A liver stent is a small, hollow tube inserted into a duct or vessel to keep it open. When cancer affects organs near the liver (such as the pancreas or bile ducts), tumor growth can compress these pathways, causing blockages. Stent placement mechanically restores flow through the obstructed area. This minimally invasive intervention manages symptoms and allows subsequent cancer treatments to proceed effectively.
The Necessity of Liver Stents in Cancer Care
The most frequent reason a patient with cancer near the liver requires a stent is malignant biliary obstruction. Tumors originating in the pancreas, bile ducts (cholangiocarcinoma), or liver can squeeze or invade the bile ducts, preventing bile flow. This blockage causes a buildup of bilirubin, leading to jaundice.
Unrelieved jaundice can lead to serious complications, including itching (pruritus), bile duct infection (cholangitis), and liver failure. Elevated bilirubin levels also make patients ineligible for systemic treatments like chemotherapy, as these drugs are metabolized by the liver. A biliary stent provides immediate drainage, resolving jaundice and improving liver function, which is necessary before starting life-extending therapies.
Some cancers can also compromise blood flow to the liver. Tumors may compress or invade the portal vein, the main vessel carrying blood from the gastrointestinal tract to the liver. This narrowing (portal vein stenosis or occlusion) can lead to severe complications like portal hypertension, causing internal bleeding and abdominal fluid accumulation. A vascular stent is required in these instances to hold the vein open, maintaining blood flow and managing symptoms.
Types and Materials of Biliary and Vascular Stents
Stents used in cancer-related liver interventions are categorized by their material: plastic or metal. Plastic stents are typically made of materials like polyethylene or polyurethane, are inexpensive and easy to place. They are temporary solutions, often used for short-term drainage before surgery or for palliation. Because they have a smaller diameter, they are prone to clogging and usually require replacement every three to six months.
Metallic stents (SEMS) are usually made from nickel-titanium alloys (nitinol) and are designed for longer-term use. These stents are compressed for delivery, then expand upon placement to a larger diameter, offering superior flow. They are the preferred choice for patients with malignant obstruction who are not candidates for surgery and have a longer life expectancy.
Metallic stents are further divided into uncovered and covered types. Uncovered stents are a mesh structure that allows surrounding tissue to grow into the mesh, which helps anchor the stent but risks re-blockage. Covered stents have a thin silicone or polymer layer that prevents tumor ingrowth, extending the time the stent remains open. Biliary stents focus on bile drainage, while vascular stents are designed for the higher-pressure environment of the portal vein.
The Stent Placement Procedure
Liver stent placement is a minimally invasive procedure, most commonly performed using an endoscopic approach. Endoscopic Retrograde Cholangiopancreatography (ERCP) is the standard technique for placing a biliary stent. During ERCP, the patient receives sedation or general anesthesia, and a flexible endoscope is guided through the mouth, stomach, and into the small intestine.
Once the endoscope reaches the bile duct opening, specialized tools and a guidewire are threaded into the duct. X-ray imaging, often with a contrast dye, visualizes the blockage and guides the stent into position. The stent is then deployed, expanding to open the channel, and the endoscope is removed, typically completing the procedure in under an hour.
If ERCP fails or the tumor is inaccessible, Percutaneous Transhepatic Biliary Drainage (PTBD) may be used. This method involves an interventional radiologist accessing the bile ducts directly through the skin and the liver. Local anesthesia is administered, and a thin needle is guided using imaging to reach the obstructed bile duct. A guidewire is then used to deliver the stent, bypassing the blockage.
Living with a Liver Stent: Follow-up and Maintenance
After stent placement, patients are monitored closely for several hours before discharge to ensure stability and recovery from sedation. Those who underwent PTBD may experience temporary soreness or pain at the puncture site, sometimes felt as referred pain in the right shoulder. Most patients can return to their usual activities quickly, though a sore throat may linger for a day or two following an ERCP.
The longevity of the stent depends heavily on the material used, necessitating routine monitoring. Plastic stents have a limited lifespan and must be exchanged or removed periodically, usually every three to six months, to prevent clogging. Metallic stents are designed to last much longer but still require regular check-ups and imaging to confirm they remain open.
Patients must be aware of signs that a stent may be failing, as a blocked stent can lead to a serious infection. Recurrence of jaundice indicates stent failure. Other urgent symptoms include fever and chills, which signal a severe bile duct infection, severe abdominal pain, dark urine, or pale stools. Any of these signs require immediate medical attention to determine if the stent needs urgent revision or replacement.