In an adult with a large, hypervascular skull‑base meningioma planned for surgical resection, is pre‑operative endovascular embolization recommended as a definitive treatment or only as an adjunct to surgery?

Preoperative Endovascular Embolization for Large Hypervascular Skull Base Meningiomas

Preoperative endovascular embolization is recommended as an adjunct to surgical resection for large, hypervascular skull base meningiomas, not as definitive treatment, with the goal of reducing intraoperative blood loss by approximately 80%, decreasing operative time, and improving surgical field visualization. 1, 2

Role of Embolization: Adjunctive, Not Definitive

• Embolization serves exclusively as a preoperative adjunct to facilitate surgical resection—it is not a standalone curative treatment for meningiomas. 3, 4
• Complete surgical resection remains the treatment of choice for meningiomas, with embolization functioning to devascularize the tumor prior to resection. 5, 1
• The primary aim is to aid successful surgical resection by reducing tumor vascularity, which is particularly critical for skull base locations where deep vascular supply precludes early devascularization during surgery. 6

Specific Indications for Embolization

• Large (>1.5 cm) and highly hypervascular skull base meningiomas are the strongest candidates for preoperative embolization. 7
• Skull base locations (parasellar, cavernous, infratentorial, clivus) benefit most because their deep arterial supply from both internal and external carotid territories makes early surgical devascularization difficult. 6, 8
• Tumors demonstrating arteriovenous shunting or incorporating multiple vascular territories warrant embolization to minimize intraoperative hemorrhage risk. 9

Optimal Timing and Technique

• Surgery should be performed 1-8 days after embolization, with optimal timing at 7-9 days for maximal tumor softening and ease of resection. 2, 7
• Very early resection (<24 hours) negates benefits by not allowing sufficient time for devascularization and tumor necrosis. 2
• In select cases of extremely hypervascular tumors, concomitant embolization and surgical resection performed as one operation may be warranted to minimize risk of post-embolization edema and acute deterioration. 9

Expected Benefits

• Embolization reduces tumor vascularity by approximately 80%, which translates to decreased intraoperative blood loss, shorter operative time, and improved visualization of the surgical field. 1, 2
• The procedure softens the tumor, making resection technically easier and potentially safer. 8
• For skull base meningiomas specifically, embolization addresses the challenge of deep vascular supply that cannot be controlled early in the surgical approach. 6

Critical Risks and Complications

• Major complications occur in 3-6% of cases and include cranial nerve palsy, stroke, skin/mucosal tissue necrosis, and rarely death. 2, 8
• Large tumors carry increased risk of post-embolization edema leading to acute neurological deterioration. 2, 9
• The complex anastomoses between external carotid branches and posterior circulation must be documented on angiography to avoid inadvertent embolization of critical structures. 7, 8

Technical Requirements

• Procedures must be performed by physicians with expertise in neuro-endovascular techniques and thorough knowledge of skull base vascular anatomy. 2, 8
• Comprehensive preoperative imaging with high-resolution CT and MRI is essential to delineate tumor extent, identify feeding vessels, and plan the embolization approach. 2, 7
• Superselective catheterization of tumor-feeding vessels is required, with meticulous attention to dangerous anastomoses. 7, 8

Common Pitfalls to Avoid

• Do not perform embolization on small, easily resectable meningiomas where complication risk may outweigh benefits. 7
• Avoid scheduling surgery too early (<24 hours) or too late (>8 days) after embolization, as this diminishes therapeutic benefit. 2
• Never proceed without documenting all vascular anastomoses on angiography, particularly connections to the ophthalmic artery and posterior circulation. 7, 9