How long does a bronchial stent last?

There is no single answer for how long a bronchial stent lasts, as it depends on several factors:

- Type of stent - Self-expanding metallic stents generally last longer than silicon or hybrid stents. Metallic stents may last over 1 year on average.

- Location - Stents placed in larger central airways tend to remain patent and functional longer than those placed in smaller peripheral airways. Central airways experience less compression.

- Underlying condition - Stents placed for malignant conditions like lung cancer may obstruct sooner than those placed for benign conditions like post-intubation tracheal stenosis. Tumor overgrowth can obstruct the stent. 

- Diameter of stent - Larger diameter stents tend to stay open longer than narrower stents in the same location.

- Patient factors - Things like continued tobacco use can lead to faster tissue ingrowth and stent obstruction. 

Overall, bronchial stents can remain functional from weeks to years. For self-expanding metallic stents in central large airways, median patency ranges from 4-12 months on average before needing replacement. However regular monitoring is important as stents may require earlier exchange if obstructed. Discussion with the interventional pulmonologist who placed the stent can provide more specifics on the expected duration.