In the United States, mediastinitis most commonly occurs in the postoperatively. It occurs in 1-2% of patients who have a sternotomy. Most of these patients are cardiac surgery patients (more than 300,000 cases per year in the US). Most of these are coronary bypass patients rather than heart valve or transplant patients. Some other causes of mediastinitis, other than postoperative, include 1) esophageal perforation; 2) trauma, especially blunt trauma to the chest or abdomen; 3) tracheobronchial perforation, due to either penetrating or blunt trauma or instrumentation during bronchoscopy; 4) descending infection following surgery of the head and neck, great vessels, or vertebrae; 5) progressive odontogenic infection (Ludwig angina); 6) mediastinal extension of lung infection; and 7) chronic fibrosing mediastinitis due to granulomatous infections. (photo credit)
- Bilateral internal mammary artery grafts
- Diabetes mellitus
- Emergency surgery
- External cardiac compression (conventional cardiopulmonary resuscitation)
- Obesity (>20% of ideal body weight)
- Postoperative shock, especially when multiple blood transfusions are required
- Prolonged bypass and operating room time
- Reoperation and/or Reexploration following initial surgery (check out Grunt Doc's post)
- Sternal wound dehiscence
- Surgical technical factors (eg, excessive use of electrocautery, bone wax, paramedian sternotomy
Effective treatment for simple sternal dehiscence without infection is rewiring the sternum. This usually yields reasonable long-term results. Cultures should be taken to exclude active infection in the cases of sternal dehiscence.
Bipedicle Muscle Flaps in Sternal Wound Repair; Plastic & Reconstructive Surgery. 101(2):356-360, February 1998; Solomon, Mark P. M.D.; Granick, Mark S. M.D.