and the identification rate of these injuries may be increased with the use of intraoperative cholangiogram. and patients do have better outcomes if the injury is identified at the time of the surgery.

So focusing just on bile duct injuries that are identified late, so not intraoperatively identified, and specifically those that are identified as a bile duct stricture. These patients are often identified due to jaundice which develops at a variable time frame after surgery.

The strictures can be caused by a number of reasons. I mentioned in the anatomy podcast on hepatobiliary that the bile duct supply is radial, so it travels along at the three and nine o'clock position on the bile duct coming from a superior and inferior direction. So if there's excessive dissection around the bile duct, this can cause local ischemia and eventually stricture formation.

In addition, direct trauma from the surgery or with the diathermy clips placed on the cystic duct can all contribute to late diagnosis of strictures.

Investigations should start with a full set of blood tests including a full blood count, coags and LFTs. and typically an ultrasound will be the first step to try to identify the level of obstruction and also to look for other potential causes in this scenario that may be a retained stone, for example. The next step is to assess the anatomy to identify where the level of the stricture is and its length to start thinking about how it might be able to be dealt with.

The options for assessing billiard anatomy as we all know include CT with IV contrast which isn't great at looking at the ductal system. A CT intravenous cholangiogram can be considered, but obviously the patient needs to have normal bilirubin. An MRCP is a good investigation to look at the biliary tree and can also exclude other courses such as malignant strictures. and ERCP is also a potential imaging option. This may not be that useful if there's a complete transaction or complete

clip across the duct as you won't be able to get any imaging above this stricture. Saying that though, in the setting of those ischemic strictures I was talking about, you may be able to traverse the stricture.

ERCP gives you a number of options you can take brushings to try to exclude a malignant stricture you may be able to balloon dilate or place stents across the stricture i've seen both multiple plastic stents fully covered metal stents used in this situation but in the absence of a malignant pathology and uncovered expandable metal stents shouldn't be used. But this again should be considered in the context of a specialist surgeon because

If you decompress the proximal ducts, that can make hepatic adeginostomy more difficult. And also you have to be mindful not to introduce infection into part of the biliary tree that may not be able to be drained in the future. And as I just briefly mentioned, hepaticodendinostomy is also an option for these patients who have strictures that aren't able to be managed endoscopically.

Hepaticojejunostomy basically includes excising the strictured part of the distal bile duct and then re-anastomising the proximal duct to a loop of jejunum. The natural history of bile duct strictures in the setting of biliary injury is that they have a significant impact on the patient's quality of life. These patients often require frequent operations, revision surgeries, they get recurrent cholangitis, and this process can even progress to cirrhosis.

liver atrophy and chronic intraoperative infections that eventually can even mean that the patient requires a liver transplant. When we do an operative episode on laparoscopic cholecystectomy, we'll spend a lot of time talking about how to avoid these injuries as obviously prevention is much better than the cure. We won't go into any detail about the other types of iatrogenic biliary injury that I mentioned including trauma.

post-surgery such as liver transplant, hepaticogegenostomy or the injection of scolocidal agents that accidentally enter into the biliary tree. I think for these pathologies it's just worth knowing that they are potential complications of all of these scenarios and they would have a similar armamentarium of management options once they have been identified as the other benign billary strictures that we are going to talk about.

Thank you. So the next type of benign biliary stricture that I mentioned is extrinsic compression of the bile duct due to a Maritzy syndrome. Maritzy syndrome is where the common hepatic duct is either partially or completely obstructed. due to extrinsic compression from an impacted stone in the gall bladder. This stone can also fistulate through the wall of the gall bladder into and through the wall of the common bile duct.

Of course there is a classification system for Moritzia Syndrome and this is the CENDES classification, spelled C-S-E-N-D-E-S. And this classifies Maritzi syndrome as type 1, 2, 3, 4 and 5. Type 1 is where there's no fistula, but an impacted gallstone is present with minimal inflammation and some minor compression of the common hepatic duct. Type 2 is where there is a fistula, but it involves less than a third of the common hepatic duct circumference.

Type 3 is where there is a fistula, but it involves up to 2 thirds of the common hepatic duct circumference. Type 4 is where more than 2 thirds of the duct is affected. Type 5 is where there is any compression of the common hepatic duct, so it can be type 1 to 4, but where there's also a bilioenteric fistula, so typically a connection between the gallbladder and the duodenum. So how do patients with Amoritzia Syndrome present?

These patients will often present with concurrent cholangitis and arranged LFTs. You may have a high index of suspicion if you have evidence of dilated bile ducts, especially if it's proximal to the common hepatic ducts. You also may be suspicious if there's evidence of a big impacted stone and deranged LFTs as I mentioned. It can sometimes be difficult to make the diagnosis of Amritzi syndrome preoperatively.

