Middle Meningeal Artery Embolization for Chronic Subdural Hematoma: Predictors of Clinical and Radiographic Failure from 636 Embolizations

Abstract

Background Knowledge regarding predictors of clinical and radiographic failures of middle meningeal artery (MMA) embolization (MMAE) treatment for chronic subdural hematoma (CSDH) is limited. Purpose To identify predictors of MMAE treatment failure for CSDH. Materials and Methods In this retrospective study, consecutive patients who underwent MMAE for CSDH from February 2018 to April 2022 at 13 U.S. centers were included. Clinical failure was defined as hematoma reaccumulation and/or neurologic deterioration requiring rescue surgery. Radiographic failure was defined as a maximal hematoma thickness reduction less than 50% at last imaging (minimum 2 weeks of head CT follow-up). Multivariable logistic regression models were constructed to identify independent failure predictors, controlling for age, sex, concurrent surgical evacuation, midline shift, hematoma thickness, and pretreatment baseline antiplatelet and anticoagulation therapy. Results Overall, 530 patients (mean age, 71.9 years ± 12.8 [SD]; 386 men; 106 with bilateral lesions) underwent 636 MMAE procedures. At presentation, the median CSDH thickness was 15 mm and 31.3% (166 of 530) and 21.7% (115 of 530) of patients were receiving antiplatelet and anticoagulation medications, respectively. Clinical failure occurred in 36 of 530 patients (6.8%, over a median follow-up of 4.1 months) and radiographic failure occurred in 26.3% (137 of 522) of procedures. At multivariable analysis, independent predictors of clinical failure were pretreatment anticoagulation therapy (odds ratio [OR], 3.23; P = .007) and an MMA diameter less than 1.5 mm (OR, 2.52; P = .027), while liquid embolic agents were associated with nonfailure (OR, 0.32; P = .011). For radiographic failure, female sex (OR, 0.36; P = .001), concurrent surgical evacuation (OR, 0.43; P = .009), and a longer imaging follow-up time were associated with nonfailure. Conversely, MMA diameter less than 1.5 mm (OR, 1.7; P = .044), midline shift (OR, 1.1; P = .02), and superselective MMA catheterization (without targeting the main MMA trunk) (OR, 2; P = .029) were associated with radiographic failure. Sensitivity analyses retained these associations. Conclusion Multiple independent predictors of failure of MMAE treatment for chronic subdural hematomas were identified, with small diameter (<1.5 mm) being the only factor independently associated with both clinical and radiographic failures. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Chaudhary and Gemmete in this issue.

Graphical abstract

Figure 1:

Flowchart shows patient inclusion and exclusion. CSDH = chronic subdural hematoma, MMA = middle meningeal artery.

Figure 2:

Temporal depiction of chronic subdural hematoma (CSDH) response after middle meningeal artery (MMA) embolization. Line graph shows the percentage of CSDHs that achieved radiographic success (≥50% reduction in maximal hematoma thickness), stratified according to preprocedural CSDH maximal thickness (group 1, <10 mm; group 2, 10 mm to <15 mm; group 3, 15 mm to <20 mm, and group 4, ≥20 mm) over prespecified imaging follow-up intervals, including 2–4 weeks (14–28 days), greater than 4 weeks to 6 weeks (29–42 days), 6 weeks to 90 days (43–90 days), and greater than 90 days. The data on the right indicate the number of cases achieving the end point (numerator) from the total cases (denominator) for each CSDH group over each time interval.

Figure 3:

Illustrative cases of each preprocedural CSDH maximal thickness group. (A) Noncontrast head CT image (left) shows a maximal hematoma thickness of 9 mm (group 1, <10 mm) in a 77-year-old man who underwent middle meningeal artery embolization (MMAE) concurrently with left-sided craniotomy for hematoma evacuation. Follow-up noncontrast head CT image (right) at 4 months shows complete resolution of the hematoma. (B) Noncontrast head CT image (left) shows a maximal hematoma thickness of 11.6 mm (group 2, 10 mm to <15 mm) in an 80-year-old man who underwent MMAE following recurrence after a prior left-sided burr hole procedure (3 months earlier). Follow-up noncontrast head CT image (right) at 9 weeks shows complete resolution of the CSDH. (C) Noncontrast head CT image (left) shows a maximal hematoma thickness of 16 mm (group 3, 15 mm to <20 mm) in a 68-year-old man who underwent MMAE following recurrence after prior left-sided craniotomy. Follow-up noncontrast head CT image (right) at 6 weeks shows a minimal hematoma thickness of 5 mm and resolution of symptoms. (D) Noncontrast head CT image (left) shows a maximal hematoma thickness of 25 mm (group 4, ≥20 mm) in a 94-year-old man who underwent MMAE following recurrence after prior left-sided craniotomy (2 months earlier). Follow-up noncontrast head CT image (right) at 8 weeks shows near resolution of the right-sided hematoma.

Figure 4:

Case illustration of clinical failure. (A) Preprocedural head CT image in a 74-year-old man with an extensive cardiovascular history (receiving aspirin and clopidogrel) and stage IV lung cancer shows a right-sided isodense subacute subdural hematoma. The patient was initially managed conservatively and eventually offered middle meningeal artery embolization because of persistent headaches, which was uneventful. The patient subsequently returned from rehabilitation after 4 weeks. (B) Head CT image in the same patient shows changes in hematoma density and decreased size. Despite these radiologic changes, the patient underwent subsequent rescue craniotomy because of progression of headaches.

Figure 5:

Case illustration of radiographic failure. (A) Head CT image in a 63-year-old woman shows a large right-sided chronic subdural hematoma (maximal thickness of 19 mm), which was discovered after the patient fell. Because of progressive headaches, the patient underwent a middle meningeal artery embolization procedure, which was uneventful. (B) Head CT image obtained at the 10-week follow-up (last available) shows minimal reduction of hematoma thickness, and the patient reported little improvement of headaches.