Novel modalities and agents in bronchoscopic lung volume reduction.

The NETT study has shown the effectiveness of lung volume reduction surgery (LVRS) in improving functional parameters and exercise tolerance in selected patients with severe pulmonary emphysema of upper lobe predominance. A number of bronchoscopic techniques have since been developed under the term "bronchoscopic lung volume reduction" (BLVR), aiming to lower the complications and the cost while facilitating the procedure of lung volume approach in patients with emphysema. These include airway bypass by creation of airway/parenchyma communications, one-way endobronchial valves occluding the airways of the targeted lobes, endobronchial coils which mechanically contract the parenchyma, hot vapour ablation thermally destroying the targeted sites and sealant which fill the alveoli with polymer material. These methods are generally simple and safe, with a favourable complications profile, requiring less infrastructure and interventional experience than the open surgical approach. Bronchial valves have produced promising results in a very narrow phenotype of emphysema patients and have the major advantage of being reversible in their action. Parenchymal interventions at the cost of producing permanent effects and a transient inflammatory syndrome, may be effective in larger group of patients regardless of the fissure integrity and the presence of collateral ventilation. New, more extensive multicentre studies are underway which aim at better selection and stratification of patients in order to further evaluate the safety and effectiveness of these techniques, before wider use of this revolutionary approach for severe lung emphysema can be advocated.