Biliary Obstruction

What is Biliary Obstruction?

Biliary obstruction, or blockage in the bile duct system, often causes hindrances in the bile flow from the liver to the intestine. Bile, a substance comprised of bile salts, bilirubin, and cholesterol, is continuously created in the liver and helps in digesting fats. This bile then travels through the bile ducts to the second section of the small intestine, known as the duodenum.

The pathway of the bile is intricate. It moves from the liver through two ducts, the right and left hepatic ducts, into a larger tube, the common hepatic duct. This tube then merges with the cystic duct from the gallbladder creating a single larger duct, the common bile duct. This common duct continues its course through the pancreas and finally meets the duodenum at the major papilla or ampulla. Most of the bile moves into the gallbladder via the cystic duct, where it becomes concentrated and is stored temporarily. The remaining bile moves directly to the duodenum through the common bile duct. The hormone Cholecystokinin (CCK), found in the duodenum, controls this flow and the release of stored bile from the gallbladder.

Blockage can happen at any point in this journey and can lead to a whole range of complications, including liver dysfunction, kidney failure, nutritional issues, bleeding complications, and infections. This disruption of the bile flow, due to difficulties in the biliary system within the liver, is known as cholestasis. Cholestasis can manifest in the form of abnormal levels of liver enzymes in the blood, such as increased bilirubin and alkaline phosphatase levels, and can cause yellowing of the skin (jaundice) and itchiness (pruritis).

It’s important to note that biliary obstruction is a common condition, affecting many people worldwide, and can lead to serious health issues. The number one cause of biliary obstruction is gallstones, which often block the extrahepatic bile duct. A severe consequence of this blockage is the possible development of infections in the bile ducts, termed as cholangitis, which could be life-threatening if left untreated.

What Causes Biliary Obstruction?

Biliary obstruction, or the blockage of the bile ducts, can happen either inside the liver (intrahepatic) or outside the liver (extrahepatic). This blockage in the liver is often called cholestasis, but we won’t discuss that in detail here. There can be several causes for cholestasis, like different types of liver infections (including from alcohol use or viruses), harm to the liver from medications (like antibiotics, painkillers, anti-seizure drugs, or heart rhythm drugs), as well as other conditions like primary biliary cholangitis and primary sclerosing cholangitis. Diseases that infiltrate the liver, like sarcoidosis, tumors, abscess, and cysts, can also cause it.

On the other hand, this passage focuses on the extrahepatic biliary obstruction, which means the blockage happens outside the liver. There can be many reasons for this type of blockage, some of them are harmless while others can be serious. Examples include gallstones in the common bile duct (choledocholithiasis), swelling or cysts of the bile ducts (choledochal cysts), or pressure from gallstones on the bile duct (Mirizzi syndrome). Some diseases, like primary sclerosing cholangitis, cause the bile duct to become narrower over time. Damage from gallstones or from medical procedures could also result in such narrowing.

Cancer can also cause this kind of blockage, like cancer of the bile duct (cholangiocarcinoma), cancer in the head of the pancreas leading to a narrow common bile duct, and cancer or benign tumors at the spot where the bile duct and pancreatic duct drain into the small intestine (ampullary carcinoma or adenoma).

Other causes of biliary obstruction can come from infections, like certain parasitic diseases (like Clonorchis sinensis, Ascaris lumbricoides) that block bile flow. Lastly, inflammation and immune system-related diseases like a type of liver disease seen in people with AIDS, and autoimmune cholangiopathy, can also block the bile ducts.

Risk Factors and Frequency for Biliary Obstruction

Gallstones obstructing the bile duct is a condition that affects about 5 in 1,000 people, while 10 to 15% of adults in the U.S develop gallstones at some point in their life. These stones form in the gallbladder and can travel into the liver’s ducts causing blockage. Around 10 to 15% of those with gallstones also find stones in their bile ducts when first diagnosed.

Women are more likely to develop gallstones than men due to factors related to estrogen, increasing their risk for bile duct stone formation. Ethnicity also affects gallstone prevalence: Hispanics, Northern Europeans, and Native Americans are the most commonly affected, with the highest rates found in Northern Native Americans (64% in females and 29% in males). Asian and African Americans show intermediate prevalence rates (13.9% in women and 5.3% in men), with the lowest rates (<5%) recorded in sub-Saharan Black Africa. The incidence among white North Americans sits at 16.6% for women and 8.6% for men.

