Recurrent subacute in-stent restenosis after carotid artery stenting due to plaque protrusion

A 70-year-old male presented with transient ischemic attacks manifesting as right hemiparesis and motor aphasia due to severe left cervical internal carotid artery stenosis. Carotid artery stenting (CAS) using a flow-reversal system was performed without complications. However, the patient exhibited transient right hemiparesis and motor aphasia 10 days after CAS. Emergent angiography demonstrated in-stent restenosis. In-stent percutaneous transluminal angioplasty and CAS were performed successfully using a distal protection system. However, duplex ultrasound scanning revealed progressive in-stent restenosis, 3 and 6 days after the re-treatment. Emergent angiography again demonstrated in-stent restenosis. Urgent stent removal and carotid endarterectomy were performed. Plaque had prolapsed through the stent. Histological examination revealed that the specimen was mainly plaque consisting of cholesterol crystals and macrophages. The patient was able to return to independent life without neurological deficit. Repeated endovascular surgery with appropriate antiplatelet and anticoagulation therapy should be attempted initially to treat in-stent restenosis. Endarterectomy with stent removal should be considered as a rescue option, especially if plaque protrusion is identified.