By: Jean Johnson for MedTech1Radical. As in arising from the root, not the branch – and thus departing markedly from the usual or customary. Clearly that’s the case in the bronchial thermoplasty procedure that Canadian researchers have been monitoring for the past two years at St. Joseph’s Healthcare Hamilton in Ontario and that the University of Chicago is poised to study in a larger clinical trial.
| Take Action |
Is a clinical trial right for me?
Each clinical trial has specific guidelines – carefully review the guidelines of any trial you are interested in.
Consider the risks vs. the benefits of a clinical trial:
Possible benefits could be:
Access to treatment that is not otherwise available, which may be safer or more effective than existing treatment options.
Increasing the total number of treatment options available to you, even if you haven’t yet received all of the standard treatments.
The chance to possibly help others who have the same condition in the future by contributing to research.
Possible risks could be:
The new treatment may have unknown side effects or other risks, which may or may not be more severe than those from existing treatments. This is especially true of early phase trials.
As with other forms of therapy, the new treatment may not work for you, even if it helps others.
There may be inconveniences such as more frequent testing, as well as time and travel commitments.
Learn more about clinical trials at www.clinicaltrials.gov
|
Because of the radical nature of the procedure which instead of relying on drugs, uses radiofrequency to disable the offending smooth muscle in bronchial airways which narrows and worsens asthma attacks, researchers have waited two years from their initial trial in 2004 to publish their initial results on 16 pilot patients. That said, the article in the May 2006 issue of the American Journal of Respiratory and Critical Care Medicine (AJRCCM) is getting noticed. Pundits around the world are giving more than passing notice and a cautious thumbs-up to the research. They are even suggesting that should success continue to mount, bronchial thermoplasty could herald a major breakthrough for asthmatics.
“Whether bronchial thermoplasty will earn a place in the treatment of asthma remains to be seen,” wrote Elizabeth H. Bel, M.D. of the Leiden University Medical Center in the Netherlands in an editorial that accompanied the scholarly article in the AJRCCM.
“However,” Bel continued, “this study shows the potential for a completely new approach of treating asthma and stimulates the development of new hypotheses. For patients with refractory asthma, bronchial thermoplasty might become a real breakthrough, particularly for those with severe airway hyper-responsiveness.”
“Completely new approach – real breakthrough.” Strong words even if couched among the careful qualifiers the medical profession uses to temper hasty conclusions on the part of the public.
More, The Netherland’s Bel is not alone. Assistant professor of medicine and pulmonologist at the University of Chicago, Imre Noth, M.D. who is directing a larger scale trial for bronchial thermoplasty even let fly with some adjectives.
“This is an entirely novel and quite exciting approach to treating asthma, unlike anything else available,” Noth observed. “The data from animal studies were impressive and early reports from three human trials in Canada, Brazil and Europe have attracted a lot of attention. But this will be the first big human trial.”
“Entirely novel.” “Unlike anything else available.” There’s definitely some rhetoric beyond the usual pale from a profession known for its conservative pronouncements.
Smooth Muscle is the Problem
Asthmatics have hyper-responsive airways that react when the smooth muscle that lines the bronchial passages narrows vigorously in response to various stimuli. According to Noth, this smooth muscle lining is vestigial and “a lot like the appendix, it serves no know purpose other than to cause serious medical problems.”
Also, the smooth muscle can become stronger over time exacerbating breathing difficulties. While developing muscles for upper body strength in the arms may make for considerable pleasure from some summer and sleeveless blouses, developing the muscles in the airways is definitely a no-win situation.
“Although there are many different triggers,” Noth said in the University of Chicago press release, “an acute asthma attack is always characterized by contraction of the smooth muscle in the airway wall. So it makes considerable sense to try and treat asthma by minimizing the ability of this smooth muscle to contract.”
Background
Spurred by extraordinarily high incidences of chronic inflammatory airway disease in Canada (one of the highest in the world at the rate of 7 to 10 percent in children alone, according to Canada’s healthcare online newspaper, Hospital News), researchers began looking for new ways to treat problems in 2004.
