Decompressive craniectomy in aneurysmal subarachnoid haemorrhage for hematoma or oedema versus secondary infarction

Decompressive craniectomy (DC) has been proposed as lifesaving treatment in aneurysmal subarachnoid haemorrhage (aSAH) patients with elevated intracranial pressure (ICP). However, data is sparse and controversy exists whether the underlying cause of elevated ICP influences neurological outcome. The purpose of this study is to clarify the role of the underlying cause of elevated ICP on outcome after DC. We retrospectively studied the one-year neurological outcome in a single-centre cohort to identify predictors of favourable (Glasgow Outcome Scale (GOS) 4-5) and unfavourable (GOS 1-3) outcome. Additionally, available individual patient data in the literature was reviewed with a special emphasis on the underlying reason for DC. From 2006-2015, 53 consecutive aSAH patients underwent DC. Nine (17%) achieved favourable, 44 (83%) unfavourable outcome (31 patients died). One fourth of the patients undergoing DC for hematoma or (hematoma-related) oedema survived favourably (increasing to 46% for patients aged <51 years), versus none of the patients undergoing DC for secondary infarction. Analysis of individual data of 105 literature patients showed a similar trend, although overall outcome was much better: half of the patients undergoing DC for hematoma/oedema regained independence, versus less than one-fourth of patients undergoing DC for secondary infarction. DC in aSAH patients is associated with high rates of unfavourable outcome and mortality, but hematoma or oedema as underlying reason for DC is associated with better outcome profiles compared to secondary infarction. Future observational cohort studies are needed to further explore the different outcome profiles among subpopulations of aSAH patients requiring DC