Methicillin-resistant Staphylococcus aureus aortitis in a cardiac transplant patient

A 57-year-old heart transplant patient presented to the Emergency Department with mild epigastric pain, nausea, and vomiting for two days. Aside from a recent hospitalization for replacement of his hemodialysis catheter, he had otherwise not been ill. He was afebrile, slightly hypertensive, and slightly tachycardic with mild tenderness over the left upper quadrant, but no guarding, rebound tenderness, or masses. His WBC count was elevated at 16.1 (normal: 3.8-10.6). A computed tomography of the abdomen showed an area of low attenuation surrounding the aorta, surrounded more peripherally by an area of higher density. He went urgently to the operating room for a presumed contained rupture of the thoracic aorta. During the operation the surgeons noted inflammatory changes, rather than rupture, and resected and replaced the affected section. Cultures from a peri-aortic swab grew methicillin-resistant Staphylococcus aureus. Among complications of cardiac transplantation, aortic involvement can be a source of significant morbidity and mortality. Primary bacterial aortitis is, however, a rare event with instances of less than 3% in all patients. The presentation of these infections may be subtle, making diagnosis difficult and requiring a high index of suspicion. CT is the initial imaging technique of choice. Therapy frequently involves surgery in addition to broad-spectrum antibiotics. This patient's infection most likely originated from an infected dialysis catheter, the one that had just been replaced, and was probably kept from becoming more symptomatic by the administration of vancomycin during the previous admission.