Answers came from work related to chronic airway problems that had been ongoing for some time. As the head of the Division of Thoracic Surgery at St. Joseph’s John Miller, M.D. told Hospital News, “These projects have been evolving for over five years as we’ve tried to find a way to bronchoscopically treat emphysema and asthma.
| In Perspective |
Understanding New Research’s Impact on Asthma
Asthma causes the airways to constrict and the smooth muscle cells in the bronchia contract to the point that it is difficult for air to move in and out. Wheezing, coughing, and chest tightness can ensue.
Asthma has traditionally been managed with medications and by removing or minimizing triggers in the environment.
Results of initial bronchial thermoplasty studies have potentially radical implications Alan Leff, M.D. – professor of medicine at the University of Chicago and consultant to Asthmatx, Inc. said in a 2006 press release. “The compelling use of this procedure is for patients who are inadequately controlled on current drug therapy. But if this therapy lives up to its early promise, bronchial thermoplasty may eventually have a very broad application, especially for patients who wish for a permanent amelioration of their symptoms or have difficulty adhering to medical regimes.”
The 16 Canadian patients involved in the initial bronchial thermoplasty trial kept diaries and participated in follow-up office visits and surveys designed to assess quality of life in the aftermath of the procedure. Initial results based on two years of tracking have been encouraging enough to spark international attention and lead to further studies including one at the University of Chicago.
|
“Initially we began looking for ways to stiffen airways for emphysema patients with dynamic airway collapse. As we developed the technology, we saw that this particular way of treating the airway had a profound effect on the smooth muscle and not much else,” Miller continued. “The amount of smooth muscle is significantly reduced by thermoplasty. We recognized that this procedure might therefore be an appropriate treatment for people with asthma.” How Bronchial Thermoplasty Works
First, a preface: According to 42 year-old Brenda Donahue who participated in the study after years of fighting for breath who spoke to the Hospital News, “I underwent three separate procedures, and I think it’s awesome. My treatment by staff at St. Joseph’s Healthcare as outstanding, and I would recommend it to other asthma sufferers.”
Now the graphic details from a University of Chicago press release for readers who aren’t too squeamish.
“In bronchial thermoplasty, physicians insert a thin flexible tube called a bronchoscope through the nose or mouth, down the throat and into the major airways of the lungs. Then they pass a narrow catheter, with a small expandable heat source at the tip, through that tube.
“Once the catheter is in position it is expanded to hold it snugly in place and heated, using radiofrequency energy, to about the same temperature as a cup of hot coffee for 10 seconds. This kills about half of the smooth muscle cells that line that segment of the airway. Then the catheter is slightly repositioned and re-heated. This routine is repeated about 30 times, until all the accessible airways from one lobe of the lung have been treated, a process that takes about 30 to 45 minutes.”
Three separate sessions with at least three weeks in between each treatment are necessary to apply the heat to smooth muscle in all the small to medium sized airways (those at least three millimeters in diameter) in the lung.
Larger Implications
Researchers are careful to underscore that even if bronchial thermoplasty proves a viable treatment option for asthma patients, it is not a cure. Nonetheless, given its ability to dramatically reduce the severity and frequency of attacks, patients like Brenda Donahue wax as eloquently as if it were.
“It’s a huge difference. My life is so much easier. I still use my inhaler occasionally, but now it’s only a few times a week. I love to walk but couldn’t enjoy it before the procedure. Since the treatment I can walk longer and farther,” she said before gathering steam for further thoughts.
“This new treatment is an opportunity. And not just for me,” said Donahue. “I’ve seen children fighting for breath, and I know how scared their parents are. I know how terrified I get when I can’t get air into my lungs. This procedure promised to be another way to hopefully reduce, if not cure, my asthma.”
For his part, Gerald Cox, M.B.B.Ch. who along with John Miller, M.D. led the initial Canadian research on 16 human patients in 2004 told Hospital News that “It is exciting to lead a project such as this, which began with a radical idea, and as a result of careful preparatory research, grew to become the topic of a major international research effort.”
Cox is head of clinical service at St. Joseph’s renowned Firestone Institute for Respiratory Health and also is associated with and accepts pay from Asthmatx, Inc., the company that makes the bronchial thermoplasty equipment.
