June 01, 2018
An estimated 3.1 million Americans have been diagnosed with emphysema, the life-threatening condition most commonly associated with smoker's lung and long-term tobacco use.
As a severe and related form of chronic obstructive pulmonary disease (COPD), the consequences of emphysema can prove anywhere from debilitating to fatal. Pulmonary specialists use a diagnostic tool known as the BODE index to determine how COPD and emphysema will impact a patient's health and lifestyle.
Those who have severe emphysema have difficulty breathing because oxygenated air entering the lungs becomes trapped. Damage to alveoli, the tiny air sacs that facilitate respiration, creates ruptures that retain air and prevent it from being expelled before a patient can take the next breath,
Existing treatments for emphysema require lung volume reduction surgery to remove portions of damaged tissue, a risky and invasive procedure that can potentially result in infection, respiratory failure or other complications. While the reward may be high for patients who are able to resume an active lifestyle, less invasive treatment methods remain a goal for medical researchers.
In a landmark clinical trial, scientists at Temple University demonstrated the effectiveness of a new minimally invasive treatment for emphysema — an endoscopic lung reduction therapy that uses a one-way valve to deflate damaged areas of the lungs.
The Zephyr Endobronchial Valve, developed by California-based Pulmonx Corp., was implanted in more than 190 emphysema patients who participated in Temple's LIBERATE clinical trial.
“The LIBERATE trial was designed to see whether Zephyr EBV was safe and effective over a relatively longer time frame, out to one year,” said Gerard Criner, chair and professor of thoracic medicine and surgery at the Lewis Katz School of Medicine, who served as principal investigator of the study.
Previous clinical trials using the Zephyr EBV were both shorter-term and tracked fewer patients than the current trial, whose findings were presented last month at the ATS 2018 International Conference and published in the American Journal of Respiratory and Critical Care Medicine.
Implanted using a bronchoscope and flexible delivery catheter, the valve works by preventing the hyperinflation that occurs when air becomes trapped in damaged lung tissue. The intended effect is to mimic the mechanism of lung volume reduction surgery, shrinking the diseased regions and enabling more efficient functioning in healthier regions.
Criner and his colleagues found that Zephyr EBV successfully reduced shortness of breath, improved lung function and enhanced quality of life with benefits lasting at least one year after the intervention. Almost half of patients in the study experienced improved lung function compared to just 17 percent of those treated using correct standard approaches for managing emphysema.
Patients receiving standard-of-care treatments did not see their conditions change or worsen over time, but those who responded to the Zephyr therapy continued to see clinical benefits 12 months after receiving treatment. Long-term frequency of adverse events were comparable between both groups.
Researchers from around the world contributed to the LIBERATE study, which was funded by Pulmonx. A similar one-way valve is also under development by Olympus.