BACKGROUND: Doctors at the University of Maryland Medical Center are testing a new approach to treat advanced emphysema, a common lung disease. They have implanted a miniature one-way valve in the lungs of a patient with emphysema as part of a 20-center-randomized study of 270 patients to see if the valves improve lung function and exercise tolerance. Known as an endobronchial valve procedure, the therapy is minimally invasive and does not involve surgery to remove part of the diseased lung.
HOW IT WORKS: In patients with emphysema, inhaled air becomes trapped in the diseased portion of the lung, making it difficult to exhale. The trapped air fills the lung like a balloon, constricting the healthy lung tissue. The one-way valves release trapped air and prevent its return by causing the diseased portion of the lung to deflate, called lung volume reduction. This creates space for healthy tissue to function normally. The valves are implanted with a bronchoscope, a thin tube equipped with a camera that allows physicians to look inside the lungs. The valves are about the size of a pencil eraser and have tiny metal tongs or tines that attach to the lung.
ABOUT EMPHYSEMA: Emphysema is a lung disease in which the walls of the air sacs in the lungs fracture or burst. Those that remain enlarge to make up for the loss. Most commonly caused by cigarette smoke, the disease leads to a progressive, irreversible breakdown of lung tissue, in which the air sacs are badly damaged. This reduces the elasticity of the lungs, impairs their ability to inflate and deflate normally, and reduces the transfer of oxygen to the blood, so that patients constantly feel out of breath.