Endoscopic lung volume reduction. A European perspective.
Endoscopic lung volume reduction (ELVR) offers a novel therapeutic approach for patients with severe pulmonary emphysema. In Europe, several types of ELVR are available. The choice of ELVR technique depends both on the distribution of emphysema and the presence or absence of interlobar collateral ventilation (CV). For this reason, accurate patient selection is crucial.
Bronchial valve implantation is the technique that has been most widely studied and represents an effective treatment option for patients with severe heterogeneous upper- or lower-lobe-predominant emphysema. Lobar occlusion and low interlobar CV are predictive factors for positive outcomes. Lung volume reduction coil implantation is an effective option for patients with upper- and lower-lobe-predominant emphysema, and the efficacy is not influenced by CV; however, the technique should be regarded as mainly irreversible.
Polymeric lung volume reduction relies on irreversible scarring and fibrosis and is especially effective in patients with chronic obstructive pulmonary disease classified as Global Initiative for Chronic Obstructive Lung Disease stage III; it also offers benefits to patients with upper-lobe-predominant emphysema and those with homogeneous emphysema. Like polymeric lung volume reduction, bronchoscopic thermal vapor ablation is also not influenced by CV and represents a good option for patients with upper-lobe-predominant emphysema. Exhale airway stents for emphysema-"airway bypass"-appeared to be a promising technique but proved ineffective in randomized clinical trials, likely in part due to long-term occlusion of the drug-eluting stents.
Although European physicians are able to choose from a host of approved bronchoscopic interventions for emphysema, future studies for techniques in use are needed to further clarify patient selection criteria.
