Foreign body granuloma reaction after endovascular therapy of an unruptured right frontal arteriovenous malformation

Foreign body reactions after endovascular procedures for brain arteriovenous malformations are extremely rare. We report the case of a cerebral foreign body granuloma reaction after embolization of a frontal arteriovenous malformation with Onyx. A previously treated 36-year-old man underwent re-embolization of a residual and recurrent unruptured right frontal vascular malformation with Onyx. The post-procedural imaging revealed a right frontotemporal heterogeneously enhancing expansive lesion associated with a residual malformation. Following microsurgical resection, the histopathological examination of the expansive lesion revealed basophilic foreign body like deposits adjacent to multi-nucleated giant cells, highly compatible with cerebral foreign body granulomas reaction to Onyx. The clinical and radiological follow-up of the patient was favorable after complete resection of the lesions.

Endovascular embolization of brain arteriovenous malformations with Eudragit-E

Eudragit-E was originally developed as a non-adhesive liquid embolic material in the late 1990s and is a copolymer of methyl and butyl methacrylate and dimethylaminoethyl methacrylate that is dissolved in ethanol and iopamidol. This material has been used for endovascular embolization of brain arteriovenous malformations (AVMs) for some time but is currently not widely used. Because safety and feasibility of Eudragit-E has not been well documented, we here report our experience using this material for treating 22 human brain AVMs. From June 1998 to February 2014, 30 endovascular procedures using Eudragit-E were performed to treat 22 patients, including 14 men and 8 women with a mean age of 41.1 years (15-70 years). The mean follow-up period was 56 months (12-129 months), and the Spetzler-Martin grades were I (4 patients), II (9 patients), III (5 patients), and IV (4 patients). Residual AVMs were treated with stereotactic radiosurgery or surgery. The rate of complete obliteration with embolization alone was 27.3%. The overall obliteration rate after endovascular embolization with/without subsequent stereotactic radiosurgery or surgery was 72.7%. Eudragit-E caused two cases of cerebral infarction. One case of intracerebral hemorrhage due to postoperative hemodynamic changes also occurred. The rate of complications directly related to embolization was 10.0%. The safety and effectiveness of Eudragit-E embolization were satisfactory.