When is decompressive hemicraniectomy (DHC) recommended for patients with increased intracranial pressure (ICP)?

Decompressive Hemicraniectomy for Increased Intracranial Pressure

Decompressive hemicraniectomy (DHC) is recommended when medical management fails to control refractory intracranial hypertension, with specific indications varying by etiology: for malignant MCA infarction in patients typically <60 years with impaired consciousness and >50% MCA territory edema with midline shift, and for traumatic brain injury when ICP remains elevated despite maximal medical therapy. 1, 2

Primary Indications by Etiology

Malignant MCA Infarction (Class I, Level A Evidence)

DHC is indicated when ALL of the following criteria are met: 1

• Age typically <60 years (though this is not an absolute contraindication)
• Impaired consciousness or progressive reduction of consciousness
• Mass effect on imaging: edema exceeding 50% of MCA territory with midline shift
• Exclusion of other causes of impaired consciousness (hypoperfusion, hypotension, cerebral reinfarction, seizures)

The mortality benefit is substantial—DHC reduces mortality by approximately 50% (26.9% vs 48.9% with medical management alone in the RESCUE-ICP trial). 2 Early intervention before brainstem compression develops yields superior outcomes. 2

Traumatic Brain Injury

DHC is indicated for: 2

• Refractory intracranial hypertension in the early phase of TBI when medical management fails
• Symptomatic extradural hematoma regardless of location
• Significant acute subdural hematoma requiring removal

ICP monitoring after DHC demonstrates that initial post-operative ICP correlates with midline shift, neurological status, and 6-month mortality, making early ICP measurement a critical prognostic indicator. 3

Cerebellar Infarction (Class III, Level C Evidence)

DHC is indicated when: 1

• Neurological signs of brainstem compression (hypertension, bradycardia, progressive reduction of consciousness)
• Mass effect on brain imaging
• Exclusion of other causes of impaired consciousness
• No age limit is suggested, but patients should not have significant prestroke handicap

Absolute Contraindications

For MCA Infarction

Do NOT perform DHC when: 1

• Bilateral, nonreactive, non-drug-induced pupillary dilation with coma
• All four unfavorable prognostic factors present simultaneously:
  • Age ≥50 years
  • Involvement of additional vascular territories
  • Unilateral pupillary dilation
  • GCS <8
• Severe comorbidity (severe heart failure, myocardial infarction, incurable neoplasia)
• Patient refusal documented through current interaction, written documents, or proxy communication

For Cerebellar Infarction

Avoid DHC with: 1

• Clinical or radiological signs of severe, irreversible brainstem ischemia

Surgical Technique

The procedure requires a large fronto-parieto-temporo-occipital craniectomy extending to the midline with diameter ≥12 cm (ideally >100 cm²), including durotomy and duroplasty to allow brain expansion. 4, 2 Both unilateral (lateral) and bifrontal approaches are used depending on pathology location. 2

Durotomy alone (without duroplasty) is a safe alternative that significantly lowers ICP while shortening operative time and avoiding graft material, with mean operation time of 115 minutes and no relevant complications. 5 ICP drops significantly in two stages: first after bone flap removal (mean 41 to 18 mmHg), then further during durotomy (to mean 10.6 mmHg). 5

Timing Considerations

Proceed to craniectomy as fast as possible upon clinical deterioration. 1 If surgery is delayed, the patient should be sedated, intubated, ventilated, and transferred to ICU with pharmacological measures initiated. 1 Early intervention before brainstem compression develops is critical for optimal outcomes. 2

Close neurological and cardiovascular monitoring in an intermediate or intensive care stroke unit is mandatory, particularly for territorial cerebellar infarctions requiring monitoring up to 5 days even if the patient appears stable. 1

Medical Management Limitations

Controlled hyperventilation and/or mannitol or hypertonic saline have little value once a decision against craniectomy is made, as these measures show only transitory effects and are associated with rebound phenomena after discontinuation, potentially increasing ICP. 1 Corticosteroids, hypotonic fluids, and sedatives (except benzodiazepines for alcohol withdrawal) are not indicated. 1

ICP Monitoring

Preoperative invasive ICP monitoring is not routinely recommended, though increasing ICP values may serve as an additional indicator for surgical intervention. 1 Post-operatively, ICP monitoring is helpful for optimizing ICU management. 1 Interpretation of ICP values alone in massive MCA infarction requires caution due to intracranial compartmentalization. 1

Maintain cerebral perfusion pressure >60 mmHg throughout the perioperative period. 1, 4, 6

Outcomes and Prognosis

DHC significantly reduces mortality despite increased risk of disability in survivors. 2 For MCA infarction, the number needed to treat is approximately 2 to prevent one death, though considerable long-term handicap is frequent despite surgery. 1 At 12 months post-injury, 45.4% of DHC patients had favorable outcomes versus 32.4% with medical management alone. 1

For spontaneous intracranial hemorrhage, DHC without clot evacuation shows favorable outcomes in 53% of patients with 26% mortality rate, though this is based on limited heterogeneous studies. 7