What is the key question?

• Chronic bronchitis is a difficult to treat phenotype of COPD and is associated with increase symptoms and mortality and worse outcomes in comparison to patients without chronic bronchitis. Current bronchoscopic treatments do not target chronic bronchitis.

What is the bottom line?

• Metered Cryospray (MCS) delivering liquid nitrogen (LN2) to the tracheobronchial airways ablates abnormal epithelium and facilitates healthy mucosal regeneration.
• The objective of this study was to evaluate the feasibility, efficacy and safety of MCS in CB.
• Chronic bronchitis patients with a FEV1, 30-80% of expected, taking optimal medication were recruited.
• The primary outcomes were:
  o feasibility – completion of treatments;
  o efficacy – 3-month change in St George’s Respiratory Questionnaire (SGRQ)
  o safety – incidence of adverse events (AEs)
• The secondary outcomes were lung function, exercise capacity, additional patient-reported outcomes (PROs).
• 35 patients were included, most with GOLD grade 3 COPD and they underwent staggered LN2 treatments. 34 completed three treatments lasting approximately 30 minutes separated by 4-6 weeks.
• Persistent clinical improvements in PROs were observed including SGRQ. CAT score (to 6 months) and Leicester Cough Questionnaire (to 9 months).
• There were no serious device or procedure related adverse events with a third having an exacerbation in the following year. There were no pneumothoraces.

Why read on?

• The authors further discuss bronchoscopic management of COPD and the role of LN2 therapy, the potential limitations of the procedure and the need for a randomized clinical trial.