A case successfully treated by conservative management for mediastinitis and infected composite graft due to methicillin-resistant coagulase negative staphylococcus.

A 72 year-old man underwent a Bentall procedure for aortic regurgitation secondary to annulo-aortic ectasia and ascending aortic aneurysm. On the 11th postoperative day, the C-reactive protein (CRP) level and white blood cell (WBC) count rose. Echocardiography and a computed tomographic scan showed the appearance of pericardial effusion. A diagnosis of mediastinitis and composite graft infection was made, and mediastinal drainage and irrigation were performed. Methicillin-resistant coagulase negative staphylococcus (MRCNS) was identified as the causative organism. Vancomycin, arbekacin and minocycline were used intravenously. Additionally, a continuous mediastinal irrigation was performed through the chest tubes. CRP level and WBC count were gradually reduced to normal range. He has now been free from signs of infection for more than 3 years. Because MRCNS is considered less virulent than methicillin-resistant Staphylococcus aureus, mediastinitis and composite graft infection due to MRCNS might be treatable by such conservative therapy even in patients with prosthetic implants. Since MRCNS often becomes ubiquitous, preventing infections by strict attention to asepsis is important.