Absence of Foramen Spinosum on Computed Tomography Scan Determines Feasibility of Middle Meningeal Artery Embolization

Abstract

BACKGROUND AND OBJECTIVES: Middle meningeal artery embolization (MMAE) has emerged as a novel treatment of chronic subdural hematoma. In 0.5% of patients, however, there exists an ophthalmic origin of the middle meningeal artery (MMA) known as the recurrent meningeal artery. It is known that the recurrent MMA is associated with failure of its skeletal aperture, the foramen spinosum, to form during development. The aim of this study was to investigate MMAE feasibility as a function of the presence/absence of the foramen spinosum on preprocedure computed tomography (CT) scan. METHODS: We performed a retrospective review of 100 consecutive patients undergoing MMAE from January 2022 to December 2023 at the Medical University of South Carolina. Preprocedure CT scan of the head was reviewed, and the presence or absence of the foramen spinosum, along with laterality, was recorded. Subsequently, angiographic studies were reviewed. RESULTS: All patients (n = 100) had preprocedural CT scan available for review. The incidence of an absent foramen spinosum was 3% (n = 3). All absent foramen spinosum were left sided (2F, 1M). All embolization attempts in these patients were aborted due to recurrent meningeal artery. 97% of patients had patent bilateral foramen spinosum (n = 97). Two of these patients possessed partial ophthalmic contribution to the MMA (2%), and embolization was not performed. In patients with patent foramen spinosum, successful embolization was achieved in 92/97 patients (94.8%). CONCLUSION: The review of preprocedure CT scan may serve as an opportunity to identify patients with ophthalmic arterial origin of the MMA, subverting unnecessary risks associated with catheter angiography.