When is surgery indicated for an epidural hematoma and what determines the choice between burr hole and craniotomy?

Management of Epidural Hematoma: Surgical Indications and Techniques

Immediate surgical evacuation is indicated for all epidural hematomas (EDH) greater than 30 cm³, regardless of the patient's Glasgow Coma Scale (GCS) score, and should be performed as soon as possible in patients with coma (GCS < 9) and anisocoria. 1

Surgical Indications for Epidural Hematoma

Absolute Indications for Surgery

• EDH greater than 30 cm³ requires surgical evacuation regardless of GCS score 1
• Patients in coma (GCS < 9) with anisocoria should undergo immediate surgical evacuation 1
• EDH with thickness greater than 15 mm 1
• EDH with midline shift greater than 5 mm 1
• Neurological deterioration attributable to the EDH 2

Conservative Management Criteria

• EDH less than 30 cm³ AND 1
• Thickness less than 15 mm AND 1
• Midline shift less than 5 mm AND 1
• GCS score greater than 8 without focal deficit 1
• Close neurological observation with serial CT scanning in a neurosurgical center 1, 3

Risk Factors for Deterioration in Initially Asymptomatic Patients

• Skull fracture crossing a major vessel or sinus (55% risk of deterioration) 3
• Diagnosis within 6 hours of trauma (43% risk of deterioration) 3
• Presence of both risk factors increases deterioration risk to 71% 3

Surgical Technique Selection: Craniotomy vs. Burr Hole

Craniotomy

• Recommended as the primary surgical approach for most EDH cases 1
• Provides more complete evacuation of the hematoma 1
• Wide craniotomy covering the entire hematoma is recommended to evacuate blood, control bleeding, and prevent reaccumulation 4
• Particularly important when there is:
  • Large hematoma volume (>30 cm³) 1
  • Significant mass effect 2
  • Active bleeding requiring direct visualization 4
  • Potential for brain swelling requiring possible conversion to decompressive craniectomy 4

Burr Hole Evacuation

• May be considered in specific circumstances:
  • As a temporizing measure in rapidly deteriorating patients when immediate craniotomy is not available 4
  • For small, well-localized hematomas in poor surgical candidates 4
  • Endoscopic burr-hole evacuation may be an option to avoid large craniotomies in select cases 4

Special Considerations

Cerebellar Epidural Hematoma

• Immediate surgical evacuation is recommended for patients with cerebellar hemorrhage who have:
  • Neurological deterioration 5
  • Brainstem compression 5
  • Hydrocephalus from ventricular obstruction 5
• External ventricular drainage alone is not recommended when there is brainstem compression 5

Timing of Surgery

• Urgent intervention is indicated for rapidly deteriorating patients 5
• Earlier intervention (within 8 hours) may improve outcomes 6
• Ultra-early craniotomy (within 4 hours) may carry increased risk of rebleeding in some cases 6

Post-Surgical Management

• ICP monitoring is advised following surgery for large hematomas 2
• Maintain cerebral perfusion pressure >60 mmHg 6
• Monitor for potential complications including:
  • Rebleeding 4
  • Wound dehiscence 2
  • Hydrocephalus 2

Pitfalls to Avoid

• Delaying surgery in patients with large EDH or neurological deterioration 1
• Inadequate exposure during craniotomy leading to incomplete hematoma evacuation 4
• Failure to identify and control bleeding sources, especially from meningeal vessels 4
• Using external ventricular drainage alone for cerebellar hematomas with brainstem compression 5
• Overlooking skull fractures crossing major vessels, which significantly increase risk of hematoma expansion 3