How long does a biliary stent stay in?

Here are some typical timelines for how long a biliary stent stays in place:

- Plastic biliary stents are usually temporary and may stay in for 3-6 months. They provide short-term relief of a bile duct blockage while waiting for a more definitive treatment.

- Metal biliary stents (also called expandable metal stents) are designed to stay in longer - often 6-12 months. Metal stents provide more durable relief of bile duct obstructions compared to plastic stents.

- Covered self-expanding metal stents may remain in place for 6-12 months on average. The covering helps prevent tissue ingrowth which can obstruct the stent.

- Uncovered self-expanding metal stents are considered permanent implants. They may stay in indefinitely unless complications arise that require removal or replacement.

- The exact time a stent remains in place depends on several factors like the type of stent, the reason it was placed, any complications that develop, and the doctor's recommendation.

- Stents may need to be changed periodically if they become clogged or migrate out of position. Plastic stents in particular may need replacement every 3-6 months.

- Any stents remaining in place for more than 12 months should be evaluated periodically to check positioning and patency. Removal or exchange may be recommended if issues arise. 

So in summary, while some stents are temporary, metal biliary stents often remain in place for 6-12 months or longer based on the clinical situation. The doctor will determine the appropriate lifespan for an individual stent.