Early radiologic and bronchoscopic changes after bronchial thermoplasty in patients with severe asthma

Bronchial thermoplasty (BT) is a treatment to reduce the airway smooth muscle mass by delivering radiofrequency thermal energy to the airways. BT is used in patients with severe asthma. The present study reported on cases of pneumothorax directly after BT and retrospectively analyzed early radiologic and bronchoscopic modifications after BT. The clinical data and radiologic and bronchoscopic findings of 12 patients with severe asthma who were subjected to BT between July 2014 and October 2017 were analyzed. A total of 33 chest radiographs were collected within 18-24 h after BT. Radiological abnormalities were observed in 32 radiographs as atelectasis (53.1%), peribronchial consolidations (84.4%), pleural effusion (18.8%), effusion in oblique fissures (3.1%), pleural thickening (6.3%) and pneumothorax (3.1%). Of note, one patient suffered pneumothorax after the third BT session and underwent chest drain insertion, followed by mechanical ventilation at the intensive care unit and multiple bronchoscopic interventions, which revealed extensive phlegm plugs. A total of six patients with worsened symptoms and lobar atelectasis also required bronchoscopic intervention, which revealed that phlegm plugs occluded the bronchus in the treated lobe. No bronchoscopic intervention was required in the remaining five patients. During 16-30 days of follow-up, 95.7% of the findings on chest radiography were resolved. To the best of our knowledge, the present study reported the first case of pneumothorax following BT. Early radiologic modifications such as atelectasis and peribronchial consolidations appear common after BT. However, whether bronchoscopic intervention is required for atelectasis following BT warrants further investigation. Of note, BT should be audited and recorded in detail to ideally contribute to a framework of clinical trials to improve risk-benefit evaluations and the selection of patients likely to benefit from treatment.