Thrombectomy accessibility after transfer from a primary stroke center: Analysis of a three-year prospective registry

Background No comprehensive study exists about mechanical thrombectomy accessibility for patients admitted to a primary stroke center without onsite interventional neuroradiology service. Aims To evaluate mechanical thrombectomy accessibility within 6 h after transfer from a primary stroke center to a distant (156 km apart; 1.5 h by car) comprehensive stroke center. Methods Analysis of data collected in a three-year prospective registry on patients admitted to a primary stroke center within 4.5 h after symptom onset and selected for transfer to a comprehensive stroke center for mechanical thrombectomy. Eligible patients had confirmed proximal arterial occlusion and no large cerebral infarction on MRI images (DWI-ASPECTS ≥ 5). The rate of transfer, transfer without mechanical thrombectomy, mechanical thrombectomy, reperfusion (TICI score ≥ 2b-3), and the main relevant time measures were determined. Results Among the 385 patients selected for intravenous thrombolysis and/or potential mechanical thrombectomy, 211 were considered as transferrable for mechanical thrombectomy. The rate of transfer was 56.4% (n = 119/211), transfer without mechanical thrombectomy 56.3% (n = 67/119), mechanical thrombectomy 24.6% (n = 52/211), and reperfusion by MT (TICI score 2b/3) 18% (n = 38/211). The relevant median times (interquartile range) were: 130 min (62) for intravenous thrombolysis start to comprehensive stroke center door, 95 minutes (39) for primary stroke center door-out to comprehensive stroke center door-in, 191 min (44) for intravenous thrombolysis start to mechanical thrombectomy puncture, 354 min (107) for symptom onset to mechanical thrombectomy puncture and 417 min (124) for symptom onset to recanalization. Conclusions Our study suggests that transfer to a distant comprehensive stroke center is associated with reduced access to early mechanical thrombectomy in patients with acute ischemic stroke and large artery occlusion. These results could be translated to other high volume distant primary stroke center.