This trial is a prospective, randomized, controlled, clinical trial based on a stroke center. We randomly assigned 151 patients 41 years of age or older (median, 65 years; range, 41 to 83) with malignant middle cerebral artery infarction to either conservative medical treatment or hemicraniectomy; assignments were made within 12 to 38 hours after the onset of symptoms. The primary end point was survival with slight or moderate disability 12 months after randomization (defined by a score of 0 to 3 on the modified Rankin scale, which ranges from 0 [no symptoms] to 6 [death]). Secondary outcome included death, Barthel Index, National Institute of Health Stroke Scale, and Stroke Impact Scale 2.0 (SIS) 6 months and 1 year after randomization. Variables for subgroup analyses were age, sex, presence of aphasia or neglect, stroke severity and time to randomization. The study was performed according to Consolidated Standards of Reporting Trials (CONSORT).

Patients between 40 to 80 years of age were included within 12 to 38 hours of a malignant middle cerebral artery infarction defined by the association of 3 criteria: a National Institutes of Health Stroke Scale score ≥16, including a score ≥1 for item 1a (level of consciousness); brain computed tomography ischemic signs involving 2/3 of the middle cerebral artery territory; and a diffusion-weighted imaging (DWI) infarct volume >150cm3. The first patient was enrolled in January 2003 and the last patient in December 2007. An independent data safety monitoring committee monitored the safety, progress, and ethics of the trial. Patients were randomized to either surgical plus medical treatment or to conservative medical treatment alone.

Inclusion Criteria:

• A National Institutes of Health Stroke Scale score ≥16
• A score ≥1 for item 1a (level of consciousness)
• Brain computed tomography ischemic signs involving 2/3 of the middle cerebral artery territory
• Diffusion-weighted imaging infarct volume >150cm3

Exclusion Criteria:

• Prestroke modified Rankin score score ≥2
• Prestroke score on the Barthel Index <95
• Score on the Glasgow Coma Scale <6
• Both pupils fixed and dilated
• Any other coincidental brain lesion that might affect outcome
• Plasminogen activator in the 12 h before randomisation
• Space-occupying hemorrhagic transformation of the infarct
• Pregnancy
• Life expectancy <3 years
• Other serious illness that might affect outcome
• Known coagulopathy or systemic bleeding disorder
• Contraindication for anesthesia

3 months after publication data will be shared