Mediastinum
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Topography
The mediastinum is a space in the middle of the thoracic cavity filled with reticular fibrous tissue. The mediastinum is located between the pleural cavities and contains all important structures except the lungs. Anatomical division
• 1 Superior mediastinum (mediastinum superius)
– craniocaudally from the superior thoracic aperture to a virtual line at the T4 level – ventrodorsally between the manubrium sterni and vertebral column 2 Inferior mediastinum (mediastinum inferius) – caudally from a virtual line at the T4 level to the diaphragm – ventrodorsally between the body of the sternum and vertebral column 2.1 Anterior inferior mediastinum (mediastinum inferius anterius) – between the body of the sternum and pericardium 2.2 Middle inferior mediastinum (mediastinum inferius medium) – an area of the pericardium with the heart inside 2.3 Posterior inferior mediastinum (mediastinum inferius posterius) – between the dorsal aspect of the pericardium and vertebral column
Division of the mediastinum is more theoretical – each part is separated from each other by virtual planes or incomplete anatomical structures (bronchopericardial membranes). Clinical division of the mediastinum refers to the continuum of the mediastinum with the cervical regions and retroperitoneum.
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Sagittal section of the mediastinum
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Clinical division 1 Anterior mediastinum (mediastinum anterius) 1.2 – between the sternum and bronchopericardial membrane 1.1 Superior anterior mediastinum (mediastinum anterius superius) – from the superior thoracic aperture to an imaginary line at the T4 level 1.2 Inferior anterior mediastinum (mediastinum anterius inferius) – from a virtual line at the T4 level to the diaphragm 2 Posterior mediastinum (mediastinum posterius) – between the bronchopericardial membrane and vertebral column
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Bronchopericardial membrane (membrana bronchopericardiaca) – a membranous plate spread between the bronchi and pericardium separating the anterior and posterior mediastinum
Clinical notes Surgical interventions in the mediastinum are considered to be very difficult due to the large number of vitally important structures in a relatively small space. The most often performed surgeries are corrections of an aortic aneurysms and operations of the oesophagus, lungs and heart.
Structures of the anterior mediastinum, anterior view
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Structures of the posterior mediastinum, anterior view
Mediastinitis is an inflammatory process spreading in the mediastinum. It can be caused by a progression of inflammatory processes from the cervical region, from a perforated oesophagus or after penetrating thoracic injuries. This is a life-threatening situation requiring prompt treatment (evacuation of pus and antibiotic therapy).