One of the most common pulmonary disorders is the accumulation of fluid in the pleural cavity or pleural effusion. The pleural cavity is a space around the lungs which normally contains only a thin layer of fluid. However, in many diseases this cavity gets filled with fluid, which can cause certain problems such as breathlessness, chest pain, fever and heaviness in the chest. Some of the common diseases which are associated with the development of pleural effusions include pneumonia, tuberculosis, lung cancer, etc.

The examination of the pleural cavity is done by means of chest X-rays and CT scans. However, in certain cases these investigations are not sufficient; thoracoscopy is needed in such situations. The thoracoscope is a specialised endoscope for examining and taking tissue samples from the pleural cavity. The procedure is done under local anaesthesia like bronchoscopy.