Valve Treatment – A Minimally Invasive Approach For Emphysema
Background: Emphysema is a type of COPD in which lung tissue is
destroyed. As a result, the person is unable to completely empty air out of the lungs. This is called lung hyperinflation which is a major cause of shortness of breath and poor quality of life.
Surgery is one way to remove parts of the lung that are hyperinflated. However, this approach is seldom used because it is invasive and carries some risk.
A safer approach is to place valves into breathing tubes in areas of poorly functioning lungs. These one-way valves allow air to leave the lungs and prevent air entry; this reduces the amount of air trapped in the lung. The valves are placed using a tube (called a bronchoscope) that is passed into the mouth and then advanced into the breathing tubes.
On left: Normal size of lungs.
On right: lungs are larger due to inability to exhale completely. This is called hyperinflation.
Diagram of a scope passed into the mouth and then advanced into the lungs (called bronchoscopy)
An endobronchial valve (called a Zephyr valve) is shown on the left. Until now, only two studies have been completed to evaluate this type of valve placed into breathing tubes. Each study was done at a single medical center. This makes it difficult to know if the results would be similar at other hospitals.
Study: A study evaluated placement of Zephyr endobronchial valves at 17 different medical centers in Europe. All patients had severe emphysema with no passage of air between parts of the lung (no collateral ventilation). The main outcome was the percentage of subjects with a 12% or higher increase in the amount of air exhaled in one second (FEV1) compared to before the procedure. The findings were published in the December 15, 2017, issue of the American Journal of Respiratory and Critical Care Medicine (volume 196; pages 1535-1543).
Results: 65 subjects received placement of one or more valves while 32 subjects continued to receive normal care (the comparison group). At 3 months after valve placements, 55% improved their breathing tests by at least 12%, while only 7% in normal care group showed improvements. At 6 months after treatment, the valve group had an average increase in FEV1 of 21%, while there was 9% decrease in those who received normal care.
In addition, the valve treatment group had significantly better scores for shortness of breath and for quality of life and walked farther on the six minute walk test.
Lung collapse (called pneumothorax) occurred in 29% of those who received valve placement.
Conclusions: The authors concluded that valve treatment resulted in clinically meaningful benefits in lung function, shortness of breath, exercise tolerance, and quality of life. They also considered that there was “an acceptable safety profile.”
My Comments: The findings in this study provide additional support for the benefits of Zephyr valve placements to “deflate” the lungs in those with advanced emphysema. From the individual’s perspective, the most important outcomes were improved shortness of breath, ability to walk farther, and quality of life.
Identifying the “right” individual with emphysema who will benefit from valve placement is important. Before entering the study, all subjects had to qualify by having: 1. low breathing test results; 2. a CT scan of the chest which demonstrated evidence of emphysema that was at least 10% different between the “bad” part of the lung and an adjacent “good” part of the lung; and 3. no evidence of collateral ventilation using a special bronchoscopy test (see my post on December 27, 2015, for measuring collateral ventilation).
One type of endobronchial valve being evaluated is called Zephyr.