Pleurodesis is a form of mesothelioma surgery that is used to manage pleural effusions, a very common problem in patients with pleural mesothelioma. A pleural effusion is a buildup of fluid between the parietal pleura that lines the chest wall and the visceral pleura that covers the lung. This fluid buildup stops lung function, causing shortness of breath, or dyspnea.
How is mesothelioma surgery used to achieve pleurodesis?
The fluid is drained in one of two ways: the first is by tube thoracostomy. In this procedure, a chest tube between 20 to 24 French (F) is used. The French scale is the method used to measure the diameter of a catheter. In this system, 1F= 0.33 millimeters (mm), so the tube that will be inserted is between 6.7 mm and 8 mm in diameter.
The tube is usually inserted in the 5th or 6th intercostal space, which is the space between the 5th and 6th rib, counting down from the collar bone. It is done through a 2 centimeter incision in the midaxillary line. Doctors use an imaginary “map” of the chest area in order to describe it for clinical purposes. On the side of the chest, there are three vertical lines, the middle line is the midaxillary line.
The second procedure to drain fluid is a video-assisted thoracoscopy. In this procedure, a surgical tool that has a triangular point, called a trocar, is inserted into the intercostal space through an incision in the skin. This allows a thin, tube-shaped instrument called a thoracoscope to be inserted. The thoracoscope has a light and a telescopic lens to see inside the chest and it can also have a tool to remove tissue. Additional incisions are made to allow for the insertion of other necessary instruments to perform the procedure.
After fluid is drained, an irritant is introduced into the space between the pleural layers either by injecting it in or by blowing it in. The most commonly used irritant is sterile talc, which is asbestos-free. It is usually administered either as a powder or slurry, meaning the powder is suspended in liquid.
The success of this procedure is compromised if there is an extremely large tumor in the space between the pleural layers, or if the lung is trapped by a thick visceral pleural peel of tumor.
Is pleurodesis the best way to treat pleural effusions?
In a study titled What is the best treatment for malignant pleural effusions? published online February 16, 2011 in Interactive Cardiovascular and Thoracic Surgery, researchers looked for previously published studies to help them determine if pleurodesis is a better treatment option than catheter drainage or pleuroperitoneal shunts in the management of patients with pleural effusions. A pleuroperitoneal shunt is a tube implanted surgically that carries fluid from a pleural space into the abdominal cavity, where it is absorbed.
They found 14, which they felt best answered the question. Six studies reported patient outcomes after pleurodesis. There was an 89.4 percent success rate in relieving symptoms and only a 2 percent mortality rate. The average hospital stay was 2.33 days with a complication rate of 16.5 percent. Length of survival after the procedure averaged 23.8 months.
Five studies reported patient outcomes using chronic intrapleural catheters. There was a 94.2 percent success rate in relieving symptoms, a 7.5 percent mortality rate, and a complication rate of 22 percent. The average survival length was 126 days. However, even in patients with trapped lung syndrome, the average survival length with this procedure was 125 days with a 90.9 percent success rate in relieving symptoms.
Three studies reported patient outcomes using pleuroperitoneal shunts. The success rate for symptom alleviation varied from 57.1 percent to 95 percent with a complication rate of 14.8 percent. The average hospital stay was 6.2 days with an average survival time of 11 months.
The evidence led researchers to conclude that, “Overall, chemical pleurodesis is the optimal treatment option for MPE (malignant pleural effusions) with use of chronic intrapleural catheters reserved in cases where talc pleurodesis is not possible.”