Predictors of Ipsilateral New Ischemic Lesions on Diffusion-Weighted Imaging after Carotid Artery Stenting in Asymptomatic Patients: A Retrospective Observational Study with Conventional Multicontrast MRI

The purpose of this study was to identify the independent risk factors for ipsilateral new ischemic lesions (NILs) during carotid artery stenting (CAS).In patients treated with CAS, the association between postoperative ipsilateral NILs on diffusion-weighted imaging (DWI) and patient demographics, intraoperative factors, the presence of plaque components, the semiquantitative grading of component size on multicontrast magnetic resonance imaging (MRI) were retrospectively analyzed.Ipsilateral NILs on DWI were detected in 85 (39.2%) patients. The debris was observed on the surface embolic protection devices in 70.97% of patients. Univariate analysis showed that different stages of intraplaque hemorrhage (IPH) (along with lipid-rich necrotic core [LRNC]) (P < 0.001), size of IPH (P < 0.001), calcification (CA) (P = 0.045), and LRNC (without IPH) (P < 0.001) as well as postdilation (P < 0.001)), stent type (P = 0.001), and aortic arch ulcer (P = 0.004) were associated with postoperative ipsilateral NILs. Multivariate logistic regression analysis showed that the acute and recent IPH (along with LRNC) (odds ratio [OR]: 5.77, P < 0.002 and OR: 28.66, P < 0.001, respectively), LRNC size in Grade 2 (OR: 6.10, P < 0.001) were independent risk factors for ipsilateral NILs. Aortic arch ulcer (OR: 3.44, P = 0.002), postdilation (OR: 4.72, P = 0.04) and open cell stent (OR: 2.88, P < 0.016) were also significantly related to ipsilateral NILs on DWI after CAS. There was a significant correlation between IPH at different stages and their grade of size (correlation coefficient: 0.89; P < 0.001).The IPH and larger LRNC along with the aortic arch ulcer, postdilation and open cell stent are associated with increased risk of ipsilateral NILs on DWI after CAS procedure. Preoperative staging of IPH and semiquantitative grading of size of plaque components based on multi-contrast MRI may be useful for predicting ipsilateral cerebral ischemic events after CAS.