Delayed Iatrogenic Dissection Caused by a Carotid Stent: A Case Report.

Iatrogenic dissection (ID) is a well-known complication of neuroendovascular treatments. ID is predominantly attribute to endothelial injury by the manipulation of wires and/or catheters, and is generally detected in angiography during the procedure. We present a rare case with delayed ID due to deployment of a carotid stent. A 71-year-old man presented with transient motor weakness in the right extremity. Magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) showed previous multiple cerebral infarctions without a diffusion sign, stenosis with vulnerable plaque in the left common carotid artery (CCA), and an extremely flexed internal carotid artery (ICA). On dual antiplatelet medication, carotid artery stenting (CAS) was completed with favorable dilation of the carotid lumen. Computed tomography angiography 4 days after the procedure revealed high-grade stenosis at the ICA adjacent to the distal edge of the deployed stent. ID with intramural hematoma was diagnosed on MRI. The ID was conservatively treated and remarkably diminished 4 months after the procedure. The patient was asymptomatic during the entire clinical course. This delayed ID was considered to be due to an endothelial injury caused by the distal edge and the constant radial force of the open-cell stent against the flexed vessel and exacerbated by dual antiplatelet therapy. Even in a patient with favorable arterial dilation in CAS procedure, the possibility of a delayed ID should always be considered.