Decompressive Hemicraniectomy

Decompressive hemicraniectomy with durotomy is a procedure first pioneered by Harvey Cushing the famous Boston neurosurgeon in 1905 [Cushing H 1905]. It did not come into usage for stroke until 1956.

About

• Certain patients with malignant middle cerebral artery infarction may benefit from decompressive hemicraniectomy. and should be referred to the neurosurgeons within 24 hours of the onset of symptoms and treated within a maximum of 48 hours. The operation is potentially lifesaving however this is at the cost of an increased number of patients with moderate to severe disability.
• Post and perioperative complications can be severe. The principle behind the surgery is to remove the overlying skull and incise the restrictive dura mater covering the brain. This enables the swollen brain tissue to herniate upwards through the surgical defect rather than downwards to compress the brainstem.
• Hemicraniectomy has been used to treat brain swelling and mass effect secondary to malignant MCA syndrome infarctions, severe encephalitis, and large parenchymal intracerebral haemorrhage in subarachnoid haemorrhage. However, the principle use nowadays is in malignant MCA syndromes.

Current guidelines are to consider those

• Aged 60 years or younger though centres may have differing criteria
• Clinical deficits suggestive of infarction in the territory of the middle cerebral artery
• National Institutes of Health Stroke Scale (NIHSS) of above 15.
• Decrease in the level of consciousness to give a score of 1 or more on item 1a of the NIHSS
• Signs on CT of an infarct of at least 50% of the middle cerebral artery territory, with or without additional infarction in the territory of the anterior or posterior cerebral artery on the same side, or infarct volume greater than 145 cm3 as shown on diffusion-weighted MRI

AHA Guidelines Feb 2018 [USA]

• Although the optimal trigger for decompressive craniectomy is unknown, it is reasonable to use a decrease in the level of consciousness attributed to brain swelling as selection criteria.
• In patients <= 60 years of age with unilateral MCA infarctions who deteriorate neurologically within 48 hours despite medical therapy, decompressive craniectomy with the dural expansion is reasonable because it reduces mortality by close to 50%, with 55% of the surgical survivors achieving moderate disability (able to walk) or better (MRS score 2 or 3) and 18% achieving independence (mRS score 2) at 12 months.
• In patients >60 years of age with unilateral MCA infarctions who deteriorate neurologically within 48 hours despite medical therapy, decompressive craniectomy with dural expansion may be considered because it reduces mortality by close to 50%, with 11% of the surgical survivors achieving moderate disability (able to walk [mRS score 3]) and none achieving independence (MRS score =2) at 12 months.
• Use of osmotic therapy for patients with clinical deterioration from cerebral swelling associated with cerebral infarction is reasonable.
• Use of brief moderate hyperventilation (Pco2 target 30-34 mm Hg) is a reasonable treatment for patients with acute severe the neurological decline from brain swelling as a bridge to more definitive therapy.
• Because of a lack of evidence of efficacy and the potential to increase the risk of infectious complications, corticosteroids (in conventional or large doses) should not be administered for the treatment of cerebral oedema and increased intracranial pressure complicating ischemic stroke.