Diagnostik und endovaskuläre Therapie intrakranieller arterieller Stenosen

Abstract

Approximately 6 - 50% of all ischemic strokes are caused by intracranial arterial stenosis (IAS). Despite medical prevention, patients with symptomatic IAS have a high annual risk for recurrent ischemic stroke of about 12%, and up to 19% in the case of high-grade IAS (≥ 70%). Digital subtraction angiography remains the gold standard for the diagnosis and grading of IAS. However, noninvasive imaging techniques including CT angiography, MR angiography, or transcranial Doppler and duplex ultrasound examinations are used in the clinical routine to provide additional information about the brain structure and hemodynamic. However, for technical reasons, the grading of stenoses is sometimes difficult and inaccurate. To date, aspirin is recommended as the treatment of choice in the prevention of recurrent ischemic stroke in patients with IAS. IAS patients who suffer a recurrent ischemic stroke or transient ischemic attack while taking aspirin can be treated with endovascular stenting or angioplasty in specialized centers. The periprocedural complication rate of these endovascular techniques is about 2 - 7% at experienced neuro-interventional centers. The rate of re-stenosis is reported between 10 and 40% depending on patient age and stenosis location. Further randomized studies comparing medical secondary prevention and endovascular therapy are currently being performed. With regard to the improvement of endovascular methods and lower complication rates, the indication for endovascular therapy in IAS could be broadened especially for stenosis in the posterior circulation.

Whole-Brain Perfusion CT Using a Toggling Table Technique to Predict Final Infarct Volume in Acute Ischemic Stroke

“…The recanalization success was also verified via different methods (TCD, MRA, and CTA) since the intracranial basal arteries could not be visualized through the transtemporal bone window in approx. 15 % of the stroke patients due to thickening of the skullcap [31]. Since the follow-up examination was not performed in any patient within the first 24 hours after the onset of symptoms, the infarct areas could be equally reliably visualized on the basis of the distinctive features in DWI MRI and the typical hypodense areas in CT.…”