What is the role of Decompressive Hemicraniectomy (DH) in managing severe brain swelling due to traumatic brain injury or stroke?

Role of Decompressive Hemicraniectomy in Managing Severe Brain Swelling

Decompressive hemicraniectomy (DH) should be performed in patients with refractory intracranial hypertension due to severe brain swelling from stroke or traumatic brain injury when medical management fails, as it significantly reduces mortality despite increased risk of disability in survivors. 1

Indications for Decompressive Hemicraniectomy

For Ischemic Stroke:

• DH with dural expansion should be considered in patients with swollen supratentorial hemispheric ischemic stroke who continue to deteriorate neurologically despite medical management 1
• In swollen cerebellar stroke, suboccipital craniectomy with dural expansion should be performed in patients who deteriorate neurologically 1
• Ventriculostomy for obstructive hydrocephalus after cerebellar infarct should be accompanied by decompressive suboccipital craniectomy to prevent upward cerebellar displacement 1
• There is uncertainty about efficacy in patients ≥60 years of age, with significantly worse outcomes in this population 1, 2

For Traumatic Brain Injury (TBI):

• DH is indicated for control of refractory intracranial pressure in the early phase of TBI 1
• Specific indications include:
  • Removal of symptomatic extradural hematoma regardless of location 1
  • Removal of significant acute subdural hematoma (thickness >5mm with midline shift >5mm) 1
  • Management of refractory intracranial hypertension after failure of medical therapy 1

Timing and Technical Considerations

• Early intervention before clinical signs of brainstem compression develop yields better outcomes 2
• The most commonly used technique is a large temporal craniectomy (>100 cm²) with enlarged dura mater plasty 1
• Both unilateral (lateral) and bifrontal approaches are used, with the choice potentially depending on the location of pathology, though evidence comparing these approaches is limited 1
• A wide craniectomy with dural expansion is crucial for adequate ICP reduction 2

Outcomes and Prognosis

• DH significantly reduces mortality (by approximately 50%) compared to medical treatment alone 2, 3
• In the RESCUE-ICP study, mortality was reduced to 26.9% in the DH group versus 48.9% in the medical group 1
• Despite reduced mortality, survivors often face significant disability:
  • For patients under 60 years, approximately 55% achieve moderate disability or better at 12 months 2
  • For patients over 60 years, only about 11% achieve moderate disability and virtually none achieve independence 2
  • One-third of patients will be severely disabled and fully dependent on care even after DH 1, 2
• Long-term complications include depression (affecting nearly half of survivors), lack of initiative, irritability, and disinhibition 2

Decision-Making Considerations

• The decision to perform DH should involve multidisciplinary discussion 1
• Age is an important consideration, with most studies excluding patients above 60-70 years 1
• Family members should be informed that while DH reduces mortality, there is a significant risk of survival with severe disability 1, 2
• Values and preferences of patients (when known) should be considered in the decision-making process 1

Monitoring and Post-Surgical Management

• Close monitoring for signs of neurological worsening is essential 2
• Intracranial pressure monitoring is suggested after severe TBI in patients with:
  • Signs of high ICP on brain CT scan
  • Extracranial surgical procedures (except life-threatening conditions)
  • Cases where neurological evaluation is not feasible 1
• Osmotic therapy is reasonable for patients with clinical deterioration from cerebral swelling 2
• Brief moderate hyperventilation may be used as a bridge to more definitive therapy 2

Common Pitfalls and Caveats

• Insufficient decompression size is associated with poor outcomes 1
• Hypothermia, barbiturates, and corticosteroids are not recommended for the management of cerebral edema 2
• The optimal timing for bone flap replacement (cranioplasty) remains insufficiently understood 1
• Current literature predominantly focuses on secondary DH (delayed removal of bone flap), with limited evidence on primary DH (leaving bone flap off during initial surgery) 1, 4