But if there is any suspicion, then it's a good idea to get further imaging such as ERCP or MRCP in order to get a better idea about what it is exactly that you're dealing with. although we haven't yet talked about lap coli i'm sure a lot of the trainees listening to this program will have done quite a few of these and you can imagine that if you have a big impacted stone Going into the common hepatic duct that area that's being affected is where your critical view of safety should be

So to find this intraoperatively means that you're putting the patient at significant risk of bile duct injury and that doing a straightforward cholecystectomy is going to be pretty difficult, if not unlikely, to be successful in these patients.

So knowing about it beforehand gives you a lot more power in planning and potentially referring this patient on to a specialist to manage. The management of these patients really depends upon their presentation. Obviously, if they're septic with acute cholecystitis and cholangitis, then you really need to be treating the sepsis, approaching this patient as per CRISP principles, providing broad-spectrum antibiotics.

And then considering biliary drainage, whether that's ERCP or PTC, or needing to do a percutaneous cholecystostomy, are all things to consider on a case-by-case basis. In terms of definitive management of a Maritzi syndrome, it really depends on the type or classification of Maritzi that you're dealing with. so in the setting of a type 1 maritzia syndrome so this is where there's no fistula you just have an impacted stone that's partially compressing the common hepatic duct

These patients may be able to undergo laparoscopic cholecystectomy. However, it's likely that you're going to have a lot of difficulty finding a critical view of safety with the big impacted stones. So you could convert to an open operation. You could open up the gallbladder, remove all the stones and then do a completion cholecystectomy if you can find a critical view from there or do a subtotal cholecystectomy.

And the other option is to refer this in the first place to a hepatobiliary specialist, which I think would probably be my first instinct in the exam. It could be very difficult to get a cholangiogram in these situations as it may be difficult to find the cystic duct with the impacted stone.

and if you're going to do a subtotal you need to make sure you really remove all of the stones out of hartman's pouch otherwise you're committing that patient to another operation For types 2, 3 and 4, if you identify this pre-operatively, it's probably best to refer this patient to a hepatobiliary specialist. because if there's a fistula into the bile duct when you take off the gallbladder there's going to be a hole in the bile duct that you're going to need to deal with.

The options to deal with this include doing a partial cholecystectomy and using the remnant gallbladder as almost a patch over the fistula and closing that. All these patients may need a bile duct repair or a hepaticogeginostomy when being dealt with in the hands of a hepatobiliary specialist. So best to avoid getting into that situation if you have the opportunity to avoid it.

So the next group of benign biliary strictures I mentioned at the start of this episode are inflammatory biliary strictures. So let's spend a little bit of time talking about some of these types of strictures. So the first of these is primary sclerosing cholangitis. And this particular pathology has been mentioned a little bit in this podcast already, especially in the colorectal module when we were talking about inflammatory bowel disease.

Primary sclerosing cholangitis or PSC is a rare immune-mediated disease of unknown cause. It's often associated with ulcerative colitis, with about 60% of cases of PSC also having a diagnosis of ulcerative colitis. And the pathophysiology buzzwords to know are that it is a progressive obliterative fibrosis of the intrahepatic and extrahepatic biliary tree.

So the characteristics of this condition is that there's multifocal diffuse strictures throughout the billary tree, including in the liver and outside of the liver. and the classic appearance is sort of beads with associated dilation between the structures. The presentation of PSC is that often in the early stages of the disease, it's asymptomatic. But as the disease progresses, patients will get jaundice due to the strictures.

They can get ill-defined pain, fevers and cholangitis associated with the disruption in the bowel flow and also have liver failure in the longer term. There's also a strong association with PSC and cholangiocarcinoma, as we mentioned in the last episode. Workup of a patient with PSC includes blood tests which should include liver function tests and autoimmune markers such as antineutrophil, cytoplasmic antibodies.

But cholangiography is the diagnostic modality that you need to be thinking about and whether that's through CT, IVC in the setting of a normal bilirubin. MRCP or ERCP this is how the diagnosis is made The characteristics as I mentioned are this beaded appearance with multifocal strictures and beading or dilated segments of the bile duct. MRCP is highly sensitive and is pretty comparable to ERCP when talking about diagnosis. So it's usually the first line choice for this pathology.

In addition, it doesn't introduce any bacteria. And as I mentioned, cholangitis is one of the longer term problems with this pathology. So trying to avoid contaminating the... billary tree with ercp especially in segments that may end up developing a stricture and not draining well is a good choice The management of this condition, like most surgical pathologies can be split up into medical, endoscopic and surgical.

