Chronic Periaortitis After Endovascular Aneurysm Repair Revealing Graft-Associated Listeria monocytogenes Infection...

Chronic peri-aortic inflammation after endovascular aneurysm repair (EVAR) is rare and may reflect sterile postoperative inflammation, immune-mediated periaortitis, or graft-associated infection. Differentiating between these entities is challenging but essential for appropriate management. An 84-year-old male with prior infrarenal EVAR in 2005 presented with persistent inflammation and peri-aortic fluid collection, initially considered immune-mediated periaortitis based on a partial response to corticosteroids. Computed tomography (CT) showed progressive enlargement of the lesion, and contrast-enhanced ultrasound demonstrated early arterial enhancement within it, supporting an active inflammatory process. Two CT-guided peri-aortic sampling yielded Listeria monocytogenes, confirming localized graft-associated infection despite negative blood cultures. The patient was treated with intravenous ampicillin for 6 weeks, followed by oral trimethoprim-sulfamethoxazole for 2 months, which led to clinical and radiological improvement. This case highlights the diagnostic value of invasive sampling and the potential role of targeted antimicrobial therapy with close imaging surveillance in selected high-risk patients with localized infection.