Bronchial thermoplasty for severe asthma - Consultation Document
Interventional procedure consultation document
Bronchial thermoplasty for severe asthma
Treating severe asthma using radiofrequency (heat) energy
Asthma is a condition that causes the airways to become narrower; the lining of the airways also becomes inflamed and starts to swell. Bronchial thermoplasty involves applying thermal energy to the airway wall. The aim is to reduce the amount of excessive muscle in the airway and limit its ability to contract and narrow the airway in patients with severe asthma.
The National Institute for Health and Clinical Excellence (NICE) is examining bronchial thermoplasty for severe asthma and will publish guidance on its safety and efficacy to the NHS in England, Wales, Scotland and Northern Ireland. NICE’s Interventional Procedures Advisory Committee has considered the available evidence and the views of Specialist Advisers, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about bronchial thermoplasty for severe asthma.
This document summarises the procedure and sets out the provisional recommendations made by the Advisory Committee. It has been prepared for public consultation. The Advisory Committee particularly welcomes:
- comments on the provisional recommendations
- the identification of factual inaccuracies
- additional relevant evidence, with bibliographic references where possible.
Note that this document is not NICE’s formal guidance on this procedure. The recommendations are provisional and may change after consultation.
The process that NICE will follow after the consultation period ends is as follows.
- The Advisory Committee will meet again to consider the original evidence and its provisional recommendations in the light of the comments received during consultation.
- The Advisory Committee will then prepare draft guidance which will be the basis for NICE’s guidance on the use of the procedure in the NHS in England, Wales, Scotland and Northern Ireland.
For further details, see the Interventional Procedures Programme manual, which is available from the NICE website (www.nice.org.uk/ipprogrammemanual).
Through its guidance NICE is committed to promoting race and disability equality, equality between men and women, and to eliminating all forms of discrimination. One of the ways we do this is by trying to involve as wide a range of people and interest groups as possible in the development of our interventional procedures guidance. In particular, we aim to encourage people and organisations from groups who might not normally comment on our guidance to do so.
In order to help us promote equality through our guidance, we should be grateful if you would consider the following question:
Are there any issues that require special attention in light of NICE’s duties to have due regard to the need to eliminate unlawful discrimination and promote equality and foster good relations between people with a characteristic protected by the equalities legislation and others?
Please note that NICE reserves the right to summarise and edit comments received during consultations or not to publish them at all where in the reasonable opinion of NICE, the comments are voluminous, publication would be unlawful or publication would otherwise be inappropriate.
Closing date for comments: 19 August 2011
Target date for publication of guidance: November 2011
1 Provisional recommendations
1.1 Evidence on the safety of bronchial thermoplasty is adequate in the short and medium term, although patients may experience exacerbation of symptoms after the procedure. More evidence is required on the safety of the procedure in the long term. With regard to efficacy, there is some evidence of improvement in symptoms and quality of life but objective evidence of improved lung function is inadequate. Therefore, this procedure should only be used with special arrangements for clinical governance, consent and audit or research.
1.2 Clinicians wishing to undertake bronchial thermoplasty for severe asthma should take the following actions.
- Inform the clinical governance leads in their Trusts.
- Ensure that patients understand the uncertainty about the procedure’s efficacy and long-term safety, and the possibility of initial worsening of their symptoms, and provide them with clear written information. In addition, the use of NICE’s information for patients (‘Understanding NICE guidance’) is recommended (available from www.nice.org.uk/IPGXXXpublicinfo). [[details to be completed at publication]]
- Audit and review clinical outcomes of all patients having bronchial thermoplasty for severe asthma (see section 3.1).
1.3 Patient selection should be carried out by a respiratory team experienced in managing severe asthma.
1.4 NICE encourages further research into bronchial thermoplasty for severe asthma. Research outcomes should include objective measurements of lung function, symptom control, medication requirements and quality of life. Long-term safety and efficacy outcomes are particularly important. Collaboration between units to publish data on patients not involved in research studies would also be valuable.
2 The procedure
2.1 Indications and current treatments
2.1.1 Asthma is a chronic disorder of the airways, characterised by increased responsiveness to various allergic stimuli and airflow obstruction. Symptoms include recurring episodes of wheezing, breathlessness, chest tightness and coughing.
