Does thoracoscopic treatment offer any advantages over closed chest tube drainage for the management of malignant pleural effusion? This controversial question was debated by Dr. Henri
Does thoracoscopic treatment offer any advantages over closed chesttube drainage for the management of malignant pleural effusion? This controversialquestion was debated by Dr. Henri Colt, Associate Professor of Medicine,the University of California, San Diego, and Dr. Carolyn Dressler, a generalthoracic surgeon from Philadelphia, in a special session at the 1996 InternationalConference of the American Thoracic Society. In the first of a two-partreport on that session, Dr. Colt presents arguments in support of the useof thoracoscopy. Dr. Dressler's remarks will be featured in a subsequentissue.
Physicians who are asked to manage patients with a malignant pleuraleffusion are faced with a great predicament, said Dr. Colt. Many of thesepatients have a short life expectancy, and any management decision willhave a major impact on the quality, and possibly, the quantity of theirremaining life.
Thus, the clinician needs to consider many factors before performingpleurodesis. Knowing the patient's primary neoplasm and prognosis is especiallyimportant. Whether the patient has undergone therapy previously is alsorelevant; many patients have had prior chemotherapy or radiation therapy.Other considerations include the patient's general health status (whichmay be poor) and performance status (ie, whether the patient is ambulatoryor bedridden).
It may be useful to know the extent of pleural involvement, said Dr.Colt, specifically, whether the lung itself is involved or whether theneoplasm is limited to the parietal pleura, because such findings as atrapped lung may alter therapy. One cannot definitively establish the extentof pleural involvement, however, without viewing the pleural space.
A 1988 study by Sahn and Good suggested that pleural pH and glucosemay be indicative of extensive disease. In patients with low pH effusionsin this study, however, tetracycline pleurodesis was rarely successfulusing classic tube thoracostomy techniques.
"Thoracoscopy, on the other hand, is our window into the pleuralspace," said Dr. Colt. He believes that thoracoscopy is advantageousfor patients and their families, as well as for physicians, health maintenanceorganizations, third-party payors, and hospitals, "because the recommendationsthat derive from what is seen during the thoracoscopic procedure will affectpatient outcome and future management decisions."
According to Dr. Colt, thoracoscopy has the following advantages:
A Simple, Safe Technique
Dr. Colt asserted that thoracoscopy is a simple, safe technique. Itcan be performed in the operating theater while the patient is under generalanesthesia, with single- or double-lumen intubation and through singleor multiple points of entry. However, it can also be done under local anesthesiawith basic instrumentation in a specially equipped bronchoscopy or endoscopysuite.
When thoracoscopy is carried out in a patient with a suspected malignantpleural effusion, a 1-cm skin incision is made, and a 7-mm pleural trocaris placed into the pleural cavity through that small incision. A telescopecan then be placed through the trocar to inspect the pleural cavity andlungs. All pleural fluid can be removed at once.
An additional advantage of this technique, said Dr. Colt, is that placementof the chest tube for pleural fluid drainage and lung reexpansion can beguided by the thoracoscope. This ensures that "the tube will be placedwhere you want it in a dependent area in order to ensure complete lungexpansion."
When thoracoscopy reveals a completely trapped lung, one or two tubescan be placed and high pleural suction applied, which may result in completelung expansion. If thoracoscopy is performed in an intubated patient, positivepressure can be applied to further enhance lung reexpansion. This is notpossible using closed chest tube drainage alone.
With regard to safety, Dr. Colt noted that the complications that mayoccur when thoracoscopy is performed for other indications usually do notapply for procedures done for a malignant pleural effusion. The main concernin the latter setting, he said, is contamination with tumor cells at thepoint of entry of the thoracoscope. This does not happen when thoracoscopyis performed in patients with metastatic pleural carcinomatosis from breast,lung, or gastrointestinal cancers but may occur in patients with malignantmesothelioma. Although such a problem is infrequent even in patients withmalignant mesothelioma, Dr. Colt treats these patients with external-beamradiation (approximately 21 Gy over 3 days), which prevents the local spreadof disease through the incision sites.
Definite Role in Management
"Thoracoscopy definitely has a role in the management of patientswith malignant pleural effusions and in those with lung cancer," Dr.Colt said. Many studies done in Europe and the United States have shownthat thoracoscopic talc insufflation (also known as talc poudrage) hasexcellent results with minimal morbidity.
In addition, thoracoscopy can immediately indicate the need to placea pleural peritoneal shunt, eg, in the patient with a trapped lung. Moreover,pleurectomy or pleural abrasion techniques can be employed for pleurodesisand are almost always successful, although these procedures may be tooinvasive (because of increased morbidity and risk of bleeding) in a patientwith substantial neoplastic involvement of the pleura.
Thoracoscopy also helps determine whether an effusion is neoplasticor paramalignant (ie, due to causes other than pleural carcinomatosis ina patient with a primary cancer in other sites), particularly when pleuralfluid cytologies have been negative on prior thoracenteses. Dr. Colt addedthat this distinction has important ramifications for prognosis and forfuture treatment recommendations. Pleural cytology is positive in perhaps40% to 80% of patients with malignant pleural effusions. Most cliniciansknow of cases in which pleurodesis was performed in patients with a suspectedmalignant pleural effusion who later were shown to have a paramalignanteffusion.
