Gerard J. Criner

Lung volume reduction surgery (LVRS) has long been the only non-medical option for patients with severe emphysema who did not respond well to optimal medical therapy. The FDA has recently approved two minimally invasive endobronchial valves (EBV) that mimic the effects of LVRS and can be placed endoscopically as a new option for these patients.

“Endobronchial valves have been worked on since the late 1990s,” said Gerard J. Criner, MD, ATSF, professor of thoracic medicine and surgery at the Lewis Katz School of Medicine at Temple University in Philadelphia. “This is a great breakthrough for patients. Devices and treatments that were previously only available as research tools are now available for selected patients.”

Dr. Criner will co-chair the ATS’s most focused and comprehensive exploration of EBV technology and application during this morning’s session, along with Daniela Gompelmann, MD, principal investigator at Translational Lung Research Center in Heidelberg, Germany, and Felix Josef Friedric Herth, MD, PhD, head of pneumology and critical care medicine at Heidelberg University in Germany. All three co-chairs have participated in EBV clinical studies and will present during the symposium.

EBVs are not new at ATS. The Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines first suggested the used of one-way endobronchial valves or coils as endoscopic options for lung volume reduction in 2017. ATS 2018 revealed the results of the pivotal LIBERATE study, which led to the FDA approval of the Zephyr Endobronchial Valve (Pulmonx Corp) as well as the EMPROVE study, which led to FDA approval of the Spiration Valve System (SVS) (Olympus). Both trials showed statistically and clinically significant improvement in lung function and quality of life in patients with severe emphysema.

The two devices provide similar clinical benefits as LVRS but without strict surgical selection criteria or the perioperative morbidity and mortality associated with surgery. Zephyr uses small duckbill-shaped valves to occlude an emphysematous lobe while SVS uses umbrella-shaped valves.

Both valves are deployed to the bronchi using bronchoscopic guidance to dramatically reduce airflow to portions of the lung that are distal to the valve. Both valves allow movement of air and mucus in the proximal direction. The one-way flow results in lobar deflation, which leads to partial or full lobar atelectasis and effectively reduces hyperinflation by mimicking the mechanisms of LVRS to improve the function of the remaining lung tissue.

“Hyperinflation is probably one of the most important pathophysiologic causes in people with severe emphysema that contributes to worsening lung function,” Dr. Criner said. “This is the most significant noninvasive method to reduce air trapping. If you can reduce air trapping and make the lungs smaller, you will improve lung and respiratory muscle function, cardiac function, and the patient’s ability to walk and to exercise with less shortness of breath. These are meaningful physiological changes for our patients that are associated with an improved quality of life.”

EBVs are not for all severe emphysema patients. Patient selection criteria must ensure that patients have enough emphysematous destruction of the targeted lobe, have evidence of little to no collateral ventilation to the target lobe, and are fit enough for an interventional procedure. Pneumothorax is the most important complication associated with endobronchial valve treatment with lobar occlusion in patients with little to no collateral ventilation.  Patients require hospitalization post-treatment to monitor for this complication and appropriate measures need to be taken to treat a pneumothorax based on individual circumstances.

“This is a novel option for patients with severe emphysema,” Dr. Criner said. “And it is the first FDA-approved and commercially available intervention that can be done endoscopically, a less invasive tool for pulmonologists whose patients are still symptomatic despite optimal medical therapy.”