Cerebral ischemia detected with diffusion-weighted MR imaging after protected carotid artery stenting: comparison of distal balloon and filter device

Abstract

Objective: The aim of this study was to examine the incidence of ischemia during protected carotid artery stenting (CAS) as well as to compare the protective efficacy of the balloon and filter devices on diffusion-weighted MR imaging (DWI).

Materials and methods: Seventy-one consecutive protected CAS procedures in 70 patients with a severe (> 70%) or symptomatic moderate (> 50%) carotid artery stenosis were examined. A balloon device (PercuSurge GuardWire) and a filter device (FilterWire EX/EZ, Emboshield) was used in 33 cases (CAS-B group) and 38 cases (CAS-F group) to prevent distal embolization, respectively. All the patients underwent DWI within seven days before and after the procedures. The number of new cerebral ischemic lesions on the post-procedural DWI were counted and divided into ipsilateral and contralateral lesions according to the relationship with the stenting side.

Results: New cerebral ischemic lesions were detected in 13 (39.4%) out of the 33 CAS-Bs and in 15 (39.5%) out of the 38 CAS-Fs. The mean number of total, ipsilateral and contralateral new cerebral ischemic lesion was 2.39, 1.67 and 0.73 in the CAS-B group and 2.11, 1.32 and 0.79 in the CAS-F group, respectively. No statistical differences were found between the two groups (p = 0.96, 0.74 and 0.65, respectively). The embolic complications encountered included two retinal infarctions and one hemiparesis in the CAS-B group (9.09%), and one retinal infarction, one hemiparesis and one ataxia in the CAS-F group (7.89%). There was a similar incidence of embolic complications in the two groups (p = 1.00).

Conclusion: The type of distal protection device used such as a balloon and filter does not affect the incidence of cerebral embolization after protected CAS.

Fig. 1

A 72-year-old man who underwent protected carotid artery stenting with a balloon device. A. Pre-stenting angiogram shows severe stenosis (86.3%) at the left internal carotid artery. B. A balloon device is deployed in the distal carotid artery (arrow). C. After carotid artery stenting, the lumen of the left internal carotid artery is successfully dilated. D. No ischemic lesion is shown in bilateral cerebral hemispheres on the pre-stenting diffusion weighted MR imaging. E. Multiple small new hyperintensities are shown on the post-stenting diffusion-weighted MR imaging. Note the new hyperintnesities are distributed in not only the ipsilateral but also the contralateral cerebral hemisphere. However, no symptomatic neurological complications occurred after carotid artery stenting.

Fig. 2

A 71-year-old man who underwent protected carotid artery stenting with a filter device. A. Pre-stenting angiogram shows a severe string like stenosis of the left internal carotid artery. The post-stenotic distal internal carotid artery is also narrow compared with the external carotid artery (pseudo-occlusion). B. A filter device is deployed in the distal carotid artery (arrow). C. After carotid artery stenting, the lumen of the left internal carotid artery is successfully dilated. D. No ischemic lesion is shown in bilateral cerebral hemispheres on the pre-stenting diffusion weighted MR imaging. E. Multiple small new hyperintensities are observed in the ipsilateral cerebral hemisphere on the post-stenting diffusion-weighted MR images. However, no symptomatic neurological complications occurred after carotid artery stenting.