Background: Endovascular treatment (EVT) has been proven to be effective for selected patients with acute ischemic stroke (AIS). We evaluated the effect of the introduction of EVT on outcome of AIS therapy in a rural broad region in Japan, covering an area within a radius of 80km by air ambulance.
Methods: Between January 2014 and July 2016, 210 consecutive patients with acute large vessel occlusion (189 patients in the anterior circulation and 21 in the posterior circulation) admitted to our institute were analyzed. EVT was introduced into the AIS therapy at our institute in April 2015. We compared the outcome of the patients during the period before (group 1: standard medical treatment including intravenous [IV] tPA) and after (group 2: standard medical treatment including IV tPA with or without EVT) the introduction of EVT.
Results: In the group 1, all 87 patients (median age, 81 years; NIHSS, 20; ASPECTS, 8; onset to door, 237min; IV tPA 24%) were treated medically (Table 1). In the group 2, among 123 patients (age, 82 years; NIHSS, 20; ASPECTS, 8; onset to door, 149min; IV tPA 16%), 47 patients were treated medically, and the remaining 76 patients underwent EVT (TICI 2b or 3, 84%). Although the median transfer distance increased (23km in the group 1 vs 30km in the group 2, p=0.028), the median time from call to admission was equivalent (42min vs 43min, p=0.93) because of the increase in the proportion of the helicopter transfer (30% vs 41%, p=0.14). The rates of patients who underwent revascularization therapy with IV tPA or EVT (24% vs 66%, p<0.001) and good outcome (mRS 0 to 2) at discharge (11% vs 24%, p=0.021) increased significantly after the introduction of EVT approach.
Conclusions: Our study showed that the introduction of EVT improved the outcome of the AIS therapy with significant increase in the number of patients receiving revascularization therapy. EVT in collaboration with air ambulance might expand the target area for revascularization therapy in a rural broad region.