What are Giant Bullae?
A giant bulla is a complication of emphysema. In areas of the lung completely damaged
by the disease, air pockets can develop. These areas threaten the patient’s health
not only because of the underlying emphysema. As an air pocket—a bulla—grows, it takes
up space in the chest cavity and can encroach on the lungs. Severe disruption of normal
lung function due to the crowding and pressure is a common result.
Bullous emphysema is also known as vanishing lung syndrome. It is most often treated
by surgical removal of the bulla, which can grow to 20 centimeters—more than a foot—in
diameter. A bulla that takes up a third or more of the space in and around the affected
lung is called a giant bulla. Because of its close association with emphysema, giant
bullae are most often found in older patients who smoke or used to smoke. A giant
bulla is classified as a chronic obstructive pulmonary disease (COPD), along with
chronic bronchitis and asthma.
The Mechanics of Giant Bullae
Emphysema causes a loss of elasticity in the walls of the small air sacs in the lung.
Eventually, the walls of the sacs stretch and break, which creates larger, less efficient
sacs that can’t properly handle the normal exchange of oxygen and carbon dioxide that
occurs during breathing. Difficulty in fully exhaling usually leads to the capture
of air in the lungs, known as hyperinflation. A giant bulla is a large cavity of captured
But giant bullae begin to take on an identity of their own. On chest x-rays they appear
as entities somewhat independent of the remaining normal structure of the affected
lung, separated by a thin, fibrous, irregular membrane. As they fill with air and
grow, giant bullae can also fill with fluid to create an infectious mix. Not only
can a giant bulla obstruct the function of the host lung; it can put pressure on the
other lung and interfere with its proper function. So even tissue not affected by
the disease becomes less effective.
Most giant bullae reach their size and status slowly over time. But there are instances
of bullae experiencing “growth spurts” and changing the situation in the patient’s
chest cavity rather quickly. Bullae also can disappear or “deflate” either spontaneously
or following an infection or hemorrhage.
Symptoms of Giant Bullae
Because of its size, a giant bulla makes its presence known and produces symptoms.
On its way to becoming a giant bulla, however, the air pocket in the lung doesn’t
show symptoms beyond what the patient is experiencing from the underlying emphysema.
Symptoms from a giant bulla can include:
- Pressure in the chest
- Difficulty drawing breath
- A bloated feeling
- General fatigue (due to lack of oxygen)
Causes of Giant Bullae
Smoking cigarettes is by far the most common cause of emphysema. And emphysema is
by far the most common cause of giant bullae in the lungs. There are limited cases
of bullae appearing in the lungs as a result of bronchial illnesses from high air
pollution levels, or occupational exposure to chemical fumes.
Despite the fact that vanishing lung syndrome is a condition most often found in older
people, giant bullae have also been found in young men.
Diagnosing Giant Bullae
A diagnosis seeks to determine whether the patient’s lung functions are being impeded
by the pressure caused by a giant bulla or the general effects of the underlying emphysema.
Like most other lung cancers, doctors rely on non-invasive chest x-rays and the more
detailed CT (computed tomography) scans to initially locate and identify giant bullae.
For more precise information, a doctor might retrieve and analyze a sample of the
bulla’s cells or fluid within the bulla. Retrieval is performed by inserting a long
surgical needle into the affected area, or by a localized surgical biopsy.
Treating Giant Bullae
In virtually every case, the treatment for a giant bulla is a bullectomy—surgical
removal of the growth. Patients with a giant bulla are divided into four groups:
- Group I—single giant bulla with underlying normal lung
- Group II—multiple giant bullae with underlying normal lung
- Group III—multiple bullae with underlying lung broadly affected by emphysema
- Group IV—multiple bullae with underlying lung affected by other diseases
Patients in the first two groups are “ideal candidates” and stand the best chance
of success. Success is defined as both a lessening of the pressure and other symptoms,
and the recovery or restoration of lung function. There are possible complications,
such as an air leak or an infection in the incision.
Group III and IV patients cannot expect similar success rates. In cases where the
lung is widely destroyed, they might be advised to undergo a lung transplant.
A Real Improvement
There are really only two lung cancer surgeries that actually restore lung function
as well as relieve symptoms. One is lung volume reduction surgery (LVRS), and the
other is a bullectomy—the removal of a giant bulla. Most patients report an increased
ability to draw breath as well as relief from the symptoms of the bulla.