What is the preferred procedure between hemicraniotomy and hemicraniectomy for managing severe traumatic brain injury with increased intracranial pressure?

Hemicraniectomy vs Hemicraniotomy for Severe TBI with Increased ICP

Decompressive hemicraniectomy (not hemicraniotomy) is the recommended procedure for managing severe traumatic brain injury with refractory intracranial hypertension, as it provides definitive ICP control through bone removal and dural expansion, whereas hemicraniotomy (bone flap replacement) does not address the underlying pathophysiology of brain swelling. 1

Terminology Clarification

The critical distinction is that hemicraniectomy involves permanent removal of a large skull bone flap (>100 cm²) with dural expansion, while hemicraniotomy refers to temporary bone removal with replacement at the end of surgery. 1 For severe TBI with elevated ICP, only hemicraniectomy provides the necessary decompression. 2

Evidence-Based Indications for Decompressive Hemicraniectomy

Perform decompressive hemicraniectomy for refractory intracranial hypertension in the early phase of TBI after multidisciplinary discussion. 1

Specific Clinical Scenarios:

• Refractory ICP elevation despite maximal medical management (sedation, osmotic therapy, normothermia, seizure control) 1
• Symptomatic extradural hematoma requiring evacuation 2
• Significant acute subdural hematoma with mass effect 2
• Progressive neurological deterioration from brain swelling despite first-line therapies 2

Surgical Technique Requirements

The most commonly used and recommended technique is a large temporal (unilateral) craniectomy exceeding 100 cm² with enlarged dura mater plasty. 1

Technical specifications:

• Unilateral (lateral) approach for focal lesions or unilateral swelling 1
• Bifrontal craniectomy for diffuse bilateral lesions (though associated with worse outcomes in some studies) 1
• Wide craniectomy with dural expansion is crucial for adequate ICP reduction 2

Mortality and Outcome Data

Decompressive hemicraniectomy significantly reduces mortality by approximately 50% compared to medical management alone. 2

Key outcome metrics:

• Mortality reduction: 26.9% with hemicraniectomy vs. 48.9% with medical management in the RESCUE-ICP trial 1, 2
• Number needed to treat: Approximately 2 patients to prevent one death 2
• Favorable outcomes at 6 months: 40-57% after unilateral craniectomy vs. 28-32% in control groups 1
• 12-month mortality benefit: Clear reduction in death or vegetative state (RR 0.68) 3

Critical Timing Considerations

Early intervention before clinical signs of brainstem compression develop yields better outcomes. 2

Timing algorithm:

• Consider within first 72 hours of injury, before initiating therapeutic hypothermia and barbiturates 1
• Do not delay when ICP remains >20-40 mmHg despite medical management, as mortality risk increases 3.95-fold 1
• Urgent intervention when ICP exceeds 40 mmHg (6.9-fold increased mortality risk) 1

Age-Related Considerations

Most evidence excludes patients above 60-70 years, and age should factor into the multidisciplinary decision. 1, 2

Age thresholds from major trials:

• Exclusion at 60 years (1 study), 65 years (2 studies), and 70 years (1 study) 1
• Decision must be individualized based on pre-injury functional status and patient/family values 1

Quality of Life Trade-offs

While hemicraniectomy reduces mortality, it increases the proportion of survivors with severe disability. 1, 3

Critical counseling points:

• Poor neurological outcome (severe disability) increased from 2.1% to 8.5% in surgical patients 1
• Favorable outcome at 6 months was not significantly different between groups (26.6% medical vs. 27.4% surgical) 1
• At 12 months, 45.4% of hemicraniectomy patients had favorable outcomes vs. 32.4% with medical management 2

Common Pitfalls to Avoid

Do not perform bifrontal craniectomy for unilateral pathology, as the DECRA study showed worse outcomes (70% poor outcome vs. 51% in controls). 1

Additional cautions:

• Do not use hemicraniotomy (bone flap replacement) when decompression is needed—this defeats the purpose 1
• Avoid delayed surgery when ICP is persistently elevated, as cumulative ischemic burden worsens outcomes 4
• Do not proceed in patients with bilateral nonreactive pupils, severe irreversible brainstem injury, or severe comorbidities 2
• Recognize higher adverse event risk in surgical patients, though distinguishing treatment-related complications from disease progression is challenging 3

Monitoring Requirements Post-Procedure

Continue ICP monitoring after hemicraniectomy, as ICP typically decreases by approximately 8 mmHg immediately post-surgery. 4

Post-operative management:

• Maintain cerebral perfusion pressure ≥60 mmHg 1, 5
• Reduce therapeutic intensity level as ICP improves 4
• Monitor for surgical complications including infection, hemorrhage, and CSF leak 3

Bilateral Hemicraniectomy

Bilateral hemicraniectomy is a heroic intervention with 67% in-hospital mortality but can be life-saving in select cases of severe diffuse injury. 6