[Laterosternal mediastinoscopy. Technic and indications. Apropos of 23 cases].

Parasternal (or anterior) mediastinostomy--a thoracic diagnosis surgery--is a simple, safe and rapid procedure which can be used either to gain access to the anterior or superior mediastinum and to the pulmonary pedicles ("hiloscopy" for exploration and biopsy, or to perform a wide lung biopsy without true thoracotomy.