Hyperintense Gefäße in der FLAIR-Sequenz bei thrombektomierten Patienten mit akutem Schlaganfall

Vascular hyperintense vessels on the FLAIR sequence (FLAIR hyperintense vessels, FHV) are frequently detected in patients with acute ischemic stroke. They are associated with large vessel stenosis or occlusion. In contrast to the hyperdense vessel sign in Computertomographie, they do not represent intravascular thrombus but collateral disordered blood-flow in vessels distal to the stenosis or occlusion. FHVs have been associated with large Perfusion-Diffusion-Mismatch. Therefore their presences do not indicate irreversibly infarcted tissue but rather potentially salvageable brain tissue. With these characteristics they can be a helping tool in clinical decision-making for thrombectomy. The aim of our study was to associate FHVs with the results of the thrombectomy in patients with acute ischemic stroke. We investigated the prae- and postinterventional MRI and the documentations of the thrombectomy in 72 patients with acute stroke in the middle cerebral artery territory who reserved a combination i.v. thrombolysis and mechanical thrombectomy. Recanalisation, complications, infarct growth and time from symptom onset until praeinterventional MRI were assessed. FHV sign was quantified prae- and postinterventional by use of the ASPECT-Score and their intensity subdivided. Despite the descriptive statistic we performed the correlation of Pearson, the Chi-Quadrat-test and the Mann-Whitney-U-test in the inductive statistic analysis. In different degree we found FHV sign in all patients. We did not find a statistic significant association of the recanalisation- and complication-rate of the thrombectomy with the paeinterventional degree of FHV. As well there was no correlation between FHV and the infarct growth. We found a correlation between a high degree of praeinterventional FHV and a short time from symptom onset, which however slightly missed the 5% level of significance (p=0,084). There was a positive association between a high degree of postinterventional FHV sign and incomplete recanalisation and a positive correlation between the degree of postinterventional FHV sign and infarct growth. The impact of FHV on clinical decision-making for thrombectomy is their association with large vessel stenosis or occlusion. If, for example, there is no angiography available, FHV can be helpful to guide patients with acute stroke to thrombectomy. The degree of praeinterventional FHV is not suitable to predict recanalisation- or complication-rate and infarct growth after thrombectomy. A high degree of praeinterventional FHV indicates a short time from symptom onset, probably due to more stable collateral flow in the early stage of stroke. Postinterventional FHV indicate incomplete recanalisation and large infarct growth and are therefore a marker of an unsuccessful thrombectomy. In the present situation it would be desirable to have a prognostic parameter in a fast and uncomplicated MRI study with standard sequences for the success of thrombectomy to carry out a patient-selection in potentially thrombectomy-candidates. In this regard FHV are not significant. Further studies are necessary to define the prognostic value of FHV in decision-making for thrombectomy in patients with acute stroke.