Endobronchial valve
Encyclopedia
An endobronchial valve is an implantable medical device--a small, one-way valve, which is implanted in an airway in the pulmonary system to treat one of several lung conditions. The one-way endobronchial valve is typically implanted such that when a patient exhales, air is able to flow through the valve and out of the lung compartment that is fed by that airway, but when the patient inhales, the valve closes and blocks air from entering that lung compartment. Thus, an implanted endobronchial valve typically helps a lung compartment to empty itself of air. This has been shown to be beneficial in the treatment of emphysema
, where lungs lose their elasticity and thus cannot contract sufficiently to exhale air, leading to air trapping and hyperaeration. When one or more diseased portions of an emphysematous lung are made to deflate and collapse, other healthier portions of the lung have more room in the chest cavity to inhale and exhale, pressure is removed from the diaphragm
, and even the heart may function better as the hyperinflated lung becomes smaller. Endobronchial valves have also been shown to be beneficial in treatment of persistent air leaks in the lungs. It has also been theorized that endobronchial valves may be useful for treatment of tuberculosis
and its complications.
Endobronchial valves were developed primarily by the start-up medical device company Emphasys Medical (now Pulmonx - Redwood City, California) as a minimally invasive alternative to lung volume reduction surgery for emphysema. In lung volume reduction surgery, a surgeon cuts into a patient's chest and cuts out one or more most diseased portion(s) of a lung. Endobronchial valves were designed to replicate the effects of that procedure without requiring incisions, by simply allowing the most diseased portions of the lung to collapse. Emphasys was purchased by Pulmonx in 2009, and Pulmonx currently markets the Zephyr® endobronchial valve (developed by Emphasys) in Europe, Australia, China and many other locations outside the U.S. Pulmonx also sells the Chartis® Pulmonary Assessment System, which is a patient assessment tool used with endobronchial valves to help physicians target appropriate lung compartments for treatment. Another company, Spiration (Seattle, Washington), developed a different type of endobronchial valve and was acquired by Olympus in 2010.
Endobronchial valves may be the first successful medical device treatment of emphysema, a disease that affects billions of patients worldwide and has no known cure. Endobronchial valves are typically implanted using a flexible delivery catheter
advanced through a bronchoscope, and thus they are very minimally invasive. The valves are also removable if they are not working properly. When properly used and correctly implanted, endobronchial valves have been shown to improve patients' ability to breathe, walk, exercise and perform their daily activities. Although not yet approved by the Food and Drug Administration
for emphysema treatment in the United States, endobronchial valves are available in many other locations throughout the world and should be available in the U.S. eventually.
Emphysema
Emphysema is a long-term, progressive disease of the lungs that primarily causes shortness of breath. In people with emphysema, the tissues necessary to support the physical shape and function of the lungs are destroyed. It is included in a group of diseases called chronic obstructive pulmonary...
, where lungs lose their elasticity and thus cannot contract sufficiently to exhale air, leading to air trapping and hyperaeration. When one or more diseased portions of an emphysematous lung are made to deflate and collapse, other healthier portions of the lung have more room in the chest cavity to inhale and exhale, pressure is removed from the diaphragm
Diaphragm
-Optics and photography:* Diaphragm , a stop in the light path of a lens, having an aperture that regulates the amount of light that passes* Diaphragm shutter, a type of leaf shutter consisting of a number of thin blades in a camera-Acoustics:...
, and even the heart may function better as the hyperinflated lung becomes smaller. Endobronchial valves have also been shown to be beneficial in treatment of persistent air leaks in the lungs. It has also been theorized that endobronchial valves may be useful for treatment of tuberculosis
Tuberculosis
Tuberculosis, MTB, or TB is a common, and in many cases lethal, infectious disease caused by various strains of mycobacteria, usually Mycobacterium tuberculosis. Tuberculosis usually attacks the lungs but can also affect other parts of the body...
and its complications.
Endobronchial valves were developed primarily by the start-up medical device company Emphasys Medical (now Pulmonx - Redwood City, California) as a minimally invasive alternative to lung volume reduction surgery for emphysema. In lung volume reduction surgery, a surgeon cuts into a patient's chest and cuts out one or more most diseased portion(s) of a lung. Endobronchial valves were designed to replicate the effects of that procedure without requiring incisions, by simply allowing the most diseased portions of the lung to collapse. Emphasys was purchased by Pulmonx in 2009, and Pulmonx currently markets the Zephyr® endobronchial valve (developed by Emphasys) in Europe, Australia, China and many other locations outside the U.S. Pulmonx also sells the Chartis® Pulmonary Assessment System, which is a patient assessment tool used with endobronchial valves to help physicians target appropriate lung compartments for treatment. Another company, Spiration (Seattle, Washington), developed a different type of endobronchial valve and was acquired by Olympus in 2010.
Endobronchial valves may be the first successful medical device treatment of emphysema, a disease that affects billions of patients worldwide and has no known cure. Endobronchial valves are typically implanted using a flexible delivery catheter
Catheter
In medicine, a catheter is a tube that can be inserted into a body cavity, duct, or vessel. Catheters thereby allow drainage, administration of fluids or gases, or access by surgical instruments. The process of inserting a catheter is catheterization...
advanced through a bronchoscope, and thus they are very minimally invasive. The valves are also removable if they are not working properly. When properly used and correctly implanted, endobronchial valves have been shown to improve patients' ability to breathe, walk, exercise and perform their daily activities. Although not yet approved by the Food and Drug Administration
Food and Drug Administration
The Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...
for emphysema treatment in the United States, endobronchial valves are available in many other locations throughout the world and should be available in the U.S. eventually.