Mediastinitis

Mediastinitis is a severe and potentially life-threatening inflammation or infection that involves the mediastinum. The mediastinum encompasses the space within the thoracic cavity, bordered by the pleural sacs laterally, the thoracic outlet superiorly, and the diaphragm inferiorly. The mediastinum contains many vital structures, including the heart, great vessels, trachea, mainstem bronchi, esophagus, phrenic nerve, vagus nerves, and thoracic duct. Although mediastinitis is uncommon, it should be considered in the differential diagnosis, as any infection involving these structures is life-threatening and requires immediate treatment. Mediastinitis has multiple etiologies, categorized into 3 subtypes—postoperative mediastinitis, descending necrotizing mediastinitis, and fibrosing mediastinitis. Postoperative mediastinitis is the most common, followed by descending necrotizing mediastinitis, both of which are typically acute and follow a more fulminant course. Fibrosing mediastinitis, the least common subtype, is a more chronic and indolent process.