Ever since the pooled analysis of three randomized controlled trials of early decompressive surgery in malignant infarction of the middle cerebral artery was published in 2007 , the consideration of decompressive hemicraniectomy for large hemispheric stroke patients has become widespread. That paper reported on the pooled results of three small randomized trials: DECIMAL , DESTINY , and HAMLET . While the analysis indicated that the procedure clearly can reduce mortality, considerable controversy persists over whether it improves functional outcome. The essence of the dispute is philosophical and essentially can be distilled down to whether one considers a modified Rankin score of four as a good or a bad outcome.
For those who maintain decompressive surgery is a reasonable intervention, careful consideration must be given to patient selection, timing of intervention, and medical alternatives. Following its publication, selection of candidates was based on the inclusion criteria for the pooled analysis: age 18–60 years, National Institutes of Health Stroke Scale (NIHSS) score >15, decreased level of consciousness (≥1 on item 1a of the NIHSS), computerized tomographic scan (CT) signs of infarct involving ≥50 % of the middle cerebral artery territory, and inclusion within 45 h of onset of symptoms. Over the ensuing years, the age limit has been pushed higher; and in 2014, a randomized trial enrolling patients aged 61–82 years found that hemicraniectomy increased survival without severe disability .
Once a patient has been identified as a potential candidate for surgery, two different approaches to timing are possible. The early surgery, or preemptive, approach moves forward with hemicraniectomy as soon as the patient is identified, ideally within 24 h of onset. The alternative strategy espouses postponing surgical intervention until evidence of increased radiographic edema and/or clinical deterioration manifests and, in the interim, instituting medical management of cerebral edema.