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

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).

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).

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.

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.