Foreign body granuloma as a complication of endovascular treatment of brain aneurysm

Abstract Objectives To describe this uncommon but outstanding vascular post-treatment complication attributable to detached polymer coatings from intravascular medical devices employed in diagnostic or therapeutic procedures. Methods In this retrospective study we report the cases of two patients who after endovascular procedures for brain aneurysms developed neurological onsets which required further radiological analysis. Results In the Magnetic Resonance studies performed after the neurological attacks the patients developed multiple millimetric enhancing lesions in the vascular area of the procedure: Both patients underwent biopsy. The imaging findings and clinical course suggested foreign body reactions in both cases, this being histologically confirmed in one case by the presence of thread-like material compatible with a polymer coating. Conclusions Fragments from polymer-coated devices used in intravascular procedures, including brain aneurysm treatment, may be released into the blood stream or treated aneurysm, occasionally causing foreign body granulomas, a complication we must be aware of to obtain an accurate diagnosis and indicate appropriate treatment.