Unfortunately, we don't have any good treatments for this pathology that will slow or stop the progression of the disease. So a lot of the treatments that we have are about managing the consequences of the disease and ultimately transplant to deal with the pathology. Medical options in the setting of cholangitis, treatment with broad spectrum antibiotics is obviously required. Patients may also be placed on immunosuppressant drugs, given this is thought to be an autoimmune condition.

Endoscopic options include dilation or stenting. Given this is usually a diffuse pathology, typically stenting and dilatation of strictures is reserved for dominant strictures that are causing pathology that could potentially be reversed by assessing or managing that one stricture. So up to 20% of patients will develop a dominant stricture that causes jaundice and can be managed endoscopically.

In the same way, if there is an extrahepatic stricture that is dominant and not able to be dealt with endoscopically, then surgical drainage may be required. Ultimately, liver transplant is the only option for patients that develop cirrhosis or liver failure due to this condition. Obviously, given malignancy is a risk in this pathology, that needs to be excluded prior to transplant.

The risk of cholangiocarcinoma with PSC is somewhere around 4 to 20%. And it's been said that it develops at a rate of about 1 to 2% incidence per year with the condition.

Some other types of inflammatory benign biliary strictures include strictures related to parasitic infections. The first of these is infections with liver flu. who also have the name of Tremato. Liver flukes are an infection that occurs after consuming inadequately cooked pickled or salted infected fish The pathophysiology is that the immature fluke travels to the biliary tree, which is where its life cycle continues and it matures.

It then secretes ova which go or are passed through to the gastrointestinal tract and excreted and then enter back into the water supply. The symptoms of this infection is that most people are asymptomatic. It can cause an acute febrile illness with the initial infection and chronic infection can lead to hepatolithiasis or the formation of stones in the biliary tree. The diagnosis is through a stool culture with over cysts and parasite cultures, and patients may also have eosinophilia.

At ERCP, there may be a finding of slender filling defects in the bile duct and fibrosis or calculi. The treatment of liver fluke infections is with a medication called triclobendazole which is given orally to patients. The next infection to talk about is Echinococcus infection. We'll definitely be talking about this in more detail when we talk about liver infections.

Echinococcus causes hydatid cysts in the liver, and these can cause biliary obstruction due to compression of the common hepatic duct by the cyst. can also have daughter cysts that rupture into the biliary tree and cause inflammation and stricturing. and also you can develop sclerosing cholangitis if the treatment is injection of scolocidal agents into the cyst.

which if there's any attachments or connections to the biliary tree can allow that agent to enter into the biliary tree where it causes inflammation and stricturing. And the last one to talk about is roundworm infection, also known as Ascarus lumbrocodes. This is the commonest worm that infects humans and rarely can present with obstructive jaundice due to migration of the worm itself into the billary tree. Roundworm is treated with albendazole.

There's another type of inflammatory biliary strictures which is HIV or AIDS associated cholangiopathy. This condition is thought to develop due to secondary opportunistic infections that occur in the billary tree and then these cause inflammation and intraductal stones and strictures. The types of infections include CMV and cryptosporidium as well as others.

MRCP may demonstrate imaging abnormalities such as ductal strictures, papillary stenosis, so stricturing of the duodenal papilla, and long segment extrahepatic strictures. ERCP with sphincterotomy can be a treatment for the papillary stenosis. Also, it's interesting that antiretroviral treatment can be associated with regression of the MRCP abnormalities. So adequate treatment with antiretrovirals is an important component to treating this type of benign biliary stricture.

And the last type of inflammatory biliary stricture to consider is IgG4 related disease. This is immunoglobulin G4 related disease. which is an immune-mediated condition that can mimic a pretty wide variety of malignant infectious and inflammatory disorders, especially of the hepatobiliary system. talk more about this over the course of other episodes but interesting to note that this can also cause benign biliary strictures.

So we're on to our last two causes of benign biliary strictures, which are the congenital causes. So I'm going to talk a little bit about collodocal cysts and biliary atresia. So, chlydecal cysts can be diagnosed in childhood or in adulthood and they occur in about 1 in 200,000 births. Collidochal cysts are essentially cystic abnormalities of the biliary tree.

And the interesting thing about the pathophysiology of this condition is that it's thought to be related to an aberrant pancreaticobiliary duct. junction. It's thought that this allows reflux of pancreatic juices up into the bile duct.

potentially contributes to the development of these conditions. In addition to contributing to the development of them, it's also thought that maybe this Reflux and chronic inflammation associated with that process increase the risk of malignancy, which is the main reason we're interested in cholidochal cysts, because they have an increased risk of biliary tree malignancies.

