What is the typical lifespan of a self-expanding biliary stent before it needs replacement?

The lifespan of a self-expanding biliary stent depends on several factors, including stent type, underlying condition, and risk of complications.

1. Uncovered Self-Expanding Metal Stents (SEMS)

• Typically permanent and designed for long-term patency, especially in malignant biliary obstructions.

• Can last 6–12 months or longer, with some remaining functional for years if no occlusion occurs.

• Risk of tumor ingrowth or sludge accumulation may eventually lead to occlusion, requiring intervention.

2. Covered Self-Expanding Metal Stents

• Designed to prevent tumor ingrowth and benign stricture recurrence, but with a higher risk of migration.

• Typically last 3–6 months before removal or exchange, especially in benign strictures.

• In malignant cases, they can last 6–12 months, but occlusion may occur due to sludge buildup or overgrowth at the ends.

3. Factors That Can Shorten Stent Lifespan

• Tumor Growth – Can lead to ingrowth (uncovered stents) or overgrowth (covered stents), causing obstruction.

• Sludge and Biofilm Formation – Biliary debris, infection, or bile stasis can lead to clogging.

• Stent Migration – More common in covered stents, requiring repositioning or replacement.

• Biliary Infections (Cholangitis) – Can accelerate blockage and necessitate early stent exchange.

4. When Is Replacement Needed?

• If symptoms return (jaundice, dark urine, pale stools, pruritus).

• If imaging (ERCP, ultrasound, MRCP) shows obstruction.

• For covered stents used in benign strictures, removal is often planned at 3–6 months to prevent embedding.

Summary

• Malignant cases: 6–12 months (sometimes longer for uncovered stents).

• Benign strictures: 3–6 months, with planned removal or replacement.

• Monitoring required to detect occlusion early and replace if needed.