ISCHEMIC STROKE / PREVENTION

Management of intracranial stenosis

Created 10/12/2021, last revision 04/02/2023

intracranial stenosis is a significant stroke risk factor [Bos, 2014]
it is a cause of ~10% of strokes
the annual risk of recurrent stroke in symptomatic IC stenosis is 4-18%
- EC/IC Bypass Trial, WASID
- the highest risk is present in the first 14 days after the first event
modern imaging modalities (TCD/TCCD, CTA, and MRA) allow non-invasive and easy diagnosis of intracranial stenoses [Degnan, 2011]

Etiopathogenesis

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detection of the stenosis itself (→ see here)
- optimal for screening and follow-up
evaluation of the distal flow, including cerebral vasomotor reactivity (CVR)
detection of MES (microembolic signals)

Intravascular sonography (IVUS) [Zacharatos, 2010]

used in cardiology, now it is tested in carotid and intracranial territories
clarifies the morphology of the stenosis (which can help in etiological diagnosis – atherosclerotic plaque vs. inflammation, etc.)

Optic coherent tomography (OCT)

OCT uses near-infrared light to image arterial anatomy with much higher resolution than IVUS (10 vs. 100 um)
used in cardiology, also tested in vascular neurology
- assessment of plaque structure (Yang, 2021)
- assessment of stent position after the procedure and in the follow-up period
- the potential for use during the stenting procedure is investigated
outperforms IVUS in the determination of plaque morphology (presence of thrombus, bleeding, fibrous cap rupture, etc.) and in differentiating other causes of stenosis

Asymptomatic stenosis

antiplatelet therapy + aggressive treatment of vascular risk factors (see below)
endovascular intervention is not indicated

Symptomatic stenosis

the risk of recurrent stroke/TIA or vascular death in patients with IC stenosis is 10-12%/year [Chimowitz,2005]
- older studies reported a risk of up to 22%/year with conservative treatment; despite that, the risk is ~2 times higher than in patients with extracranial stenosis

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after the procedure, maintain dual antiplatelet therapy (aspirin 100 mg + clopidogrel 75 mg)
duration of DAPT
- coated stents: 6-12 months (Taxus, Pharos)
- standard stent (Wingspan): at least 4 weeks
then switch to long-term monotherapy

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