Presented by: Joseph Shrager, MD
Chief, Division of Thoracic Surgery
Stanford University Medical Center
May 21, 2009
- Emphysema is a type of chronic obstructive pulmonary disease, the fourth leading cause of death in the U.S.
- In emphysema, the tissues that support the shape and function of the lung are destroyed
- Smoking is the leading cause of emphysema
- A large national study showed that lung volume reduction surgery (LVRS) can help certain patients with advanced, heterogeneous disease
- Only a limited number of patients qualify for LVRS
- Stanford is one of only a few centers expert in LVRS for emphysema
Normally, the lungs are very spongy and elastic. During inhalation, the chest wall inflates, expanding the tissue like a sponge soaking in water. A type of chronic obstructive pulmonary disease (COPD), emphysema is characterized by the gradual destruction of the air sacs at the ends of the airways called alveoli.
As it progresses, emphysema turns the alveoli into large, irregular pockets with holes in their inner walls. The deterioration makes the alveoli less effective and keeps oxygen from reaching the bloodstream. In addition, the elastic fibers that hold open the lung’s airways are slowly destroyed in emphysema, so they collapse during exhalation, making it difficult to breathe.
Smoking is the leading cause of emphysema, and COPD ranks as the fourth leading cause of death in the United States.
“Medical treatments may slow, but they do not reverse, the process,” said Joseph Shrager, MD, chief of the Division of Thoracic Surgery, who discussed ways to treat the disease at a presentation sponsored by the Stanford Health Library. “There’s really no therapy available to halt the downward course.”
Among non-surgical therapies, only oxygen therapy in patients with low blood oxygen levels appears to improve survival, he said.
Unlike other types of COPD, like chronic bronchitis and asthma, which are mainly inflammatory conditions, emphysema is a structural problem that is sometimes amenable to surgery, he said.
Surgery for emphysema evolved from a procedure used to treat giant bullae: When these large dilated airspaces were removed, nearby lung tissue could expand. The same logic held for emphysema—removing a portion of the damaged lung created more space for the working areas. The theory underlying lung volume reduction surgery (LVRS) is to reduce the lung size by taking out the parts that are taking up space but not contributing much to the exchange of oxygen and CO2. The airways will be held open better and the breathing muscles will return to a more normal position, making breathing easier.
“You are generally better off taking out more rather than less of the lung tissue,” said Dr. Shrager, who has performed 67 LVRS surgeries to date using both traditional sternotomy to open the chest and less-invasive thorascopic techniques.
LVRS was first used to treat emphysema in the 1950s but didn’t gain popularity until the 1990s. In 1997, the National Emphysema Treatment Trial was established to clarify the risks and benefits of the surgery. The study showed that certain patients had impressive, improvement in function and in quality of life, and it helped identify the criteria for the people who would most benefit from this approach. One group of patients even showed an improved longevity after the operation.
The ideal patient for LVRS has heterogeneous disease, with some sections of the lung more affected than others; has severe disease, with lungs more than double the normal size; and has emphysema, not chronic bronchitis. Age is not necessarily a factor—only physiology.
“Only a limited number of patients qualify for LVRS, and it’s important to be careful in patient selection,” said Dr. Shrager. “We screen at least twice as many patients as we do surgeries on because we want to provide a successful result. Stanford is one of only about 30 centers in the country experienced in treating emphysema by surgery, and the results have been outstanding.”
Though advanced cases can be treated with lung transplantation, Dr. Shrager said there is usually a wait of one year or more for a transplant, and four-year survival rates are about 60 percent. Also, with the need for lifelong immunosuppressant drugs, he added, “you are replacing one disease with another.” Lung transplant is therefore reserved for emphysema patients who are not candidates for LVRS.
About the Speaker
Joseph Shrager, MD, is a professor of cardiothoracic surgery and chief of the Division of Thoracic Surgery at Stanford. His clinical expertise is in surgery for lung cancer, emphysema, and mediastinal masses, and his research focus is in the molecular physiology of the diaphragm and other respiratory muscles. He received his MD from Harvard Medical School, trained in surgery at the University of Pennsylvania, and completed his thoracic surgery training at Massachusetts General Hospital. He served as chief of thoracic surgery at Pennsylvania Hospital and the Hospital of the University of Pennsylvania before joining Stanford in 2008. Dr. Shrager is listed as one of “America’s Top Doctors” and appeared for several years as a “Top Doc” in Philadelphia Magazine.
For More Information:
Stanford Division of Thoracic Surgery
Stanford Chest Clinic
National Emphysema Treatment Trial