In cases of negative pleural cytology, because as many as 20% of exudativeeffusions may go undiagnosed, it is important to recognize that one-thirdto one-half of these may actually be malignant. For example, Boutin etal have demonstrated the value of the thoracoscopic approach. Their workshowed that thoracoscopic appearance is evocative of cancer in almost 90%of patients with effusions of unknown origin despite negative thoracentesisand negative pleural biopsy. Knowing that a patient has cancer metastaticto the pleura alters prognosis and may affect lifestyle and treatment decisions.
Changes in Treatment, Prognosis
The knowledge gained through thoracoscopic visualization changes decisionsregarding treatment and even alters a patient's prognosis in many situations,Dr. Colt stated. For example, a breast cancer patient who develops a pleuraleffusion may be told that it is probably malignant, and therefore, thatpleurodesis needs to be performed. The patient may even be advised thatshe has a 40% to 50% or even greater risk of dying in 4 to 6 months. If,on the other hand, that patient underwent thoracoscopy, it might revealthat the effusion is not due to neoplastic involvement, but rather, iscaused by radiation fibrosis or some other cause of paramalignant effusion.In such a case, the patient's prognosis would be much more favorable.
Dr. Colt described another man who had undergone supposedly curativeresection of a head and neck cancer. In the first year post-resection,he underwent drainage of pleural fluid on two separate occasions, and cytologywas negative both times. As a result, it was presumed that he did not havemetastatic disease. Upon this patient's presentation to Dr. Colt, however,thoracoscopy was performed, which revealed substantial metastatic pleuralinvolvement. The patient is now receiving salvage chemotherapy--a treatmenthe would otherwise not have received until much later in his disease course,when general health and performance status might have deteriorated.
Efficacy of Thoracoscopy
Pleurodesis has many goals: to obliterate the pleural cavity entirely,control the effusion, avoid morbidity, maintain the patient's quality oflife, and, hopefully, conserve health-care resources. "I have no doubtthat thoracoscopy meets all of those goals," Dr. Colt asserted.
Many studies have demonstrated the efficacy of the thoracoscopic approachfor diagnosis and palliative treatment. In a 1993 paper by Sanchez-Armengolet al, thoracoscopy was even effective in more than 60% of patients whohad suspected extensive neoplastic involvement of the pleura and a lowpH pleural effusion. A retrospective study of thoracoscopy and pleurodesisby Ohri et al showed that thoracoscopy not only was diagnostic but alsosuccessfully guided treatment in 28 of 30 patients; the only failures ofpleurodesis occurred in patients with a trapped lung.
Even when the thoracoscope reveals that the patient's lung is trapped,Dr. Colt noted, various other therapeutic options are possible. Multiplechest tubes can be inserted, high pleural pressures can be administeredimmediately to see whether the lung will expand, adhesions can be lysedin an attempt to enhance lung expansion, or a pleural peritoneal shuntcan be placed.
Alternatively, it may be decided that pleurodesis is not appropriatein this setting. In this case, the patient is spared prolonged chest tubedrainage and hospitalization. Multiple subsequent thoracenteses can alsobe avoided since they will not result in lung reexpansion or resolutionof symptoms. If such a patient experiences increasing shortness of breath,he or she can receive oxygen and other comfort care measures. Further interventionwould be indicated only if a mediastinal shift occurred, in which case,pleural fluid removal might avoid or delay hemodynamic compromise.
The Cost Issue
Although pleurodesis by tube thoracostomy is expensive because of theneed for prolonged hospitalization, thoracoscopy is even more so, Dr. Coltconceded. However, he argued that other considerations must be figuredinto the cost equation. Patients who have undergone chest tube pleurodesisoften require repeat thoracentesis or pleurodesis when the fluid subsequentlyrecurs. If, in the interim, the patient develops a fibrothorax, there'svery little that can be done. "What can you do then when your patientis gasping for breath?" Dr. Colt asked.
Thoracoscopy may be somewhat expensive, but its results are excellent,with successful pleurodesis noted in more than 90% of cases. Moreover,other procedures used in patients with malignant disease are also costly,said Dr. Colt. "You wouldn't hesitate to offer brachytherapy to yourpatient with an obstructed airway, even though most studies have demonstrateda limited survival of only 6 months. And you wouldn't hesitate to offerlaser resection or stenting to your patient, even though, in a recent studyby Dumon, 40% of the patients stented for cancer were dead within 100 days."
In conclusion, Dr. Colt said that he prefers thoracoscopic pleurodesisto closed chest tube drainage because it is efficient, allows one to determinethe extent of disease, and provides tissue diagnosis when necessary. Also,thoracoscopy is almost always effective, and thoracoscopic findings havea definite impact on subsequent patient management.
Finally, Dr. Colt pointed out that thoracoscopy has fostered researchon the pleural space. It has catalyzed the development of video-assistedthoracic surgery (VATS) techniques and has promoted a resurgence of interestin sclerosis techniques.
1. Sahn SA, Good JT: Pleural fluid pH in malignant effusions: Diagnostic,prognostic and therapeutic implications. Ann Intern Med 108:345-349, 1988.
2. Colt HG: Thoracoscopic management of malignant pleural effusions.Clin Chest Med 16:505-518, 1995.
3. Boutin C, Viallat JR, Carginino P et al: Thoracoscopy in malignantpleual effusion. Am Rev Resp Dis 124:588-592, 1981.
4. Sanchez-Armengol A, Rodriguez Panadero F: Survival and talc pleurodesisin metastatic carcinoma, revisited. Chest 67:536-539, 1993.
5. Ohri SU, Shashi KO, Townsend ER, et al: Early and late outcome afterdiagnostic thoracoscopy and talc pleurodesis. Ann Thorac Surg 53:1038-1041,1992.