Optical Coherence Tomography-Guided Stenting for Common Carotid Free-Floating Thrombus.

A 57-year-old male with a history of esophagus cancer presented with acute dysarthria and mild weakness in his left extremities. Carotid duplex ultrasonography demonstrated a carotid free-floating thrombus (CFFT) in the right common carotid artery (CCA) extending to innominate artery (IA). It was difficult to determine the entity and the proximal end of the thrombus on digital subtraction angiography (DSA), but intravascular optical coherence tomography (OCT) showed unique morphological features and identified the exact location of the proximal and distal ends of the thrombus through the number of guide-wire artifacts, facilitating in making an informed decision regarding stent landing. After OCT-guided carotid artery stenting, DSA showed no residual free-floating thrombus and stenosis with complete recanalization in the CCA and IA. Our case highlights the rarity of a CFFT occurring in an uncommon location and OCT as a valuable adjunct to DSA in the management of CFFTs.Clinical ImpactDigital subtraction angiography (DSA) has traditionally been considered an effective method for visualizing carotid free-floating thrombus (CFFT), but it falls short in providing detailed structures of the lumen and the composition of thrombi, making it challenging to determine the etiology. Intravascular optical coherence tomography (OCT) is a valuable adjunct to DSA that can precisely evaluate the characteristics of the intrinsic vessel wall and accurately distinguish between red and white thrombus, providing clues to the etiology of CFFTs. Moreover, OCT not only precisely determined the scope of a floating thrombus but also provided guidance for decision-making in endovascular treatment.