Mycotic Aneurysms

March 18, 2013
Mario Martínez-Galdámez, MD

Case History: A 23-year-old man with a congenital bicuspid aortic valve with a two-month history of fatigue, progressive headaches, generalized weakness, weight loss and leg pain.

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Figure 1: MRI

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Figure 2: MRA

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Figure 3: DSA

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Figure 4: CTA

Streptococcus oralis was identified in blood culture and echocardiography showed vegetations and moderate aortic stenoses with a paravalvular abscess. A cerebral magnetic resonance (MRI and MRA) (Fig.1,2) and digital substraction angiography (DSA. Fig 3)showed an unruptured aneurysm of the superior division of the right MCA, and a computed tomography angiography (CTA) of the lower extremities showed an unruptured aneurysm of the left tibioperoneal trunk (Fig 4; arrow), probably corresponding to mycotic aneurysms.

The patient underwent cardiac surgery, and then was put on a six-week course of antibiotics. MRA and CTA follow-up were performed showing that aneurysms had not changed in size.
An elective surgical repair of the aneurysms was performed to prevent hemorrhage, and the patient remains asymptomatic six months later.

Discussion: Cerebral mycotic aneurysms of an infectious etiology are rare neurovascular pathologies. Cerebral aneurysms far distal to the usual sites of congenital aneurysms, organisms in blood chemistry, endocarditis, symptoms of infection, atypically located intracerebral hemorrhages, and young patients with immunodeficiency are strong factors for an infectious aneurysm. Cerebral angiography is mandatory to exclude aneurysms at other sites and early targeted antimicrobial treatment is crucial in these cases. Reconstructive procedures without sacrificing the parent artery often fail due to the fusiform and fragile aneurysm wall.

Mario Martínez-Galdámez, MD
Hospital Clínico Universitario de Valladolid, Spain