Embolic Materials' Comparison in Meningeal Artery Embolization for Chronic Subdural Hematomas: Multicenter Propensity Score-Matched Analysis of 1070 Cases

Background and objectives: Multiple preferences exist for embolic materials selection in middle meningeal artery embolization (MMAE) for chronic subdural hematoma with limited comparative literature data. Herein, we compare different embolic materials.

Methods: Consecutive patients undergoing MMAE for chronic subdural hematoma at 14 North-American centers (2018-2023) were classified into 3 groups: (a) particles, (b) Onyx, (c) n-butyl cyanoacrylate (n-BCA). The end points were unplanned rescue surgery, radiographic success (≥50% reduction in hematoma thickness at last imaging "minimum of 2 weeks"), and major complications. Initial unmatched analysis compared the 3 groups; subsequent propensity score matching (PSM) compared particles vs liquid embolics (groups b and c combined). Additional subgroup PSM analyses compared particles vs Onyx, particles vs n-BCA, and Onyx vs n-BCA. All matched analyses controlled for age, sex, concurrent surgery, previous surgery, hematoma thickness, midline shift, pretreatment antithrombotics, and baseline modified Rankin Scale.

Results: Eight hundred and seventy-two patients (median age 73 years, 72.9% males) underwent 1070 MMAE procedures. Onyx was most used (41.4%), then particles (40.3%) and n-BCA (15.5%). Surgical rescue rates were comparable between particles, Onyx, and n-BCA (9.8% vs 7% vs 11.7%, respectively, P = .14). Similarly, radiographic success (78.8% vs 79.3% vs 77.4%; P = .91) and major complications (2.4% vs 2.3% vs 2.5%; P = .83) were comparable. The PSM comparing particles vs liquid generated 128 matched pairs; general anesthesia and bilateral procedures were significantly higher in particles (37.8% vs 21.3%; P = .004 and 39.8% vs 27.3%; P = .034, respectively). No differences in surgical rescue, radiographic improvement, or major complications were noted (P > .05). Concurrently, PSM comparing particles vs Onyx, particles vs n-BCA, and Onyx vs n-BCA, resulted in 112, 42, and 40 matched pairs, respectively, without differences in surgical rescue, radiographic success, or major complications (P > .05).

Conclusion: We found no differences in radiological improvement, surgical rescue, or major complications between embolic materials in MMAE. Current randomized trials are exclusively using liquid embolics, and these data suggest that future trials involving particles are likely to produce similar outcomes.