A Rare Case of Aspergillus Mediastinitis After Coronary Artery Bypass Surgery: A Case Report and Literature Review.

BACKGROUND Mediastinitis is a serious complication after cardiac surgery; it is a deep sternal wound infection following sternotomy, with clinical evidence and/or microbiological involvement and sternal osteomyelitis. The most common pathogens are Staphylococcus spp (S. aureus), followed by gram-negative organisms. Establishing an etiological diagnosis of fungal mediastinitis is often a challenging issue, given the nonspecific clinical presentation. CASE REPORT A 74-year-old man was diagnosed with a three-vessel coronary artery disease in a university hospital. The patient had as clinical background hypertension, a body mass index (BMI) of 29.78 kg/m², and no diabetes mellitus. After an uneventful coronary artery bypass surgery, he presented clinical and radiological mediastinitis manifestations on the 9th postoperative day. He was treated with a range of antibiotics, with no clinical improvement until the 33rd postoperative day. Then, mediastinal fluid and biopsied tissue were collected and he was started on voriconazole due to growing Aspergillus spp. On the 93rd postoperative day, he had clinical improvement and, after several exams, was released from the hospital. We present the first report of Aspergillus fumigatus mediastinitis after cardiac surgery in Brazil, successfully treated with voriconazole. CONCLUSIONS Aspergillus infection should be considered in the differential diagnosis of mediastinitis after coronary surgery, especially in a clinical case of unexplained sepsis, negative blood culture, and no clinical improvement despite antibiotic therapy. This case report highlights that the mediastinal fluid and biopsy tissue culture can be useful for the diagnosis of fungal mediastinitis.