Cell-free DNA (cfDNA) is an important pro-inflammatory and prothrombotic mediator. With this study the investigators aim to gain new insights into the role of cfDNA in stroke and to perform a combined analysis of cfDNA in the hyperacute phase of the disease using blood and thrombus analyses. The main objectives are to analyse cfDNA in different stroke etiologies, to investigate the relationship between cfDNA and important procedural factors such as secondary embolisation and reperfusion outcomes, to analyse the correlation between blood and thrombus content of cfDNA and to investigate the specific source of cfDNA in distinct stroke subtypes.