Bronchial thermoplasty can treat severe asthma. It may be a suitable option for people with asthma that does not respond to standard treatments. It uses heat to help open the airways and make them less likely to narrow.

Asthma is a long-term condition that affects the airways of the lungs. Asthma causes the airways to swell and narrow, making it harder to move air in and out of the lungs.

Around 1 in 13 people in the United States have asthma. But 5–10% have persistent, severe asthma despite having regular preventive therapy.

Bronchial thermoplasty (BT) is a treatment option for people with severe asthma. It reduces the thickened smooth muscle in the airway to improve breathing and prevent future asthma attacks.

In this article, we explore bronchial thermoplasty, including its uses, how it works, and its benefits and effectiveness.

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The primary cause of breathing difficulty during an asthma attack is the constriction of the airway smooth muscle. This can occur due to triggers, such as allergens or infections.

One hallmark feature of asthma is the thickening of the smooth muscles in the airways. As such, the more severe a person’s asthma, the thicker the smooth muscle.

BT is a minimally invasive procedure that selectively heats and shrinks the smooth muscles in medium to large airways. It aims to reduce airway smooth muscle mass, which helps open the airways, making it easier to breathe.

Evidence suggests that BT is safe and suitable for people with severe asthma.

BT may be an option for people ages 18 or older whose asthma is not controlled by standard therapies, such as inhaled corticosteroids and long-acting beta-agonists.

Other signs of poorly controlled asthma include:

  • severe asthma attacks
  • altering lifestyle to avoid triggers
  • absences from school, work, or other daily activities
  • presence of symptoms despite medical therapy

Doctors may also offer BT to people with allergic or eosinophilic asthma that has not responded to targeted biologic therapy.

However, BT is not appropriate for the following groups of people:

  • people under 18 years
  • people with a pacemaker, internal defibrillator, or other implantable electronic device
  • people with a known sensitivity to medications a doctor may use during the procedure, such as lidocaine, atropine, and benzodiazepines
  • people who have previously had BT

The doctor may ask the person to take 50 milligrams of prednisone per day for 3 days before the procedure, on the day of the procedure, and the day after the procedure to prevent post-procedure airway inflammation.

BT involves three separate bronchoscopic procedures, with 3 weeks between each session. The sessions sequentially target the following:

  • right middle/lower lobe
  • left lower lobe
  • bilateral upper lobes

A pulmonologist performs BT in a bronchoscopy/endoscopy suite. This type of doctor specializes in lung health. People typically undergo the procedure under general anesthesia, but the doctor may opt for moderate sedation.

Before the procedure, the doctor suctions mucus. Then they do a standard airway examination before the treatment.

The procedure involves using a radiofrequency controller and catheter. The doctor inserts a catheter through a bronchoscope connected to the radiofrequency (RF) controller.

The RF controller delivers thermal energy at 65°C (149°F) for 10 seconds. The doctor controls each activation via a foot switch pedal.

The catheter has an umbrella-like, expandable four-electrode basket, which the doctor expands to ensure proper contact with the airway wall when delivering the thermal energy. When the wires contact the airway wall, the energy turns into heat and destroys the muscle.

The doctor treats each airway per segment and subsegment, beginning at the farther ones before moving closer to the center. The doctor will then collapse the electrode basket and withdraw it to the following site.

The length of the procedure depends on the number of activations but typically takes about an hour. The medical team will monitor and observe the person for approximately 2–4 hours.

BT offers the following benefits:

  • reduced daily asthma symptoms
  • reduced absences from work or school
  • decreased need for steroids
  • reduced hospitalizations and emergency room visits

In a 3-year follow-up of people with severe asthma who received BT, people had a 45% reduction in asthma exacerbations, hospitalizations, and emergency department visits, according to a 2020 review.

Review authors note that people with more severe asthma have the most to gain from the treatment. Consolidated results from three registries found that BT is effective at:

  • reducing symptoms
  • improving a person’s quality of life
  • reducing the frequency of symptom exacerbation
  • reducing dependency on oral corticosteroids

A person can expect a short-term worsening or increase in respiratory-related symptoms within 1 day after the procedure. Symptoms typically resolve within 7 days with standard medical care.

Side effects may include:

  • breathlessness
  • wheezing
  • cough
  • chest discomfort
  • night awakenings
  • productive cough

If symptoms worsen, a person may need an overnight hospital stay to help manage the symptoms.

BT is generally well tolerated. Procedure-related adverse reactions occurring in the week after the procedure are manageable with standard medical care.

The medical team may continue assessing the person’s medical status up to 7 days after the procedure. A person may need chest physical therapy, therapeutic bronchoscopy, or both to manage symptoms.

Bronchial thermoplasty (BT) is a safe and effective treatment for people with severe asthma. It may be suitable for people with asthma that has not responded to conventional therapies.

BT uses heat to reduce the thickened smooth muscle in the airway walls, which can help improve symptoms and reduce exacerbations.

People eligible for the procedure can discuss with their doctor whether BT is appropriate.