Interventional Chest/Diagnostic Procedures
Endobronchial valve therapy receives FDA approval for bronchoscopic LVR
Lung volume reduction surgery (LVRS) is an established approach to improve exercise capacity and lung function in patients with heterogeneous emphysema and may confer survival benefit in patients with apical-predominant disease (Fishman, et al. N Engl J Med. 2003;348:2059). Despite this, LVRS case numbers remain low due to patient and procedural morbidity. Bronchoscopic alternatives for LVRS have advanced considerably over the last decade with endobronchial valve (EBV) therapy emerging as a viable option for select subsets of patients with heterogeneous emphysema. Endobronchial valves are removable devices placed in segmental/subsegmental airways, which allow efflux of air during exhalation but close during inspiration, resulting in distal atelectasis in the absence of collateral ventilation.
The LIBERATE study, a multicenter randomized controlled trial demonstrated improvement in FEV1 ≥15% in 48% of patients after EBV placement compared with 17% of patients receiving standard medical therapy has resulted in FDA approval (Criner G, et al. Am J Respir Crit Care Med. 2018 May 22. doi: 10.1164/rccm.201803-0590OC. [Epub ahead of print]). Patients with EBV had improved subjective dyspnea scores, residual volume, and 6-minute walk distance; however, the pneumothorax rate was 27%.
All study patients with EBV underwent bronchoscopic evaluation for collateral ventilation using a proprietary digital system, which measures expiratory airflow in target airways to establish the presence of collateral ventilation. Previous data have demonstrated improved transplant-free survival when implanted EBVs result in atelectasis of the target lobe, which requires intact interlobar fissures (Garner, et al. Am J Respir Crit Care Med. 2016;194:519). Ongoing clinical trials are attempting to clarify the role of EBV therapy in different phenotypes of COPD, including patients with homogenous emphysema. Long-term follow-up data will be important in determining the broader implementation of bronchoscopic lung volume reduction moving forward.
Vivek Murthy, MD
Jason A. Akulian, MD, FCCP
Steering Committee Members
Pediatric Chest Medicine
Cystic fibrosis (CF) is a progressive genetic disorder resulting in multiorgan disease with progressive respiratory decline. CF is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. This codes for the CFTR anion channel and contributes to the movement of salt in and out of the cell. CFTR dysfunction leads to thickened secretions in the lungs and other organs, such as the gut and pancreas. This leads to more lung infections and other organ dysfunction that ultimately leads to premature death.
Established CF treatments include pulmonary and nutritional interventions. CFTR modulators are recent novel therapies that improve the function of CFTR and target the basic defect. Two types of modulator drugs (potentiators and correctors) have been developed with effectiveness depending upon the kind of CF mutation the person has.
CFTR potentiators, such as Kalydeco® (ivacaftor monotherapy), increase the likelihood that the CFTR channel will transport ions through the cell membrane, ie, they increase the channel’s “open probability.” Kalydeco has been approved for patients 12 months or older with mutations that result in partial CFTR protein function in the cell membrane. CFTR correctors, such as lumacaftor and tezacaftor, increase the amount of normal or mutated CFTR protein that gets transported, increasing the amount of CFTR protein on the cell surface. Combination drugs such as Orkambi® (lumacaftor/ivacaftor) for patients 2 years and older, and Symdeko™ (tezacaftor/ivacaftor) for patients 12 years and older, are considered in patients homozygous for the F508del mutation.
Sumit Bhargava, MBBS, FCCP
Steering Committee Member