Thoracentesis, also known as a pleurocentesis, is a technique used to drain and assess pleural fluid buildup in the chest cavity. It is a minimally invasive procedure with diagnostic and therapeutic applications for malignant pleural mesothelioma.

A common result of mesothelioma is fluid buildup between the layers of the pleural lining surrounding the lungs. This buildup, known as a pleural effusion, often results in pain and breathing difficulties. While it is considered normal to have some fluid present in the pleural space, an excess amount requires removal with thoracentesis or another technique to relieve symptoms and avoid complications.

Facts About Thoracentesis

• When excess pleural fluid builds up around the lungs, it must be removed.
• Thoracentesis uses a hollow needle to extract the fluid. 
• It can be used to diagnose and treat causes of pleural effusion.
• It can also provide palliative benefits for late-stage mesothelioma patients.
• Other names for thoracentesis include “pleural tap,” “pleurocentesis,” and “pleural fluid aspiration.” 

The main advantage of thoracentesis over a chest x-ray is that it is more likely to identify the cause of the pleural effusion. Pleural effusion can be caused by multiple diseases. The fluid collected via thoracentesis is analyzed to help determine the cause. The results may be suggestive of mesothelioma. A biopsy of the cancerous tissue is performed to confirm the diagnosis. 

Palliative Thoracentesis

Palliative care is traditionally used in late-stage mesothelioma. Its primary function is to improve an individual’s quality of life by reducing their pain and discomfort, rather than attempting to cure the disease. By draining a pleural effusion, the pressure on the lungs and chest is significantly reduced, alleviating pain and shortness of breath. In turn, more room is available for lung expansion, which helps improve stamina. 

Thoracentesis vs. Other Treatments for Pleural Effusion

Thoracentesis is a less common method for treating a pleural effusion due to mesothelioma. Alternative procedural and surgical treatments include

• Indwelling Pleural Catheter: a one-time procedure that provides continuous drainage of the pleural effusion, avoiding the need for repeat thoracentesis
• Pleurodesis: a procedure that drains extra fluid and seals up the pleural space to prevent future buildup
• Surgery: a common treatment to remove cancerous pleural tissue in patients without advanced disease

Patients with late-stage mesothelioma are often more concerned with quality of life over quantity of life. In these circumstances, thoracentesis, which is less invasive and does not require hospitalization, may be a more therapeutic alternative. 

Thoracentesis: Step-by-Step

A patient undergoing thoracentesis can remain in a seated position or lie on their unaffected side or back, depending on the circumstances. The site of insertion is sterilized and then numbed with local anesthetic. Next, a long, hollow needle, known as a cannula, is inserted between the ribs using ultrasound or CT guidance. The patient should be able to feel pressure but little to no pain. With the cannula inserted, the doctor drains the pleural effusion until some or all of the fluid has been removed, depending on the condition. The whole process typically lasts about 15 minutes, providing there are no complications.

The extracted fluid is then sent for analysis to help determine the cause of the pleural effusion. The needle is removed, and the insertion site is cleaned and dressed. Next, a chest x-ray is ordered to assess how much fluid was taken off and to screen for possible complications of the procedure.¹ 

Risks and Complications of Thoracentesis 

As with all procedures, complications can occur, even though thoracentesis is relatively simple. The most common complication is pneumothorax or a collapsed lung. A pneumothorax can occur if the cannula accidentally punctures the lung or if there is a disturbance in the volume of air within the pleural space. Other complications may include

• Pain
• Bleeding
• Infection
• Injury to the diaphragm
• Laceration to the liver or spleen
• Tumor seeding, or manual deposition of cancerous cells into healthy tissue

Some patients have a higher risk of complications than others. Patients who have previously undergone extensive lung surgery, have a clotting disorder, or have chronic lung conditions, such as emphysema or asthma, may face greater risks. Certain symptoms of the primary disease are also associated with an increased risk of complications. The risk of pneumothorax is significantly decreased when thoracentesis is aided with ultrasound guidance.²