Patients with large bullae (large empty air sacs in the lung) may benefit from bullectomy (surgery to resect these bullae), however this is a major surgery with significant potential morbidity and long hospital stays. Many patients are not well enough to have this surgery, or may not wish to have it. A less invasive means of attempting to shrink the size of the bullae is to directly inject the patients' own blood into the bullae (we believe that this can lead to an inflammatory reaction leading to gradual scarring and volume loss). This can be performed bronchoscopically in a 20-30 minute procedure using conscious sedation (avoiding general anaesthesia).

The aim of this study is to assess the effects on lung function, quality of life measures, functional measures and CT measured lung volumes of bronchoscopic intrabullous blood instillation in patients with bullous emphysema.

Inclusion Criteria:

• Age > 35 years
• Large bulla on CT scan where bullectomy is contraindicated or is actively avoided.
• Hyperinflation - TLC ≥100% predicted, RV ≥150% predicted
• Exertional breathlessness (mMRC >0)
• Optimum COPD treatment for at least 6 weeks
• No COPD exacerbation for at least 6 weeks
• Fewer than 3 admissions for infective exacerbations in the preceding 12 months
• Written informed consent

Exclusion Criteria:

• Inability to obtain informed consent
• Co-morbidities that would render bronchoscopy or sedation unsafe.
• Anaemia or other reasons precluding venesection.
• Clinically significant bronchiectasis
• Arrhythmia or cardiovascular disease that poses a risk during procedure
• Lung nodule requiring further investigation or treatment
• Subject taking clopidogrel, warfarin, or other anticoagulants and unable to abstain for 5 days pre-procedure