EDEN - Enhanced Dispatch for Efficient Neurointervention: mathematical model from national data

Abstract

Background: Mechanical thrombectomy (MT) has been proven to be an effective treatment for large vessel acute ischemic strokes. A debate is ongoing about whether to use the mothership or the drip-and-ship strategy for stroke patient transfers. Precious time could be lost if prehospital triage is incorrect. Combining a helicopter with an ambulance on the ground may further reduce prehospital delays. Methods: We conducted a single MT-capable center mathematical model study to assess how many individuals could reach Tampere University Hospital (Tays) within a 120-minute time limit. Population data were obtained from the Finnish Institute of Health and Welfare. Finland is divided into 1-square-kilometer grid cells in the dataset. Travel times were calculated using OpenRouteService. The primary outcome was the number of individuals reaching Tays within the time limit. We evaluated three scenarios: (1) ground transportation only, (2) the Emergency Medical Services (EMS) personnel dispatch the Helicopter Emergency Medical Services (HEMS) unit after being on scene for 10 minutes, and (3) HEMS and EMS are dispatched at the same time. Results: In the first scenario, 1,016,180 individuals could reach Tays within 120 minutes. When ground transportation is combined with a helicopter, 981,391 more individuals could reach Tays within time in scenario 2 settings, corresponding to a 97% increase. Simultaneous dispatch of EMS and HEMS further increased the population reaching Tays with 37,495 individuals. A total of 2,035,067 individuals lived within 120 minutes of the MT center we studied. Conclusions: A hybrid transportation strategy improved access to MT in a single center study. The use of a helicopter nearly doubled the population in the catchment area of Tays, while early recognition of large vessel occlusion stroke provided only a modest additional increase in the number of individuals accessing Tays within the time limit.