What is Bile Duct Stricture?

Biliary strictures, or bile duct strictures, is a term used to describe areas of tightening in the biliary duct system which is located in your liver or outside of it. When these areas become narrowed, they prevent the normal flow of bile – a fluid that helps in digestion. This blockage then causes the area behind the narrowed spot to swell, leading to symptoms and physical changes often associated with bile duct blockage.

Patients suffering from long-term biliary strictures present a unique problem if a cancerous growth is suspected. Diagnosing and treating individuals with biliary strictures often needs a team approach, involving professionals like endoscopists, surgeons, radiologists who perform procedures using imaging techniques, and liver and bile duct specialists. The simplified image provided shows what a bile duct stricture looks like.

What Causes Bile Duct Stricture?

Narrowing of the bile duct, also known as bile duct strictures, can either be present at birth (congenital) or develop later (acquired). Acquired strictures, are more common and can be either non-cancerous (benign) or cancerous (malignant). There are a variety of non-cancerous conditions that can lead to these strictures, and one-third of all bile duct strictures are due to these benign conditions.

One common cause is accidental injury to the bile duct during gallbladder surgery. In these instances, the bile duct is sometimes mistaken for another duct and gets injured, which could be either a partial injury or complete. Over time, these injuries can lead to non-cancerous bile duct strictures. A special x-ray procedure called an intraoperative cholangiogram can be done during surgery to help decrease this risk of bile duct injury, particularly in complicated cases such as a rotting gallbladder or one filled with pus.

Having a good understanding of the anatomy of the bile duct’s blood supply is highly significant when it comes to repairing bile duct injuries. Bile duct narrowing can also happen after a liver transplantation or after a certain kind of surgery called a Whipple procedure, typically performed on the pancreas due to a mass or injury. This is more likely in delicate small bile ducts.

Though less common, bile duct strictures can also be caused by infections, such as tuberculosis, and other benign causes include chronic inflammation of the pancreas, inflammation of bile ducts, physical trauma to the stomach, autoimmune diseases, Mirizzi syndrome, ischemic cholangiopathy, swelling in the bile duct due to inflammation and certain infections. Radiation treatment can also lead to bile duct narrowing.

Nevertheless, the most common cause of bile duct strictures is cancer. The majority of malignant, or cancerous, bile duct strictures are due to pancreatic head cancer and cancer of the bile duct, also known as cholangiocarcinoma. Other cancers such as periampullary cancer, gallbladder cancer, liver cancer, lymphoma, and metastasis to nearby solid organs and lymph nodes can also cause biliary strictures.

Risk Factors and Frequency for Bile Duct Stricture

There is a global increase in the occurrence of biliary strictures, mainly due to unintended bile duct injuries that happen during a common surgery called laparoscopic cholecystectomy. To reduce these injuries and related complications, several strategies have been suggested, like the critical view of safety. These injuries occur in about 0.7% of those who undergo laparoscopic cholecystectomy, but most of these are minor or result in bile leaks. Biliary strictures are not common in children. There’s no evidence that these occur more frequently in either men or women. However, certain risk factors like alcoholic chronic pancreatitis are more common in men.

Signs and Symptoms of Bile Duct Stricture

Biliary strictures, or blockages in the bile ducts, can show different symptoms based on their location and what’s causing them. Some people may not have any noticeable symptoms, and a doctor’s physical examination may not find anything unusual. However, other people may experience symptoms of obstructive jaundice, which happens when bile can’t flow properly. Such symptoms include yellowing of the eyes and skin, itching, light-colored stools, fatty stools, and dark urine. These people may also feel generally unwell, with weight loss, fever, nausea, vomiting, and tiredness. In some cases, the bile duct stricture could cause severe pain in the abdomen, as well as inflammation of the bile duct or a liver abscess.

