Mario Castro, M.D., a pulmonologist at Washington University School of
Medicine in St. Louis, Mo., talks about a surgical procedure that's offering
relief to asthma patients who don't respond well to medication.
Which asthma patients are candidates for this new treatment?
Dr. Mario Castro: Bronchial thermoplasty is for patients that have severe
asthma. That represents about 10 percent of the population of patients out
there with asthma.
Why is there a need for this treatment?
Dr. Castro: Severe asthma patients are receiving the best treatment we
have available today, but despite that, they're still having disabling
symptoms. They're having continuous shortness of breathing, coughing,
chest tightness, wheezing. They're experiencing these symptoms
throughout the day and even at night; they're awakening often as well.
What are the current treatments for severe asthma?
Dr. Castro: The current therapy that we have for the treatment of severe
asthma includes medications that are used through an inhaler. The types
of medications for use are inhaled steroids and bronchodilators. The
steroids decrease the inflammation inside your windpipes. The other type
of medication that we use is called a bronchodilator. The bronchodilator
opens up your windpipes so you can breathe easier, and it works very
quickly. Our patients that have severe asthma use these two types of
medications to control their disease and to be able to function better. But
despite using these medications, even at high doses, often these patients
are quite disabled.
How does the new treatment work?
Dr. Castro: The new treatment is called Bronchial Thermoplasty using the
Alair® system. The thermoplasty means that we are providing heat to the
windpipes, to the lining of your windpipes, that you breathe air through into
your lungs. By applying that heat through a procedure we call the
bronchoscopy, we're able to decrease the smooth muscle that's around
What happens when you have an asthma attack is that that muscle
constricts. It actually tightens down, so you're trying to breathe through a
very tight, narrow opening. What we're trying to do is decrease that smooth
muscle that's surrounding the windpipe with this treatment, which is long
lasting. In fact, there have been some patients that have been treated over
five years ago with this treatment, and the effects of that have been long
lasting for those patients.
How is Bronchial Thermoplasty different than other treatments?
Dr. Castro: The way it treats the muscle is really why it works so
differently. The medications that I mentioned earlier – the bronchodilators –
those medications work in your windpipe. They help relax the smooth
muscle. However, they only last for about four to six hours, whereas this is
a permanent treatment where we actually alter the smooth muscle; we
decrease the muscle that's surrounding the windpipe. It's a long lasting
and effective treatment for these patients.
How is the Bronchial Thermoplasty delivered to the patient?
Dr. Castro: The Bronchial Thermoplasty is actually delivered through an
Alair® catheter, a very small skinny catheter that goes through an
instrument called a bronchoscope. The bronchoscope is a flexible
instrument that we use very often as lung doctors to go down into your
windpipes and get access to your lungs to do various treatments. The
bronchoscopy procedure itself for this treatment takes about 30 to 45
minutes to accomplish. We do the thermoplasty in a series of three
treatments. We try to span a recovery period in between the treatments of
about two to three weeks. In total, most patients will require six to nine
weeks in order to get all three treatments accomplished.
With the first treatment, we'll go down into your right lower lung or treat the
entire right lower lung. We'll stop there and let the patient recover. The
second treatment will go over to the left side – we'll treat the left lower
lung. The last treatment will treat the upper lungs on both sides.
Who is the best candidate for this procedure?
Dr. Castro: The optimal candidate for this procedure is really somebody
with severe asthma that is seeing an asthma specialist, lung doctor or
allergist, and despite optimizing the treatment as much as possible, they're
still not getting control of their asthma, they're still having very frequent
asthma symptoms. They may be having hospitalizations, emergency room
visits due to their asthma not being controlled. Those are the type of
patients that really would benefit from this type of procedure.
The patients that we don't think would benefit from this would be patients
that really have mild-moderate asthma or those that have primarily
exercise induced asthma. For those patients, the medications that we have
currently are really good at controlling their asthma. This would not be a
treatment that you would like to offer to somebody that really has mild
What kind of results have you seen in patients?
Dr. Castro: We have quite a bit of experience now with the procedure and
following these patients after a long period of time, and really that is what's
convinced us is that it's really made a marked difference for some of these
patients. We've had patients that have been disabled and they were not
able to work and now have been able to return to their work and lead a
much more normal life. Once we see what the outcome of this treatment is
for that particular patient, it really indicates to us bronchial thermoplasty
offers a breakthrough in what we have to offer our patients with severe
What are the potential side effects to the treatment?
Dr. Castro: When we discuss this with a patient, one of the first things I do
is make sure they're aware of what the treatment is and exactly why it's
indicated for them. We balance that with explaining what risks are involved
in the procedure and what the adverse effects are related to the treatment
itself. With bronchial thermoplasty, what we're doing is we're heating the
inside of the airway, the lining there, and that actually does induce a mild
asthma attack in most patients.
That mild asthma attack lasts for about 24 hours after the procedure, on
average. Some patients, it will linger on for a few days, up to about a week,
and that's why we allow you a recovery time of about two weeks in
between treatments. We've had some patients where the treatment has
exacerbated their asthma enough that they needed to come into the
hospital to be observed.
We clearly want to discuss that with our patients ahead of time so they're
aware of that short-term risk. You then have to balance that with the
benefits from the procedure and decide what's right for you. It's not right
for everybody because if you are really well controlled and the medications
are working for you, you don't really want to go through that additional risk
of the procedure. We ask the appropriate patient with severe asthma that
things are just not being controlled for them, 'Are you willing to take this
risk in order to achieve this long term benefit?'
Is Bronchial Thermoplasty a cure for asthma?
Dr. Castro: This is not a cure for asthma. This is a treatment that we
believe benefits those patients with severe asthma uncontrolled with
current medications. The reason bronchial thermoplasty is not a cure is
that asthma is not just a problem of the smooth muscle – it's also a
problem of inflammation in your windpipes and the allergies that are
contributing to that. We can only treat the smooth muscle part with
Bronchial Thermoplasty. The symptoms that are related to that will be
improved, but we can't cure it all together.
When will this treatment be available?
Dr. Castro: The FDA is currently reviewing all the material that's been
done, including a large study of bronchial thermoplasty (AIR2) that was just
completed. The hope is that the FDA will have completed their review of it
and have made a decision by the end of the years, so that we can offer
this new promising therapy to our patients with severe asthma by early