Bronchial thermoplasty

Summary

Bronchial thermoplasty[1] is a treatment for severe asthma approved by the FDA in 2010 involving the delivery of controlled, therapeutic radiofrequency energy to the airway wall, thus heating the tissue and reducing the amount of smooth muscle present in the airway wall. This reduces the capacity of the immune system to cause bronchoconstriction through nitric oxide signalling, which is the main root cause of asthma symptoms.[2] Bronchial thermoplasty is normally used to treat patients with severe persistent asthma who do not respond well to typical pharmacotherapy regimens.[3]

Bronchial thermoplasty
Specialtypulmonology
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Procedure edit

Animation of bronchial thermoplasty catheter use

A full course of bronchial thermoplasty treatment[4] includes three separate bronchoscopic procedures: one for the each lower lobe of the lung and another for both upper lobes. Each outpatient procedure is performed approximately three weeks apart.

Under sedation, a catheter inside a bronchoscope—a thin, flexible tube-like instrument introduced through the patient’s nose or mouth and into their lungs—delivers thermal energy into the airways. The patient is monitored after the procedure and usually returns home the day of the procedure or early the following day. The catheter delivers a series of 10-second temperature controlled bursts of radio frequency energy which heat the lining of the lungs to 65 degrees Celsius. It is this heat that destroys some of the muscle tissue which constricts during an asthma attack, reducing the number and severity of exacerbations.

Through a standard bronchoscopy procedure, a small flexible tube is advanced into the airway, via mouth or nose, to mildly heat the airway walls. This treatment has been shown to result in acute epithelial destruction with regeneration observed in the epithelium, blood vessels, mucosa and nerves; however, airway smooth muscle has demonstrated almost no capacity for regeneration, and it is instead replaced with connective tissue. The treatment has been shown in prospective studies to be safe and effective with duration up to five years.[5] Bronchial thermoplasty is indicated for the treatment of severe persistent asthma in patients 18 years and older whose asthma is not well controlled with inhaled corticosteroids and long acting beta agonists as per GINA guidelines.

Benefits edit

In a double-blind, randomized, sham-controlled clinical study of bronchial thermoplasty,[6] adults with severe asthma treated with bronchial thermoplasty had improved asthma-related quality of life out to a year compared to the control (sham-treated) patients. Additionally, when compared to control patients, patients treated with bronchial thermoplasty also experienced the following benefits, although none reached statistical significance:

  • 32% reduction in asthma attacks
  • 84% reduction in emergency room visits for respiratory symptoms
  • 66% reduction in days lost from work, school, or other daily activities due to asthma symptoms
  • 73% reduction in hospitalizations for respiratory symptoms

In a clinical study, bronchial thermoplasty has been proven to provide long-term reduction in asthma induced breathing difficulty to at least 5 years and improve the quality of life for severe persistent asthma patients.[7] Reduction in asthma attacks, ER visits, and hospitalizations for respiratory symptoms are maintained to at least 5 years.[8] These benefits were observed during clinical studies where patients continued to take their standard maintenance asthma medications which included combinations of inhaled corticosteroids and long-acting bronchodilators.

Risks edit

In the period immediately following the bronchial thermoplasty procedure, there was an expected transient increase in the frequency and worsening of respiratory-related symptoms. Bronchial thermoplasty is not appropriate for patients who:[9]

  • Are under 18 years old
  • Have a pacemaker, internal defibrillator, or other implantable electronic device
  • Have a known sensitivity to medications required to perform bronchoscopy, including lidocaine, atropine and benzodiazepines
  • Have previously been treated with bronchial thermoplasty

Bronchial thermoplasty is irreversible; the smooth muscle tissue which is destroyed cannot be recovered.

Procedure Availability edit

Bronchial thermoplasty was first approved by FDA in April 2010.[10] Bronchial thermoplasty is now being used as a treatment in many countries which include United Kingdom,[11] India,[12] and United States.

References edit

  1. ^ "Bronchial Thermoplasty – Pulmonology". www.bostonscientific.com.
  2. ^ Cox G, Miller JD, McWilliams A, Fitzgerald JM, Lam S (May 2006). "Bronchial thermoplasty for asthma". American Journal of Respiratory and Critical Care Medicine. 173 (9): 965–9. doi:10.1164/rccm.200507-1162OC. PMID 16456145.
  3. ^ "Global Strategy for Asthma Management and Prevention". Global Initiative for Asthma: 48. 2018. Retrieved 2018-05-21.
  4. ^ Mayse ML, Laviolette M, Rubin AS, Lampron N, Simoff M, Duhamel D, et al. (April 2007). "Clinical Pearls for Bronchial Thermoplasty". Journal of Bronchology. 14 (2): 115–123. doi:10.1097/LBR.0b013e318054dbed. S2CID 56733680.
  5. ^ Thomson NC, Rubin AS, Niven RM, Corris PA, Siersted HC, Olivenstein R, et al. (February 2011). "Long-term (5 year) safety of bronchial thermoplasty: Asthma Intervention Research (AIR) trial". BMC Pulmonary Medicine. 11 (1): 8. doi:10.1186/1471-2466-11-8. PMC 3045390. PMID 21314924.
  6. ^ Castro M, Rubin AS, Laviolette M, Fiterman J, De Andrade Lima M, Shah PL, et al. (January 2010). "Effectiveness and safety of bronchial thermoplasty in the treatment of severe asthma: a multicenter, randomized, double-blind, sham-controlled clinical trial". American Journal of Respiratory and Critical Care Medicine. 181 (2): 116–124. doi:10.1164/rccm.200903-0354OC. PMC 3269231. PMID 19815809.
  7. ^ Thomson NC, Rubin AS, Niven RM, Corris PA, Siersted HC, Olivenstein R, et al. (AIR Trial Study Group) (February 2011). "Long-term (5 year) safety of bronchial thermoplasty: Asthma Intervention Research (AIR) trial". BMC Pulmonary Medicine. 11: 8. doi:10.1186/1471-2466-11-8. PMC 3045390. PMID 21314924.
  8. ^ Wechsler ME, Laviolette M, Rubin AS, Fiterman J, Lapa e Silva JR, Shah PL, et al. (December 2013). "Bronchial thermoplasty: Long-term safety and effectiveness in patients with severe persistent asthma". The Journal of Allergy and Clinical Immunology. 132 (6): 1295–1302. doi:10.1016/j.jaci.2013.08.009. PMC 4114404. PMID 23998657.
  9. ^ Thomson NC (2019-11-19). "Recent Developments In Bronchial Thermoplasty For Severe Asthma". Journal of Asthma and Allergy. 12: 375–387. doi:10.2147/JAA.S200912. PMC 6875488. PMID 31819539.
  10. ^ "Asthmatx, Inc. Alair Bronchial Thermoplasty System - P080032". U.S. Food and Drug Administration. 2010-05-19.
  11. ^ Ravenscroft N (8 June 2011). "UK doctors begin pioneering asthma treatment". BBC News.
  12. ^ "Apollo Hospitals, Chennai successfully performed Bronchial Thermoplasty on a patient, suffering from severe asthma for over 40 years". Apollo Hospitals Southern Region. 20 February 2018. Archived from the original on 2018-03-19.