Malignant infarction of the middle cerebral artery (MCA) is associated with an 80%
mortality rate. Non-randomised studies have suggested that decompressive surgery reduces
this mortality without increasing the number of severely disabled survivors. To obtain
sufficient data as soon as possible to reliably estimate the effects of decompressive
surgery, results from three European randomised controlled trials (DECIMAL, DESTINY,
HAMLET) were pooled. The trials were ongoing when the pooled analysis was planned.
Individual data for patients aged between 18 years and 60 years, with space-occupying
MCA infarction, included in one of the three trials, and treated within 48 h after
stroke onset were pooled for analysis. The protocol was designed prospectively when
the trials were still recruiting patients and outcomes were defined without knowledge
of the results of the individual trials. The primary outcome measure was the score
on the modified Rankin scale (mRS) at 1 year dichotomised between favourable (0-4)
and unfavourable (5 and death) outcome. Secondary outcome measures included case fatality
rate at 1 year and a dichotomisation of the mRS between 0-3 and 4 to death. Data analysis
was done by an independent data monitoring committee.
93 patients were included in the pooled analysis. More patients in the decompressive-surgery
group than in the control group had an mRS<or=4 (75%vs 24%; pooled absolute risk reduction
51% [95% CI 34-69]), an mRS<or=3 (43%vs 21%; 23% [5-41]), and survived (78%vs 29%;
50% [33-67]), indicating numbers needed to treat of two for survival with mRS<or=4,
four for survival with mRS<or=3, and two for survival irrespective of functional outcome.
The effect of surgery was highly consistent across the three trials.
In patients with malignant MCA infarction, decompressive surgery undertaken within
48 h of stroke onset reduces mortality and increases the number of patients with a
favourable functional outcome. The decision to perform decompressive surgery should,
however, be made on an individual basis in every patient.