A pancreatic stent is a slender, hollow tube placed within the pancreatic ductal system. This medical device helps maintain the openness of a duct, facilitates the drainage of pancreatic fluids, or bypasses an obstruction. Its purpose is to restore proper flow, alleviating symptoms and preventing complications.
What is a Pancreatic Stent?
A pancreatic stent is a small, flexible tube inserted into the pancreatic duct. Stents are made from plastic (e.g., polyethylene, polyurethane, Teflon) or metal. Plastic stents vary in size (2-25 cm long, 3-11.5 Fr diameter). They can be straight, curved, or have a single pigtail shape. Many include side holes to promote drainage from smaller side ducts.
Stents keep the pancreatic duct open, allowing fluids to flow freely. Some have internal flanges or pigtail designs to prevent movement. Choice of stent type and design depends on the patient’s condition and anticipated duration.
Why a Pancreatic Stent is Needed
Pancreatic stents address conditions that obstruct or impair pancreatic fluid flow. Common reasons include pancreatic duct strictures, narrowings often caused by chronic pancreatitis. Stents widen strictures, restoring flow and alleviating pain.
Pancreatic stones can block ducts; stents bypass obstructions or facilitate stone removal. In chronic pancreatitis, inflammation and scarring cause blockages. Stents improve drainage, reduce intraductal pressure, manage pain, and prevent complications. Stents may also seal pancreatic duct disruptions or drain fluid collections like pseudocysts.
For pancreatic cancer patients, stents relieve bile duct or duodenal obstruction caused by tumors. This alleviates symptoms like jaundice and improves quality of life, especially for palliative care or when surgery is not an immediate option. Stents are also used prophylactically to prevent post-ERCP pancreatitis, a common complication after certain endoscopic procedures.
The Stent Placement Procedure and Recovery
Pancreatic stents are most commonly placed via Endoscopic Retrograde Cholangiopancreatography (ERCP). During ERCP, a flexible endoscope (a tube with a camera and light) is guided through the mouth, throat, stomach, and into the small intestine. The endoscope reaches the ampulla of Vater, where bile and pancreatic ducts drain into the duodenum.
Once located, a thin catheter and guidewire are advanced into the pancreatic duct, often with X-ray imaging and contrast dye to visualize the system. If a stricture is present, a balloon may widen the duct before the stent is guided into place over the wire. The procedure takes 30 to 90 minutes.
After stent placement, patients are monitored in a recovery area for 1 to 2 hours as the sedative wears off. Common immediate sensations include a sore throat for a day or two and mild abdominal discomfort or bloating, which subside within a few hours. Patients are advised to rest for 1 to 2 days before gradually returning to usual activities.
Potential Issues and What to Expect
While pancreatic stent placement is generally safe, potential issues can arise. One concern is stent migration, where the stent moves from its intended position. Distal migration, where the stent moves into the duodenum, is more common, while proximal migration into the pancreatic duct can lead to complications such as obstructive pancreatitis.
Another issue is stent occlusion, or blockage, which can occur due to the buildup of pancreatic fluid components or tissue overgrowth. A blocked stent can cause symptoms similar to the original obstruction, including pain, and may lead to infection, such as pancreatitis or cholangitis. Signs of infection, such as fever, chills, or returning jaundice, warrant immediate medical attention.
Discomfort in the upper abdomen can also occur after stent placement. If any of these symptoms develop or worsen, or if there is severe abdominal pain, nausea, or vomiting, promptly contact a medical team. These issues are managed by re-intervention to remove or replace the stent, or with medications like antibiotics for infections.
When and How Stents Are Removed
Pancreatic stents are often temporary and require either removal or exchange after a certain period. The typical duration a plastic stent can remain in place varies, but they are often replaced or removed every 3 to 6 months to prevent complications like blockage or infection. Some treatment plans involve exchanging plastic stents every 3 to 4 months for up to a year. Metal stents generally have a longer patency, often remaining effective for 8 to 12 months.
The removal process is usually similar to the placement procedure, performed via ERCP. An endoscope is guided to the stent, and specialized tools are used to grasp and withdraw it. In some cases, stents without internal flanges are designed for spontaneous migration, meaning they pass naturally out of the body, often within two weeks. Regular follow-up, including imaging, helps determine the appropriate time for removal or exchange.