Additional symptoms, such as fever and high white blood cell count, may suggest that infection has caused or contributed to the strictures. If a patient reports weight loss, pain in the abdomen or back, or a decrease in their overall health and functionality, this could indicate a possible cancerous growth.

It’s also crucial to find out about any previous related health issues the patient may have had. This could include previous surgery on the liver or bile ducts, an autoimmune disease, pancreatitis, gallstones, or chemotherapy. Knowing this history could help determine possible causes of the stricture or rule some out.

During the physical examination, the doctor will also look for specific signs that could help identify the cause of the jaundice. For example, the presence of hard lumps in the abdomen could indicate advanced cancer.

Testing for Bile Duct Stricture

Diagnosing your health condition can be a process that combines various methods, like blood tests, imaging studies, and careful assessment of your symptoms and medical history. In the case of biliary strictures, or abnormalities in the bile ducts of your liver, several steps might be involved.

First, your doctor might order some blood tests. A liver function test might show high levels of specific proteins and enzymes, suggesting an issue with your liver. A coagulation profile will check how well your blood clots, and a complete blood count gives information about the cells in your blood. Immunological studies can help identify if certain auto-immune conditions are causing the abnormalities in your bile ducts.

Your doctor might also order some imaging tests, like a trans-abdominal ultrasound or a CT scan. These tests can provide pictures of the liver and bile ducts to help locate any strictures, or narrow areas. These tests are crucial because the pictures they provide help the doctor visualize what’s going on inside your body. An ultrasound is a great starting point since it can quickly and safely identify if there’s an obstruction in your bile ducts, but it may not be the best at detecting the strictures themselves.

A CT scan, on the other hand, has a higher chance of spotting biliary malignancy. The CT scan can also give more detailed information on the state of your biliary tree, or the path that bile takes from your liver to your intestine.

Another tool called magnetic resonance cholangiopancreatography (MRCP) can create a detailed image of your biliary tree. It has a similar chance of spotting strictures as an ERCP test, but without the exposure to ionizing radiation, making it a safer option.

Last but not least, doctors can use an ERCP (endoscopic retrograde cholangiopancreatography) to diagnose, collect tissue samples and even offer treatment by opening up any blocked areas. This procedure involves using a narrow tube with a camera on the end to examine and treat the digestive system. However, it can cause pancreatitis in some cases. Consequently, other more advanced technologies like laser endomicroscopy are increasingly being used.

Lastly, some areas of hurt bile ducts releases certain chemicals that can be spotted by a special type of scan called a hepatobiliary iminodiacetic acid (HIDA) scan. This can be helpful in identifying bile leaks.

These are just a few of the tools your doctor might use to try and identify what’s causing your illness and how best to treat it. Remember, everyone’s case is unique, and your doctor will use all the information available to them to formulate the best treatment plan for your individual needs.

Treatment Options for Bile Duct Stricture

The treatment for biliary strictures, or blockages in your bile ducts, often involves medication to relieve pain and tackle infections, along with measures to maintain stable blood pressure and heart functioning. The target for such treatment is usually to handle the complications that result from the blockages. Sometimes, the treatment aims to manage the underlying cause of the biliary stricture. The high bilirubin levels that can result from these strictures may also be addressed. It’s important to note that these treatments are typically used as a form of support in preparing for a more permanent solution.

Certain interventions are designed to restore the normal functioning of the bile ducts and to avoid further medical procedures. There are different methods available for this, including endoscopy (where a thin tube with a camera is inserted into your body), traditional open surgery, or a percutaneous procedure (a procedure done through the skin). These methods are chosen depending upon the cause and location of the blockage, the stability of the patient’s vital signs, and their nutritional health.

Before planning any treatment procedure, detecting any malignant or cancerous changes is crucial, as it helps avoid unnecessary exploratory surgery. Various classifications like the Bismuth and Strasberg classifications can help doctors decide the best course of action.

