How to: Bronchial thermoplasty in asthma

Abstract

• Bronchial thermoplasty, which involves the delivery of radio frequency energy to the airways, is a nonpharmacological intervention developed for the treatment of patients with moderate-to-severe asthma that is poorly controlled despite maximal therapy• Randomised controlled clinical trials of bronchial thermoplasty in patients with moderate and severe asthma have shown modest improvements in asthma quality of life and clinically worthwhile reductions in severe exacerbations and emergency department visits• The treatment involves three bronchoscopy sessions with repeated, precise and carefully recorded activations of a radiofrequency catheter within the medium and large airways• Bronchial thermoplasty causes short-term increases in asthma-related morbidity including increased admissions to hospital for asthma; follow-up data, to date, supports the longterm safety of the procedureHow to: Bronchial thermoplasty in asthma Educational aims N To provide an overview on how to perform bronchial thermoplasty for the treatment of asthma N To summarise the development, mode of action and evidence for the effectiveness of bronchial thermoplasty as well as its place in the management of asthma SummaryBronchial thermoplasty, which involves the delivery of radio frequency energy to the airways, is a nonpharmacological intervention developed for the treatment of moderate-to-severe asthma. The mode of action of bronchial thermoplasty is not established, but could be due to reduction in airway smooth muscle mass induced by thermal energy. Bronchial thermoplasty results in modest improvements in asthma quality of life questionnaire scores and clinically worthwhile reductions in severe exacerbations and emergency department visits in the year post-treatment, which may persist for up to 5 years.The procedure involves systematic, controlled heating of the airways using dedicated radiofrequency equipment during a series of three bronchoscopy sessions. Bronchial thermoplasty causes short-term increases in asthma-related morbidity, including hospital admissions. Follow-up data, to date, supports the long-term safety of the procedure. Bronchial thermoplasty is a novel treatment option for selected patients with moderate-to-severe asthma that is poorly controlled despite maximal therapy.

Personalised medicine in asthma: from curative to preventive medicine

“…After 1 year of follow-up, a significant improvement in the Asthma Quality of Life Questionnaire score and a reduction in the rate of hospitalisations for asthma were observed in the thermoplasty group compared with the placebo group. In this trial, as in other, smaller studies, no improvement in lung function was observed [100]. In these studies, all the patients had a baseline FEV1 greater than or equal to 60% of the predicted value.…”

“…Three divided sessions are required to treat all the bronchi >3 mm in diameter, avoiding the middle lobe. The mechanism of action has been partially elucidated in animal and human studies, with demonstration of a reduction in airway smooth muscle mass [100,101].…”

Effectiveness of bronchial thermoplasty in severe asthma in ‘real life’ patients compared with those recruited to clinical trials in the same centre

“…Details are described elsewhere [Bicknell et al 2014]. There are currently no data on factors that predict a good response to BT.…”

Patient-specific targeted bronchial thermoplasty: predictions of improved outcomes with structure-guided treatment

“…The model examines a single human lung for reasons of computational complexity, choosing the left lung to avoid complicating effects of the untreated right middle lobe (3). In this study, we compare our patient specific methods (further described below) to current clinical practice (CCP) treatment across three full bronchial thermoplasty sessions.…”

“…However, BT is not successful in all patients. Current clinical practice involves the treatment of a standard set of airways at specific anatomic locations applied across three separate bronchoscopy procedures at one month intervals (3). This approach is essentially performed "blind" in that the choice of which airways to treat is not driven by structural or functional data to detect optimal treatment sites.…”