Citation, DOI & article data
Mediastinitis refers to inflammation of any of the soft tissues within the mediastinum.
In clinical practice, mediastinitis is generally used to refer to acute mediastinitis, resulting from bacterial infection within the mediastinum. This is considered a serious and potentially life-threatening condition.
Acute mediastinitis is uncommon, and is associated with high morbidity and considerable mortality. Infection secondary to median sternotomy has been reported to have a prevalence of 0.5-5% 1,2.
Risk factors for mediastinitis include:
factors which could contribute to increased postoperative complications, such as 2,3:
Patients may experience retrosternal pain and exhibit systemic signs such as fever, tachycardia or hypotension. Blood results may reveal a raised white cell count +/- neutrophilia and elevated C-reactive protein (CRP) 2,3.
Additional symptoms and signs depend upon the etiology and specific clinical scenario.
Mediastinitis secondary to esophageal perforation may present after a recent endoscopy, or after a bout of forceful vomiting (Boerhaave syndrome). Patients with a mediastinal infection secondary to an infected median sternotomy wound may have signs of wound infection on examination 2. Infection spreading from the head and neck may have additional signs pointing to a localized source of infection such as dental, neck or throat pain.
Acute mediastinitis is usually a result of the spread of infection from an adjacent source 1-3.
this may also occur due to anastomotic dehiscence post-esophageal surgery
deep sternal wound infection
post-operative infection after median sternotomy
spread from an odontogenic or oropharyngeal infection
less common causes
extension of infection from the lung or extension of adjacent osteomyelitis (e.g. sternoclavicular joint)
Findings are non-specific and overlap with other pathologies involving the mediastinum. Findings may include mediastinal widening and abnormality of the right paratracheal stripe. Additional features which could indicate esophageal perforation in the correct clinical context include pneumomediastinum and subcutaneous emphysema. Pleural effusions may also be seen 1.
Features may include:
evidence of mediastinal inflammation such as fat stranding, edema and loss of the normal fat planes
single or multiple mediastinal fluid collections which may contain gas locules and demonstrate an enhancing wall
It is important to note that a level of inflammatory change, fluid and hemorrhage is expected following recent cardiac surgery and may last up to 2 weeks 1,2. A combination of comparison to previous imaging, judgment of the expected appearance, and discussion with the clinical team regarding the patient's current condition may be helpful in guiding interpretation.
Additional findings depend on the etiology:
deep sternal wound infection: associated subcutaneous stranding/collection may be evident
descending necrotizing mediastinitis: imaging of the neck may reveal the infection extending through the neck spaces into the mediastinum
Treatment and prognosis
Acute mediastinitis is a serious and potentially life-threatening condition with considerable mortality. Early diagnosis, antibiotic therapy and surgical drainage are essential in the control of infection 2,3. Image-guided drainage could be considered in specific instances. Microbiological analysis of fluid samples is important in guiding further antibiotic therapy. Further management will depend on the underlying specific cause of infection 2.
- 1. Akman C, Kantarci F, Cetinkaya S. Imaging in mediastinitis: a systematic review based on aetiology. (2004) Clinical radiology. 59 (7): 573-85. doi:10.1016/j.crad.2003.12.001 - Pubmed
- 2. Pastene B, Cassir N, Tankel J, Einav S, Fournier PE, Thomas P, Leone M. Mediastinitis in the intensive care unit patient: a narrative review. (2020) Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases. 26 (1): 26-34. doi:10.1016/j.cmi.2019.07.005 - Pubmed
- 3. Ridder GJ, Maier W, Kinzer S, Teszler CB, Boedeker CC, Pfeiffer J. Descending necrotizing mediastinitis: contemporary trends in etiology, diagnosis, management, and outcome. (2010) Annals of surgery. 251 (3): 528-34. doi:10.1097/SLA.0b013e3181c1b0d1 - Pubmed