Mycotic pseudoaneurysm by vancomycin-intermediate Staphylococcus aureus: a rare cause of persistent bacteraemia

Pseudoaneurysms are vessel wall ruptures, that are often mistaken for deep vein thrombosis (DVT). A middle-aged man presented with right leg pain, swelling and erythema. His history was significant for persistent Staphylococcus aureus bacteraemia. Ultrasound revealed subacute DVT and laboratory parameters were suggestive of sepsis. He was started on intravenous heparin and antimicrobials. Owing to persistent anaemia despite blood transfusion, MRI of the right thigh was obtained. It revealed a 13×17 cm superficial femoral artery infected mycotic pseudoaneurysm (MPA) with a fresh haematoma. The patient underwent arterial ligation and extensive debridement. Intraoperative cultures revealed daptomycin-resistant vancomycin-intermediate S. aureus (VISA) and he was managed with 6 weeks of intravenous ceftaroline. MPAs are most common in the femoral artery and form <1% of aneurysms. Therapy involves surgical debridement and prolonged antimicrobials. VISA causing MPA is associated with worse outcomes. We report the first time use of ceftaroline in the management of a VISA MPA.