TREATING PLEURAL EFFUSIONS

Shunt – Pleuroperitoneal shunting is used only rarely for patients with malignant chylothorax, lung entrapment, or failed pleurodesis. Generally, an indwelling catheter is used instead of a pleuroperitoneal shunt because it is less invasive and has less number of problems in comparison to the frequency of shunt-related problems.

Generally, this procedure is carried out during thoracoscopy, using general anesthesia. The shunt catheter, which can either be an active version requiring repeated activation of a manual pump (Denver pleuroperitoneal shunt) or a passive version (LeVeen pleuroperitoneal shunt), is introduced with one end guided into the pleural cavity and the other into the peritoneum through a tunnel. The shunt pumping chamber is positioned in a subcutaneous pocket overlying the costal margin.

The procedure of placing the pleuroperitoneal shunt is considered reasonably safe if done by experienced operators, although shunt-related complications have been noticed in around 15 percent cases. Major problems faced include shunt failure, which occurs mostly due to infection and occlusion of the catheter. In a retrospective review involving 160 patients who received a pleuroperitoneal shunt in order to control malignant pleural effusion, 12 patients developed shunt occlusion (necessitating revision in 5 and replacement in 7 patients); while 7 others developed infection. In one patient, malignant seeding of the chest wall was observed at the site where the shunt was inserted. However, peritoneal seeding was not noted. It is unclear whether patients who have had a shunt occlusion face an increased risk of occlusion when a new shunt is placed.

Palliation of pleural effusion is successfully achieved in around 73 to 90 percent of carefully chosen patients.

Choosing the most appropriate option – Selecting the most appropriate approach is largely determined on the basis of practice patterns and local expertise. Explained below are some of the factors that guide the selection process.

• Placement of an indwelling pleural catheter requires very little time in the hospital, although there may be problems due to the longer dwell time of the tube and also the increased risk of infection. Moreover, family members or the patients themselves should be able to carry out intermittent drainage at home. This method is most suited for those who have a shorter duration of survival and patients who prefer a less invasive intervention and outpatient management.
• For patients who have only a few months of expected survival, talc slurry instilled through a chest tube is considered a reasonable alternative. The primary drawback is the initial pain experienced during instillation.
• To some extent, Intrapleural doxycycline is less effective than talc and may cause more pain. Hence, it may be used in specific conditions when talc may not be available.
• For patients with longer expected survival duration, video-assisted thoracoscopy with talc insufflation is considered a good option, especially when a pleural malignancy has recently been detected during a diagnostic thoracoscopy or when partial decortication or lysis of adhesions is required to treat lung entrapment.
• Pleurodesis is not recommended if there is occurrence of irremediably entrapped or trapped lung. In case of patients who have a combination of recurrent malignant pleural effusion and an unexpandable lung, an indwelling catheter is considered the best option.
• Pleuroperitoneal shunting is used only rarely for patients with failed pleurodesis or the combination of lung entrapment, recurrent malignant effusion, and the inability to carry out intermittent drainage through an indwelling catheter at home.

Antitumor therapy – This includes radiation and systemic chemotherapy and may be beneficial when used as an adjunct in specific cases. However, in general, this is not considered adequate for effective management of symptoms caused due to malignant pleural effusion.

Chemotherapy – When systemic chemotherapy is used, the response of malignant pleural effusion has largely been disappointing for most types of malignancies. However, there have been exceptions such as pleural effusion due to lymphoma, small cell carcinoma of the lung, breast cancer, prostate cancer, germ cell tumors, thyroid cancer and ovarian cancer.

Radiation therapy – Radiotherapy administered to treat primary tumor can help resolve malignant pleural effusions in cases where mediastinal lymph node disease predominates (for instance, lymphoma). Mediastinal radiation can also be useful towards resolving paramalignant effusion among patients with lymphomatous chylothorax.