Chemical meningitis after cerebral aneurysm treatment using two second-generation aneurysm coils: report of two cases.

OBJECTIVE AND IMPORTANCE: In the quest for effective and durable endovascular aneurysm treatment, second-generation aneurysm colls endeavor to increase the biological healing response to the implanted material. We teport two cases of large cerebral aneurysms treated concurrently with both available second-generation aneurysm colls and the subsequent development of symptomatic nonbacterial meningitis. CLINICAL PRESENTATION: Two previously healthy patients underwent endovascular treatment for large (≥2 cm) cerebral aneurysms. Both aneurysms were treated using multiple Hydrogel colls (MicroVention, Inc., Aliso Viejo, CA) and Matrix colls (Boston Scientific/Target, Fremont. CA). Careful aseptic technique was observed throughout each procedure, and prophylactic intravenous antibiotics were administered during the perioperative period to both patients. Treatment proceeded uneventfully in both cases with excellent aneurysm occlusion and no immediate postoperative neurological deficits. INTERVENTION: In both cases, the patients were discharged from hospital but quickly were readmitted with stigmata of meningitis. Imaging demonstrated durable occlusion of the aneurysms in both patients and also abnormalities indicative of perianeurysmal and diffuse intracranial inflammatory response. Complete septic workup failed to identify an organism in either patient. Both patients responded to treatment with corticosteroid medication used to modulate the inflammatory response induced by the coll implants. CONCLUSION: Second-generation aneurysm colls were developed to promote more durable occlusion of cerebral aneurysms by promoting more complete volumetric aneurysm occlusion or by eliciting a more prolific inflammatory response. The concurrent use of Hydrogef and Matrix coll systems in large aneurysms may cause an exuberant inflammatory response with both local and systemic manifestations. Although vigilant evaluation and treatment for presumptive bacterial meningitis is required in all such case, patients respond to immunomoduiatory therapy with corticosteroids More information to understand better the interaction of Hydrogel and Matrix coils is needed.