BACKGROUND
Bronchial thermoplasty is a novel procedure being developed as a potential treatment for asthma. Experience with animal studies has enabled development of appropriate reliable equipment, definition of therapeutic parameters, and descriptions of tissue effects of treatment.
STUDY OBJECTIVES
This study was undertaken to assess the feasibility and general safety of the application of bronchial thermoplasty in the human airway, and to determine if the reduction in airway smooth muscle seen in animal studies could be replicated.
DESIGN
A prospective study.
SETTING
Academic thoracic surgery center.
PARTICIPANTS
Nine patients scheduled to undergo lung resection for suspected or proven lung cancer.
INTERVENTIONS
Bronchial thermoplasty was performed during routine preoperative bronchoscopy up to 3 weeks prior to prescheduled lung resection. Treatment was limited to areas of the segmental bronchi within the lobe that was to be removed. Treated airways were inspected via bronchoscopy at the time of thoracotomy, and were examined histologically following surgical resection.
RESULTS
There were no adverse clinical effects of the procedure, including no new symptoms and no unscheduled visits for medical care. Treated sites exhibited slight redness and edema of the mucosa within 2 weeks of treatment, and appeared normal at later time points. There was narrowing (visually estimated at 25 to 50%) in four airways in two subjects examined at 5 days and 13 days after treatment, with excess mucus in two of these airways. There was no bronchoscopic evidence of scarring in any of the airways examined. Histologic examination showed a reduction in airway smooth muscle, and the extent of the treatment effect was confined to the airway wall and the immediate peribronchial region.
CONCLUSION
Application of bronchial thermoplasty to the human airway appears to be well tolerated. Treatment resulted in significant reduction of smooth muscle mass in the airways. Bronchial thermoplasty may provide therapeutic benefit in disease states such as asthma.
[1]
J. Hogg,et al.
Reduction in airway hyperresponsiveness to methacholine by the application of RF energy in dogs.
,
2004,
Journal of applied physiology.
[2]
W. Mitzner,et al.
Radiofrequency ablation of airway smooth muscle for sustained treatment of asthma: preliminary investigations
,
2004,
European Respiratory Journal.
[3]
A. Manolis,et al.
Radiofrequency Ablation in Pediatric and Adult Patients: Comparative Results
,
2001,
Journal of Interventional Cardiac Electrophysiology.
[4]
P. Bhatia.
Radiofrequency ablation of lung cancer
,
2003
.
[5]
Brigit VanGraafeiland,et al.
National Asthma Education and Prevention Program.
,
2002,
The Nurse practitioner.
[6]
D. Postma,et al.
Difficult/therapy-resistant asthma: the need for an integrated approach to define clinical phenotypes, evaluate risk factors, understand pathophysiology and find novel therapies. ERS Task Force on Difficult/Therapy-Resistant Asthma. European Respiratory Society.
,
1999,
The European respiratory journal.
[7]
S. Johnson,et al.
Synthetic functions of airway smooth muscle in asthma.
,
1997,
Trends in pharmacological sciences.
[8]
R. Pauwels,et al.
GLOBAL STRATEGY FOR ASTHMA MANAGEMENT AND PREVENTION
,
1996
.
[9]
P. Paré,et al.
The mechanics of airway narrowing in asthma.
,
1989,
The American review of respiratory disease.