Parallel activation of helicopter and ground transportation after dispatcher identification of suspected anterior large vessel occlusion stroke in rural areas: a proof-of-concept case with modeling from the LESTOR trial

Background: When stroke patients with suspected anterior large vessel occlusion (aLVO) happen to live in rural areas, two main options exist for prehospital transport: (i) the drip-and-ship (DnS) strategy, which ensures rapid access to intravenous thrombolysis (IVT) at the nearest primary stroke center but requires time-consuming interhospital transfer for endovascular thrombectomy (EVT) because the latter is only available at comprehensive stroke centers (CSC); and (ii) the mothership (MS) strategy, which entails direct transport to a CSC and allows for faster access to EVT but carries the risk of IVT being delayed or even the time window being missed completely. The use of a helicopter might shorten the transport time to the CSC in rural areas. However, if the aLVO stroke is only recognized by the emergency service on site, the helicopter must be requested in addition, which extends the prehospital time and partially negates the time advantage. We hypothesized that parallel activation of ground and helicopter transportation in case of aLVO suspicion by the dispatcher (aLVO-guided dispatch strategy) could shorten the prehospital time in rural areas and enable faster treatment with IVT and EVT.

Methods: As a proof-of-concept, we report a case from the LESTOR trial where the dispatcher suspected an aLVO stroke during the emergency call and dispatched EMS and HEMS in parallel. Based on this case, we compare the provided aLVO-guided dispatch strategy to the DnS and MS strategies regarding the times to IVT and EVT using a highly realistic modeling approach.

Results: With the aLVO-guided dispatch strategy, the patient received IVT and EVT faster than with the DnS or MS strategies. IVT was administered 6 min faster than in the DnS strategy and 22 min faster than in the MS strategy, and EVT was started 47 min earlier than in the DnS strategy and 22 min earlier than in the MS strategy.

Conclusion: In rural areas, parallel activation of ground and helicopter emergency services following dispatcher identification of stroke patients with suspected aLVO could provide rapid access to both IVT and EVT, thereby overcoming the limitations of the DnS and MS strategies.