A biliary stent is a small, tube-like device placed within the bile ducts, which are channels that carry bile from the liver and gallbladder to the small intestine. Its purpose is to restore normal bile flow when these ducts become blocked or narrowed. This helps alleviate symptoms and prevent complications from bile buildup. Biliary stent placement is a common procedure to manage conditions affecting the bile drainage system.
Understanding Biliary Stents and Their Role
Biliary stents are small, hollow tubes made from either plastic or metal. Plastic stents are temporary and for short-term placement. Metal stents are more durable, intended for longer-lasting or permanent placement. Plastic stents usually range from 1 to 25 centimeters in length, while metal stents are typically between 4 and 12 centimeters long with an expanded diameter of 6 to 10 millimeters.
The liver produces bile, a greenish-yellow fluid that aids digestion and carries waste. Bile travels through a network of ducts from the liver and gallbladder to the small intestine. When this system is obstructed, bile backs up, leading to symptoms like jaundice and pain.
A biliary stent becomes necessary when bile ducts are blocked, preventing bile from draining properly. Common causes include gallstones, tumors like pancreatic cancer or cholangiocarcinoma, or liver cancer that compress the ducts. Narrowing of the ducts, known as strictures, can also occur due to chronic pancreatitis, inflammation, or complications from surgeries. By holding the narrowed or blocked duct open, the stent creates a pathway for bile to flow.
The Biliary Stent Placement Procedure
Biliary stents are placed using two methods: Endoscopic Retrograde Cholangiopancreatography (ERCP) or Percutaneous Transhepatic Cholangiography (PTC). ERCP is the more common technique, performed by a gastroenterologist. During an ERCP, the patient receives sedation. A flexible tube with a camera, called an an endoscope, is guided through the mouth, stomach, and into the small intestine.
Once the endoscope reaches the bile duct opening, a contrast dye is injected to visualize the ducts under X-ray guidance. A guidewire is then advanced through the obstruction, and the stent is threaded over this wire and positioned across the narrowed segment. If a metal stent is used, it often expands on its own, while plastic stents require manual placement.
Alternatively, PTC is performed by an interventional radiologist, especially when ERCP is not feasible due to anatomical changes or complete blockages. For this procedure, the skin over the abdomen is numbed. A needle is then guided through the skin and liver to access the bile ducts.
Similar to ERCP, a contrast dye is injected through the needle to visualize the bile ducts and blockage on X-ray images. A guidewire is then inserted through the needle, and a hollow tube is placed over the wire to insert the stent. The stent is maneuvered through this tube and positioned across the obstruction.
Potential Risks and Complications
While biliary stent placement is a safe procedure, potential risks and complications exist. Immediate, short-term risks include pancreatitis, causing severe abdominal pain. Bleeding can also occur at the stent insertion site. Infection of the bile ducts, called cholangitis, may arise if bacteria enter the bile system. Rarely, perforation of the bile duct or intestine can occur during the procedure.
Beyond immediate procedural risks, longer-term issues can develop with the stent. A common concern is stent blockage or occlusion, due to bile sludge, tissue overgrowth, or tumor ingrowth, impeding bile flow. Another complication is stent migration, where the stent moves from its intended position. Covered metal stents, designed to prevent tissue ingrowth, may have a higher chance of migration because they have less friction against the duct walls.
Patients should be vigilant for signs of complication or stent malfunction. These include jaundice (yellowing of the skin or eyes), indicating bile buildup. Persistent or worsening abdominal pain, particularly in the upper right abdomen, can also signal a problem. Fever or chills indicate possible infection, such as cholangitis. Other symptoms include nausea, vomiting, dark urine, pale or clay-colored stools, and itchy skin.
Living with and Managing a Biliary Stent
After biliary stent placement, patients receive instructions for post-procedure care. Pain management is addressed; a sore throat may occur after ERCP, and pain at the PTC puncture site is common. Patients are advised to rest and gradually resume activities, avoiding heavy lifting or strenuous exercise for several days to a week. Dietary recommendations include consuming smaller, more frequent meals and avoiding greasy or spicy foods to ease digestion.
The lifespan of a biliary stent varies depending on its material. Plastic stents are temporary and require replacement every three to six months due to blockage from bile sludge or tissue. Metal stents are more durable, intended for longer-lasting or permanent placement. Some covered metal stents can be removed or repositioned if necessary.
Regular follow-up appointments are scheduled within days to a week after placement, then every one to three months. These appointments involve imaging tests, such as ultrasound, CT scans, or X-rays, to monitor the stent’s position and bile flow. Blood tests, including liver function tests, bilirubin levels, and white blood cell counts, are also conducted to check for drainage and signs of infection.
Individuals with a biliary stent should recognize signs of potential malfunction and seek prompt medical attention. These include jaundice, persistent abdominal pain, fever, chills, dark urine, pale stools, or itchy skin. If any of these symptoms appear, contact a healthcare provider immediately to address the issue and prevent further complications.