Shift from drip-and-ship towards mothership model for mechanical thrombectomy during COVID-19 pandemic: A retrospective analysis of a stroke network performances

Background and Aims: The choice between transport of acute ischemic stroke patients to the nearest Primary Stroke Centers (drip-and-ship model) versus direct transport to the Comprehensive Stroke Center (mothership model) is still a matter of debate. We shifted from a dripand-ship towards a mothership model during the first wave of COVID-19 pandemic in spring 2020. We retrospective analyzed stroke network performances comparing the two models. Methods: All spoke-district patients treated with endovascular thrombectomy (EVT) between 15th March -15th June 2019 (drip-and-ship) and 2020 (mothership) were included in the study.We compared call-to-door time (CDT), door-to-CT time (DCT), door-to-needle time (DNT), doorto-groin time (DGT), call-to-needle time (CNT) and call-to-groin time (CGT) between the two periods. We also compared functional independence (modified Rankin Scale, mRS) at 3 months. Results: 24 spoke-district patients in 2019 (drip-and-ship) and 26 in 2020 (mothership) underwent EVT. In 2020 a higher number of patients received IV thrombolysis in combination with EVT (p=.030). The groups did not differ for age, sex, risk factors, pre-stroke mRS 0-1, NIHSS and ASPECTS distribution. In 2020 we found longer CDT (+23 minutes, p<.005), but shorter DCT (-11.5 minutes, p=.017), DNT (-20.5 minutes, p=.001), and DGT (-78 minutes, p<.005). Overall, in 2020 we found a significant decrease in CGT time (-55.5 minutes, p<.005) without significant differences in CNT (p=.324). We found no effects of the stroke network model on the 3-month mRS (shift analysis, p=.241;mRS categories 0-1 vs 2-6, p=.706). Conclusions: The mothership model guaranteed quicker EVT without significantly delaying IVT.