Embolization-induced angiogenesis in cerebral arteriovenous malformations

Endovascular occlusion of cerebral arteriovenous malformations (AVM) is often utilized as adjunctive therapy in combination with radiosurgery or microsurgery. Evidence supports that partial occlusion of AVM via endovascular embolization leads to increased angiogenesis. This phenomenon may be a contributing factor to the decreased efficacy of AVM radiosurgery following embolization. We review the literature for potential mechanisms of embolization-induced angiogenesis. A comprehensive literature search was performed using PubMed to identify studies that sought to elucidate the pathophysiology behind embolization-induced angiogenesis. The terms "arteriovenous malformation", "embolization", and "angiogenesis" were used to search for relevant publications individually and together. Three distinct mechanisms for embolization-induced angiogenesis were described in the literature: (1) hypoxia-mediated angiogenesis, (2) inflammatory-mediated angiogenesis, and (3) hemodynamic-mediated angiogenesis. Embolization-induced angiogenesis of cerebral AVM likely results from a combination of the three aforementioned mechanisms. However, future research is necessary to determine the relative contribution of each individual mechanism to overall post-embolization AVM neovascularization. (C) 2014 Elsevier Ltd. All rights reserved.