Hemicraniectomy versus medical treatment with large MCA infarct: a review and meta-analysis

OBJECTIVE: Large middle cerebral artery stroke (space-occupying middle-cerebral-artery (MCA) infarction (SO-MCAi)) results in a very high incidence of death and severe disability. Decompressive hemicraniectomy (DHC) for SO-MCAi results in large reductions in mortality; the level of function in the survivors, and implications, remain controversial. To address the controversy, we pooled available randomised controlled trials (RCTs) that examined the impact of DHC on survival and functional ability in patients with large SO-MCAi and cerebral oedema. METHODS: We searched MEDLINE, EMBASE and Cochrane library databases for randomised controlled trials (RCTs) enrolling patients suffering SO-MCAi comparing conservative management to DHC administered within 96 hours after stroke symptom onset. Outcomes were death and disability measured by the modified Rankin Scale (mRS). We used a random effects meta-analytical approach with subgroup analyses (time to treatment and age). We applied GRADE methods to rate quality/confidence/certainty of evidence. RESULTS: 7 RCTs were eligible (n=338 patients). We found DHC reduced death (69-30% in medical vs surgical groups, 39% fewer), and increased the number of patients with mRS of 2-3 (slight to moderate disability: 14-27%, increase of 13%), those with mRS 4 (severe disability: 10-32%, increase of 22%) and those with mRS 5 (very severe disability 7-11%: increase of 4%) (all differences p<0.0001). We judged quality/confidence/certainty of evidence high for death, low for functional outcome mRS 0-3, and moderate for mRS 0-4 (wide CIs and problems in concealment, blinding of outcome assessors and stopping early). CONCLUSIONS: DHC in SO-MCAi results in large reductions in mortality. Most of those who would otherwise have died are left with severe or very severe disability: for example, inability to walk and a requirement for help with bodily needs, though uncertainty about the proportion with very severe, severe and moderate disability remains (low to moderate quality/confidence/certainty evidence).