Objective: To examine the safety and efficacy of pre-operative embolization of intra-and extracranial tumors and determine the selection criteria of patients for this procedure.
Material and Method: Between June 2008 and August 2012, 37 patients (17 males, 20 females; mean age, 44.2+14.2years), underwent pre-operative embolization of intra- and extracranial tumors, were retrospectively reviewed. Tumor characteristics (type, location, volume, percentage of supplying artery, presence of an early draining vein), angiographic extent of tumor devascularization, timing between embolization and surgery, estimated blood loss, and complication related embolization were evaluated.
Results: There were 37 tumors (mean volume, 90.9+83.6 cm3) composed of 18 meningiomas, six hemangioblastomas, six hemangiopericytomas, one metastasis, one osteoblastoma, one osteosacroma, one neurofibroma, one central neurocytoma, one glomus jugulare, one mixed oligoastrocytoma, and one glioblastoma multiforme. Early of draining veins were visualized in 24 patients (64.9%). Failure of pre-operative embolization occurred in four patients. Median time to surgery after
embolization was seven days (ranged 1-171 days). There was statistically significant difference between grading of angiographic devascularization and estimated blood loss (p = 0.009, Kruskal-Wallis test). Two patients (5.4%) had embolization-related complications, including hemorrhage during sub-selective catheterization and postoperative scalp necrosis.
Conclusion: Although pre-operative embolization of intra- and extracranial tumors was safe, only extensive or complete angiographic devascularization has been effective in less intra-operative blood loss. From this present study, indications regarding when to perform pre-operative embolization include history of excessive bleeding from previous surgery, known hypervascular tumor types (e.g., hemangiopericytoma, hemangioblastoma, paraganglioma), the presence of multiple flow voids on MRI, hypervascular tumors of skull or scalp, deep-seated tumors (e.g., cranial base tumor, intraventricular tumor) with difficulty in early surgical access of the main feeding vessels, and tumors associated with intratumoral aneurysm.

Keywords: Pre-operative embolization, Brain tumor, Cranial tumor, Meningioma, Hemangiopericytoma, Hemangioblastoma, Paraganglioma, Intra-axial tumor