Follow-up study on in-stent thrombosis after carotid stenting using multidetector CT angiography

The purpose of the present study was to evaluate the role of multidetector three-dimensional computed tomography angiography (3D CTA) for evaluating both the residual arterial lumen and the sequential change in the intraluminal diameter and thrombus formation following carotid artery stenting (CAS). Twenty consecutive patients consisting of 23 successfully stented carotid arteries were examined by 3D CTA with volume-rendering at 2, 4, 8, 12 weeks and 6, 12 months of follow-up. The eccentric in-stent hypodense area could be detected in ten of 23 (43.5%) carotid arteries at 2 weeks of follow-up, and they then gradually declined until they almost disappeared at 12 weeks. Eccentric in-stent hypodense areas in the acute and subacute phase (up to 12 weeks after CAS) were found in nine out of 16 carotid arteries with longer stents (3 or 4 cm in size) deployed across the carotid bifurcation, whereas no eccentric in-stent hypodense area could be observed in the patients with a short stent (2 cm) deployed only to the internal carotid artery. Seven of the ten observed eccentric hypodense areas presented on the dorsal surface at the carotid bifurcation level. Carotid 3D CTA for evaluating residual lumen and in-stent thrombus formation after CAS is considered to be a useful diagnostic method. To avoid stent occlusion, both the acute and subacute phases following CAS (up to 12 weeks) call for the administration of appropriate anti-platelet therapy and careful observations of the patients.