Adjunctive middle meningeal artery embolization with low-viscosity liquid embolic agents for acute epidural hematoma: technical considerations and a case series.

OBJECTIVE

To assess the feasibility, safety, and short-term outcomes of adjunctive middle meningeal artery (MMA) embolization using low-viscosity liquid embolic agents (1:1 diluted Onyx/DMSO and 1:9 diluted Glubran 2/Ethiodized Poppyseed Oil Injection) for acute epidural hematoma (AEDH).

METHODS

We retrospectively reviewed 9 consecutive AEDH patients evaluated for MMA embolization at our institution. Eight underwent embolization, and one was converted to immediate craniotomy after pre-procedural cranial CT showed rapid hematoma expansion. In the embolization subgroup, low-viscosity agents included 1:1 diluted Onyx with dimethyl sulfoxide (DMSO) (n = 6) and 1:9 diluted Glubran 2/ethiodized oil (n = 2). Primary observations included technical success, radiographic evolution, clinical outcomes, and periprocedural complications.

RESULTS

Technical success was achieved in all embolized cases (8/8). Across the eight embolized cases, low-viscosity agents reached distal dural branches without relevant proximal reflux, and no catheter adherence or catheter entrapment was observed. No procedure-related complications occurred. Follow-up imaging showed stable or resolving hematomas in all embolized patients, and none required rescue surgery for post-embolization expansion. Median discharge GCS was 15, and no new neurologic deficits were observed. In the non-embolized conversion case, immediate pre-procedural CT showed interval progression, and prompt craniotomy was performed.

CONCLUSION

In selected AEDH patients, adjunctive MMA embolization with low-viscosity liquid embolic agents (1:1 diluted Onyx/DMSO and 1:9 diluted Glubran 2/ethiodized oil) was technically feasible with a favorable short-term safety profile and may help control bleeding and reduce the risk of hematoma expansion while balancing distal penetration and catheter control. This strategy may provide a minimally invasive treatment option for high-risk AEDH, but multicenter studies with larger retrospective case series are needed for confirmation.