Characteristics of Ischemic Brain Lesions After Stenting or Endarterectomy for Symptomatic Carotid Artery Stenosis

Abstract

Background and Purpose-In a substudy of the International Carotid Stenting Study (ICSS), more patients had new ischemic brain lesions on diffusion-weighted magnetic resonance imaging (MRI) after stenting (CAS) than after endarterectomy (CEA). In the present analysis, we compared characteristics of diffusion-weighted MRI lesions. Methods-Number, individual and total volumes, and location of new diffusion-weighted MRI lesions were compared in patients with symptomatic carotid stenosis randomized to CAS (n=124) or CEA (n=107) in the ICSS-MRI substudy. Results-CAS patients had higher lesion numbers than CEA patients (1 lesion, 15% vs 8%; 2-5 lesions, 19% vs 5%; >5 lesions, 16% vs 4%). The overall risk ratio for the expected lesion count with CAS versus CEA was 8.8 (95% confidence interval, 4.4-17.5; P<0.0001) and significantly increased among patients with lower blood pressure at randomization, diabetes mellitus, stroke as the qualifying event, left-side stenosis, and if patients were treated at centers routinely using filter-type protection devices during CAS. Individual lesions were smaller in the CAS group than in the CEA group (P<0.0001). Total lesion volume per patient did not differ significantly. Lesions in the CAS group were more likely to occur in cortical areas and subjacent white matter supplied by leptomeningeal arteries than lesions in the CEA group (odds ratio, 4.2; 95% confidence interval, 1.7-10.2; P=0.002). Conclusions-Compared with patients undergoing CEA, patients treated with CAS had higher numbers of periprocedural ischemic brain lesions, and lesions were smaller and more likely to occur in cortical areas and subjacent white matter. These findings may reflect differences in underlying mechanisms of cerebral ischemia. Clinical Trial Registration-URL: http://www.isrctn.org. Unique identifier: ISRCTN25337470. (Stroke. 2013;44:80-86.)

Extensive Leukoaraiosis Is Associated With High Early Risk of Recurrence After Ischemic Stroke

“…In the International Carotid Stenting Study (ICSS), patients with extensive leukoaraiosis (as defined by age-related white matter changes score, ≥5) were 1.5× more likely to develop periprocedural infarction on DWI after stenting than those with lower leukoaraiosis scores. 26 In the present study, patients with high-risk pathogeneses for asymptomatic recurrence, such as large artery atherosclerosis or acute arterial dissection, had 2 to 3× higher odds of symptomatic recurrence in the presence of extensive leukoaraiosis when compared with those with lower risk pathogeneses, such as small artery occlusion (Table 4). This finding further supports the view that the brain is more vulnerable to develop symptomatic stroke in an event of recurrent infarction in the presence of extensive leukoaraiosis.…”

“…1,2 Given that asymptomatic new infarcts are substantially more common, as much as 17× more common-than symptomatic infarcts during the first few days after an ischemic stroke, 24 impaired ability of the brain to tolerate ischemia and its reduced capacity to compensate for the lost function in the presence of extensive leukoaraiosis could potentially facilitate conversion of asymptomatic infarcts into symptomatic infarcts. In support of this view, procedures that are associated with high risk of embolism to the brain, such as carotid artery stenting, 25,26 carotid endarterectomy, 26,27 and total aortic arch replacement, 28 confer a higher perioperative risk of symptomatic stroke in patients with extensive leukoaraiosis when compared with those with less severe leukoaraiosis. In the International Carotid Stenting Study (ICSS), patients with extensive leukoaraiosis (as defined by age-related white matter changes score, ≥5) were 1.5× more likely to develop periprocedural infarction on DWI after stenting than those with lower leukoaraiosis scores.…”

Periprocedural Hemodynamic Depression Is Associated With a Higher Number of New Ischemic Brain Lesions After Stenting in the International Carotid Stenting Study-MRI Substudy

“…10 In the ICSS-MRI substudy, 35% of the patients treated by CAS and 9% of those treated by CEA had ≥2 new ischemic lesions on DWI. 27 Because the number of patients with ≥2 new DWI lesions after CAS was substantially higher than the number with hemodynamic depression requiring treatment, it is clear that the difference in the risk of hemodynamic depression requiring treatment between CAS and CEA is not the only determinant of the difference in the occurrence of new ischemic lesions between the 2 treatments. However, smaller reductions in blood pressure that did not require treatment were not reported in ICSS, and it is possible that these may have contributed to the development of new lesions in some patients not fulfilling our definition of hemodynamic depression.…”

Predictors of Acute and Persisting Ischemic Brain Lesions in Patients Randomized to Carotid Stenting or Endarterectomy

“…Characteristics of patients participating and not participating in the substudy did not differ ( Table). 2 In the stenting group, acute lesion count was higher in older patients by trend (≥71 years; RR, 2.1; 95% CI, 1.0-4.6; P=0.067), men (RR, 2.4; 95% CI, 1.00-5.8; P=0.042), and patients with stroke as the qualifying event (RR, 2.5; 95% CI, 1.2-5.5; P=0.021; Figure). Higher systolic blood pressure (≥158.5 mm Hg) was associated with an increased acute lesion count in the endarterectomy group (RR, 4.2; 95% CI, 1.00-16.7; P=0.044).…”