This study aims to investigate the efficacy and safety of Bronchial Thermoplasty on moderate bronchial asthma in China, by observing the improvement of quality of life, the decrease of acute attack and emergence, as well as the incidence of related complications.

This is a multi-center, open-label and single arm study. At least 50 patients with moderate asthma receive Bronchial Thermoplasty for three times. Asthma Quality of Life Questionnaire (AQLQ), Asthma Control Questionnaire (ACQ), Frequency of mild asthma acute attack, PEF, FEV1, Emergency and Hospitalization are compared between before and after BT treatment.

The unified peak flow test meter will be provided to all subjects enrolled in this study. They will get a follow-up diary book before leaving hospital. In order to ensure the efficiency, all enrolled asthma patients are trained and tested by doctors and nurses from in-patient or out-patient department when they follow up, including how to use the PEF meter, how to read and record the data. As for the dosage of medication, all the medication uses are followed the doctor's advice, once the rescue medications were used, the times and dosages are mandatory to be recorded in the diary book by the patients themselves.

Inclusion Criteria:

1. age between 18y and 65y.
2. no improvement after ICS and LABA treatment in patients with moderate asthma
3. have not received BT before
4. stable more than 6 weeks before enrolled in this study
5. no implantable electrical device (e.g. cardiac pacemaker)
6. no permanent anticoagulant is being used

Exclusion Criteria:

1. Smoking and have obvious emphysema
2. Chest CT showed lower lobe bronchial stenosis or distal complete atelectasis
3. FEV1 < 65% predicted value after using bronchodilator
4. airway infection(within 6 weeks)
5. any circumstances as the following within the past 1 year: lower respiratory tract infection (LRTI) for 4 times or above; hospitalization due to respiratory diseases for more than 3 times; increase the dosage of oral corticosteroids due to asthma exacerbation for more than 4 times
6. received endotracheal intubation or ICU admission due to asthma attack within the past 2 years
7. concomitant allergic bronchopulmonary aspergillosis
8. Implantable electronic devices (such as cardiac pacemaker)/NYHA class IV and/or acute myocardial infarction within the past 3 months
9. coagulation disorders,cannot stop taking anticoagulant、antiplatelet drugs or nonsteroidal anti-inflammatory drugs
10. increasing the risk of adverse reactions during bronchoscopy or anesthesia as the followings: pregnancy, insulin-dependent diabetes, epilepsy, or the other severe complications, such as uncontrolled coronary heart disease, acute or chronic renal failure or uncontrolled hypertension
11. others:vocal cord dysfunction、chronic nasosinusitis、airway obstruction or uncontrolled obstructive sleep apnea syndrome