2.1.2 In the UK, the management of asthma is currently based on a stepwise approach to treatment in both adults and children, ranging from inhaled therapy for mild intermittent asthma to continuous or frequent courses of oral corticosteroids.
2.2 Outline of the procedure
2.2.1 The aim of bronchial thermoplasty for severe asthma is to reduce airway smooth muscle mass, thereby decreasing the ability of the airways to constrict, reducing both the severity of asthma symptoms and daily medication requirements.
2.2.2 Bronchial thermoplasty is usually performed with the patient under moderate sedation or light anaesthesia. A specially designed catheter is passed through a bronchoscope and introduced into the bronchial tree. Short pulses of radiofrequency energy are applied to sequential portions of the airway wall, moving from distal to proximal at 5mm intervals. This process is repeated in all lobes of the lungs except the middle lobe, treating airways from 3 mm and stopping at the main bronchi. Treatment is usually delivered in 3 sessions with an interval of at least 3 weeks between each session. After the first treatment session, previously treated airways are evaluated by bronchoscopy before proceeding with further treatment.
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, available at http://www.nice.org.uk/guidance/IP/675/overview
2.3.1 A randomised controlled trial (RCT) of 288 patients treated by bronchial thermoplasty or sham reported a mean improvement in Asthma Quality of Life Questionnaire (AQLQ) score (on a scale from 1 to 7; higher score indicates better quality of life) of 1.35 and 1.16 respectively at 12-month follow-up (posterior probability of superiority [PPS] = 0.960).
2.3.2 An RCT of 109 patients treated by bronchial thermoplasty or medical management alone reported an improvement in AQLQ score of 1.3 and 0.6 respectively at 1-year follow-up (p = 0.003).
2.3.3 The RCT of 109 patients treated by bronchial thermoplasty or medical management alone reported an improvement in mean morning peak expiratory flow of 39.3 and 8.5 litres/minute respectively at 1-year follow-up (p = 0.003) and a reduction in short-acting beta‑2 agonist use of 26 puffs per 7 days in the bronchial thermoplasty group versus 6 puffs per 7 days in the control group (p < 0.05).
2.3.4 The RCT of 288 patients treated by bronchial thermoplasty or sham reported 0.48 and 0.70 severe exacerbations per patient per year respectively, during the post-treatment period (weeks 6–52; PPS = 0.995).
2.3.5 The Specialist Advisers listed key efficacy outcomes as improved lung function, reduction in hospital admissions and days lost from work or school due to asthma symptoms.
2.4.1 The RCT of 288 patients treated by bronchial thermoplasty or sham reported that 8% (16/190) and 2% (2/98) of patients respectively were admitted to hospital for respiratory symptoms during the treatment period (weeks 0–6). Admissions in the bronchial thermoplasty group were for worsening of asthma (n = 10), segmental atelectasis (n = 2), lower respiratory tract infection (n = 1), low forced expiratory volume in 1 second (FEV1) (n = 1), haemoptysis (n =1) and 1 aspirated prosthetic tooth; most events resolved with conservative management but the haemoptysis required bronchial artery embolisation.
2.4.2 The RCT of 109 patients treated by bronchial thermoplasty or medical management alone reported that 7% (4/55) and 4% (2/54) of patients respectively, were admitted to hospital during the treatment period. There were 6 admissions in the bronchial thermoplasty group: 4 exacerbations of asthma, 1 partially collapsed lower lung and 1 report of pleurisy.
2.4.3 The Specialist Advisers considered bronchial stenosis to be a possible complication in the long term.
2.5 Other comments
2.5.1 The Committee noted the poor quality of life often associated with severe asthma, and the fact that multiple medications are often needed. Bronchial thermoplasty has the potential to offer substantial improvements in quality of life.
3 Further information
3.1 This guidance requires that clinicians undertaking the procedure make special arrangements for audit. NICE has identified relevant audit criteria and is developing an audit tool (which is for use at local discretion), which will be available when the guidance is published.
3.2 For related NICE guidance see www.nice.org.uk
Chairman, Interventional Procedures Advisory Committee
Personal data will not be posted on the NICE website. In accordance with the Data Protection Act names will be anonymised, other than in circumstances where explicit permission has been given.
It is the responsibility of consultees to accurately cite academic work in order that they can be validated.
This page was last updated: 19 August 2011