2 The procedure
2.1.1 Subglottic or tracheal stenosis is most often caused by prolonged endotracheal intubation, but it may also result from other types of trauma. In some patients it is congenital. Symptoms include hoarseness, stridor, exercise intolerance and respiratory distress. In severe cases the airway may be completely obstructed, requiring continued intubation or tracheostomy. This guidance only refers to benign strictures excluding those caused by malignancy.
2.1.2 Treatments for subglottic or tracheal stenosis include inhaled or oral steroids to reduce inflammation and swelling. Severe stenosis may be treated endoscopically, by stent insertion or laser ablation, or by open surgery (stenting, grafting or resection of the stenosed segment).
2.2.1 Endoscopic balloon dilatation aims to dilate the narrowed airway with minimal mucosal trauma.
2.2.2 The procedure is usually done with the patient under general anaesthesia and using direct laryngoscopic or bronchoscopic visualisation. A balloon catheter is introduced into the airway and the balloon is gently inflated, applying radial pressure circumferentially to the stricture. After dilatation, the balloon is deflated and the device withdrawn. The procedure may be used in combination with other measures and techniques (described in section 2.1.2). The procedure can be repeated if required.
Sections 2.3 and 2.4 describe efficacy and safety outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the overview.
2.3.1 A case series of 10 infants with acquired subglottic stenosis reported that 70% (7/10) had resolution of symptoms after the first or second balloon dilatation. A second case series of 10 children with subglottic or tracheal stenosis reported that symptoms were resolved or improved in 70% (7/10) at mean follow‑up of 10 months.
2.3.2 A case series of 35 patients, which included 11 patients with tracheal stenosis after prolonged mechanical ventilation, reported that all patients had initial symptom relief. Insertion of a stent within 30 days of balloon dilatation was needed in 36% (4/11) of patients (details not provided).
2.3.3 The Specialist Advisers listed key efficacy outcomes as avoidance of need for tracheostomy or surgery to the airway, improvements in lung function tests and exercise tolerance, reduction in stridor and shortness of breath and voice, and anatomical improvements on endoscopy or radiological imaging.
2.4.1 A case series of 37 patients reported 1 death thought to be related to balloon dilatation. This was a patient with severe stenosis at the carina who developed a bronchial leak following their fourth weekly dilatation. The leak was repaired, but the patient died as a result of respiratory insufficiency (no further details).
2.4.2 A case report described a patient who had a transmural tracheobronchial disruption after a second balloon dilatation procedure for tracheal stenosis. The injury was repaired by open surgery and the patient recovered.
2.4.3 A case series of 97 patients reported tracheobronchial lacerations in 52% (64/124) of procedures but all resolved spontaneously.
2.4.4 Two case series, each including 10 infants or children with subglottic or tracheal stenosis, reported that there were no complications.
2.4.5 The Specialist Advisers listed reported adverse events as airway obstruction, vocal cord avulsion, bleeding and tracheobronchial tears. They listed theoretical safety concerns as ruptured trachea or bronchi, arytenoid dislocation, pneumothorax, aspirated balloon fragments (which could cause airway obstruction) and tracheobronchomalacia.
2.5.1 The Committee noted that the published evidence was related to a variety of different techniques, some of which are no longer used. There was very little evidence on balloon devices in use at the time this guidance was produced.
Information for patients
NICE has produced information on this procedure for patients and carers. It explains the nature of the procedure and the guidance issued by NICE, and has been written with patient consent in mind.