C GÄTCHER¹, A MENDEZ², M DIEPERS³, AR HUBER², HJ HUNGERBÜHLER<sup>1

1</sup>Department of Neurology, Cantonal Hospital Aarau, Aarau, ²Institute for laboratory Medicine, Cantonal Hospital Aarau, Aarau, ³Institute for Neuroradiology, Cantonal Hospital Aarau, Aarau

It is well known that D-dimer-levels are usually highly elevated in acute aortic dissection (AD). In this study we investigated whether this relationship can also be detected in acute internal carotid artery dissection (ICAD). For analysis purposes the data of 10 patients admitted to the department of Neurology from 2008 to 2010 with clinical suspected and imaging confirmed diagnosis of ICAD were retrospectively included. Additionally D-dimer analysis in patients with AD treated in the neurological clinic (n=5) were collected for comparison. Only in 2 of the 10 patients with ICAD the D-dimer-levels were above the normal value (0.5 mg/l), while in AD all patients showed considerably high D-dimer-levels (≥4 mg/l). The correlation of elevated D-dimer-levels in ICAD could not be seen as in AD. This might be due to a smaller surface of the injured vessel and the fact that, in contrast to the AD, a significant communication between the true and the false lumen is mostly absent, which could prevent a relevant activation of the extrinsic pathway of the coagulation cascade. Accordingly, D-dimers are not a valuable biomarker to exclude an ICAD. Diagnosis or exclusion of ICAD remains challenging and dependent on clinical examination and imaging tools.