Surgical decompression for space-occupying cerebral infarction (the Hemicraniectomy After Middle Cerebral Artery infarction with Life-threatening Edema Trial [HAMLET]): a multicentre, open, randomised trial.

BACKGROUND: Patients with space-occupying hemispheric infarctions have a poor prognosis, with case fatality rates of up to 80%. In a pooled analysis of randomised trials, surgical decompression within 48 h of stroke onset reduced case fatality and improved functional outcome; however, the effect of surgery after longer intervals is unknown. The aim of HAMLET was to assess the effect of decompressive surgery within 4 days of the onset of symptoms in patients with space-occupying hemispheric infarction.

METHODS: Patients with space-occupying hemispheric infarction were randomly assigned within 4 days of stroke onset to surgical decompression or best medical treatment. The primary outcome measure was the modified Rankin scale (mRS) score at 1 year, which was dichotomised between good (0-3) and poor (4-6) outcome. Other outcome measures were the dichotomy of mRS score between 4 and 5, case fatality, quality of life, and symptoms of depression. Analysis was by intention to treat. This trial is registered, ISRCTN94237756.

FINDINGS: Between November, 2002, and October, 2007, 64 patients were included; 32 were randomly assigned to surgical decompression and 32 to best medical treatment. Surgical decompression had no effect on the primary outcome measure (absolute risk reduction [ARR] 0%, 95% CI -21 to 21) but did reduce case fatality (ARR 38%, 15 to 60). In a meta-analysis of patients in DECIMAL (DEcompressive Craniectomy In MALignant middle cerebral artery infarction), DESTINY (DEcompressive Surgery for the Treatment of malignant INfarction of the middle cerebral arterY), and HAMLET who were randomised within 48 h of stroke onset, surgical decompression reduced poor outcome (ARR 16%, -0.1 to 33) and case fatality (ARR 50%, 34 to 66).

INTERPRETATION: Surgical decompression reduces case fatality and poor outcome in patients with space-occupying infarctions who are treated within 48 h of stroke onset. There is no evidence that this operation improves functional outcome when it is delayed for up to 96 h after stroke onset. The decision to perform the operation should depend on the emphasis patients and relatives attribute to survival and dependency.