Malignant pleural effusions arise as a result of malignant infiltration of the parietal and visceral pleurae, resulting in decreased reabsorption of pleural fluid and its subsequent accumulation within the pleural space. This results in extrinsic compression of the underlying lung parenchyma with secondary atelectasis, ventilation perfusion mismatch, and dyspnoea. In some instances the effusion may be under tension, resulting in decreased systemic venous return and a low cardiac output state. The pleura is a frequent site of metastatic disease from a host of primary tumours, including bronchogenic carcinoma, colorectal malignancies, uterine and ovarian carcinomas, breast carcinoma, and renal carcinoma, and a host of others. Primary pleural malignancies, predominantly malignant mesothelioma, frequently present with dyspnoea secondary to a malignant pleural effusion. It is generally accepted that pleurodesis not be attempted if the predicted survival of the patients is less than 3 months.

The prognosis for a patient with a malignant pleural effusion varies depending on the primary malignancy and the functional status of the patient and the median survival from time of diagnosis is in the order of 4 months [2]. A significant number of patients, however, die within 30 days of a procedure aimed at effecting a pleurodesis [3, 4], and accordingly, the treating surgeon must use all the information at hand to select the patients who will benefit from such treatment. Such patients generally have a symptomatic effusion, drainage of which results in a qualitative reduction in dyspnoea. Once a diagnosis of pleural malignancy has been made, one must identify any entrapment of the underlying lung by a malignant visceral pleural rind. This is a critically important point that is frequently overlooked and which will affect any attempted surgical palliation. Surgical treatment aims to remove the malignant pleural effusion, allows full expansion of the underlying lung, and prevents reaccumulation of the pleural fluid by affecting a pleurodesis. The extent of lung entrapment is inversely proportional to the amount of lung that can be effectively pleurodesed. This can usually be determined prior to surgery by tube thoracocentesis and draining the pleural space completely. If, on post-drainage plain chest x-ray, the lung re-expands completely, then one can be confident that complete pleural apposition can be achieved and any intervention to affect a pleurodesis will have a high likelihood of success. If, on the other hand, the lung fails to re-expand fully, indicating entrapment by a malignant pleural rind, then any attempt to achieve a pleurodesis will have a high failure rate.

Once the state of the visceral pleura (and, thus, lung expansion) has been established, one must select a minimally invasive option to achieve a permanent pleurodesis. In cases where it has been established that the lung has re-expanded fully after pleural drainage, the most effective surgical option is that of a videoscopic talc pleurodesis. This procedure requires general anaesthesia, double-lumen endotracheal intubation, and positioning of the patient in the lateral decubitus position. One or two sub-centimetre ports can be made in the 4th to 6th intercostal spaces between the mid- and anterior axillary lines. It is preferable to use a single intercostal space for all ports so as to minimise the number of intercostal nerves injured. The pleural fluid is aspirated, and under videoscopic visualisation, sterile talc is insufflated to effectively cover all areas of the visceral and parietal pleura. The standard dose is 5–10 g. A chest drain is then inserted (either through one of the ports or through a separate incision), the lung is re-expanded, and the remaining ports are closed. The patient is then extubated and the chest tube is left in situ (attached to an underwater sealed drainage bottle) for 48–72 h. Ideally the chest tube should be removed when less than 150 ml of pleural fluid is produced over a period of 24 h. This usually occurs at 48–72 h postoperatively. The success rate of a talc pleurodesis performed in this manner is in the order of 75–95 % [5, 6]. Talc is still the most effective sclerosant material available [7, 8] and is still the most widely used sclerosant outside of the experimental setting. Other substances such as anticancer drugs (bleomycin, cisplatin), antibiotics (tetracycline, erythromycin, doxycycline), and cytokines (interferon, transfer growth factor) are still undergoing investigation for widespread use as sclerosants [9].

Talc insufflation does have several common adverse effects including pyrexia, pleuritic pain, acute respiratory distress syndrome (ARDS), systemic inflammatory response, and pleural space infection. There is no evidence, however, that talc insufflation increases overall mortality

Less frequently used techniques in the situation where the lung re-expands fully after pleural drainage include videoscopic pleural abrasion, videoscopic parietal pleurectomy, and combinations of these two procedures.

In cases where the lung does not fully re-expand after pleural drainage, but where significant symptomatic relief is achieved by pleural drainage, standard surgical pleurodesis techniques will be unsuccessful. It is not uncommon for the upper lobes of the lung to re-expand fully whilst the lower lobe is trapped, and these patients present the most difficult therapeutic challenge. A standard videoscopic talc pleurodesis may result in pleurodesis of the upper lobe, but the lower lobe of the lung will remain trapped and there will be a persistent (obligatory) pleural effusion in the lower hemithorax. In such cases, particularly in those where significant symptomatic benefit is achieved by pleural drainage, a permanent indwelling tunnelled pleural catheter may be the most effective option. There are several such drainage systems available currently on the market including the PleurX (CareFusion Corp. San Diego, California) and Aspira (Bard Access Systems, Salt Lake City, Utah). These catheters are inserted under either local or general anaesthesia using a Seldinger technique with tunnelling of the catheter a certain distance under the skin and subcutaneous tissues in order to reduce the risk of pleural space infection. These systems allow for effective palliation of symptoms on an outpatient basis and allow the patients to drain their own effusion at intervals commensurate with their symptom deterioration [10].

In patients in whom a videoscopic talc pleurodesis is considered high risk from an anaesthetic viewpoint, or when the patient preference is for outpatient treatment, the permanent tunnelled pleural catheter may be the option of first choice [11].

Talc slurry, where talc is mixed with normal saline (5 g talc: 50–100 ml sterile normal saline) and instilled via an intercostal catheter, is a useful technique for achieving pleurodesis in the patient who is not fit for or declines surgical intervention. In this technique, performed at the bedside, the talc slurry is instilled via the intercostal catheter and the tube clamped. The patient is then positioned on each side in the supine position for approximately 20 min and then in the upright position, leaning left and right for a further 20 min. The procedure, by virtue of the acute pleuritis, can be quite painful and adequate analgesia should be provided to the patient.