P037 Management of EHEC-associated brain abscess complicating partially embolized arteriovenous malformation (AVM)

<h3>Introduction</h3> (Cerebral arteriovenous malformations (AVMs) represent a complex vascular disorder, with an annual hemorrhage risk of 1-4%. While intracranial hemorrhage and ischemic stroke are recognized complications, post-embolization intracranial infections are underreported.) <h3>Case Description</h3> (A 37-year-old immunocompetent male presented in March 2022 with new-onset headache, memory impairment, weakness, and seizures. Evaluation revealed a giant (63×51mm) left frontal lobe AVM (Spetzler–MartinV, Buffalo score _5 points). Its blood supply originated from the internal and common carotid arteries, as well as vertebral arteries, drained through superficial and deep veins into the sagittal and transverse sinuses and was accompanied by a 13.1 × 13.6 mm deep vein aneurysm. Two sequential embolizations were performed with ’Onyx’ over several months. In June 2023, he developed motor aphasia, facial asymmetry, right hemiparesis, and fever, with MRI revealing an abscess causing midline shift. Surgical drainage revealed Enterohemolytic Escherichia coli (EHEC) sensitive to antibiotics. Despite antibiotic therapy (Amoxicillin-clavulanate 1.2gx2 daily) and initial improvement, recurrent abscesses persisted. Consequently, in April 2024, complete excision of the AVM was performed to prevent further recurrences. <h3>Results</h3> The absence of previous illnesses or gastrointestinal issues, no infection upon whole-body examination, and normal blood tests (the patient declined lumbar puncture) distinguish this case from other rare instances of EHEC abscesses in medical literature. Prolonged, repetitive endovascular procedures and substantial embolization material usage can exacerbate inflammation and thrombus formation, increasing the risk of infectious complications post-surgery. Broader considerations beyond antibiotherapy or drainage and early total AVM removal, including its embolic material upon infection detection, may be advisable.