Topics:

Malignant Pleural Effusion: Thoracoscopy or Closed Chest Tube Drainage?

Malignant Pleural Effusion: Thoracoscopy or Closed Chest Tube Drainage?

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 Colt, Associate Professor of Medicine,
the University of California, San Diego, and Dr. Carolyn Dressler, a general
thoracic surgeon from Philadelphia, in a special session at the 1996 International
Conference of the American Thoracic Society. In the first of a two-part
report on that session, Dr. Colt presents arguments in support of the use
of thoracoscopy. Dr. Dressler's remarks will be featured in a subsequent
issue.

Physicians who are asked to manage patients with a malignant pleural
effusion are faced with a great predicament, said Dr. Colt. Many of these
patients have a short life expectancy, and any management decision will
have a major impact on the quality, and possibly, the quantity of their
remaining life.

Thus, the clinician needs to consider many factors before performing
pleurodesis. Knowing the patient's primary neoplasm and prognosis is especially
important. Whether the patient has undergone therapy previously is also
relevant; many patients have had prior chemotherapy or radiation therapy.
Other considerations include the patient's general health status (which
may be poor) and performance status (ie, whether the patient is ambulatory
or bedridden).

It may be useful to know the extent of pleural involvement, said Dr.
Colt, specifically, whether the lung itself is involved or whether the
neoplasm is limited to the parietal pleura, because such findings as a
trapped lung may alter therapy. One cannot definitively establish the extent
of pleural involvement, however, without viewing the pleural space.

A 1988 study by Sahn and Good suggested that pleural pH and glucose
may be indicative of extensive disease.[1] In patients with low pH effusions
in this study, however, tetracycline pleurodesis was rarely successful
using classic tube thoracostomy techniques.

"Thoracoscopy, on the other hand, is our window into the pleural
space," said Dr. Colt. He believes that thoracoscopy is advantageous
for patients and their families, as well as for physicians, health maintenance
organizations, third-party payors, and hospitals, "because the recommendations
that derive from what is seen during the thoracoscopic procedure will affect
patient outcome and future management decisions."

According to Dr. Colt, thoracoscopy has the following advantages:

  • The procedure is easily performed and safe.
  • Thoracoscopy allows for both diagnosis and staging of disease.
  • The extent of parietal pleural and/or visceral pleural involvement
    can be determined, as well as whether or not the lung is trapped.
  • In case of malignant pleural effusion, pleurodesis by talc insufflation
    or even insertion of a pleurocutaneous or pleuroperitnoeal shunt can be
    performed immediately, if indicated.
  • In some cases, thoracoscopic findings lead to modifications in medical
    management that may favorably alter prognosis.

A Simple, Safe Technique

Dr. Colt asserted that thoracoscopy is a simple, safe technique. It
can be performed in the operating theater while the patient is under general
anesthesia, with single- or double-lumen intubation and through single
or multiple points of entry. However, it can also be done under local anesthesia
with basic instrumentation in a specially equipped bronchoscopy or endoscopy
suite.

When thoracoscopy is carried out in a patient with a suspected malignant
pleural effusion, a 1-cm skin incision is made, and a 7-mm pleural trocar
is placed into the pleural cavity through that small incision. A telescope
can then be placed through the trocar to inspect the pleural cavity and
lungs. All pleural fluid can be removed at once.

An additional advantage of this technique, said Dr. Colt, is that placement
of the chest tube for pleural fluid drainage and lung reexpansion can be
guided by the thoracoscope. This ensures that "the tube will be placed
where you want it in a dependent area in order to ensure complete lung
expansion."

When thoracoscopy reveals a completely trapped lung, one or two tubes
can be placed and high pleural suction applied, which may result in complete
lung expansion. If thoracoscopy is performed in an intubated patient, positive
pressure can be applied to further enhance lung reexpansion. This is not
possible using closed chest tube drainage alone.

With regard to safety, Dr. Colt noted that the complications that may
occur when thoracoscopy is performed for other indications usually do not
apply for procedures done for a malignant pleural effusion. The main concern
in the latter setting, he said, is contamination with tumor cells at the
point of entry of the thoracoscope. This does not happen when thoracoscopy
is performed in patients with metastatic pleural carcinomatosis from breast,
lung, or gastrointestinal cancers but may occur in patients with malignant
mesothelioma. Although such a problem is infrequent even in patients with
malignant mesothelioma, Dr. Colt treats these patients with external-beam
radiation (approximately 21 Gy over 3 days), which prevents the local spread
of disease through the incision sites.

Definite Role in Management

"Thoracoscopy definitely has a role in the management of patients
with malignant pleural effusions and in those with lung cancer," Dr.
Colt said. Many studies done in Europe and the United States have shown
that thoracoscopic talc insufflation (also known as talc poudrage) has
excellent results with minimal morbidity.[2]

In addition, thoracoscopy can immediately indicate the need to place
a pleural peritoneal shunt, eg, in the patient with a trapped lung. Moreover,
pleurectomy or pleural abrasion techniques can be employed for pleurodesis
and are almost always successful, although these procedures may be too
invasive (because of increased morbidity and risk of bleeding) in a patient
with substantial neoplastic involvement of the pleura.

Thoracoscopy also helps determine whether an effusion is neoplastic
or paramalignant (ie, due to causes other than pleural carcinomatosis in
a patient with a primary cancer in other sites), particularly when pleural
fluid cytologies have been negative on prior thoracenteses. Dr. Colt added
that this distinction has important ramifications for prognosis and for
future treatment recommendations. Pleural cytology is positive in perhaps
40% to 80% of patients with malignant pleural effusions. Most clinicians
know of cases in which pleurodesis was performed in patients with a suspected
malignant pleural effusion who later were shown to have a paramalignant
effusion.

In cases of negative pleural cytology, because as many as 20% of exudative
effusions may go undiagnosed, it is important to recognize that one-third
to one-half of these may actually be malignant. For example, Boutin et
al have demonstrated the value of the thoracoscopic approach. Their work
showed that thoracoscopic appearance is evocative of cancer in almost 90%
of patients with effusions of unknown origin despite negative thoracentesis
and negative pleural biopsy.[3] Knowing that a patient has cancer metastatic
to the pleura alters prognosis and may affect lifestyle and treatment decisions.

Pages

 
Loading comments...
Please Wait 20 seconds or click here to close