O-033 Pre-operative meningioma embolization with ethylene vinyl alcohol copolymer

Introduction The benefit of pre-operative embolization of meningioma and hemangiopericytoma continues to be debated. Several large cohort studies of 80–198 patients have reported complication rates of 2.5% to 9% using particles or n-butyl cyanoacrylate (nBCA).[1–5] However, although a recent national registry of 898 patients found an association between liquid embolysate and complication rates, with an odds ratio of 3.9.[6] Endovascular technology continues to evolve and ethylene vinyl alcohol (EVOH or Onyx Medtronic) has been available for embolization of arteriovenous malformations for over a decade. The off-label use of EVOH for pre-operative embolization of meningiomas or hemangiopericytomas has only been reported in small series. This study reviewed the safety profile and embolization duration of our experience with EVOH embolization. Methods Review of institutional records identified 72 consecutive cases of meningiomas and hemangiopericytomas that underwent pre-operative embolization with EVOH prior to surgical resection from 2007 to 2017. The imaging and medical records were reviewed to identify tumor dimensions, vascular pedicles, endovascular equipment, outcomes and complications. Embolization rate was compared with Wilcox signed-rank test and complication rates were compared using the Fisher exact test. Results The tumors measured 5 cm (IQR 4.4–6.3) or 45 cm3 (23–71) and were located on the convexity (26%), tentorium (22%), falx (20%), sphenoid ridge (15%), petrous (5%), anterior cranial fossa (5%), infratemporal fossa (4%), and middle cranial fossa (3%). The most frequent pedicle embolized was a middle meningeal artery. In 83% of cases, this was the first pedicle embolized and in 24% of cases, an additional MMA catheterization was used for embolization. Additional pedicles included the internal maxillary (8), occipital artery (7), superficial temporal (4), posterior meningeal (2), posterior auricular (1), and ascending pharyngeal (1) arteries. Tumor supply from branches of the internal carotid artery were typically not embolized: anterior cerebral branches (3 embolized: 7 not embolized), middle cerebral branches (0:11), ophthalmic branches (0:11). In 7 cases, nBCA was also used, most commonly in the superior cerebellar artery (3:7). There were symptomatic complications from embolization in 8% of cases. Twice, tumor necrosis and edema required earlier craniotomy and tumor evacuation, and four patients had new neurologic deficit from infarct. Two occurred from reflux and two occurred from embolysate migration across the tumor to pial vessels. The complication rate was not different from studies in meningiomas with 75 or more cases using other embolysates (p-value 0.15–1.0). In power analysis, comparison against previously published studies would distinguish a complication rate of 23% in a series of this size. Conclusion Embolization with EVOH is comparable in safety to other embolization techniques in meningioma or hemangiopericytoma. Similar to what has been described in arteriovenous malformations, simultaneous dual catheter embolization may decrease procedural time and radiation exposure. Disclosures A. See: None. B. Flores: None. A. Ducruet: None. F. Albuquerque: None.