Impact of the drip-and-ship model for the treatment of acute ischemic stroke in relation to distance from thrombectomy center

Franziska Lieschke^1,2Gina Mueller¹Fee Keil³Ferdinand O. Bohmann¹Christian Grefkes¹Jan Hendrik Schaefer^1*

• ¹Goethe University Frankfurt, University Hospital, Department of Neurology, Frankfurt/Main, Germany, Frankfurt, Germany
• ²Department of Neurology with Experimental Neurology, Charité Universitätsmedizin, Berlin, Germany, Berlin, Germany
• ³Goethe University Frankfurt, University Hospital, Institute of Neuroradiology, Frankfurt/Main, Germany, Frankfurt, Germany

Background The drip-and-ship-model is common practice for patients with ischemic stroke due to large-vessel-occlusion (LVO), providing initial diagnostics and thrombolysis in transition to endovascular treatment (EVT). However, hospital transfer results in delays for patients requiring EVT, potentially affecting outcome. We sought to explore the association between distance from residence and time intervals to admission with clinical outcome after EVT. Methods In this monocentric retrospective cohort study, patients with acute ischemic stroke due to LVO who underwent EVT at Frankfurt University Hospital between 2017 and 2023 were analyzed. Patients were grouped by direct-to-center (DC) or drip-and-ship (DS) admission. Clinical outcome parameters included patient global disability after 90 days as measured on the modified Rankin Scale (mRS) and National Institutes of Health Stroke Scale (NIHSS) score improvements analyzed in relation to geographical distance and time metrics. A subgroup analysis based on the distance from residence in 10 km intervals was added. Results In total, 334 patients were included. Of these, 41.9% were DC and 58.1% DS admissions. Distances from home to center were shorter for DC patients (11.1km vs. 36.4km, p<0.001), resulting in significantly shorter times from symptom onset to admission (-114 min; 71min vs. 185min; P < 0.001) and to flow restoration (-88min; 213min vs. 301min; P<0.001). After 90 days, no significant differences in clinical outcome between DC and DS were observed. However, DC patients living closer than 10km to the center were more likely to achieve a mRS score <3 (OR 2.995; 95%-CI 1.296–7.318; P=0.012). Conclusions Proximity of residence to a thrombectomy center may be advantageous for stroke patients, most likely in association with direct pre-hospital transfers. Distances above 30km more frequently led to drip-and-ship, which may facilitate care through early diagnostics as signified by a reduction of the relative time delay to flow restoration.