Stenosis of the central airway leads to dyspnea and asphyxia, which are highly likely to be life-threatening. The treatment is often provided as a lifesaving emergency measure.
The most common malignant cause is tracheal or bronchial stenosis due to advanced lung cancer, followed by esophageal cancer, esophagotracheal fistula, thyroid cancer, mediastinal-type malignant lymphoma, metastasis to the airway (renal, breast, melanoma, hepatic, etc.), and low-grade tumors of the central airway.
Benign diseases include post-tracheostomy stenosis, idiopathic subglottic stenosis, tracheobronchial tuberculosis, primary tracheal tumors, GPA (Wegener's granulomatosis), and tracheobronchomalacia.
Stenting should be performed under general anesthesia using a rigid bronchoscopy as much as possible. Central airway procedure is hazardous to the patient.
We can use three types of airway stents: silicone stents, self-expandable metallic stents (SEMS), and fully-covered hybrid stents.
Silicon stents are available in many lengths, shapes, and sizes, and the length can be adjusted by cutting or combining multiple stents to suit individual cases.
SEMS have been widely used because they can be inserted under local anesthesia. By FDA recommendations, it is not usually used for benign diseases.
The hybrid stent is a self-expandable metallic stent made of laser-cut Nitinol tubing, fully covered with polyurethane.
For tailor-made stents, human studies using 3-D printers to fabricate silicone stents, 4-D printing technology to deform to the airway over time, drug-permeable stents, and biodegradable stents that can be absorbed by the body are on developing.