Patients with heterogeneous emphysema distribution and little to no collateral ventilation benefit from Zephyr Endobronchial Valve treatment according to the results of the LIBERATE study published in the American Journal Respiratory and Critical Care Medicine.

With the exception of lung transplantation and bullectomy, only lung volume reduction surgery (LVRS) is an effective intervention for emphysema. However, not all patients can benefit from these procedures. Zephyr EBVs are small duckbill valves that are placed via bronchoscope to occlude an emphysematous lobe. Following EBV insertion, partial or full lobar atelectasis reduces hyperinflation and mimics the more invasive LVRS.

Gerard J. Criner, MD, of the Lewis Katz School of Medicine at Temple University, Department of Thoracic Medicine and Surgery in Philadelphia, Pennsylvania, and colleagues conducted a multicenter controlled trial and randomly assigned 190 patients to either EBV or standard of care (SoC) at 24 sites (128 to EBV and 62 to SoC).