In developed countries, gallstones causing bile duct blockage are typically cholesterol stones. In Asia, stones often result from infection or blood cell breakdown. Some medical conditions are region-specific such as recurrent bacterial infection of the bile ducts, a condition common in Asia but rare in the West. Additionally, gallbladder cancer is more common in Central and South America, Central and Eastern Europe, Northern India, and East Asia.

Signs and Symptoms of Biliary Obstruction

Biliary obstruction, or blocked bile ducts, can show itself in a variety of ways depending on what’s causing it. Usually, it shows up as yellowish skin (jaundice), light-colored or white stools, and dark urine. Chronic biliary obstruction might make the skin itch. Other symptoms can include pain in the upper right abdomen, fever, nausea, vomiting, and weight loss. How quickly these symptoms appear can vary. They might appear suddenly or develop more gradually over several months.

When diagnosing, it’s important to understand how quickly the symptoms started, as well as any notable accompanying symptoms like weight loss, appetite loss, and nausea/vomiting. Pain in the right side of the abdomen, along with how intense it is and whether it radiates, is important to know. Information about diarrhea, blood in the stools, and upper gastrointestinal bleeding symptoms is also relevant to figuring out the underlying cause. Past medical history including the patient’s personal and family history of conditions like bile duct or pancreatic cancer, inflammatory bowel disease, or primary liver disease, is also critical. In addition, the patient’s lifestyle information like smoking, drinking, drug use, and travel history to areas with high rates of parasitic diseases is useful. Sometimes, medications the patient has been taking can help to tell the difference between cholestasis (blocked bile flow in the liver) and biliary obstruction (blocked bile ducts).

Performing a detailed physical examination is also essential. Doctors check basic things like body temperature and heart rate. General checks for any discomfort, pallor (pale skin), jaundice, yellowing of the whites of the eyes (scleral icterus), reddened palms, and signs of malnutrition are also important. Special attention is given to the abdomen – specifically the upper right section, to look for any tenderness. The presence of liver and spleen enlargement, fluid buildup in the abdomen (ascites), identifiable masses, and signs of cirrhosis (such as ‘caput medusae’, or dilated veins around the belly button) can be significant indicators of the cause. A cardiac examination is done to check for signs of heart failure like jugular venous distension and displacement of heart sounds. Similarly, a lung check might be needed to look for excess fluid in the spaces around the lungs, which can suggest certain causes. Checking for swollen lymph nodes in the neck, especially the left supraclavicular lymph nodes, can provide useful information. A check for swelling in the lower extremities is also important.

Testing for Biliary Obstruction

If your doctor suspects that your bile duct could be blocked, they will carry out several tests to confirm the diagnosis. They may begin with blood tests, a urine test, and a stool test.

Blood tests will likely include a complete blood count (CBC) and a comprehensive metabolic profile (CMP), which assess a variety of your body’s functions. Your doctor might also analyze your levels of bilirubin, a yellowish substance in your blood that could indicate liver or bile duct problems. Other blood tests could look for signs of viral hepatitis or problems with blood clotting. In some cases, the doctor might test for specific types of proteins produced by tumors.

The urine test will look for bilirubin in your urine. If present, it could further suggest issues with your liver or bile duct. The stool test will look for hidden, or ‘occult’, blood in your feces. This can indicate a number of health issues, including cancer in your digestive system.

Additionally, your doctor may want to carry out imaging studies – pictures of the inside of your body. This could start with an abdominal ultrasound. It’s relatively cheap, non-invasive (it doesn’t penetrate the skin or body), and widely available. This test is effective at detecting gallstones and dilation (enlarging) of the bile duct.

If the ultrasound results suggest further investigation is needed, the next step could be an abdominal CT scan. This can help the doctor examine the head of the pancreas and liver, and rule out other processes in the abdomen that might be causing your symptoms. Another type of imaging test, the HIDA scan, can check for blockages in the duct transporting bile from your gallbladder.

A magnetic resonance cholangiopancreatography (MRCP) might also be carried out. This is a type of MRI scan that can assess the bile ducts for abnormalities such as cholangiocarcinoma (bile duct cancer), strictures (narrowing), or stones in the bile duct. Based on these results, your doctor may then carry out endoscopic tests such as an endoscopic ultrasound (EUS) with needle aspiration, or ERCP with cell studies and biopsies for further evaluation. ERCP is a test that uses a small tube with a camera (endoscope) to examine the pancreas and bile ducts; in cases of gallstones causing bile duct obstruction, it can also be used for treatment. Occasionally, doctors may also perform a percutaneous transhepatic cholangiogram (PTCA) to check for bile duct narrowing and to take biopsies.

