Malignant pleural effusion is a common clinical problem in neoplastic diseases. Approximately half of all patients with metastatic cancer develop a malignant pleural effusion as a consequence of their disease.¹ Although there have been no epidemiologic studies, the annual incidence of malignant pleural effusion in the United States is estimated to be more than 200,000 cases.² The main problem that patients who develop such effusions experience is a reduction in the quality of life owing to symptoms such as dyspnea, chest pain (primarily related to involvement of the parietal pleura and chest wall), and cough.²

Treatment options for malignant pleural effusions are determined by the symptoms and performance status of the patient, the primary tumor and its response to systemic therapy, lung reexpansion after pleural fluid evacuation, and expected survival. The therapeutic goal of palliative treatment is permanent resolution of the pleural effusion. For patients who are symptomatic from pleural effusions, dramatic improvement or complete resolution of symptoms with remaining or limited recurrence of the effusion can be called a partial success. It must always be remembered that controlling a malignant pleural effusion is a local phenomenon that has no effect on the underlying systemic disease.

A number of different techniques have been used over the past 20 years to treat malignant pleural effusion.³ The most common method is pleurodesis (i.e., obliteration of the pleural space), effected by instilling a chemical sclerosant in the pleural space after the effusion has been drained completely, either during thoracoscopy (under sedation or general anesthesia) or at bedside thoracostomy.^1,4 There is no single unified approach to thoracoscopy. It can be performed by using flexible or rigid thoracoscopes, with or without video assistance, under local, regional, or general anesthesia, and with or without selective one-lung ventilation.⁵ It provides access to the entire pleural cavity, permits biopsy under direct visualization, and by means of a video-assisted procedure, enables optimal preparation of the pleural surface and homogeneous distribution of the sclerosing agent under visual guidance, thereby maximizing the chances for complete pleurodesis.^6,7

Malignancy must always be in the differential diagnosis of an undiagnosed unilateral or bilateral pleural effusion, and a thoracentesis must be performed. Complete drainage of the effusion is important for evaluating the underlying lung. If the lung remains collapsed after drainage, it usually indicates trapped lung syndrome. Options in cases involving trapped lung are tailored to the individual patient and include either implantation of a chronic indwelling pleural catheter,^8,9 internal drainage from the pleura to peritoneum using a Denver pleuroperitoneal shunt,¹⁰ or pleurectomy (which is performed rarely for effusion control).

It is important to perform bronchoscopy when endobronchial lesions are suspected with accompanying symptoms of hemoptysis and atelectasis, or for large effusions without contralateral mediastinal shift. Moreover, is it important to exclude endobronchial obstruction before attempting a pleurodesis if the entire lung remains collapsed after therapeutic thoracentesis.¹¹

To determine the optimal management approach, the patient must be thoroughly examined and evaluated. Because of the limited survival of patients with malignant pleural effusions,^4,8 the selected treatment should have low procedure-related mortality and morbidity.

The ideal patient for sclerotherapy has been recently diagnosed with a malignant pleural effusion and still has a free-flowing effusion without loculations. Failure of sclerotherapy is related to the inability of the lung to reexpand and completely fill the pleural space, and nonexpansion is usually observed with chronic effusions that have been either neglected or drained on multiple occasions. Thickening of the visceral pleura, leading to loss of volume and trapping of the lung, will prevent successful obliteration of the pleural cavity. A large volume pleural tumor is also associated with increased failure of the technique.⁴

Video-Assisted Thoracoscopic Surgery

For video-assisted thoracoscopic surgery (VATS) procedures, general anesthesia with selective one-lung ventilation via a double-lumen endotracheal tube is commonly preferred.^5,12 However, in some patients with poor cardiac output and increased risk for general anesthesia, conscious sedation consisting of local or locoregional anesthetics and administration of systemic analgesic and sedative medications can be used.¹³

After placing the patient in the lateral decubitus position and instituting selective one-lung ventilation under general anesthesia, the table should be flexed to 30 degrees to widen the intercostal spaces on the operative side. The skin is prepared and draped as for a standard posterolateral thoracotomy. In adult patients, 5- or 10-mm thoracoscopes are often used; however, a smaller 2-mm mini thoracoscope can be used for diagnostic procedures. For general exploration, the first (camera) port is often made in the midaxillary line in the seventh intercostal space. The first port site tunnel is always created bluntly, with digital exploration performed to detect and release adhesions around the port site before the camera is inserted. Additional trocars are inserted under video guidance. After the pleural fluid has been drained, the pleural cavity is inspected, and directed biopsy specimens are taken. In the presence of adhesions or trapped lung syndrome, adhesiolysis or limited decortication can be done to achieve complete lung reexpansion.

After the lung has been observed to expand and fill the hemithorax, chemical pleurodesis is performed by instilling a chemical irritant such as talc, doxycycline, silver nitrate, or iodopovidone into the pleural space to promote adhesion of the parietal and visceral pleurae.³ Five grams of sterile purified talc powder (most commonly used) is insufflated through a talc atomizer under video-thoracoscopic vision to ensure that talc covers the entire visceral pleura (Fig. 120-1). At the end of the procedure, usually one or two 28 F chest tubes are inserted. This practice is recommended to maintain complete expansion of the lung after the thoracoscope is withdrawn. Of note, if the pH values decrease below 7.3, the success of thoracoscopic pleurodesis decreases.¹⁴ Also, if the patient undergoing pleurodesis is receiving corticosteroid therapy, the medication should be stopped or the dose, if possible, should be reduced because it may reduce the efficacy of pleurodesis.¹¹