E-242 Are We Hitting the Target?: Middle Meningeal Artery Embolization for Chronic Subdural Hematomas

Introduction

The recurrence of cSDHs has been linked to the neovascularization of subdural membranes via the middle meningeal artery (MMA). Thus, recent efforts focus on MMA embolization as a less invasive measure to block vascular supply to these subdural membranes and subsequently allow subdural fluid resorption over time. It is possible that penetration of the membrane with an embolic agent, beyond the visible MMA, is necessary to maximally devascularize cSDHs. In most cases, specific visualization of embolic agents in subdural membrane vasculature is unexplored.

Objective

A microscopic analysis of subdural membranes after undergoing MMA embolization.

Methods

Three patients were identified who had cSDHs initially treated with MMA embolization followed by craniotomies for evacuation due to symptom progression. Intra-operative samples of subdural membranes for each patient were sent for histologic analysis to determine if embolization material was seen penetrating membrane vasculature.

Results

Of the three samples, two patients had bilateral cSDHs and one had a unilateral cSDH. One patient was treated with Onyx (Medtronic, MN, USA), one with 150–250um polyvinyl alcohol particles (PVA; Boston Scientific, MA, USA), and one with 100–300u Embosphere particles (Guerbet Biomedical; Louvres, France). Two patients underwent craniotomies for evacuation within 10 days from the time MMA embolization was performed; one had a prior craniotomy at an external institution and was re-operated on at our institution 35 days after MMA embolization. Upon pathological examination, all had fibrotic and granulation tissue consistent with chronic inflammation. No specimen demonstrated the embolic agent.

Conclusion

In our patients who had cSDH recurrence despite MMA embolization, embolic material was not seen in the vasculature of subdural membranes. While possibly related to sampling bias, this finding may support the theory that penetration of the subdural membranes is important to the success of MMA embolization in curbing progression of cSDHs.

Disclosures

S. Ajmera: None. M. Gubbiotti: None. B. Jankowitz: None.