Date Published: 27 November 2005
Non-surgical lung volume reduction treatment for emphysema
Investigational therapy may improve breathing among patients with advanced emphysema
Doctors at the University of Maryland Medical Center are testing a new approach to treat advanced emphysema, a lung disease most commonly caused by cigarette smoke. They have implanted a miniature one-way valve in the lungs of a patient with emphysema as part of a 20-center, randomized study to see if the valves improve lung function and exercise tolerance. The therapy, called an endobronchial valve procedure, is minimally invasive and does not involve surgery.
Martine Cantler of Owings, in Calvert County, Md., is the first patient to receive the therapy as part of the study in Baltimore. She says she is doing quite well nearly six months after the procedure.
" I am breathing better than I have in several years," she said.
Her symptoms of emphysema worsened last year:
" I couldn't climb stairs, and couldn't do chores without running out of breath. Now, I'm much more active," said Ms. Cantler.
The study is known as the Endobronchial Valve for Emphysema Palliation Trial or VENT. Eventually, 270 participants across the United States and Europe will receive the investigational treatment. The VENT study is assessing patient quality of life and the procedure's cost effectiveness.
" We believe this procedure could make a big difference in helping patients breathe more easily if it reduces the diseased portions of the lung,"
said Mark J. Krasna, M.D., professor of surgery at the University of Maryland School of Medicine and head of Thoracic Surgery at the University of Maryland Medical Center.
" We anticipate that patients will have fewer side effects and complications compared to lung volume reduction surgery,"
said Dr. Krasna, who is the principal investigator of the VENT study at the University of Maryland.
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 used in this experimental procedure release trapped air, and prevent its return. The valves cause diseased parts of the lung to deflate, an effect called lung volume reduction, which makes space for healthy tissue to function normally. The valves are designed to be removable, providing the potential to reverse the procedure.
During the endobronchial procedure, the valves are implanted in the lungs with a bronchoscope, a thin tube equipped with a camera that allows physicians to look inside the lungs. A bronchoscope is usually used to take biopsies and samples of secretions. The valves are about the size of a pencil eraser and have tiny metal tongs or tines that attach to the lung.
In the surgical counterpart to the endobronchial valve procedure, known as lung volume reduction surgery, surgeons remove part of the diseased lung to provide space for the lung to expand and contract. The University of Maryland Medical Center participated in a national study called the National Emphysema Treatment Trial, which recently concluded that lung volume reduction surgery could benefit certain patients. The University of Maryland Medical Center is one of a select group of centers in the United States approved by Medicare to perform the complex procedure. So far, 18 patients have undergone the surgery at the University of Maryland Medical Center.
More than 40,000 patients suffer from emphysema in Maryland, according to E. James Britt, M.D., a pulmonologist involved in the VENT study who is a professor of medicine at the University of Maryland School of Medicine. Nationally, emphysema affects more than three million Americans. It costs more than $2.5 billion in annual health care expenses and causes or contributes to 100,000 deaths in the U.S. each year.
Emphysema leads to a progressive, irreversible breakdown of lung tissue, in which the lung's alveoli or air sacs are damaged. This breakdown reduces the elasticity of the lungs, impairs their ability to inflate and deflate normally, impairs the transfer of oxygen to the blood, and leaves patients constantly feeling out-of-breath.
Source(s): University of Maryland, (USA)