One of the common pathways of all patients who have
an asthmatic attack is that the smooth muscle
contracts and the airway gets smaller and they end
up with shortness of breath or a trip to the
emergency room. "Bronchial thermoplasty, delivers
controlled thermal (radio frequency) energy to the
airway walls and reduces the amount of airway smooth
muscle thereby altering the ability of the muscle in
the airway to contract or narrow the airway," said
Dr. Miller.
Under general or local anesthetic, the device is
passed through a standard bronchoscope and
positioned in small to medium sized airways. Several
airways are treated under direct vision in a
half-hour procedure; to fully treat both lungs it
usually requires three treatment episodes.
Having found that this novel technique could be
performed safely, Dr. Miller, in collaboration with
respirologist Dr. Gerard Cox, head of Clinical
Service at St. Joseph 's renowned Firestone
Institute for Respiratory Health, began
investigating bronchial thermoplasty as an effective
treatment for asthma when compared to the standard
medical treatment.
"Many of the symptoms of asthma are due to narrowing
of airways. In asthma, airway narrowing is
profoundly influenced by contraction of muscle
located in the airway wall. There is circular muscle
around the airway, so that as it contracts the
airway gets smaller," says Dr. Cox. "Bronchial
thermoplasty interrupts that ring of muscle so that
it is incomplete and thereby decreases the
constriction of the airways, and this may be of
great benefit in potentially reducing the frequency
and severity of asthma attacks."
