Mediastinum

Abstract

The term mediastinum refers to the region of the body located between the two pleural spaces. It is derived from the Latin words medius (middle) and stare (to stand) and means literally standing in the middle Although this definition is anatomically descriptive, it belies the fact that the mediastinum is a complex and tightly knit package of structures immediately vital to the life of the individual-The central airways, the heart, and the great vessels. Also contained within the mediastinum are myriad other tissues, glands, and organs, including the esophagus, thymus, thoracic duct, vagus and phrenic nerves, and lymphatics. The mediastinum extends from the diaphragm to the thoracic inlet and is divided by anatomists into four regions that are defined by their relationship to the pericardium: superior, anterior, middle, and posterior. In this scheme, the middle compartment is equivalent to the pericardial sac and its contents. In contrast, as is discussed in more detail later in this chapter, thoracic surgeons generally divide the mediastinum into just three compartments: anterior, middle, and posterior. In this scheme, the anatomists' superior compartment is divided between the anterior and middle compartments, and the esophagus is included in the middle rather than posterior compartment. © 2008 Springer New York.