What drives the increasing utilisation of hemicraniectomy in acute ischaemic stroke?

Background Survival after malignant middle cerebral artery infarcts is dismal. In 2007, a pooled analysis of randomised trials in Europe demonstrated a substantial survival benefit from decompressive hemicraniectomy, with a number needed to treat of 2 for survival. Our objective was to review factors driving the nationwide utilisation of this potentially lifesaving procedure in the USA. Methods Data from the Nationwide Inpatient Sample for 2001-2009 were reviewed. Hospitalisations with a discharge diagnosis of an acute ischaemic stroke were included. Hemicraniectomy utilisation was determined within this subset. Nationwide estimates of utilisation were calculated for each year. Trends across the years were estimated for various subgroups. Results From 2001 to 2009, there were an estimated 4 909 519 acute ischaemic stroke discharges. The estimated frequency of hemicraniectomy increased from 118 (0.02% of stroke discharges in 2001) to 804 (0.15% of stroke discharges in 2009) (trend p < 0.001). The increased utilisation was greatest for younger subjects (age < 45 years; trend p < 0.001) and men (trend p < 0.001). Urban teaching hospitals were responsible for the greatest increase in hemicraniectomy utilisation: from 0.05% of stroke discharges in 2001 to 0.28% in 2009. The increase was steady and sustained over the decade. In comparison, rural and urban non-teaching hospitals showed a much smaller improvement in utilisation. Conclusion Utilisation of hemicraniectomy in the USA has increased significantly, in line with compelling results from European clinical trials. Early transfer of patients with malignant infarctions to urban teaching centres could potentially extend the survival benefit to a larger population.