Pleurodesis: Definition, Procedure, and Indications

Pleurodesis is a procedure sometimes performed for people with pleural effusions (the build up of fluid between the membranes surrounding the lungs) that recur as a result of lung cancer and other conditions. In the procedure, a chemical is placed between the two membranes that line the lungs causing them to scar together. This scarring obliterates the pleural space so that fluid can no longer build up in the space. It is done in the operating room with a general anesthetic. The procedure is very effective in general, but may be less effective if there are several areas of effusion present (loculated effusions). In this case, other procedures, such as removing the pleura may be needed. With lung cancer, an alternative to pleurectomy in the advanced stages is to place a stent between the pleural cavity and the outside of the body, allowing people to remove the fluid that builds up at home. What else should you know about this procedure?

Pleurodesis is a procedure that is designed to get the two layers of the lung lining (the pleura) to stick together. This works to obliterate the space between the layers (the pleural cavity) so that fluid (water, blood, or pus) can no longer build up between the layers. There is ordinarily three to four teaspoons of fluid between the outside (parietal) and inside (visceral) pleural membranes. When a pleural effusion occurs, due to both benign and malignant causes, this amount of fluid builds up and the pleural space can sometimes hold a few extra liters of fluid.

Before a pleurodesis is recommended, doctors want to first see that a pleural effusion (or pneumothorax) will recur again in the future. If it is a one-time event, performing a thoracentesis to remove the fluid is often all that is needed. Unfortunately, benign pleural effusion (and pneumothoraces) and especially malignant pleural effusion often recur.

In a pleurodesis, a chemical is injected between the two pleural layers via a chest tube. These chemicals then cause inflammation which in turn causes scarring. This scarring pulls and holds the two membranes together so that fluid or air can no longer build up and collect in the space. The inner pleural lining is called the visceral pleura, and the outside pleural membrane is called the parietal pleura. Depending upon the underlying condition, the procedure may be done through a small incision (video-assisted thoracoscopy or VATS) or a thoracotomy (open lung surgery.)

There are two types of pleurodesis, which are often used together:

• Mechanical pleurodesis causes inflammation and scarring by mechanically rubbing the parietal (outside) pleura with gauze.
• Chemical pleurodesis involves injecting a chemical (most often talc) between the pleural membranes to create inflammation and scarring (fibrosis.)

There are several conditions for which a pleurodesis may be done, which in turn result from medical conditions such as lung cancer, mesothelioma, cystic fibrosis, and other illnesses.

• Malignant pleural effusion – People with lung cancer, breast cancer, or metastases to the lung from other cancers may develop a malignant pleural effusion, a pleural effusion which contains cancer cells. When this is the case there are 2 options. One is to do a thoracentesis and place a stent that will continually drain the fluid in the effusion to another part of the body (an indwelling pleural catheter or tunneled pleural catheter.) The other is pleurodesis. 
• Recurrent pleural effusion
• Persistent pneumothorax - A pneumothorax is a term used to describe a collapsed lung. If a pneumothorax occurs and a chest tube is placed, the pneumothorax often resolves. If the pneumothorax persists (a persistent air leak,) or goes away and then recurs, further treatment to resolve the pneumothorax or prevent a recurrence are needed.
• Recurrent pneumothorax

Before a pleurodesis is performed, physicians consider several things.

Most importantly, it’s important that removing the pleural fluid results in an improvement of symptoms (decreased shortness of breath) for those with cancer. A pleural effusion which is not causing symptoms such as chest pain or shortness of breath in this setting is usually left alone. In addition to this, some physicians recommend the procedure only if life expectancy is greater than one month.

On the other hand, spontaneous pneumothoraces may occur in people who are young and otherwise healthy. In this case, the procedure may be done to prevent another pneumothorax from occurring in the future.

In general, a pleurodesis procedure is well tolerated. For a certain percentage of people, the procedure will be ineffective and further treatment with an indwelling catheter to drain the fluid, or a pleurectomy (removal of the pleural) will be needed. Another concern, for people who may have a lung transplant in the future, is that a previous pleurodesis can make this procedure more difficult.

For those who have pleural effusion due to minor conditions, or have recurrent pneumothoraces (often related to a hereditary factor,) pleurodesis can bring reassurance that another effusion or pneumothorax will not occur when immediate medical help is not available.

Example: Frank's lung cancer was causing recurrent pleural effusions, so his doctor recommended that he have a procedure called pleurodesis.