Thermal treatment reduces asthma attacks

[Neil D]

Thermal treatment reduces asthma attacks: study

Sharon Kirkey, CanWest News Service

Published: Wednesday, March 28, 2007

Asthma sufferers may soon be able to breathe easier thanks to a new treatment that reduces by half the number of major flare-ups in a year.

The treatment essentially burns away muscle that can make airways squeeze shut.

"I think it's really the launch of a new era for the treatment of asthma," says Dr. John Miller, co-principal investigator of the Canadian-led international study published in this week’s New England Journal of Medicine.

"This is the first non-drug treatment for asthma that has been shown to be effective," says Miller, division head of thoracic surgery at St. Joseph’s Healthcare Hamilton and McMaster University.

Most asthma drugs work by attacking the inflammatory part of the disease or by keeping immune cells that line the airways in check.

Bronchial thermoplasty, by contrast, targets the smooth muscle mass in the airways. Dust, smoke, perfume and other irritants trigger the smooth muscle to twitch and contract. The airway gets smaller and nearly closes off, causing an asthmatic attack.

Asthma affects more than two million Canadians; every year about 500 people die from asthma.

During thermoplasty, a catheter with a small wire basket at its tip is fed through a tube down into the airways via the nose or mouth. The basket's four arms stretch out to touch the walls of the central airway, and thermal energy is passed through the wires for about 10 seconds at a time.

The smooth muscle "selectively disappears," Miller reports.

"There are all kinds of cells in the airways. You apply this current to them and everything seems to recover except the smooth muscle."

The procedure involves three 40-minute sessions and can be done in a clinic using mild sedation and topical freezing.

In the new study, 112 patients, aged 18 to 65, with moderate to severe asthma, were enrolled. They had been treated with inhaled corticosteroids and a class of drugs called LABAs, or long-acting beta agonists. Half were assigned to thermoplasty, and the other to a control group. The patients were followed for one year.

Those assigned to the treatment group had nine flare-ups in a year, compared to 18 in the control group.

The number of symptom-free days went from three months worth before treatment to eight months of disease-free days after treatment.

The treated group also used their "rescue" medications less often and reported having a better quality of life.

The procedure can cause irritation of the airway and bronchitis that can cause a cough and wheezing for a week or two.

Asthmatx, makers of the thermoplasty system tested, paid for the study.

[Toni]

Very interesting! I've suffered with asthma all of my life, and to get rid of my medications would be a blessing!