Mediastinitis: A Comprehensive Clinical Review of Acute and Chronic Forms—Pathophysiology, Diagnostic Strategies, and Management

Mediastinitis, an inflammatory condition involving the central compartment of the thoracic cavity, remains one of the most formidable challenges in clinical medicine due to its anatomical proximity to vital structures and its potential for rapid progression to septic shock and multisystem organ failure. This comprehensive review synthesizes current knowledge on the three principal etiologic subtypes: postoperative mediastinitis (most commonly following median sternotomy, with an incidence of 0.5–2.5%), descending necrotizing mediastinitis (arising from deep neck space infections in 2–5% of cases), and fibrosing mediastinitis (a chronic, often idiopathic fibroproliferative disorder). While postoperative and descending necrotizing variants present acutely with fever, chest pain, and respiratory compromise, fibrosing mediastinitis follows an indolent course, frequently manifesting with compressive symptoms such as superior vena cava syndrome or airway obstruction. The pathophysiology of acute forms centers on microbial contamination—predominantly gram-positive cocci in poststernotomy cases and polymicrobial oropharyngeal flora in descending infections—whereas fibrosing mediastinitis is increasingly understood as an aberrant immune-mediated hypersensitivity response, often triggered by Histoplasma capsulatum or Mycobacterium tuberculosis. Diagnosis relies heavily on contrast-enhanced computed tomography, though laboratory markers (procalcitonin, C-reactive protein) and microbiologic cultures provide adjunctive value. Management mandates early, aggressive source control through surgical debridement combined with tailored broad-spectrum antimicrobial therapy, followed by intensive care unit support. Mortality for descending necrotizing mediastinitis remains substantial at 20–40%, whereas postsurgical mortality has improved markedly to 1–14% with contemporary techniques such as vacuum-assisted closure and flap reconstruction. Fibrosing mediastinitis carries a guarded long-term prognosis due to recurrent pneumonia and progressive cor pulmonale. Effective outcomes depend critically on an interprofessional team approach encompassing thoracic surgery, infectious diseases, critical care, nursing, and pharmacy, with prevention—through aseptic technique, glycemic control, and S. aureus decolonization—remaining the single most impactful strategy.