Mesothelioma Aid

Malignant Pleural Effusions

Individuals with multiple malignancies can develop a paramalignant or malignant pleural effusion. Research doctors have identified direct or indirect tumor effects as the primary causes of paramalignant pleural effusions. These include lymph node infiltration, bronchial obstruction, and pulmonary emboli. Pleural biopsy and pleural fluid cytology are negative. In case of malignant pleural effusions, the fluid cytology and/or pleural biopsy show in diagnostic tests as positive for cancer.

If you get a diagnosis of paramalignant or malignant pleural effusion, you may wish to discuss the following with your doctor:

• What is the prognosis?
• Does the effusion require treatment?
• What options are available in terms of treatments?
• How to determine which treatment option will be best for me?

Doctors typically consider a number of therapeutic modalities in order to find a strategy that may be best for specific individuals. The medical website uptodate.com reports a median survival of four months following a diagnosis of malignant pleural effusion, although some patients may experience prolonged survival. Clinical variables used to develop a prognosis include the histology of the cancer, tumor stage, characteristics of pleural fluid, presence of adhesions, and extensive pleural involvement with tumor. In most cases, the prognosis is determined on the basis of whether the underlying tumor will respond to systemic treatment therapy.

Treatment Options

Doctors usually recommend patients undergo therapeutic thoracentesis to drain the fluid. The choice of subsequent therapies depends on the patient’s prognosis, the reaccumulation rate of the pleural effusion, and the intensity of the patient’s symptoms.

Patients who experience slow reaccumulation of malignant pleural effusion can be treated with repeat therapeutic thoracentesis. To manage malignant pleural effusions which reaccumulate slowly, a simple approach such as multiple repeat therapeutic thoracentesis can be used. Topical analgesia is administered briefly, after which a catheter is percutaneously guided under sterile conditions to reach the pleural space. Subsequently, a large volume of the accumulated pleural fluid is drained out. This procedure can be carried out in an office setting or at the bedside.

In cases where malignant pleural effusion reoccurs rapidly (for instance, less than a month), a more aggressive intervention procedure may be required. In such cases, the increased frequency of therapeutic thoracentesis procedures is burdensome. Treatment options include pleurodesis, pleurectomy, and indwelling catheter drainage.

Catheter Drainage

The preferred initial procedure for most patients experiencing recurrent malignant effusions involves placement of a long-term indwelling pleural catheter, allowing intermittent outpatient drainage by the patient or an attendant. This is the preferred method because it is the least invasive of all and requires less time in the hospital; the catheter is generally placed in an outpatient setting. Moreover, indwelling catheter drainage is useful when a patient has irremediable lung entrapment or endobronchial obstruction caused by tumor. In such cases, chemical pleurodesis is not used because of high failure rates when the lung loses the ability to expand against the chest wall.

At home, family members or the patients themselves should be able to carry out pleural fluid drainage using the indwelling catheter under sterile conditions.

In a study of pleural effusion patients, researchers found indwelling pleural catheters resolved dyspnea in 39 percent of cases whereas improvement was visible in around 50 percent cases.

Spontaneous pleurodesis can occur in around 50-70 percent of cases after 2-6 weeks of pleural fluid drainage via the indwelling catheter. In a study, pleurodesis was achieved in 70 percent cases at a mean interval period of 90 days, subsequent to the placement of the catheter. This study involved patients with pleural effusions from different causes, not just from mesothelioma.

In cases where spontaneous pleurodesis does not occur after several days or weeks of continued drainage, a pleural sclerosant needs to be instilled via the catheter. Doctors or medical technicians either instill a sclerosant (chemical pleurodesis), a chest tube, or pleural abrasion (mechanical pleurodesis). Chemical pleurodesis is usually preferred over prolonged chest tube drainage or mechanical pleurodesis because it is the least invasive of all and is relatively more effective.

The chemical pleurodesis procedure starts with the removal of pleural fluid using a chest tube. After this, a chemical sclerosant (for instance, talc slurry) is introduced into the pleural space, accompanied by one or more days of pleural fluid drainage. Hospitalization is usually required for 3-7 days, although specific health centers can undertake this in an outpatient setting.

In many studies, talc pleurodesis for recurrent malignant effusion has shown to be more effective in comparison to other types of sclerosants. A meta-analysis of 10 randomized trials involving 308 patients showed that the probability of nonrecurrence of effusion was more when talc was used in comparison to other sclerosants (for instance, mustine, tetracycline, bleomycin) or tube drainage alone. Overall, use of talc has shown to prevent reoccurrence in around 80-90 percent of pleural effusion cases (not necessarily mesothelioma-related). An alternative sclerosant is the tetracycline derivative doxycycline which has a reported success rate of approximately 80 percent.

It is not clear whether talc slurry instillation through the chest tube or talc insufflation during video-assisted thoracoscopy is preferable. The choice is usually based on the medical conditions requiring pleurodesis because these procedures have relatively the same level of effectiveness. If pleural malignancy is detected during a diagnostic thoracoscopy, it is usually considered reasonable to initiate talc insufflation during the procedure.

Adverse events that are often noted after talc pleurodesis include fever (in 10-17 percent cases), pain and gastrointestinal complications. In rare cases respiratory failure and/or a systemic inflammatory response may occur. Usually, these complications can be prevented by avoiding talc that has small-sized particles and not instilling talc too fast.

Pleurectomy

In case of patients with failed chemical pleurodesis, malignant pleural effusions can be controlled through decortication (removal of fibrous pleural rind) and radical or subtotal pleurectomy (resection of visceral and parietal pleura). These two methods are also used as a primary therapeutic technique for patients experiencing malignant effusions resulting from malignant pleural mesothelioma.

Doctor use these procedures only on patients who are considered good surgical candidates with a reasonably long expected rate of survival. This is because total radical pleurectomy/decortication involves a thoracotomy and is a major surgical procedure linked with significant morbidity and a few mortalities. Subtotal pleurectomy/decortication can be achieved thoracoscopically. In majority of cases, pleurectomy is almost always effective in eliminating the pleural space in order to control malignant pleural effusions.