O37 180 Day results for EMBOLISE surgical trial: impact of adjunctive middle meningeal artery embolization in the surgical managment of subdural hematoma

<h3>Introduction</h3> Subacute/chronic subdural hematomas are common and frequently recur after surgical evacuation.. <h3>Aim of Study</h3> The effect of embolization of the middle meningeal artery on the need for repeat surgery has not been rigorously studied <h3>Methods</h3> EMBOLISE is a multicenter, prospective, randomized, interventional, adaptive design trial of middle meningeal artery embolization combined with surgical evacuation of the subdural clot compared to surgery only. The primary endpoint was the rate of hematoma recurrence/progression requiring repeat surgical drainage. <h3>Results</h3> A total of 197 patients were assigned to the treatment group and 203 to the control group. The absolute risk of the primary endpoint was 4.1% [1.8%, 7.8%] in the embolization group vs. 11.3% [7.3%, 16.5%] in the surgery only group (relative risk 0.36 [0.11, 0.80], P = 0.008). The secondary endpoint of deterioration in neurologic function (defined as having mRS &lt; 3 at baseline and ≥ 3 at 90 days or having ≥ 3 at baseline and having an increase of ≥ point at 90 days) occurred in 11.9% vs. 9.8%, respectively. No adverse events within 90 days were related to Onyx. The 30- and 90-day rate of serious adverse events, including death, were similar in both arms. <h3>Conclusion</h3> In patients with symptomatic subacute/chronic subdural hematoma requiring surgical drainage, adjunctive middle meningeal artery embolization was associated with a lower rate of hematoma recurrence/progression requiring repeat surgical drainage, without any increase in adverse events. Adjunctive middle meningeal artery embolization should be considered for patients presenting with subacute/chronic SDH requiring surgical evacuation. ClinicalTrials.gov number NCT04402632 <h3>Disclosure of Interest</h3> yes Funded by medtronic, with consulting agreements for Drs. Knopman, Davies, and Siddiqui.