Management of Biconvex Shaped Lesion
For a biconvex-shaped lesion (epidural hematoma), urgent craniotomy is indicated if the patient is symptomatic, has neurological deterioration, or demonstrates significant mass effect, while stable patients with small hematomas and minimal symptoms may be admitted for close observation with serial imaging. 1, 2
Understanding the Lesion Type
A biconvex (lentiform) shaped lesion on CT is the classic radiographic appearance of an epidural hematoma (EDH), not a subdural hematoma. This distinction is critical:
- Epidural hematomas appear biconvex because they are limited by the dura's firm adherence to the skull at suture lines, creating a lens-shaped collection that does not cross suture lines 3
- Subdural hematomas appear crescent-shaped and can cross suture lines 4, 5
Decision Algorithm for Management
Immediate Surgical Evacuation (Option A: Urgent Craniotomy)
Perform urgent craniotomy for symptomatic EDH in the following situations 1, 2:
- Any neurological deterioration (declining Glasgow Coma Scale, new focal deficits, pupillary abnormalities)
- Significant mass effect with midline shift or brainstem compression
- Large hematoma volume (generally >30 mL or thickness >15 mm)
- Glasgow Coma Scale <9 at presentation
- Associated skull fracture with brain compression 2
Observation with Admission (Option B: Admit and Observe)
Conservative management with close monitoring is appropriate for 1, 2:
- Small EDH (<30 mL volume, <15 mm thickness, <5 mm midline shift)
- Neurologically stable patient (GCS ≥13 without deterioration)
- No significant mass effect on imaging
- Reliable neurological examination possible
Critical monitoring requirements during observation 1:
- Serial neurological examinations every 1-2 hours initially
- Repeat CT imaging at 6-12 hours and with any clinical change
- Continuous blood pressure monitoring maintaining SBP >110 mmHg
- Immediate neurosurgical availability for emergent intervention
Essential Initial Stabilization (Regardless of Surgical Decision)
Before and during decision-making, implement these measures 1, 2:
- Airway control: Endotracheal intubation with mechanical ventilation for GCS ≤8 or inability to protect airway
- Hemodynamic support: Maintain systolic blood pressure >110 mmHg using immediate vasopressors (phenylephrine or norepinephrine) if needed—do not wait for fluid resuscitation
- Imaging: Obtain non-contrast head CT immediately with inframillimetric reconstructions viewed in both brain and bone windows
- End-tidal CO2 monitoring: Maintain normocapnia (PaCO2 35-45 mmHg), avoiding hypocapnia which causes cerebral vasoconstriction
Critical Pitfalls to Avoid
- Never delay neurosurgical consultation while attempting "stabilization" at a non-neurosurgical facility—immediate transfer is essential 2
- Never allow even brief hypotensive episodes (SBP <90 mmHg), as a single episode markedly worsens neurological outcome 1, 2
- Never use bolus sedation instead of continuous infusions, which causes hemodynamic instability 1, 2
- Never assume a biconvex lesion is always EDH—rare cases of chronic subdural hematoma can mimic this appearance, though this is uncommon 5
Surgical Technique Considerations
When craniotomy is indicated 1, 2:
- Standard craniotomy with hematoma evacuation is the procedure of choice
- Decompressive craniectomy is generally not the primary approach for isolated EDH (reserved for refractory intracranial hypertension or severe associated brain injury)
- Ensure adequate exposure to completely evacuate the hematoma and achieve hemostasis
Post-Operative or Observation Period Management
For all patients (surgical or conservative) 1:
- ICP monitoring if GCS ≤8 or unable to perform reliable neurological examination
- Maintain normothermia using targeted temperature control
- Seizure prophylaxis strategies
- Maintain cerebral perfusion pressure ≥60 mmHg once ICP monitoring available