Complicated Mycotic Thoracic Aortic Aneurysm Secondary to Staphylococcus aureus Endocarditis

Abstract

A mycotic aortic aneurysm is a rare and life-threatening condition, with the most common culprit being Staphylococcus aureus. The incidence varies widely from 0.6% to 13%. It usually affects immunocompromised patients, such as those undergoing haemodialysis who are subjected to repeated skin punctures. The insidiousness of the presentation of this high-risk condition makes diagnosis and management challenging. The authors document the case of a 75-year-old woman with multiple comorbidities on maintenance haemodialysis, who also recently underwent central line reinsertions, presenting with progressive leukocytosis and persistent anaemia. Diagnostic work-ups initially showed pneumonia and methicillin-resistant S aureus bacteraemia, later revealing infective endocarditis and a mycotic aortic aneurysm in the descending aorta with contained rupture. A hybrid two-step procedure with debranching and anastomoses of aortic branches was employed, followed by transthoracic endovascular aortic repair. However, the initial success was complicated by a type IIIa endoleak and was repaired using a tapered endograft stent deployed in an overlapping fashion to cover the leak. Long-term management involves a single antiplatelet and antibiotics taken according to the patient’s condition and close surveillance of imaging.