Mediastinoscopy, devised by Prof. Carlens in 1959, is a method of exploration and biopsy of the superior mediastinum. Historically it has been developed from mediastinostomy step by step.
In general, the extent of the mediastinoscopical examination is limited to the anterior and superior parts of the mediastinum. In 1917 a flexible mediastinoscope was developed by the present author in Japan to investigate not only the superior and anterior parts but also the posterior or the lower part of the mediastinum. This scope is 40cm in length and 10mm in diameter. It has a firm but round end with which the connective tissues in the mediastinum can be safely divided. The tip can be bent by remote control. It has also a guide-tube through which either a special dissector or biopsy forceps can be inserted.
In practical use of this scope, the upper mediastinum must be dissected by a normal rigid scope first and a flexible scope is then introduced through the rigid scope. The flexible mediastinoscope must be controlled by the operator himself under his direct vision and by the radiologist observing in a fluoroscopical television.
Clinically, flexible mediastinoscopy is particularly useful for diagnosis of mediastinal tumors situated in the lower part of the mediastinum.
