The Alair bronchial thermoplasty system is designed to reduce the amount of smooth muscle in the airway walls, with the aim of improving symptoms in people with severe, difficult to control asthma. Evidence from 3 systematic reviews (reporting on 3 randomised controlled trials of mixed quality) suggests that use of the Alair system is associated with some patient benefits (such as improved quality of life, and morning peak expiratory flow), but not all benefits were considered to be clinically significant. There is mixed evidence in relation to other outcomes (including asthma exacerbations, hospitalisations and emergency department visits).

The procedure must be done 3 times, once every 3 weeks. The device cost for 3 procedures is up to £6,930 (for 3 single‑use catheters), with a capital cost of up to £31,500 for the radiofrequency controller. Additional costs include more detailed pre‑bronchoscopy assessments, increased patient monitoring and treating short‑term adverse events.

Product summary and likely place in therapy

  • The Alair system uses radiofrequency energy (delivered during bronchoscopy procedures) to reduce the amount of smooth muscle in the airway walls. Excessive smooth muscle mass can contract causing breathlessness during asthma attacks.

  • It is intended for use in adults with severe difficult to control asthma, despite optimal therapy at step 4/5 of the British Thoracic Society/Scottish Intercollegiate Guidelines Network guidelines, as an add‑on to standard therapy.

  • NICE interventional procedures guidance on bronchial thermoplasty for severe asthma recommends submitting details of all patients having the procedure to the 'difficult asthma' registry because more evidence is needed on long‑term safety.

Effectiveness and safety

  • The evidence in this briefing is taken from 3 systematic reviews, 2 of which have been published since the development of NICE interventional procedures guidance bronchial thermoplasty for severe asthma in January 2012. The systematic reviews reported on results from 3 randomised controlled trials (N=112, 34 and 288), all 3 of which were available when the NICE guidance was developed.

  • Pooled results from the 3 trials (N=429) showed patient benefits associated with using bronchial thermoplasty, such as improved quality of life and morning peak expiratory flow, but there is uncertainty about the clinical significance of the benefits.

  • Pooled results also showed that the risk of hospitalisation for adverse events increased in the first 6 weeks after treatment but not from 6 weeks to 1 year. There was no statistically significant differences in use of rescue medication or asthma control at 1 year.

  • Pooled results from the 3 trials (N=216) found that people having bronchial thermoplasty experienced had no significant decline in pre‑ or post‑bronchodilator FEV1 over 5 years. The number of ER visits for adverse respiratory events remained unchanged and there was no significant increase in the incidence of hospitalisation for respiratory adverse events.

Technical and patient factors

  • The Alair system consists of a sterile, single‑use catheter and a reusable radiofrequency controller. The catheter is positioned using a bronchoscope. The catheter includes an expandable electrode array which delivers controlled thermal energy from the radiofrequency source to a patient's airways.

  • Bronchial thermoplasty is delivered in 3 separate procedures, a minimum of 3 weeks apart, to different sections of the lungs. Each session takes between 45 and 60 minutes to complete and typically involves 40 device activations.

  • The Alair system is the only bronchial thermoplasty system currently available and is indicated for patients aged 18 years and older. The system should be used by respiratory clinicians familiar with bronchoscopy procedures and trained in its use.

Cost and resource use

  • The cost of 3 procedures, each requiring a single‑use catheter at £2,310 and a patient return electrode at £4.04, is £6,942.12. There is also a capital cost for the reusable radiofrequency controller of up to £31,500. Assuming a 10‑year life for the controller, the associated cost per patient ranges from £157.50 to £315.00, giving a total cost per patient of £7,099.62 to £7,257.12.

  • In addition to the device costs, patients having bronchial thermoplasty with the Alair system need 3 complex bronchoscopies, follow‑up monitoring at a tertiary centre, and treatment of adverse events, if any.