What are the complications of tracheal stents?

Some potential complications that can occur with tracheal stents include:

- Migration - the stent can shift from its original placement, either moving up or down the trachea. This can obstruct breathing.

- Mucus plugging - mucus and secretions can build up inside the stent, blocking airflow. This requires active cleaning.

- Granulation tissue - tissue can grow through the stent openings, narrowing the inner diameter. Lasers or cautery can be needed to ablate it.

- Infection - bacteria can colonize the stent surface and lead to recurrent respiratory infections. May require antibiotics or antimicrobial-coated stents. 

- Stent fracture - metal and hybrid stents may fatigue and fracture over time. Fragments can detach and be aspirated.

- Erosion - pressure from the stent can cause ulceration in the tracheal wall long-term. This can cause bleeding.

- Perforation - very rare, but stents can wear through the tracheal wall, causing dangerous leakage of air into tissues.

- Swallowing issues - stents crossing the larynx can impair swallowing and cause aspiration issues.

- Vocal changes - stents can alter the vibration of the vocal cords, causing hoarseness.

Careful sizing, monitoring, and patient education on signs of complications are important to minimize risk when stents are placed. Most stent-related complications require repeat bronchoscopic procedures to resolve.