- Lung blebs, air-filled cysts that form on the lung pleura, tend to be asymptomatic.
- Primary spontaneous pneumothorax (PSP), also known as a collapsed lung, is nearly 10 times less common in females than males.
- Tall stature, low-body mass index, and smoking are some risk factors for PSP.
- Treatment options for lung blebs can range from chest tube placement to thoracic surgery for pleural resection.
- Surgical intervention is usually only necessary following one or more recurrence of PSP.
- Compared to chest X-ray screening, low-dose computed tomography reduces lung cancer deaths by 20%.
Small air-filled blisters or cysts (blebs) can sometimes develop on the outer layer of your lungs called the pleura. A lung bleb may sound intimidating, but is usually easy to treat.
Often, blebs are asymptomatic, so you can have them without knowing. A person can have just one lung bleb or numerous blebs, and might never know they are there unless detected by a CT scan.
However, when sufficient air has become trapped in the pleural space, sometimes indicated by chest pain, blebs can trigger lung collapse (spontaneous pneumothorax).
Partial or wholly collapsed lungs can be life-threatening.
Lung blebs can also rupture the visceral pleura, which causes air to escape into the chest cavity or pleural space.
Bulla (plural: bullae) is the term used for air-filled cavities within the lung tissue, which sometimes occurs when several blebs are close to each other.
In this article, we’ll discuss who is at risk for lung blebs or bulla, and what causes them. We’ll also talk about the repercussions of an undiagnosed lung bleb or bulla and treatment options.
Who is at risk for lung blebs and bullae?
Men are far more likely than women to develop blebs and bullae by a margin of approximately 70% to 30%.
Likewise, there are certain high-risk occupations that could increase your risk of developing lung blebs, such as those that put you in close contact with dust, chemicals, fibers, germs, or smoke among other things.
Blebs and bullae are thought to be tied to an underlying disease such as bronchitis, emphysema (known as a chronic obstructive pulmonary disease (COPD)), cystic fibrosis, and even cancer.
However, even otherwise healthy young men (18-20+) can fall prey to a primary spontaneous pneumothorax (PSP) event, characterized by abnormal air accumulation in the pleural space.
That accumulated air can lead to a partial or complete lung collapse.
When patients have no other underlying medical conditions or triggering events, doctors call it primary spontaneous pneumothorax (PSP).
What causes blebs?
Researchers suspect that tobacco and cannabis smoking, emphysema (also called Chronic obstructive pulmonary disease, or COPD), and other lung conditions can lead to the development of blebs and bullae. That’s because blebs are especially prevalent in damaged lung tissue.
Emphysema is a type of COPD characterized by damage to the lung alveoli (air sacs) attached to the bronchi that complete the gaseous exchanges of air and carbon dioxide.
Emphysematous lung tissue can be particularly weak. Because the lung’s air sac tissue is weakened, it’s easier for air to escape the ruptured alveoli.
What is a pneumothorax?
Depending on the degree of collapse and a patient’s overall respiratory status, symptoms can include shortness of breath, difficulty breathing, and chest or chest wall pain.
In larger pneumothoraces or complete lung collapse, a patient may become cyanotic or develop other respiratory distress symptoms.
PSP usually isn’t tied to any underlying lung disease. And, clinical experience and research have shown that PSP isn’t caused by the simple rupturing of blebs and bullae.
Instead, it’s associated with diffuse and often bilateral (both lungs) abnormalities, such as pleurisy (pleura inflammation) or “water on the lungs” (pleural effusion), which is a gathering of fluid between the layers of tissue that line your lungs and your chest cavity.
Emphysematous changes in the alveoli, inflammation, and pleural porosity also contribute to PSP.
The symptoms of a collapsed lung may be mild or severe and include:
- Shortness of breath
- Chest pain, which could be stronger on one side or the other
- Sharp pain when you inhale
- Lung pressure that increases with time
- Lips or skin turning blue
- Increased heart rate
- Rapid breathing
In most pneumothorax cases, a chest X-ray is the first-line diagnostic tool. Doctors may also order an ultrasound to identify pneumothorax. For more detailed images, a CT scan may be necessary.
CT scans use multiple X-rays from different angles and computer-processed combinations to produce high-quality images of the pleural space and any blebs or bullae. Those images can determine the size and location of a bleb or bulla.
Technicians may also use computed tomography to help with the placement of a tube thoracostomy.
There are several pneumothorax treatment options, which may be a relief to hear. However, part of the reason for that is some treatments are debated in the medical community.
For instance, while oxygen has been the traditional treatment for small, asymptomatic, or mildly symptomatic pneumothorax, recent medical literature has questioned its effectiveness and recommended further study.
A tube thoracostomy (chest tube placement) is one of the most common lines of treatment. A chest tube or catheter evacuates air from the thoracic cavity, allowing the lung to heal and re-expand. The line is removed after a successful water seal trial, preventing air backflow into the pleural space.
Most surgeons consider video-assisted thoracoscopic surgery (VATS) to be the gold standard in treating pneumothoraces and blebs/bullae. VATS is a low-intrusion technique that can help with diagnosis and treatment.
Clinicians and researchers continue to discuss whether prophylactic VATS is advised. Generally, the criteria for surgical intervention in pneumothorax include:
- A persistent air leak
- Recurrence or multiple pneumothoraces
- Radiologically demonstrated large bulla
- Only partial lung expansion even with drainage and suction
- Tension pneumothorax
- Bilateral pneumothorax
- Spontaneous pneumothorax for high-risk occupations
During a VATS procedure, the surgeon inserts a thoracoscope (chest tube) and surgical instruments into the chest through small incisions in the chest wall. The thoracoscope transmits internal images of the chest to a video monitor to guide the surgeon.
It is unknown whether radiological evidence of pulmonary blebs or bullae is a predictor of pneumothorax. Many professionals are also skeptical that blebs or bullae can cause Primary Spontaneous Pneumothorax (PSP). For instance, nearly 89% of PSP patients with PSP in “normal lungs” had visible blebs or bullae when examined by an endoscope.
Typically, the first instance of symptomatic PSP is treated through observation and chest tube placement. Your doctor may recommend bleb or bulla resection combined with mechanical pleurodesis — manual scarring of the pleura to prevent the recurrence of spontaneous pneumothorax or pleural effusion — or a pleurectomy, which removes portions of the parietal pleura.
Resection may be indicated for returning patients who have more than one pneumothorax event.
While there’s no real consensus about PSP treatment, clinicians and surgeons tend to treat blebs conservatively because there are still many controversies regarding diagnostic tools and management plans.
A low-dose CT scan (LDCT) can help determine where blebs and bullae are.
Diagnostic imaging, such as a CT scan that reveals blebs or bullae, is also a predictor for surgical intervention, since the recurrence risk is progressively higher in patients who have had a previous occurrence of bleb ruptures or pneumothorax.
Low-dose computed tomography (LDCT) is the only recommended CT scan for people who are high-risk for lung cancer or coronary heart disease.
The National Lung Cancer Screening Trial (NLST) has shown that a LDCT scan reduces lung cancer mortality by 20% in high-risk subjects compared to chest X-ray screening. LDCT screening of heavy smokers is advised.
If you’re at a higher risk for lung bullae, you may want to consider receiving regular screening.
At Ezra, we know that the best defense against cancer is prevention through early detection.
Not only do we offer low-dose CT scanning — we also offer a full-body MRI scan, that takes less than an hour and screens your body for abnormalities and potential cancer in up to 13 organs.
To get a better understanding of your risk for cancer, take our five-minute quiz today.