Etiologies of internal carotid artery pseudo-occlusions in acute stroke patients: what neurointerventionalists can expect.

In cases of acute stroke, differentiation between an occluded and a patent internal carotid artery (ICA) is crucial for diagnosis and management. Although CT angiography (CTA) can be highly accurate in defining high-grade stenosis and ICA occlusions, misleading ICA occlusion patterns are not rare in patients with acute stroke. We investigated the underlying causes of ICA pseudo-occlusions with CTA with respect to digital subtraction angiography. 11 out of 72 patients had pseudo-occlusion on CTA. Of these, there were three cases of tandem occlusions accompanying high-grade ICA stenosis, five cases of Distal ICA bifurcation occlusion as a result of atrial fibrillation, two cases of cervical ICA dissection and one acute thrombosis of the stent. Consideration of the aforementioned aetiologies by interventionists is warranted, as it may change the planning of endovascular intervention and treatment of acute stroke.