Endoscopic treatment is usually the first choice for managing biliary strictures. This includes:

Dilation: This is the preferred method for managing benign or non-cancerous blockages. It involves expanding the strictures, usually with a balloon, to allow for the normal flow of bile.

Stenting: This is another method that can be used for both benign and malignant blockages. A hollow tube or stent is placed into the bile duct to hold it open. If used before a major surgery, it can help reduce symptoms like jaundice or inflammation of the bile duct.

Resection and Anastomosis: Depending on the kind of blockage and the desired result, a portion of the duct may be removed, which is then reattached to allow the normal flow of bile. Although effective, this method can be costly and present considerable side-effects.

Bypass: This is a method of creating an alternative route for bile flow when the duct cannot be repaired.

Other methods used to manage biliary strictures include the placement of a drainage catheter guided by images, biliary sphincterotomy (division of the biliary sphincter to facilitate stone removal or stent placement), and novel techniques like magnetic compression anastomosis, biodegradable stents, and large bore catheterization.

When a doctor is trying to figure out the cause of a problem with your bile ducts, they need to decide if it is caused by a benign (non-cancerous) problem or a malignant (cancerous) one. This can be really tough to figure out, so the doctor will need your complete medical history, a physical exam, and other medical tests.

To make sure they’re getting the most accurate diagnosis, some additional tests can also be included, like:

Fluorescence in situ hybridization (FISH): a test to look for abnormal cells.
Kras/p53 mutation analysis: a test to look for specific changes in your genes that could suggest cancer.
Intraductal biopsies: taking a small piece of tissue from your bile ducts to examine under a microscope.
Confocal laser endomicroscopy (CLE): a test that uses a special microscope to examine your cells in detail.

In some cases, the doctor may also consider that there might be gallstones in your bile ducts (a condition called choledocholithiasis) that are causing the blockage.

What to expect with Bile Duct Stricture

The chance of survival for patients with biliary strictures, which are blockages or narrowing of the bile ducts, largely depends on the root cause of these blockages. Biliary strictures resulting from chronic pancreatitis (long lasting inflammation of the pancreas), trauma, radiation, or surgical damage typically have a good outlook.

However, those caused by malignant or cancerous growths, and primary sclerosing cholangitis which is a long-term liver disease that slowly damages the bile ducts, may have a less favorable outcome. The same applies to biliary strictures occurring in patients with HIV cholangiopathy, which refers to bile duct complications seen in patients with HIV.

Possible Complications When Diagnosed with Bile Duct Stricture

Biliary strictures are a medical condition that can be complicated by a persistent, low-grade blockage of the bile duct. Some of the problems that can arise from this include:

Recurrent infections of the bile duct
Infections spreading up the bile duct
Bloodstream infection caused by certain bacteria
Stone formation in the bile duct
Liver abscesses
Secondary cirrhosis of the bile duct
End-stage liver diseases
Cancer of the bile duct

Adding to this, procedures meant to relieve these strictures also come with their own set of possible complications, such as:

Inflammation of the pancreas
Infections in the bile duct
Bleeding
Puncture or tear in the bile duct

There have also been instances of biliary stents (tubes inserted to keep the bile duct open) moving and causing a puncture in the small intestine. Sometimes tumors can overgrow these stents, making them useless.

Preventing Bile Duct Stricture

Doctors should advise their patients against consuming alcohol, particularly if their medical condition, like chronic pancreatitis caused by alcoholism, is connected to drinking. Furthermore, patients who’ve had biliary stents inserted need to know how to identify symptoms that their stents might be blocked.

A biliary stent is a small tube that opens a blocked bile duct to allow bile to drain from the liver.

Additionally, patients with external drains should learn the sterilized way of cleaning their drains to prevent infection. An external drain is a tube placed to remove fluid or gas from the body.

Finally, it’s essential for both the patient and their caregiver to understand the expected course or outcome (prognosis) of the patient’s illness. This includes information on likely progression or regression, and the likelihood of recovery or recurrence.