Extradural Haematoma

An extradural, or epidural, haematoma is bleeding between the inner table of the skull and dura mater.

The commonest mechanism is arterial bleeding after temporal skull fracture injures the middle meningeal artery.

Other sources include:

• Middle meningeal vein
• Dural venous sinus
• Diploic vessels
• Fracture surfaces

Because the dura is tightly adherent at cranial sutures, EDH classically forms a biconvex lentiform collection that generally does not cross sutures.

A rapidly expanding arterial EDH can produce catastrophic transtentorial herniation in a previously lucid patient.

The classic sequence is:

• Initial loss of consciousness
• Lucid interval
• Progressive deterioration

This is memorable but occurs in only a minority of patients.

Other findings include:

• Severe headache
• Vomiting
• Progressive drowsiness
• Ipsilateral dilated pupil
• Contralateral weakness
• Seizure
• Coma

A deteriorating patient with a temporal EDH and new ipsilateral pupillary dilatation requires immediate operative intervention.

Noncontrast CT: demonstrates a lentiform extra axial haematoma.

Assess:

• Volume
• Maximum thickness
• Midline shift
• Basal cisterns
• Skull fracture
• Associated intracranial injuries

Posterior fossa EDH deserves particular caution because relatively small lesions can rapidly compress the fourth ventricle and brainstem.

Immediate surgical indications

Evacuate an EDH larger than approximately:

30 cm³

regardless of GCS.

An EDH can be observed when all of the following are present:

• Volume below 30 cm³

• Thickness below 15 mm

• Midline shift below 5 mm

• GCS greater than 8

• No focal neurological deficit

• Capacity for intensive neurological observation and serial CT.

A patient with:

• GCS below 9

and

• Anisocoria

requires evacuation as soon as possible.

Do not delay emergency surgery for repeated CT when the patient has known EDH and clear herniation physiology.

Procedure

Perform craniotomy large enough to:

• Evacuate the clot fully

• Identify the bleeding source

• Control the middle meningeal artery or venous sinus bleeding

• Inspect the dura

• Achieve secure haemostasis from skull and dural surfaces

Replace the bone flap when swelling permits.

Leave it off when severe associated cerebral swelling makes replacement unsafe.

Observed EDH

Admit to a neurosurgical environment.

Perform:

• Frequent GCS and pupil examinations

• Repeat CT during early observation, commonly within several hours, or sooner with deterioration

Immediate surgery is required if there is:

• Enlargement

• Falling GCS

• New focal deficit

• Increasing midline shift

• New pupillary abnormality