What is the treatment approach for an adult or elderly patient with a subdural hematoma, particularly those with a vascular anomaly, and a history of trauma or falls, considering comorbidities such as hypertension, diabetes, or bleeding disorders, and would an embolization procedure be a viable option?

Treatment of Subdural Hematoma with Embolization

Middle meningeal artery (MMA) embolization is an effective treatment for chronic subdural hematoma (cSDH), either as primary therapy or adjunctive to surgery, with significantly lower recurrence rates compared to surgery alone. 1, 2

Primary Treatment Decision Algorithm

For Chronic Subdural Hematoma (cSDH):

MMA embolization should be strongly considered as first-line or adjunctive therapy based on the following clinical scenarios:

• Symptomatic cSDH with surgical indication: MMA embolization plus surgery reduces reoperation risk to 4.1% versus 11.3% with surgery alone (relative risk 0.36) 1
• Primary treatment without surgery: MMA embolization as standalone therapy achieves complete hematoma resolution in appropriately selected patients 3
• Recurrent cSDH after prior surgery: MMA embolization is highly effective, with only 5.0% requiring revision surgery versus 15.1% with repeat surgery alone 3
• Patients on anticoagulation/antiplatelet therapy: MMA embolization is particularly valuable in this high-risk population 3

Treatment Outcomes:

The most recent high-quality evidence demonstrates:

• Treatment failure reduction: 16% with embolization versus 36% with standard treatment alone (odds ratio 0.36) 2
• Hematoma thickness reduction: Median 71% reduction, with 70.8% of patients achieving >50% improvement 4
• Recurrence requiring reoperation: 6.5% with embolization versus significantly higher rates with surgery alone 4

Technical Considerations

Embolization Materials:

Both particle and liquid embolics are effective with no significant outcome differences 4. The procedure can be performed under conscious sedation or general anesthesia (46.1% use general anesthesia) 4.

Procedural Success:

• Technical success rate: 97.4% of procedures successfully completed 4
• Clinical improvement: 31.9% of patients show clinical improvement, with 70.8% demonstrating >50% radiographic improvement 4

Safety Profile

Short-term Safety (30 days):

• Major disabling stroke or death: 3% in both embolization and control groups 2
• Procedure-related serious adverse events: 2.0% including disabling stroke in 1.0% of patients 1
• Overall complication rate: 6.5%, with most complications (6.5%) due to continued hematoma expansion rather than procedural complications 4

Important Safety Caveat:

The 90-day mortality was slightly higher in embolization groups (5.1% vs 3.0% in one trial 1, 8% vs 5% in another 2), though most deaths were unrelated to the procedure and attributed to underlying comorbidities 4. This requires careful patient selection and informed consent discussions.

Clinical Algorithm for Treatment Selection

Step 1: Confirm cSDH Diagnosis

• CT imaging showing subdural collection with characteristic features 5
• Measure hematoma thickness (median presentation: 14 mm) 4

Step 2: Assess Symptomatology and Surgical Indication

• Large symptomatic cSDH requiring evacuation: Recommend MMA embolization PLUS surgery 1, 2
• Moderate symptomatic cSDH: Consider MMA embolization as primary treatment 3, 4
• Recurrent cSDH after prior surgery: Strongly favor MMA embolization 3

Step 3: Evaluate Anticoagulation Status

• Patients on antiplatelet/anticoagulation: MMA embolization is particularly beneficial in this population 3
• Bleeding disorders: Consider embolization to reduce surgical bleeding risk 6

Step 4: Operator Expertise

• Procedures must be performed by experienced interventional neuroradiologists with specific cerebrovascular expertise 7
• Multidisciplinary decision-making involving neurosurgery and interventional neuroradiology is essential 6

Follow-up and Monitoring

Imaging Follow-up:

• Mean follow-up period: 3.4 months with CT imaging to assess hematoma resolution 3
• Expected timeline: Median hematoma thickness reduction to 4 mm by 90 days 4

Clinical Monitoring:

• Neurologic assessment: Monitor for deterioration using standardized scales 1
• Watch for recurrence: 6.5% may require additional treatment within 90 days 4

Key Pitfalls to Avoid

Do not perform MMA embolization without experienced interventional neuroradiology expertise, as procedural complications including disabling stroke can occur 1. The procedure requires specific training in endovascular neurointerventional techniques 7.

Do not assume embolization eliminates all mortality risk—careful patient selection is critical, particularly in elderly patients with multiple comorbidities where 90-day mortality may be elevated regardless of treatment modality 1, 2, 4.

Do not use embolization for acute subdural hematoma with mass effect requiring emergent decompression—these patients need immediate surgical evacuation 6. MMA embolization is specifically indicated for subacute and chronic subdural hematomas 1, 2.

Contraindication to Embolization

While not explicitly stated in guidelines, acute subdural hematoma with significant mass effect and midline shift requires emergent surgical decompression, not embolization 6. The evidence for embolization applies specifically to subacute and chronic subdural hematomas 1, 2.