Evaluation of ultrasonographic images according to type of carotid artery stent

Abstract

Purpose: Image evaluation of post-carotid artery stenting (CAS) using non-invasive carotid ultrasonography is widely performed. Three types of carotid artery stents are currently used in Japan: “Carotid WALLSTENT,” “PRECISE,” and “PROTEGE.” Shapes and materials differ for each stent. On post-CAS ultrasonography, findings differ by stent type. We compared ultrasonographic images for each type.
Methods: We weighed B-mode and color Doppler images with each stent type. And, in patients with in-stent plaque, ultrasonographic images were compared with CT angiography. Moreover, a stent was fixed underwater, and long- and short-axis views from a 12-MHz linear probe were examined.
Results: The Carotid WALLSTENT showed fewer artifacts and was best observed in B-mode. In some cases, observation of in-stent plaque was difficult without B-flow or color Doppler imaging. Near-wall artifacts were most frequently observed in PROTEGE. Furthermore, depiction of color flow within PRECISE or PROTEGE was poor, because these stents were curved in accordance with the vessel wall in the proximal portion of the internal carotid artery.
Conclusions: Ultrasonographic images differ according to stent type. Ultrasonography must be performed with an understanding of the features and ultrasonic image characteristics of the stents involved.