Relation between plaque characteristics on MR imaging and distal protection device in predicting risks of thromboembolic events during carotid artery stenting

Abstract

Objective: To evaluate risk in relation to plaque characteristics for estimating thromboembolic events during carotid artery stenting (CAS). Methods: MR imaging of 64 carotid artery stenotic lesions were reviewed retrospectively in patients for CAS with a balloon protection device (Guardwire) and filter (Angioguard XP). Magnetization-prepared rapid acquisition with gradient echo (MPRAGE) was used for MR plaque imaging. Lesions were classified into three types according to the intensities on MPRAGE: high-intensity, intermediate-intensity and iso¬intensity groups. If the plaque displayed signal intensity of 200% compared to sternocleidomastoid muscle intensity, it was categorized as “high signal intensity.” Results: Periprocedural adverse events occurred in 10 of 64 procedures (15.6%). Persistent neurological deficit was related to 3 procedures (5.1%). Transient neurological ischemic events occurred in 4 procedures (6.3%). Thromboembolic events of CAS for high- and intermediate- intensity plaques on MPRAGE were 21.1% and 16.7%, respectively. Incidence of thromboembolic events for high-intensity plaques (21.1%) was significantly higher than that for iso-intensity plaque (0%) (P=0.013). Incidence of thromboembolic events for high-intensity plaques with use of a filter device (21.1%) was significantly higher than that with a balloon protection device (7%) (P=0.013). Although incidence of neurological ischemic event in CAS with a filter device (26.7%) was significantly higher than that with a balloon protection device (6.1%) (P=0.026), the morbidity rate was not significantly different between the two groups (0% vs 6.1%). Conclusions: High-intensity plaque on MPRAGE is related to a high rate of thromboembolic events during CAS. To avoid thromboembolic complications during CAS, an individual approach is needed for each case. © 2009, The Japanese Society for Neuroendovascular Therapy. All rights reserved.