Windpipe can sometimes become narrow due to various causes. These include presence of a tube in the wind pipe (endotracheal tube) in patients who have been on ventilator for long, creation of an artificial opening in the wind pipe (tracheostomy) or presence of tumours in the wind pipe. In such cases, the narrowed area is dilated using specialised balloons, inserted through bronchoscope. This procedure widens the narrowed area. Many a times, the area narrows again and the procedure needs to be repeated several times on a regular basis. If the narrowing is occurring too frequently, a stent (a specialised silastic or metal mesh tube) is positioned at the diseased area to keep it open. It can be left there for many months. After its removal, many a times, the diseased area remains open. In case it narrows again, patients are usually referred for surgery.