Mycotic Aneurysm Management — EECC MCQ

Correct answer: D — IV antibiotic therapy with serial neuroimaging; most mycotic aneurysms resolve with prolonged antibiotics alone — neurosurgical or endovascular intervention is reserved for enlarging aneurysms, rupture, or persistent haemorrhage despite adequate antibiotic therapy

Mycotic (infected) aneurysms are focal dilatations of cerebral arteries caused by septic emboli from endocarditis that damage the arterial wall. Despite the name, they are caused by bacteria (not fungi). They complicate 2-4% of IE cases. The 2023 ESC IE Guidelines recommend: (1) IV antibiotics for 4-6 weeks — many mycotic aneurysms resolve with adequate antibiotic therapy alone (~50-70% resolution); (2) serial neuroimaging (CT/MR angiography) at 2-4 week intervals to monitor size; (3) neurosurgical/endovascular intervention (clipping, coiling, or excision) ONLY for: enlarging aneurysms despite antibiotics, ruptured aneurysms with haemorrhage, or symptomatic mass effect. Anticoagulation increases the risk of aneurysm rupture and should be discussed with the neurovascular team. Timing of cardiac surgery should be balanced against the neurological risk.

Reference: ESC (2023): IE Guidelines