So it would not be a surgical podcast if we didn't have another classification system to learn. So the Tadani classification is the classification system that relates to collidochal cysts. And this is types 1, 2, 3, 4 and 5. So type 1 is a solitary cyst of the extrahepatic biliary tree, usually described as a fusiform dilation of the biliary tree. And this is the most common type of collidoical cyst.

Type 2 is a diverticulum off the common bile duct. So this is a little outpouching or cystic outpouching of the bile duct. Type 3 is also known as a collidococele and this is where there is dilatation of the distal common bile duct within the actual duodenal wall. for type 4 there is both a 4a and 4b and these basically have to do with both of them having multiple extrahepatic biliary tree cysts so it's not just a single cyst but there's multiple cysts in the extrahepatic tree

Type 4a is where there's multiple extrahepatic cysts, but there is also intrahepatic cysts. And type 4b is where there is only extrahepatic cysts. And then type 5 is also known as Corolli's disease. And this is where there are multiple intrahepatic cysts, but no extrahepatic cysts or choledococytes. These patients present in a variety of ways. As expected, a lot of these lesions are asymptomatic and are found incidentally on imaging studies. But patients may present with cholangitis

jaundice, right upper quadrant pain, fevers or even pancreatitis. The diagnosis of this condition is made on billiard tree imaging, so on CTIVC, MRCP or ERCP.

The reason we're interested in these lesions as I've already mentioned is that they do have a risk of malignancy The associated risk of malignancy about 12% in general but it may be higher And it's postulated, as I've mentioned, to be due to that aberrant pancreatic obiliary duct junction and the chronic inflammation associated with that reflux of pancreatic juice into the biliary epithelium.

The treatment of chlydecal cysts is essentially aimed to prevent the risk of developing a malignancy and also to prevent recurrent episodes of sepsis or pancreatitis associated with these abnormalities. The management sort of depends a little bit on the type of collodocal cyst that is present.

so for type 1 which was that fusiform dilation of the extrahepatic biliary tree resection of the extrahepatic biliary tree is recommended And this usually involves a complete excision of the extrahepatic biliary tree, preservation of the pancreatic duct junction, and then anastomosis, so usually hepatico-jejunostomy. For type 2 cysts, so this is where there was a diverticulum of cysts off the side of the billary tree.

This is best managed with a cholecystectomy and a cyst excision, where the bile duct is then repaired over a T-tube, with the alternative being a extrahepatic bile duct resection and hepaticodiginostomy. There's a thought that the type 2 cysts may be more related to a true congenital malformation of the biliary tree and that these have a lower association with that aberrant pancreaticobiliary duct junction. For type 3, This is where there is dilatation of the distal CBD within the duodenal wall.

Malignant transformation of these types of colludecal cysts is very rare and they're often asymptomatic and typically are managed with an endoscopic sphincterotomy.

For type IVa, which is where there is multiple extra-hepatic cysts and then also intra-hepatic cysts, the management is a little bit more complex so in general if the patient has cirrhosis present and there's biloba intra-hepatic cystic lesions then the patient may need a liver transplant If there's no cirrhosis and only one side of the liver is affected, then these patients may be treated with a local hepatic resection and hepaticogeginostomy.

For type 4b, which was just multiple extrahepatic biliary tree cysts, then these can be resected and hepaticodeginostomy formed. And type 5 is the last one, which is Corolli's disease with intrahepatic cystic lesions, but no extrahepatic biliary tree involvement. Again, it depends a little bit on the distribution of disease. If it's uniloba, then a local resection may be performed. And if it's diffuse biloba and associated with liver failure, then a transplant may be required.

and we've made it to our last one of the day which is a brief mention of billory atresia This is a congenital abnormality that affects about 1 in 10,000 live births. The buzzwords to know for the pathophysiology of this condition is that it is an obliterative cholangiopathy and basically is an intense fibrotic process within the intra and extrahepatic biliary diet. which causes complete fibrosis of the duct.

This condition usually presents in the early neonatal period and usually presents with prolonged jaundice, although it can present slightly later than that. and the characteristic imaging finding is that there's a fibrous cord above the porter but often they don't have a patent extrahepatic biliary tree The management is an operation called the KASAI operation, also known as a portoenterostomy.

which is essentially where the entire hyla plate of the liver is cleared of all fibrous tissue and a loop of bowel is sutured to that area hoping that there are small autoducts that are going to adequately drain the liver. Although this is not always successful and has its own potential complications, about 50% of patients will have some long-term success from this procedure with the only other option being liver transplant.

About 50 to 60% of patients who are born with biliary atresia may need a liver transplant in the short or longer term. And that brings us to the end of this whirlwind summary on benign biliary strictures with some talk about choledocal cysts. I hope you found this useful. I definitely did going over all of these topics as I feel like they are a little bit niche but could definitely come up at some point during the exam.

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