Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bronchial thermoplasty offers significant improvement for asthmatics in small study

02.05.2006


Asthmatic patients showed significant improvement in peak expiratory flow, airway responsiveness and number of symptom-free days after treatment with bronchial thermoplasty, a new procedure designed to reduce the ability of airway smooth muscle to narrow from inflammation.



These results appear in the May 1 issue of the American Journal of Respiratory and Critical Care Medicine, published by the American Thoracic Society.

Gerard Cox, M.B., F.R.C.P.C., of the Firestone Institute for Respiratory Health in Ontario, Canada, and four associates examined the safety, impact on lung function and airway responsiveness of bronchial thermoplasty on 16 asthma patients over a two-year period. The study cohort included 6 men and 10 women who had an average age of 39.


On each individual, the researchers performed bronchial thermoplasty to lower the potential for muscle-related bronchoconstriction by reducing the mass of smooth muscle in their airways.

In this 30-minute procedure, doctors applied radio frequency thermal energy directly to the airway through a bronchoscope. This radio frequency energy heated the airway tissue to about 65 degrees Celsius (149 degrees Fahrenheit), a temperature high enough to reduce airway smooth muscle mass, but low enough to avoid tissue destruction and scarring. Three separate sessions were needed to treat all accessible airways of both lungs.

"The procedure was well tolerated," said Dr. Cox. "Side effects were transient and typical of what is commonly observed after bronchoscopy. All subjects also demonstrated improvement in airway responsiveness."

Data collected over 12 weeks from patient-kept diaries indicated that the subjects showed significant improvement in number of symptom-free days, and in morning and evening airway peak flow as determined by a meter. (A peak flow meter is a hand-held device designed to measure how well a person can blow air out of their lungs.)

"A total of 312 adverse events were reported over the 2-year period," said Dr. Cox. "Of these, 230 (74 percent) were ’mild,’ 79 (25 percent) were ’moderate’ and 3 (1 percent) were ’severe.’ All three severe adverse events, which included allergic reaction to peanuts, ovarian cyst and fibroid removal, and partial mastectomy, involved hospitalization and were considered not related to the procedure."

The researchers will continue to follow the study patients for five years to determine if there are longer term safety concerns associated with bronchial thermoplasty.

In an editorial in the same issue of the journal, Elizabeth H. Bel, M.D., Ph.D., of Leiden University Medical Center in The Netherlands, wrote: "This study by Drs. Cox and colleagues is important both from pathophysiologic and clinical points of view. First, it provides a unique insight into the mechanisms of airway hyperresponsiveness in asthma. The ability of asthmatic airways to constrict more promptly and excessively to inhaled stimuli than is the case for normal airways is considered a key factor of the disease, and may be fundamental to its pathogensis."

Dr. Bel continued: "The study, as simple as it is, is uniquely hypothesis-testing and shows that modifying structural elements of the airway wall can profoundly influence airway hyperresponsiveness. Does it indicate that airway smooth muscle is the sole contributor to this characteristic form of asthma? No, unfortunately, is doesn’t. Although it is intuitively obvious that airways with reduced muscle mass are likely to contract less in response to stimulation, there are other possibilities, including damage to the nerves or vessels, changes in mucus gland structure and function, alterations in the type of inflammation and changes in airway compliance that may modulate this effect. Thus, the debate on the relative importance of muscular and non-muscular elements in bronchial hyperresponsiveness in asthma has not been resolved by this study."

"From a clinical point of view," Dr. Bel wrote, "the study is even more fascinating because it suggests that bronchial thermoplasty has the potential to become a realistic therapeutic option in chronic asthma not satisfactorily controlled with pharmacotherapy. There are, however, several important issues to be considered. First, the long-term consequences of the procedures are not yet determined. The good news is that over a period of 2 years, none of the serious concerns speculated about, such as the development of fixed obstruction, bronchial instability or chronic progressive tissue damage, have developed. However, one could still envisage adverse effects in the long term."

"A second point of concern is whether the procedure targets the appropriate airways. There is now abundant evidence that distal airways are involved in asthma, particularly in severe asthma. Inadequate treatment of the peripheral airways might be the primary reason why patients with refractory asthma do not respond satisfactorily to inhaled therapy, and are at risk of severe exacerbations. Bronchial thermoplasty does not access the peripheral airways, which may not only be a drawback of the technique, but also may impose risks. If patients refrain from pharmacotherapy after bronchial thermoplasty because of symptomatic improvement, the distal airways might become more inflamed and obstructed than before."

"Whether bronchial thermoplasty will earn a place in the treatment of asthma remains to be determined," Dr. Bel noted. "However, 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 hyperresponsiveness."

Suzy Martin | EurekAlert!
Further information:
http://www.thoracic.org
http://www.mcmaster.ca

More articles from Health and Medicine:

nachricht Millions through license revenues
27.04.2017 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht New High-Performance Center Translational Medical Engineering
26.04.2017 | Fraunhofer ITEM

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>