Supplementary Material for: Ischemic Lesions in Diffusion-Weighted Imaging after Carotid Artery Stenting: Correlation with Access Route

Introduction: Despite recent advances in stents and stenting techniques, ischemic complications associated with carotid artery stenting (CAS) remain unresolved. Although plaque characteristics have attracted attention as risk factors, only a few studies have focused on access routes. This study aimed to identify ischemic factors following CAS, including access routes and plaque instability, using computed tomography angiography (CTA). Methods: We retrospectively collected the clinical data of consecutive patients who underwent CAS and preoperative CTA. The access route was evaluated as having aortic plaques and a stenosis at proximal segment lesions beyond carotid plaques (brachiocephalic/common carotid artery). Aortic plaques were further classified based on the presence or absence of calcifications. The outcome was the presence of hyperintense lesions (ipsilateral/non-ipsilateral/bilateral) on postoperative diffusion-weighted imaging (DWI). Multivariate analysis was conducted using two models: aortic plaques (Model 1) and calcified aortic plaques (Model 2). Results: Among the 115 patients who underwent CAS, the mean age was 74.7 years, and 16 (13.9%) were female. Aortic arch plaques were detected in 33 (28.7%) cases, and calcified plaques in 10 (8.7%). Plaques at proximal segment lesions were detected in 27 (23.5%) cases. DWI lesions were detected in 49 (42.6%) cases; 41 (35.7%) on the ipsilateral side, 19 (16.5%) on the non-ipsilateral side, and 11 (9.6%) bilaterally. The following variables were significantly associated in the univariate analysis: age (ipsilateral, p=0.005; non-ipsilateral, p=0.007; bilateral, p=0.005), proximal segment lesions (ipsilateral, p=0.04; non-ipsilateral, p=0.002; bilateral, p=0.02), aortic plaques (non-ipsilateral, p<0.001; bilateral, p<0.001), and calcification (non-ipsilateral, p<0.001; bilateral, p<0.001). For ipsilateral lesions, proximal segment lesions were associated in both models (Model 1: odds ratio [OR], 4.30; 95% confidence interval [95% CI], 1.5–13.5; p=0.006, and Model 2: OR, 4.40; 95% CI, 1.6–13.5; p=0.004). For non-ipsilateral and bilateral lesions, aortic plaques (non-ipsilateral: OR, 5.33; 95% CI, 1.8–16.5; p=0.002; bilateral: OR, 13.16; 95% CI, 3.0–93.4; p=0.001) and calcification (non-ipsilateral: OR, 11.55; 95% CI, 2.6–63.0; p=0.001; bilateral: OR, 18.51; 95% CI, 3.7–106.5; p=0.0003) were associated in both models. Conclusion: Ischemic lesions are likely to occur after CAS, depending on the access route. CTA, which allows the evaluation of access routes, is a useful modality for predicting ischemic lesions after CAS.