Diagnosis and Treatment of Intracranial Stenoses.

Stroke is one of the most frequent and most significant vascular diseases. According to estimates, 16.9 million people suffered a stroke in 2010, and over one-third of the incidents were lethal. The risk of suffering a stroke due to intracranial stenosis is between 7 and 24%. As opposed to extracranial stenoses of the internal carotid artery, there is no standardized treatment concept for intracranial stenoses. At present, treatment with a low daily dose of 100 mg aspirin is recommended by the guidelines for intracranial stenoses to additionally prevent dose-dependent gastrointestinal side effects and bleeding complications. The WINGSPAN study showed stroke rates and mortality rates amounting to 4.5% after 30 days and 7.0% after 6 months. The Stenting versus Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis study is a randomized, multicenter study that compared endovascular stent treatment in patients with symptomatic arteriosclerotic intracranial stenoses with intensified drug therapy. After the inclusion of 451 of 764 study patients planned initially, study recruitment was terminated prematurely because the stroke rate or mortality rate within 30 days was 14.7% in the endovascular treatment group compared with 5.8% in the drug therapy group and 20% within 12 months compared with 12.2%. Quite recently the results of a second randomized study of intracranial stents were published in the Vitesse Intracranial Stent Study for Ischemic Stroke Therapy study. In an analysis published by Liebeskind et al. concerning the impact of collateral vessels on the stroke risk based on data from the Warfarin-Aspirin Symptomatic Intracranial Disease study, it was demonstrated that a sufficiently formed collateral network in patients with high-degree vascular constrictions (≥ 70%) plays a crucial role in the avoidance of strokes. If there is no system of collateral vessels or if it is insufficient, the stroke risk in the dependent vascular territory is six times higher. So far it has not yet been possible to conclusively answer the question of optimal treatment for intracranial stenoses. There is particularly need for action regarding the treatment of high-degree recurrent symptomatic stenoses, not only in light of the unfavorable prognosis but also within the scope of demographic change.