Preoperative Embolization of Lesions in the Posterior Fossa: Analysis of 41 Patients from a Single-Center Case Series

Background: Preoperative endovascular embolization has been increasingly used as a facilitating adjunct to surgical treatment of meningiomas and extra axial lesions. Embolization of lesions in the posterior fossa can pose unique challenges. Pattern of feeding vessels, efficacy in pathologies other than meningioma, and rates and timing of symptomatic or life threatening tumor and brain swelling remains uncharacterized.

Objective: This article aims to evaluate the feasibility and safety of performing preoperative endovascular embolization of extra-axial tumors in the posterior fossa.

Materials and Method: The electronic medical records were retroactively reviewed for patients who underwent endovascular embolization prior to open surgical resection of a posterior fossa lesion between January 2015 and June 2024 at a single urban tertiary hospital. Demographic, clinical, imaging and perioperative data were collected. We used an angiographic devascularization grading scale, previously published by our group: grade 0 for no embolization, 1 for partial (<50%) embolization, 2 for near-complete (50–99%) embolization, 3 for complete external carotid artery (ECA) embolization, and 4 for complete embolization with no residual external or internal or posterior supply.

Results: Forty-one consecutive patients were included. Fourteen patients underwent preoperative angiography with intention to treat but did not receive embolization due to lacking suitable or safe feeders.

For the 27 patients who received embolization, there were 18 meningiomas (15 World Health Organization grade I, 3 grade II), 3 paragangliomas, 2 hemangioblastomas, 2 vestibular schwannomas, and 2 hemangioblastomas. In terms of lesion location, 7 were in the cerebellopontine angle, 6 cerebellar convexity, 5 tentorial, 3 jugular fossa, and 2 foramen magnum.

The most common feeders were the occipital artery (11), direct feeders from the vertebral artery (8), and the middle meningeal artery (7). The most commonly embolized feeders were the occipital artery (11), other external carotid branches (7), and the middle meningeal artery (7). 48% (13) of embolizations used coils, 40% (11) used Onyx, and 14% (4) used particles. 22% (6) achieved grade 4 devascularization, 11% (4) for grade 3, 52% (14) for grade 2, and 11% (3) for grade 1.

Comparing patients who received only angiography and who received embolization, there were no differences in length of stay, rates of postprocedural and postoperative complications. No patients had concerns for symptomatic elevated intracranial pressure from tumor swelling or peritumoral edema. The patients who received embolization were more likely to achieve gross total resection (p = 0.0212).

Conclusion: Preoperative embolization in posterior fossa lesions appears to be safe and may facilitate more complete tumor resection. The distribution of specific arterial feeders differed significantly among different tumor locations and pathological types. We will be evaluating its direct effects on the lesion and surrounding brain in subsequent studies with volumetric analyses of pre- and post-embolization MRIs and conduct subgroup analyses between different pathological and location groupings.

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Artikel online veröffentlicht:
07. Februar 2025