Current Findings in Embolization of Intracranial Meningiomas: Feasibility, Utility, Classification, and Techniques

Intracranial meningiomas are the most prevalent primary tumors of the central nervous system. Although usually benign and slow-growing, their vascularity and strategic location often complicate surgical resection. Preoperative embolization has emerged as a valuable adjunct to reduce intraoperative blood loss, facilitate tumor removal, and improve surgical outcomes. This chapter reviews current evidence regarding the feasibility, benefits, classification, and technical aspects of embolization in intracranial meningiomas. Embolization is the most effective when the tumor is supplied by external carotid branches, whereas supply from the internal carotid or vertebrobasilar systems requires more selective techniques due to higher risks. Clinically, embolization reduces blood loss, shortens surgery, and improves gross total resection rates, particularly in large, hypervascular tumors. We also introduce the Preoperative Embolization of Meningiomas Mexican Classification (PEMMCO), a novel grading system that categorizes the depth of embolic agent penetration into four levels, ranging from proximal vessel occlusion to complete intra- and peritumoral saturation. This classification aims to predict surgical complexity and optimize outcomes. Advances such as the plug-and-push, pressure-cooker, and balloon-assisted techniques, together with modern agents like ethylene-vinyl alcohol copolymers (e.g., Onyx), have enhanced the safety and efficacy of embolization. Nevertheless, potential risks—including ischemia, edema, and cranial nerve injury—highlight the importance of careful patient selection and expert technical execution. In conclusion, preoperative embolization is a safe and effective adjunct for selected intracranial meningiomas. When planned within a multidisciplinary approach, it can significantly contribute to safer resections and better overall patient outcomes.