Abstract
Following the implantation of a carotid artery stent (CAS), the aetiology of in-stent occlusion typically shifts from embolic events in the acute phase to intimal hyperplasia in the chronic phase. A man in his 70s with a history of CAS implantation (performed 5 years ago) for left internal carotid artery (ICA) stenosis was admitted to our hospital with a chief complaint of left-sided transient scotoma. MRI revealed an acute occlusion of the left ICA, and an urgent digital subtraction angiography (DSA) was performed. The DSA results suggested the presence of an in-stent thrombus instead of in-stent stenosis. An urgent endovascular thrombectomy was performed, and the thrombus was successfully retrieved from the carotid stent. Full reperfusion was achieved, and no damage occurred to the carotid stent. This case highlights the importance of thorough examination of MRI and DSA findings for accurate differentiation between the causes of vessel occlusion.