Pleural effusion is a common problem in hospital patients. It may arise from a wide range
of diseases. There is a multitude of recognised causes of pleural effusion, and in
addition, other pleural conditions such as pleural thickening and pneumothorax represent
a significant burden to the healthcare system and to patients. However, the diagnosis of
this condition may sometimes be difficult. In pleural effusions undiagnosed by
thoracocentesis, closed pleural biopsy increases the yield by ∼10% and 40%, respectively,
in malignant and tuberculous pleural effusions, whereas the diagnostic yield of
thoracoscopy is ∼93% in both malignant and tuberculous pleural effusions. Hence, medical
thoracoscopy (MT) (pleuroscopy) is the gold standard in the diagnosis of pleural effusion
and it is indicated when less invasive tests have failed. MT is a procedure in which the
pleura is directly and visually examined. An endoscope is inserted into the intercostal
space by creating a pneumothorax with an incision through the chest wall. The pleural
space and its lining can be inspected and therapeutic interventions performed.
There are two different techniques that can be performed for diagnostic and therapeutic
thoracoscopy. One method recommends a single-entry site, the use of a usually 9-mm rigid
thoracoscope (or of a semi-rigid/semi-flexible 7-mm pleuroscope) with a working channel
for accessory instruments and an optical biopsy forceps, both performed under local
anaesthesia. The other method requires two entry sites: one for a 7-mm trocar for the
examination telescope, and the other for a 5-mm trocar for accessory instruments
including the biopsy forceps, and is usually performed with conscious sedation or general
anaesthesia.
In the trained hands of a pulmonologist, MT is a safe and effective procedure for
diagnosing and treating multiple pleural diseases. Valsecchi et al reported a
pathological diagnostic yield of 71% over a span of 30 years in around 2000 patients. The
unfamiliarity of the pulmonary physician with the rigid instrument and familiarity with
the flexible bronchoscope has led various investigators to attempt thoracoscopy even with
a fibreoptic bronchoscope.
The use of a flexible fibreoptic instrument to examine the pleural space was reported by
Senno et al in the 1970s in the United States. Studies showed that flexible bronchoscope,
when used as a thoracoscope, maintains a clear optical field by allowing concurrent
suctioning, which is analogous to the suction techniques used during flexible
bronchoscopy and better views at the apex and paravertebral gutters.This method is,
therefore, considered to be useful for surgeons or physicians with experience in chest
drainage and flexible bronchoscopy as well as safe and well tolerated with a minimal
degree of discomfort and expense.