Treatment Options for Biliary Obstruction

The initial treatment plan for a patient depends on their current health state and the likely cause of their illness. If the patient is generally stable, they can often be treated in an outpatient setting, which means they can go home and return for regular check-ups at the gastroenterology clinic. However, if the patient has a fever, shows signs of a severe widespread infection (sepsis), and has liver dysfunction, it may be necessary to admit them to the hospital for assessment and treatment. This is especially true in cases where the patient has acute cholangitis (inflammation of the bile ducts), cholecystitis (inflammation of the gallbladder), or acute liver failure.

The exact treatment varies widely depending on the cause of biliary obstruction, which is a blockage in the tubes that carry bile from the liver to the gallbladder and intestines. Here, we will discuss the common causes and their typical treatments:

Gallstones and common bile duct stones: If the common bile duct (CBD) is less than 1.5cm with small stones, a procedure called ERCP (endoscopic retrograde cholangiopancreatography) is typically performed along with a sphincterotomy (cutting of the muscle that controls the opening of the bile duct) and removal of the gallbladder (cholecystectomy). If the common bile duct is more than 1.5cm with large stones, several different procedures can be utilized including the aforementioned ERCP and sphincterotomy along with lithotripsy (a procedure to break up stones), choledochotomy (opening of the bile duct), or surgeries connecting the bile duct to the first part of the small intestine or to a segment of the jejunum (a part of the small intestine).

Common bile duct stricture (narrowing): For benign (non-cancerous) strictures, doctors often recommend endoscopic sphincterotomy and balloon dilation (stretching of the narrowed area) or endoscopic stenting (placement of a tube to keep the duct open), which is typically removed or exchanged after 4 to 6 weeks. In some cases, surgical bypass of the bile duct may be needed. For malignant (cancerous) strictures, treatments can include endoscopic or percutaneous (through the skin) drainage, stenting, or even surgical bypass of the bile duct in cases where the cancer cannot be removed. If the disease is able to be resected, removal of the tumor with subsequent surgical joining of two organs or structures is performed.

Parasitic infections: In these cases, medications like albendazole, mebendazole, or pyrantel pamoate may be used. For more severe cases, an ERCP with sphincterotomy and extraction may be necessary. If the gallbladder is invaded, a gallbladder removal (cholecystectomy), exploration of the common bile duct, and the placement of a T-tube may be required.

Choledochal cysts: These, a type of cyst present from birth, are typically evaluated for cancer risks and may require removal (excision) and a surgical procedure called hepaticojejunostomy.

Neoplasms (abnormal proliferation of cells leading to a mass): In advanced stages, palliative treatments such as endoscopic biliary stenting (keeping open the bile duct using a tube), chemoradiotherapy, or photodynamic therapy (using light to activate a drug that kills cancer cells) may be performed. Other options include percutaneous transhepatic endobiliary radiofrequency ablation (a technique that uses heat to destroy cancer cells), or stenting in the first part of the small intestine (duodenal stenting) if the cancer is located at the junction of the bile duct and the small intestine (ampullary carcinoma). If the disease is resectable, excision with clear margins can be performed, often accompanied with a technique called bilioenteric anastomosis. Specific treatment options are also available for pancreatic head carcinoma, ampullary carcinoma, and gallbladder malignancy.

What else can Biliary Obstruction be?

When a person has a blockage in their bile duct, the medical professional has to consider multiple diseases that could be causing this issue. These diseases could be either benign, which means not serious, or malignant, which means serious or cancerous. Some possible causes include:

Benign Diseases:

• Gallstones leading to sudden inflammation of the gallbladder or gallstone pain (Acute cholecystitis and biliary colic from cholelithiasis)
• Sudden inflammation of the pancreas (Acute pancreatitis)
• Liver disease often due to excessive drinking (Alcoholic hepatitis)
• An intestinal infestation (Ascariasis)
• Narrowing of the bile duct and inflammation (Bile duct strictures and cholangitis)
• Injury or leakage of bile duct (Biliary trauma and leaks)
• Bile duct growth (Choledochal cysts)
• Long-term inflammation of the pancreas (Chronic pancreatitis)
• Scarring and poor function of the liver due to various reasons (Cirrhosis)
• Long-term liver infections like hepatitis B and C (Viral hepatitis)
• Liver tumors both benign and malignant (Hepatocellular adenoma and carcinoma)
• A condition causing severe gallbladder or bile duct pain (Mirizzi syndrome)
• A slowly progressive disease causing inflammation and damage to the bile ducts of the liver (Primary biliary cholangitis)
• A disease causing inflammation and scarring of bile ducts in the liver (Primary sclerosing cholangitis)

Malignant Diseases:

• Cancer or tumors in the area where the bile duct and pancreatic duct join to empty into the duodenum (Ampullary carcinoma or adenoma)
• Bile duct cancers or tumors (Bile duct tumors: cholangiocarcinomas)
• Gallbladder cancer
• Pancreatic cancer
• Liver cancers (Primary hepatic malignancies)
• Enlargement of cancerous lymph nodes near bile duct

By considering all of these diseases and conducting the appropriate tests, a physician can accurately diagnose the patient’s condition.

