An international study has shown that a new heat treatment called bronchial thermoplasty can help moderate to severe asthma sufferers control their condition for up to 12 months.
The study is published in the New England Journal of Medicine (NEJM) and was conducted in 11 hospitals in the UK, Brazil, Canada and Denmark.
Bronchial thermoplasty uses radio waves to burn away excess smooth muscle in the airways of the asthma patient and helps them breathe more easily.
According to Dr John D Miller, co-author of the study and an associate professor at McMaster University in Hamilton, Ontario, Canada, the study is the first non-drug treatment to be tested recently and showed a remarkable response.
To administer bronchial thermoplasty, patients first receive a mild anaesthetic, then a a tube is pushed into their nose or mouth so that wires that emit radio waves can get to the tissue in the airways. The radio waves generate heat in the targeted muscle tissue and burn it away.
Excess smooth muscle causes problems because when it contracts it narrows the airways.
In this study, 66 patients with moderate to severe asthma were treated with bronchial thermoplasty in three sessions of one hour each over a nine week period. Another 66 patients did not receive thermoplasty and carried on with their regular medication.
After a year, the patients who received the thermoplasty were breathing 39 litres of air per minute compared to the patients on regular drugs alone, whose air flow was only 8.5 litres per minute.
The thermoplasty patients also had an average of 40 days without symptoms, whereas the drugs only patients had 17. And they also experienced fewer symptoms and used drugs less often than the non thermoplasty group.
A larger controlled trial that includes a group that will receive a “placebo” treatment is now under way that could eventually lead to bronchial thermoplasty receiving approval from the US Food and Drug Administation (FDA).
Authors writing an accompanying editorial say that the value of this research is that it has brought medical attention back to airway muscle and away from immunology and inflammation. Bronchial thermoplasty is not without risks and other methods could also be developed that are less invasive and have similar effects, they say. As examples they suggest drugs that paralyze the excess muscle or destroys it chemically.
Eventually we could see bronchial thermoplasty as a routine emergency room procedure for patients who are brough in with a bad attack.
The study authors are hopeful that a less invasive way of achieving the same ends can eventually be developed.
Whatever the future holds, the study has certainly challenged conventional wisdom and set a new direction for improved treatments.
Over 5 million people in the UK are on asthma medication.
“Asthma Control during the Year after Bronchial Thermoplasty.”
Gerard Cox, Neil C. Thomson, Adalberto S. Rubin, Robert M. Niven, Paul A. Corris, Hans Christian Siersted, Ronald Olivenstein, Ian D. Pavord, David McCormack, Rekha Chaudhuri, John D. Miller, MMichel Laviolette, for the AIR Trial Study Group.
NEJM Volume 356:1327-1337
March 29, 2007, Number 13
Written by: Catharine Paddock
Writer: Medical News Today