Elsevier

Clinics in Chest Medicine

Volume 34, Issue 3, September 2013, Pages 437-444
Clinics in Chest Medicine

Bronchial Thermoplasty: A Novel Therapy for Severe Asthma

https://doi.org/10.1016/j.ccm.2013.03.003Get rights and content

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Key points

  • Traditional asthma controller medications are often unsuccessful in controlling the symptoms of patients with severe asthma.

  • Bronchial thermoplasty presents a novel therapy in which radiofrequency energy is used to decrease bronchoconstriction by a reduction in airway smooth muscle.

  • Current clinical evidence suggests that bronchial thermoplasty may be effective in reducing asthma exacerbations and improving asthma symptoms.

  • Long-term data suggest that bronchial thermoplasty is safe and a disease

Airway smooth muscle in asthma

The smooth muscle within the walls of airways, or airway smooth muscle (ASM), has been postulated to play a role in multiple normal processes in the healthy airway, including regulation of bronchomotor tone, immunomodulation, and extracellular matrix deposition, although some also claim that it is a vestigial structure without a real salutary function.9 However, ASM mass is considerably increased in asthma when compared with healthy controls and these same processes contribute to the chronic

The Alair bronchial thermoplasty system

The Alair Bronchial Thermoplasty System comprises the Alair Controller System (Fig. 1), which includes the RF controller, a footswitch, and a return electrode, and the Alair catheter (Fig. 2), which contains an expandable 4-arm array and a handle with depressible actuator. The flexible catheter is 1.5 mm in diameter, sterile, disposable, and designed to be introduced in the working channel of a bronchoscope (ideally 4.9–5.2 mm outer diameter) with a working channel of at least 2.0 mm. Larger

Preprocedure assessment

The Food and Drug Administration has approved the Alair Bronchial Thermoplasty System for the treatment of severe persistent asthma in patients 18 years and older (Alair package insert). Selection criteria are outlined in Box 1 and are adapted from inclusion and exclusion criteria from the Asthma Intervention Research 2 (AIR2) trial, discussed later.19 A thorough clinical assessment of the patient is imperative before performing BT. To perform BT safely, any potential patient must have stable

Performing bronchial thermoplasty

BT should be performed by an experienced bronchoscopist in conjunction with an asthma specialist. Airways are treated in 3 separate sessions, each 3 weeks apart: the right lower lobe is treated in the first session, the left lower lobe in the second session, and both upper lobes in the final session. The right middle lobe is not treated because of concerns of airway collapse secondary to right middle lobe syndrome.20 In each session, the airway tree is carefully visualized, and the

Postprocedure assessment

After the BT procedure is complete, the patient should be monitored as per normal institutional postbronchoscopy guidelines. Patients may take longer to recover because of the greater amount of sedation typically required for BT, again due to the fact that BT often takes longer than typical bronchoscopy. Lung sounds should be auscultated immediately after the procedure and again before discharge. After patients recover from sedation, post-BT spirometry measurements are performed. Patients must

Clinical evidence for bronchial thermoplasty

The first trial of BT in humans was performed to determine the safety of the procedure in 8 subjects who were scheduled to undergo lung resection for suspected or proven lung cancer.21 All subjects tolerated the therapy well and proceeded to their planned surgery. One subject showed signs of airway narrowing but was asymptomatic. When the Alair system was used to apply a temperature of 65°C to the airways, a notable reduction in ASM was observed on histopathologic specimens. Subsequently, Cox

Summary

Bronchial thermoplasty is a novel treatment option for patients 18 years of age and older with severe asthma for whom management with conventional pharmacotherapy has been ineffective in controlling asthma symptoms. The procedure should be performed by an experienced bronchoscopist in conjunction with an asthma specialist. Clinical studies have shown improved asthma symptoms, fewer severe exacerbations, and decreased health care use with bronchial thermoplasty. Clinical experience has shown

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    Disclosures: A. Sheshadri has no professional or financial interests to disclose. A. Chen has lectured for Asthmatx/Boston Scientific. M. Castro served as consultant or on the advisory board for Genentech, IPS, Medimmune, NKT Therapeutics, and Schering. He lectured for Asthmax/Boston Scientific, Boehringer Ingelheim, Genentech, GSK, Merck, and Pfizer. His University received industry-sponsored grants from Amgen, Asthmatx/Boston Scientific, Ception/Cephalon, Genentech, GSK, Kalbios, MedImmune, Merck, Novartis, and Sanofi-Aventis. His University received grant monies from the NIH and the ALA and received royalties from Elsevier.

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