About 150,000-200,000 people in the United States develop malignant pleural effusion every year. Malignant pleural effusion by definition is not treatable. Typically, the length of survival for patients with malignant effusion is about six months. The exception to the course would be malignant pleural effusion secondary to breast cancer, ovarian cancer, and some lymphomas.
Signs and symptoms of malignant pleural effusion would be
- shortness of breath,
- chest pain, and
- respiratory failure
Tumors that metastasize to the lymph nodes in the mediastinum can occlude the lymphatics. Once the lymphatics are occluded, the pleural effusion develops because the fluid has nowhere to drain through. Lung cancer causes about 40% of all malignant pleural effusions.
Other malignancies that cause malignant pleural effusion include gastric cancers and cancers of unknown etiology. Other causes of malignant pleural effusion include direct invasion of the tumor into the pleura and hematogenous tumor spread into the pleural cavity with release of inflammatory molecules including cytokines that can increase vascular permeability.
The diagnosis of malignant pleural effusion is made by observing malignant cells in the fluid. Many times, the diagnosis is missed because there are not enough cells in the fluid to be seen under the microscope.
Treatment of malignant pleural effusion is a complicated algorithm which depends on the longevity of the patient, the cell type and the primary cancer, the control of the tumor in the rest of the body, symptomatic benefit from therapeutic thoracentesis, and other comorbidities including general debility and COPD.
Patients who do not experience symptomatic relief from a thoracentesis are generally not a good candidate for more aggressive treatment. In these patients, symptoms of dyspnea and shortness of breath are secondary to other pathology including primary pathology in the lung. However, if the patient does respond symptomatically to a thoracentesis, they would be a candidate for further aggressive treatment including video-assisted thoracoscopic surgery and pleurodesis. When patients are being assessed for possible VATS and pleurodesis, other factors have to be evaluated including the patients’ symptoms, functional status, caregiver support, the cell type, life expectancy, and response to chemotherapy.
Video-assisted thoracoscopic surgery and pleurodesis is the procedure that is done under general anesthesia. It requires a higher level of surgical expertise. In our experience treating many patients with malignant pleural effusion, we have learned that pleurodesis needs to be done with multiple modalities. These modalities include both electrical and argon beam coagulation in addition to mechanical pleurodesis and chemical pleurodesis which includes talc pleurodesis into the pleural cavity. The procedure usually takes about two hours for a complete pleurodesis of one side of the chest cavity. The patient subsequently will have a chest tube for further drainage over the course of the next several days.
In our recent observation in order to discharge patients sooner to their home and to their loved ones, we have also used a tunneled pleural catheter/PleurX catheter in at the time of the pleurodesis. The tripled pleurodesis modality that we use works in the high percentage of patients achieving pleurodesis and resolution of the pleural effusion. However, this process takes time, usually between one to several weeks after the procedure is completed for the pleural effusion to mostly go away. We have learned that during this time patients can go home with a small PleurX catheter that would drain the fluid in a home environment. This allows for patients to spend valuable time with the family members and the loved ones until the final pleurodesis results are achieved. The patient drains the fluid into a small bag on a daily basis. The amount of fluid drained is reported to our office on a daily basis. Once the drainage is acceptable, the PleurX catheter can be removed on an outpatient basis and the patient goes home the same day.
Patients who have only a few weeks or months left to live are probably best treated with repeat thoracentesis and are not good candidate to undergo VATS with pleurodesis. However, it should be remembered that every thoracentesis has risks that are associated with it.
These risks include possibility of damage to the lung causing pneumothorax and possibility of damage to the blood structures of the thoracic cavity including the lung and intercostal blood vessels with bleeding.
If the patient responds symptomatically to a thoracentesis with improved symptoms and is a candidate for video-assisted thoracoscopic surgery, then long-term symptomatic relief would be expected as a palliative procedure. Thoracentesis is also a procedure that is short lived. On an average about four to five days after a thoracentesis, pleural effusion would recur and would require a second thoracentesis.