Direct Middle Meningeal Artery Embolization During Mini-Craniotomy for Subdural Hematoma Evacuation: Case Series

BACKGROUND AND OBJECTIVES: Adjunctive middle meningeal artery (MMA) embolization has been shown to be effective in reducing subdural hematoma recurrence rates after surgical evacuation. In hospitals that do not have a hybrid neurointerventional suite and operating room, embolization and surgical evacuation must be carried out as separate procedures. The objective of this study was to examine whether intraoperative direct catheterization of the MMA for embolization is safe and effective. This operative approach has not been described so far in a larger case series. METHODS: A prospectively collected single-institution database of 21 consecutive cases of direct MMA embolization during mini-craniotomy for subdural hematoma evacuation was analyzed for safety and efficacy. RESULTS: Direct MMA embolization was technically feasible in 20 of 21 cases. Initial false catheterization of the middle meningeal vein occurred in 7 cases (33%), but the MMA was subsequently successfully catheterized in all but one of these cases. The frontal branch of the MMA was exposed for catheterization in 19 cases, and the parietal branch in 2 cases. For proximal embolization, the catheter tip was most commonly advanced to the radiographic projection of the greater sphenoid wing (47%) and in some cases below the foramen spinosum (11%). Seventeen (81%) proximal (retrograde) and 12 (57%) distal (anterograde) embolizations of the MMA were performed using Onyx, n-butyl cyanoacrylate, or coils. Ophthalmic artery or orbital collaterals were noted in 5 of 20 cases during final pre-embolization runs (25%). The average catheterization and embolization portion of the operation took 32 minutes ±22 minutes. No patient sustained a permanent neurological deficit from the embolization, and no patient required a reoperation. At 90 days, all subdural hematomas showed radiographic improvement or resolution. CONCLUSION: Intraoperative direct MMA embolization during chronic subdural hematoma evacuation can safely merge 2 procedures into 1 leading to improved workflows for patients and surgeons.