Bronchoscopic Lung Volume Reduction in Management of Localized Emphysema

Emphysema is a progressive phenotype of chronic Obstructive Pulmonary Disease (COPD), poses a significant global health burden characterized by irreversible lung parenchymal destruction and airspace enlargement.

In recent years, bronchoscopic lung volume reduction (BLVR) has considerable interest as a minimally invasive approach to reducing hyperinflation and improving lung function in patients with emphysema.

BLVR techniques aim to achieve lung volume reduction by occluding or ablating emphysematous lung tissue through endobronchial delivery of various agents. Many techniques are available for BLVR as coil, endo-bronchial valve, and biological as thrombin, autologous blood and chemicals as silver nitrate solution.

Chemical lung volume reduction is an endo-bronchial approach, which uses chemical agents aiming to reduce lung volume by blocking off the most emphysematous areas with a rapidly polymerizing sealant. Endobronchial Valves (EBVs) show an overall success rate of 70-80% in reducing lung volume and improving lung function. Lung volume reduction coils (LVRC-Coils) have a success rate of 50-60%.

Bronchoscopic lung volume reduction with silver nitrate as a chemical agent was used in previous studies using a concentration of 0.5% and showed significant improvement in forced expiratory volume in first second (FEV1), diffusion capacity of lung to carbon monoxide (DLCo), modified Medical Research Council (mMRC) score when compared to base line values and reduction of the High Resolution Computed Tomography (HRCT) volumetry of the emphysematous regions.

Silver nanoparticles (AgNPs) are the most widely used nanomaterial today. These have found a wide range of applications in various areas such as textiles, agriculture, renewable energy, food, catalysis, bioremediation, and biomedicine

Inclusion criteria

• COPD of grade III and IV according to GOLD 2024 staging of COPD with localized (heterogeneous) emphysema as determined by high resolution computerized tomography (HRCT) of the chest with area of destruction >-950 Hounsfield units (HU) and respiratory symptoms despite optimal medical therapy with the following criteria: Patient less than 75 years of age not candidate for or had refused lung volume reduction surgery but fit for fibro-optic bronchoscope (FOB). Lung volumes criteria: FEV1 less than 60% of predicted value, Residual volume (RV) more than 100% of predicted value, Total lung capacity (TLC) more than 100% of predicted value, 6 MWT of less than 450 meters.

Exclusion criteria

• Significant co-morbidities that limits exercise capacity or prognosis as cardiovascular diseases (heart failure, arrhythmia, ischemic heart disease) and lung cancer.
• Patients unfit or refused FOB.
• Homogenous emphysema.
• More than 75 years of age.
• Associated lung fibrosis.
• FEV1 > 60%.
• Current smoker.