What to expect with Biliary Obstruction

The outcome of biliary obstruction, which is a blockage in the tubes that transport bile from the liver to the gallbladder and small intestine, can greatly vary depending on the cause. If it is not treated, it can lead to potentially fatal infections. Persistent and long-lasting biliary obstruction is usually tied to a chronic liver disease, which commonly has a poor outlook.

However, most cases that are of short duration can be successfully treated with medications, surgery, or a procedure known as endoscopy. In such cases, patients usually fully recover. Obstruction caused by chronic liver disease and a condition where cells in your body start to grow uncontrollably (known as malignant etiology) typically has a less optimistic outlook.

Possible Complications When Diagnosed with Biliary Obstruction

One of the serious complications of a blocked bile duct is acute ascending cholangitis, which is an infection caused by the obstruction. This can quickly cause a full-body infection, potentially leading to multiple organ failure.

Acute cholangitis may show symptoms like Charcot’s triad (pain in the upper right area of the abdomen, fever, and yellowing of the skin and eyes) or Reynold’s pentad (Charcot’s triad plus mental confusion and shock). To help identify the condition, doctors might look for signs such as a high white blood cell count with an overabundance of a certain type of white blood cell, abnormal liver test results including high bilirubin levels, and several other specific tests. They might conduct an abdominal ultrasound, CT scan, and MRCP (a type of imaging).

The severe form of cholangitis can cause:

• Low blood pressure requiring medication
• Mental confusion
• A specific ratio of oxygen in the blood lower than 300
• A creatinine level in the blood over 2.0 mg/dL
• A specific ratio of blood clotting factors over 1.5
• Platelet count below 100000 per cubic millimeter

For treating acute cholangitis, initial steps include hospital admission for intravenous fluids, electrolyte replacement, pain control, and antibiotics that target certain types of bacteria. Low-risk infections caught in the community can be treated with specific antibiotics, either individually or combined. High-risk infections caught in the community can be treated with another set of specific antibiotics, or a combination thereof.

Eventually, most patients with cholangitis will require one of the following procedures, which aim to relieve the blockage in the bile duct:

• ERCP, a procedure used to examine the pancreatic and bile ducts and remove any obstructions
• Biliary stone removal and bile drainage, often with sphincterotomy, a procedure to cut the muscle between the common bile duct and the pancreatic duct
• PTC, a procedure used to drain bile from the liver via a needle
• Surgery, either open or through small incisions (laparoscopic), to relieve biliary blockage, remove the obstruction, and potentially remove the gallbladder if necessary

Preventing Biliary Obstruction

Biliary obstruction is a condition where the bile ducts, which carry bile from the liver to the small intestine to help digest fats, become blocked. This blockage can disrupt the normal flow of bile.

The most common reason for this blockage is gallstones – hard pieces that form in the gallbladder and can move into the bile ducts, causing an obstruction.

People with biliary obstruction often experience pain in the upper right side of their stomach or in the back under the shoulder blade. They may also feel nauseous, may vomit, and can develop jaundice – a condition where the skin and the whites of the eyes turn yellow.

To diagnose biliary obstruction, doctors often use lab tests and imaging methods such as abdominal ultrasound. They might need to do more tests depending on the initial results.

The treatment for biliary obstruction depends on what’s causing it. In some cases, doctors may recommend surgery to remove the gallbladder (called a cholecystectomy) if gallstones are the cause. They may also use a method called ERCP with sphincterotomy, which is a special procedure to remove gallstones from the bile ducts.

For non-surgical treatment, doctors might propose measures to stabilize the patient, control pain, and use medications to help dissolve gallstones that are causing the obstruction.

Patients with this condition should follow a healthy diet that is low in fat and high in fiber. Fried foods, canned fish, processed meats, full-fat dairy products, processed baked goods, fast food and most packaged snack foods should be avoided. On the other hand, fresh fruits and veggies that are high in vitamin C, like kiwis, broccoli, oranges, and grapefruits, can be beneficial.

Preventing biliary obstruction from recurring can be achieved by maintaining a healthy weight through proper diet and regular exercise.