Malignant Middle Cerebral Artery Infarction & Decompressive Hemicraniectomy

You have been diagnosed with a large MCA infarction—what does this mean?

If you or a loved one has been diagnosed with a large infarction in the territory of the middle cerebral artery (MCA), the medical team is likely closely monitoring for:

• a tendency toward massive cerebral edema (swelling) on one side of the brain,
• rising intracranial pressure,
• decline in level of consciousness over the next 2–4 days.

In the most severe cases, this is referred to as “malignant MCA infarction.” In these patients, even the best possible intensive medical care may not be sufficient on its own. This is why decompressive hemicraniectomy is discussed as a potential option.

This is an extremely stressful moment. Our aim is to explain the options in clear language, outline the potential benefits and drawbacks, and support patients and families in making a decision that respects their values and priorities.

What exactly is “malignant” middle cerebral artery infarction?

When a large portion of the brain suddenly loses its blood supply (ischemic stroke), brain cells die and the surrounding tissue develops severe edema. In “malignant” infarctions:

• the infarcted area is very extensive (often involving most of the MCA territory),
• edema progressively increases over 48–96 hours,
• the brain has no room to expand within the rigid cranial cavity,
• critical structures are compressed and the brain may begin to herniate.

Without decompression, this process frequently leads to death despite maximal medical therapy. This is why the condition is termed “malignant.”

Who is at risk & which factors influence the decision?

The likelihood of malignant edema is higher when:

• the infarct is very large (imaging >50% of the MCA territory),
• the patient is younger (the brain tends to swell more within a less compliant skull),
• there is already significant neurological deficit (e.g., dense hemiplegia, aphasia),
• early edema and midline shift are seen on initial imaging.

When considering hemicraniectomy, we also take into account:

• age (initial trials focused on patients <60 years; more recent data suggest benefit in selected patients >60),
• whether the lesion involves the dominant hemisphere (language-dominant side),
• comorbidities (cardiac, pulmonary disease, malignancy, etc.),
• the patient’s pre-stroke functional status (independent vs already dependent).

There is no single “correct” answer for everyone. Each decision is highly individualized.

What are the symptoms & typical clinical course?

During the first 24 hours, the stroke may resemble a “typical” large infarct:

• sudden weakness or paralysis on the opposite side of the body,
• speech impairment (in left MCA strokes in right-handed individuals),
• loss of vision in one visual field,
• confusion or drowsiness depending on extent.

In malignant infarctions, over the next 48–96 hours we often observe:

• progressive decline in consciousness,
• difficulty arousing the patient, loss of meaningful interaction,
• changes in neurological examination (e.g., pupillary reflexes).

How is the diagnosis made & how is the condition monitored?

We use a combination of clinical assessment and imaging:

• Brain CT – rapid identification of infarction and edema, assessment of midline shift.
• MRI/MR perfusion – more detailed evaluation of infarct core and ischemic penumbra where available.
• CT/MR angiography – to identify occlusion of the MCA or another major cerebral artery.
• Intracranial pressure (ICP) monitoring – in selected centers, an ICP catheter may be placed.

Neurological status is documented systematically (e.g., GCS, NIHSS). Changes in the clinical picture—whether the patient stabilizes or deteriorates—are as important as the imaging findings themselves.

What is the intensive / medical management?

All patients with large infarctions and risk of malignant edema require care in a neurological or neurosurgical intensive care unit. Core measures include:

• close monitoring of vital signs and neurological status,
• optimization of blood pressure, oxygenation, and glucose,
• osmotherapy/diuretics (mannitol, hypertonic saline) to control ICP,
• careful sedation and analgesia when needed,
• in some protocols, structured medical regimens (e.g., HeADDFIRST).

Despite optimal conservative therapy, many patients continue to have dangerously elevated intracranial pressure—this is when surgical intervention must be considered.

When is decompressive hemicraniectomy recommended?

Large European and international trials (DECIMAL, DESTINY, HAMLET, among others) have shown that when hemicraniectomy is performed early (within approximately 48 hours of symptom onset):

• mortality is significantly reduced,
• the likelihood of survival with moderate to severe disability is increased.

In general, surgery is recommended when:

• the infarct is very large on CT/MRI,
• the patient begins to show deterioration in level of consciousness,
• medical/intensive therapy is insufficient,
• clinical judgment suggests that without surgery, the outcome will likely be fatal in the near term.

Age (< or > 60), involvement of the dominant hemisphere, and pre-stroke functional status are discussed in depth with the family and incorporated into shared decision-making.

How is the operation performed in practice?

Decompressive hemicraniectomy is a technically “standard” neurosurgical procedure, but it is performed in an extremely critical clinical setting.

Key steps include:

• General anesthesia and positioning of the patient in the operating room.
• A scalp incision covering nearly the entire affected side of the skull (frontal–parietal–temporal–occipital arc).
• Elevation of a musculocutaneous flap.
• Wide hemicraniectomy: removal of a large bone flap, with additional temporal bone removal down to near the zygoma to decompress the middle cranial fossa.
• Extensive opening of the dura (often cruciate or curvilinear incisions) and placement of a synthetic dural graft.
• The bone flap is not replaced but preserved (cryopreserved under sterile conditions) for later cranioplasty.
• Closure of soft tissues and skin.

At a later stage, once edema has resolved (typically after several months), a cranioplasty is performed to reconstruct the skull defect.

What are the risks & potential complications?

As with any major neurosurgical procedure, hemicraniectomy carries immediate and long-term risks:

Immediate risks

• Bleeding, infection, worsening neurological status
• Anesthetic complications, cardiopulmonary events
• Rarely, death despite surgery

Late complications

• Hydrocephalus – up to ~30–40% of patients may require a ventriculoperitoneal (VP) shunt.
• Syndrome of the trephined (sinking skin flap) – pronounced scalp depression over the skull defect, with headaches, dizziness, or neurological worsening that often improves after cranioplasty.
• Complications related to cranioplasty (infection, graft rejection, etc.).

Beyond medical risks, there is also an ethical dimension: survival with severe disability. For some patients this may be acceptable; for others it may not. This discussion is always conducted thoroughly with the patient’s family.

Recovery, disability & quality of life—what should I expect?

Large studies show that decompressive hemicraniectomy:

• saves lives that would otherwise be lost,
• but many survivors live with moderate to severe disability.

In practical terms, many patients:

• have permanent hemiplegia (difficulty or inability to move one side),
• require assistance with daily activities (eating, dressing, mobility),
• may have speech or comprehension deficits (especially with left-hemisphere injury in right-handed individuals),
• need long-term neurorehabilitation (physiotherapy, occupational therapy, speech therapy).

Our goals are to:

• maximize achievable independence,
• support families practically and emotionally,
• maintain honest, realistic, yet compassionate communication about the chances of recovery.

What constitutes an “acceptable quality of life” is deeply personal. The decision to proceed with hemicraniectomy should reflect the patient’s own values and wishes, to the extent that these are known.

When is it urgent & what should I do?

In any suspected stroke:

• Call 166 immediately.
• Request transfer to a hospital with a dedicated stroke unit and neurosurgical coverage.

If the patient already has a large infarct and is hospitalized, the following may signal progression to malignant edema:

• progressive drowsiness or difficulty arousing,
• new worsening of movement, speech, or awareness,
• new pupillary abnormalities (size difference or light response).